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Marine Vessels are Unsuspecting Hosts of Invasive Species
7/11/2017

Half of the ships passing along the Mediterranean coast of Israel carry damaging ascidians, TAU researchers say

Invasive ascidians — sac-like marine invertebrate filter feeders — are nuisance organisms that present a global threat. They contribute to biodiversity loss, ecosystem degradation and impairment of ecosystem services around the world.

A new Tel Aviv University study finds that ships play an unknowing but dominant role in introducing and dispersing these tough-shelled non-indigenous organisms into new environments. The research showed that these marine invertebrates hitch a ride on half of all the marine vessels passing through Israel's Mediterranean coast.

The research was conducted by Mey-Tal Gewing, of TAU's School of Zoology and led by Dr. Noa Shenkar, also of TAU's Department of Zoology and of The Steinhardt Museum of Natural History and Israel National Center for Biodiversity Studies. It was published in Marine Pollution Bulletin.

Hitching a ride

"These organisms are well known in the US and Canada," Dr. Shenkar said. "In Israel, they are passing through the Suez Canal, latching onto ropes and the bottom of the ship. They're filter feeders, so they cover and clog every surface they latch onto, creating a lot of drag for the ship and damaging marine biodiversity in their new environments. They're a major threat to our coasts and are very costly to ship owners."

The researchers inspected 45 vessels pulled from the sea and cleaned in various shipyards around Israel. They investigated both commercial and military boats, finding that the military vessels, which undergo maintenance every six months, were actually more prone to ascidian invasion. Commercial ships are cleaned every two years by law.

"Military vessels are cleaned every six months but are not being properly cleaned for these invasive species," said Dr. Shenkar said. "These species hide on the sea chest, under the bottom of the boat. Maintenance for commercial ships is much more thorough, including repainting and hosing down every nook and cranny of the vessel."

Dr. Shenkar recommends that all areas of the boats be checked. Boat owners should use the same paint for the bottom of the boat but use silicon-based paint, to which larvae can't attach, to cover areas such as the seachest.

They also found a correlation to seawater temperatures. "As temperatures rise, so too do the ascidians' numbers," said Dr. Shenkar. "We recommend conducting maintenance before the warm season begins. Early detection and rapid response are essential when a new potential nuisance species is discovered."

Discovery of new species in the region

In the course of their research, the scientists also discovered a Caribbean species new to the region. This suggests that the monitoring of marine vessels can serve as an effective tool for the early detection of non-indigenous ascidians.

"Our research is an example of the great cooperation that needs to exist between academia and commercial interests to form a realistic recommendation related to what is actually happening in the field," Dr. Shenkar said.

The researchers are currently working with policymakers in Israel and the EU to tailor environmental protection measures that would ward off non-indigenous ascidians.

Wild Wheat Genome Sequencing Provides "Time Tunnel" Capable of Boosting Future Food Production and Safety
7/6/2017

A global team of researchers has published the first-ever Wild Emmer wheat genome sequence in Science magazine. Wild Emmer wheat is the original form of nearly all the domesticated wheat in the world, including durum (pasta) and bread wheat. Wild emmer is too low-yielding to be of use to farmers today, but it contains many attractive characteristics that are being used by plant breeders to improve wheat.

The study was led by Dr. Assaf Distelfeld of Tel Aviv University's School of Plant Sciences and Food Security and Institute for Cereal Crops Improvement, in collaboration with several dozen scientists from institutions around the world and an Israel-based company, NRGene, which developed the bioinformatics technology that accelerated the research.

"This research is a synergistic partnership among public and private entities," said Dr. Daniel Chamovitz, Dean of TAU's George S. Wise Faculty of Life Sciences, who was also involved in the research. "Ultimately, this research will have a significant impact on global food security."

"Our ability to generate the Wild Emmer wheat genome sequence so rapidly is a huge step forward in genomic research," said Dr. Curtis Pozniak from the University of Saskatchewan, a project team member and Chair of the Canadian Ministry of Agriculture Strategic Research Program. "Wheat accounts for almost 20% of the calories humans consume worldwide, so a strong focus on improving the yield and quality of wheat is essential for our future food supply."

"From a biological and historical viewpoint, we have created a 'time tunnel' we can use to examine wheat from before the origins of agriculture," said Dr. Distelfeld. "Our comparison to modern wheat has enabled us to identify the precise genes that allowed domestication — the transition from wheat grown in the wild to modern day varieties. While the seeds of wild wheat readily fall off the plant and scatter, a change in two genes meant that in domesticated wheat, the seeds remained attached to the stalk; it is this trait that enabled humans to harvest wheat."

"This new resource allowed us to identify a number of other genes controlling main traits that were selected by early humans during wheat domestication and that served as foundation for developing modern wheat cultivars," said Dr. Eduard Akhunov of Kansas State University. "These genes provide invaluable resource for empowering future breeding efforts. Wild Emmer is known as a source of novel variation that can help to improve the nutritional quality of grain as well as tolerance to diseases and water-limiting conditions."

"New genomic tools are already being implemented to identify novel genes for wheat production improvement under changing environment," explains Dr. Zvi Peleg of the Hebrew University of Jerusalem, Israel. "While many modern wheat cultivars are susceptible to water stress, Wild Emmer has undergone a long evolutionary history under the drought-prone Mediterranean climate. Thus, utilization of the wild genes in wheat breeding program promote producing more yield for less water."

"The wheat genome is much more complex than most of the other crops and has a genome three times the size of a human genome." said Dr. Gil Ronen, NRGene's CEO. "Still, the computational technology we developed has allowed us to quickly assemble the very large and complex genome found in Wild Emmer's 14 chromosomes, to a standard never achieved before in genomic studies."

For the first time, the sequences of the 14 chromosomes of wild emmer wheat are collapsed into a refined order, thanks to additional technology that utilizes DNA and protein links. "It was originally tested in humans and recently demonstrated in barley, both of which have smaller genomes than Wild Emmer wheat," says Dr. Nils Stein, the Head of Genomics of Genetic Resources at Leibniz Institute of Plant Genetics and Crop Plant Research in Germany. "These innovative technologies have changed the game in assembling the large cereal genomes."

"This sequencing approach used for Wild Emmer wheat is unprecedented and has paved the way to sequence durum wheat (the domesticated form of Wild Emmer). Now we can better understand how humanity transformed this wild plant into a modern, high-yielding durum wheat," said Dr. Luigi Cattivelli, coauthor of the work and coordinator of the International Durum Wheat Genome Sequencing Consortium.

"We now have the tools to study crops directly and to make and apply our discoveries more efficiently than ever before," concluded Dr. Distelfeld.

Earliest Human Impact on Geological Processes Took Place 11,500 Years Ago
6/5/2017

The earliest geological indication of humans' impact on the environment discovered in the Dead Sea, TAU researchers say

A new Tel Aviv University study has uncovered the earliest known geological indications of manmade impact on geological processes, in particular erosion of the surface, from 11,500 years ago. Within a core sample retrieved from the Dead Sea, researchers discovered basin-wide erosion rates dramatically incompatible with known tectonic and climatic regimes of the period recorded.

"Human impact on the natural environment is now endangering the entire planet," said Prof. Shmuel Marco, Head of TAU's School of Geosciences, who led the research team. "It is therefore crucial to understand these fundamental processes. Our discovery provides a quantitative assessment for the commencement of significant human impact on the Earth's geology and ecosystems." The results of the study were published in Global and Planetary Change.

The research was conducted by TAU post-doctoral student Dr. Yin Lu and in collaboration with Prof. Dani Nadel and Prof. Nicolas Waldman, both of the University of Haifa. It took place as part of the Dead Sea Deep Drilling project, which harnessed a 1,500-foot-deep drill core to delve into the Dead Sea basin. The core sample provided the team with a sediment record of the last 220,000 years.

The newly-discovered erosion occurred during the Neolithic Revolution, the wide-scale transition of human cultures from hunting and gathering to agriculture and settlement. The shift resulted in an exponentially larger human population on the planet.

"Natural vegetation was replaced by crops, animals were domesticated, grazing reduced the natural plant cover, and deforestation provided more area for grazing," said Prof. Marco. "All these resulted in the intensified erosion of the surface and increased sedimentation, which we discovered in the Dead Sea core sample."

A natural laboratory in the Dead Sea

The Dead Sea drainage basin serves as a natural laboratory for understanding how sedimentation rates in a deep basin are related to climate change, tectonics, and man-made impacts on the landscape.

"We noted a sharp threefold increase in the fine sand that was carried into the Dead Sea by seasonal floods," said Prof. Marco. "This intensified erosion is incompatible with tectonic and climatic regimes during the Holocene, the geological epoch that began after the Pleistocene some 11,700 years ago."

The researchers are currently in the process of recovering the record of earthquakes from the same drill core. "We have identified disturbances in the sediment layers that were triggered by the shaking of the lake bottom," Prof. Marco said. "It will provide us with a 220,000-year record — the most extensive earthquake record in the world."

Solving the Riddle of the Snow Globe
5/25/2017

TAU research explains the process of sedimentation in natural and industrial contexts

If you've shaken a snow globe, you've enjoyed watching its tiny particles slowly sink to the bottom. But do all small objects drift the same way and at the same pace?

A new Tel Aviv University study finds the sedimentation of asymmetric objects in liquid is very different from that of symmetrical objects like spheres. The research solves a long-standing puzzle concerning the cause and the extent of "storminess" in sedimentation, and may be useful in improving water treatment and industrial processes that rely on suspensions, which are liquids that contain small solid particles. The research may also have use in the study of geological deposits, because variations in the concentration of particles from place to place affect the progress of sedimentation.

The research was led by Prof. Haim Diamant of TAU's School of Chemistry in collaboration with Prof. Thomas Witten of the University of Chicago, and conducted by TAU doctoral student Tomer Goldfriend. It was sponsored by the US-Israel Binational Science Foundation (BSF) and published in Physical Review Letters.

The calm and the storm

"Our research clarifies a common, complex phenomenon and offers ways of controlling it," Prof. Diamant said. "We have demonstrated that the 'storminess' of sedimentation is specific to symmetrical objects such as spheres and ellipsoids. It disappears in the more general case of asymmetric objects, which can have arbitrary shapes. Asymmetric objects render the sedimentation process more uniform and less chaotic."

Certain chemical reactors and water-treatment facilities rely on processes closely related to sedimentation, Prof. Diamant explained. "These are called 'fluidized beds,' where settling particles are made to hover in the liquid by an opposing upward flow of liquid, which facilitates their chemical activity. Fluidized beds are used in the production of polymers such as rubber and polyethylene. They are also used to improve the efficiency of water and waste treatment facilities. Our work might lead to improvements of such processes by controlling the uniformity of particles distributed in the liquid."

The team is currently studying the organizational properties of other kinds of materials. "We now intend to look for physical scenarios other than sedimentation that may show a similar kind of 'self-taming' — that is, a tendency of the material's constituents to self-organize into extremely uniform configurations," Prof. Diamant said. "The basic question is whether the behavior that we have found is unique to the process of sedimentation or can be found in a much broader class of materials. We think — we hope — that the latter is true."

Where the Jordan Stops Flowing
4/3/2017

Regional cooperation key to river restoration strategy that could be emulated around the world, says TAU researcher

A new study conducted at Tel Aviv University and published in the journal Water Research argues that Israel's Jordan River may be a useful case study for the challenges facing stream restoration initiatives around the world. The Jordan River has been ravaged by unbridled population growth and defunct sewage treatment plants.

"No river enjoys better PR and has worse environmental conditions than the Jordan River," said Prof. Alon Tal, Chair of TAU's Department of Public Policy, who led the research. "The river has a biblical pedigree and the potential to bring about environmental cooperation."

The Jordan River now has only 3% of its original flow. It has been decimated by a drop in water supply as a result of population growth, climate change, and contamination from a range of pollution sources. Human wastewater and even fish ponds contribute to the extremely poor water quality.

"While the rehabilitation of the Jordan River is of mutual concern to Israel, Jordan, and the Palestinians, the benefits of this rehabilitation have been extremely difficult to convey to decisionmakers, who are aware of how much they must spend to create them," Prof. Tal said. "When the water evaporates, though, wells run dry and agricultural systems and communities quickly collapse."

According to Prof. Tal's research, a two-pronged strategy that would both remove pollution sources and increase water flow to revive associated ecosystems requires regional cooperation.

"A restoration strategy requires ensuring a minimum flow and removing all pollution sources," said Prof. Tal. "We would also need to develop a program for ecologically sensitive tourism that will provide critical justification for ongoing commitment to environmental protection by all parties, regardless of their relative levels of prosperity.

"Regional thinking is critical to overcoming the population pressures of scarcity. Only a focused strategy that engages all the countries in the watershed can lead to a sustainable future for this iconic water resource. If we can't find he political will and economic resources required to revive a small, iconic river like the Jordan, it will be that much more difficult to find politicians and donors who will provide the funds to bring less famous streams back to life."

A cautionary tale

According to Prof. Tal, the case of the Jordan River has direct bearing on water-scarce regions around the world. China alone has some 24,000 rivers that are drying up.

Desalination, the process of removing salts and minerals from saline water to produce water suitable for human consumption or irrigation, has been hailed as a game-changer in countries long suffering from freshwater scarcity and has produced unique opportunities for cooperation in the region. But while desalination facilities have been instrumental in improving water supplies for populations around the world, they have not solved the crisis facing the planet's rivers and streams, including the Jordan River.

"People are mistakenly euphoric about desalination," said Prof. Tal. "Israel recycles 86% of its wastewater and is considered revolutionary in terms of its water management, but even Israel can't get a handle on the Jordan River. Our study is a response to those who think that if you can desalinate water, you don't have a water crisis. Let them come to the Jordan River and see for themselves."

Sponge Bacterium Found to Encapsulate Arsenic Drawn from Environment
2/27/2017

Entotheonella sequesters and neutralizes toxins within sponge host, say TAU researchers

Arsenic is the leading freshwater contaminant on the planet, affecting millions of people worldwide and causing an untold number of deaths every year. Removing arsenic from groundwater and freshwater is a major challenge still facing scientists and policymakers. Now a new Tel Aviv University study published in Nature Communications sheds light on a unique biological model of arsenic detoxification.

According to the new research, the Entotheonella bacterium that inhabits the Theonella swinhoei sponge is one of the only known cases of a bacterium protecting its host from metal poisoning. Entotheonella safeguards these sponges against the dangers of arsenic and another common toxin, barium.

"This particular sponge species, which is among the most ancient animals inhabiting the earth today, is home to a very diverse, very crowded number of microorganisms," said Prof. Micha Ilan of the Department of Zoology at TAU's Faculty of Life Sciences, who led the study. "These sedentary animals evolved to contain an in-house arsenal of chemicals and associated microbiota to deal with predators and pathologies."

A curious finding

While studying the biology of the sponge, which dwells in the Red Sea and the Indo-Pacific Ocean, Prof. Ilan and his colleague Dr. Boaz Mayzel discovered the curious ability of these sponges to accumulate and concentrate a million times more arsenic than that found in seawater. The results of that study were published in PLOS One in 2014.

Dr. Ray Keren, also of TAU's Department of Zoology and co-author of the new research with Dr. Mayzel, suspected a bacterium was involved in the detoxification. Indeed, after extensive testing, a single bacterial species was found to drive the accumulation of both arsenic and barium.

"We have not only discovered that a single bacterial species was the accumulator of both arsenic and barium. We have also found that this bacterium mineralizes the toxic elements, transforming them into inert products within its cells in a controlled manner," said Dr. Keren. "Sponges are eaten by turtles and worms, and even though they are exploding with arsenic, the bacteria renders them non-toxic. They become biologically inert. It is a very unique biological model."

The TAU scientists, in collaboration with Prof. Boaz Pokroy of the Technion Institute of Science and Dr. Sirine Fakra of the Advanced Light Source in the Lawrence Berkeley National Lab, harnessed cutting-edge technology to validate their initial findings, which were procured using the backscatter mode of a scanning electron microscope. "Prof. Pokroy took a sample of Entotheonella to the European Synchrotron Radiation Facility within a week of seeing that first image," said Dr. Keren. "There, he saw that barium is mineralized as barite and arsenic formed smaller peaks of an unknown mineral."

"More work to be done"

Subsequent diffraction analysis revealed that the mineral, crystalline arsenic, was in fact calcium arsenate. Dr. Fakra then validated the presence of these minerals under subfreezing cryogenic conditions.

"To render this unique detox method applicable to other situations, we need to somehow get rid of the sponge," said Prof. Ilan. "In other words, there is a lot more work to be done before we, human beings, can capitalize on this."

The researchers are currently researching the mechanism the bacterium uses to control the mineralization of the elements. "Once we identify the enzymes involved in the process, we can either look for them in bacteria in polluted water or find a way to grow Entotheonella in polluted areas," said Dr. Keren.

Bioinvasion is Jeopardizing Mediterranean Marine Communities
1/23/2017

Non-indigenous organisms introduced through the Suez Canal are causing irreversible damage, say TAU researchers

Non-indigenous species (NIS) are harming indigenous species and habitats in the Mediterranean Sea, impairing potentially exploitable marine resources and raising concern about human health issues, according to a new Tel Aviv University study.

The 2015 expansion of the Suez Canal, one of the world's most important corridors of commerce, facilitated an influx of non-indigenous species into the Mediterranean Sea, according to Prof. Bella Galil of the Israel National Center for Biodiversity Studies at TAU's Steinhardt Museum of Natural History, the lead author of a study published last month in Management of Biological Invasions.

"The Mediterranean Sea is the most invaded marine basin in the world," says Prof. Galil. "The number of NIS greatly increased between 1970 and 2015. 750 multicellular non-indigenous species were recorded in the Mediterranean Sea, far more than in other European seas, because of the ever-increasing number of Red Sea species introduced through the Suez Canal. This raises concerns about the increasing introductions of additional NIS and associated degradation and loss of native populations, habitats and ecosystem services."

A slow reaction

The development and implementation of a management policy have been slow, despite a century of scientific documentation of marine bioinvasions in the Mediterranean Sea. The Convention for the Protection of the Marine Environment and the Coastal Region of the Mediterranean, part of the United Nations Environment Programme (UNEP) Regional Seas Programme, adopted an "Action Plan concerning species introductions and invasive species in the Mediterranean Sea" in 2003. But the UNEP has "shied away from discussing, let alone managing, the influx of tropical non-indigenous biota introduced through the Suez Canal. So far no prevention and management measures have been implemented," according to Prof. Galil and her associates.

In their new study, the authors present data that marine-protected areas in the eastern Mediterranean, from Turkey to Libya, have been overwhelmed by non-indigenous species and serve as veritable "hot spots" of bioinvasion. Biotic communities are already fragile, suffering from manmade stressors such as pollution and overfishing. The colonization of these communities by NIS redistributes nutritional resources, removes important actors and renders them more susceptible to extinction.

Eastern Mediterranean algae-dominated rocky habitats have been decimated by large populations of herbivorous fish introduced through the Suez Canal. The two voracious grazers, Siganus luridus and S. rivulatus, have transformed lush rocky reefs into "barrens," dramatically reducing habitat complexity and altering the community structure and food web. Within 30 years, a small Red Sea mussel has replaced the native mytilid along the entire Mediterranean coast of Israel, forming dense nearly mono-specific species "carpets."

A hope for effective intervention

The authors of the study led a discussion on effective management of non-indigenous species introductions into the Mediterranean Sea at a EuroMarine workshop that took place in Ischia, Italy, in 2016. The discussion resulted in the "Ischia Declaration" that laid down principles for an effective, science-based, transboundary management. The declaration was approved by the general assembly of EuroMarine, a network of 73 research institutions and universities, funded by the European Union.

"We hope that this new research will be used to construct a science-based effective management of marine bioinvasions, and prevent, or at least minimize, the influx of additional non-indigenous species into the Mediterranean," says Prof. Galil. "Time will tell whether these aims are achieved or legislators and management continue to put off confronting this difficult issue and pass the environmental, economic and social burden to future generations."

The researchers are currently investigating pollution and other NIS-related factors.

Photo caption: A shoal of the Red Sea marbled spinefoot on an overgrazed rocky reef off northern Israel. Photo: Z. Fayer.

Harnessing Algae for the Creation of Clean Energy
10/6/2016

TAU researchers discover algae can yield mass quantities of hydrogen, the world's cleanest energy source

Researchers at Tel Aviv University have revealed how microalgae produce hydrogen, a clean fuel of the future, and suggest a possible mechanism to jumpstart mass production of this environmentally-friendly energy source. Their results have been published in back-to-back studies in Plant Physiology and Biotechnology for Biofuels.

The research was led by Dr. Iftach Yacoby, head of TAU's renewable energy laboratory, and Rinat Semyatich, Haviva Eisenberg, Iddo Weiner and Oded Liran, his students at the School of Plant Sciences and Food Security at TAU's Faculty of Life Sciences.

Researchers in the past believed that algae only produce hydrogen in the course of a single microburst at dawn lasting just a few minutes. But Dr. Yacoby and his team used highly sensitive technology to discover that algae produce hydrogen from photosynthesis all day long. Armed with this discovery, the team harnessed genetic engineering to increase algae's production of this clean energy source 400 percent.

Increasing algae's output of hydrogen

Laboratory tests revealed that algae create hydrogen with the assistance of the enzyme hydrogenase, which breaks down when oxygen is present. The researchers discovered effective mechanisms to remove oxygen so hydrogenase can keep producing hydrogen.

"The discovery of the mechanisms makes it clear that algae have a huge underutilized potential for the production of hydrogen fuel," said Dr. Yacoby. "The next question is how to beef up production for industrial purposes — to get the algae to overproduce the enzyme."

Some 99% of the hydrogen produced in the US comes from natural gas. But the methods used to draw hydrogen from natural gas are toxic — and wasteful.

Answering the need for clean energy

"I grew up on a farm, dreaming of hydrogen," said Dr. Yacoby. "Since the beginning of time, we have been using agriculture to make our own food. But when it comes to energy, we are still hunter-gatherers. Cultivating energy from agriculture is really the next revolution. There may be other ways to produce hydrogen, but this is the greenest and the only agricultural one.

"The world burns in just one year energy it took the earth over a million years to produce," Dr. Yacoby continued. "We must stop being hunters and gatherers of energy. We must start producing clean energy — for our children and for our children's children."

Dr. Yacoby is now researching synthetic enzymes capable of increasing hydrogen production from microalgae to industrial levels.

Sunscreen Is Proven Toxic to Coral Reefs
10/20/2015

TAU researchers discover chemical found in most sunscreen lotions poses an existential threat to young corals

The daily use of sunscreen bearing an SPF of 15 or higher is widely acknowledged as essential to skin cancer prevention, not to mention skin damage associated with aging. Though this sunscreen may be very good for us, it may be very bad for the environment, a new Tel Aviv University study finds.

New research published in Archives of Environmental Contamination and Toxicology finds that a common chemical in sunscreen lotions and other cosmetic products poses an existential threat — even in minuscule concentrations — to the planet's corals and coral reefs. "The chemical, oxybenzone (benzophenone-3), is found in more than 3,500 sunscreen products worldwide. It pollutes coral reefs via swimmers who wear sunscreen or wastewater discharges from municipal sewage outfalls and coastal septic systems," said Dr. Omri Bronstein of TAU's Department of Zoology, one of the principal researchers.

The study was conducted by a team of marine scientists from TAU, including Prof. Yossi Loya, also of the Department of Zoology, the Haereticus Environmental Laboratory in Virginia, the National Aquarium (US), the US. National Oceanic & Atmospheric Administration, Ben Gurion University of the Negev, and other labs in the US.

A deadly day at the beach

A person spending the day at the beach might use between two to four ounces of sunblock if reapplied every two hours after swimming, towelling off, or sweating a significant amount. Multiply this by the number of swimmers in the water, and a serious risk to the environment emerges.

"Oxybenzone pollution predominantly occurs in swimming areas, but it also occurs on reefs 5-20 miles from the coastline as a result of submarine freshwater seeps that can be contaminated with sewage," said Dr. Bronstein, who conducted exposure experiments on coral embryos at the Inter University Institute in Eilat together with Dr. Craig Downs of the Heretics Environmental Laboratories. "The chemical is highly toxic to juvenile corals. We found four major forms of toxicity associated with exposure of baby corals to this chemical."

Forms of toxicity include coral bleaching, a phenomenon associated with high sea-surface temperature events like El Niño — and with global mass mortalities of coral reefs. The researchers found oxybenzone made the corals more susceptible to this bleaching at lower temperatures, rendering them less resilient to climate change. They also found that oxybenzone damaged the DNA of the corals, neutering their ability to reproduce and setting off a widespread decline in coral populations.

The study also pointed to oxybenzone as an "endocrine disruptor," causing young coral to encase itself in its own skeleton, causing death. Lastly, the researchers saw evidence of gross deformities caused by oxybenzone — i.e., coral mouths that expand to five times their healthy, normal size.

It only takes a drop

"We found the lowest concentration to see a toxicity effect was 62 parts per trillion — equivalent to a drop of water in six and a half Olympic-sized swimming pools," said Dr. Bronstein. The researchers found concentrations of oxybenzone in the US Virgin Islands to be 23 times higher than the minimum considered toxic to corals.

"Current concentrations of oxybenzone in these coral reef areas pose a significant ecological threat," said Dr. Bronstein. "Although the use of sunscreen is recognized as important for protection from the harmful effects of sunlight, there are alternatives — including other chemical sunscreens, as well as wearing sun clothing on the beach and in the water."

The researchers hope their study will draw awareness of the dangers posed by sunscreen to the marine environment and promote the alternative use of sun-protective swimwear.

TAU/Tsinghua University Project Uses Crowdsourced Computing to Improve Water Filtration
7/6/2015

The research, a product of the new TAU-Tsinghua XIN Center, was conducted by 150,000 volunteers at IBM's World Community Grid

Nearly 800 million people worldwide don't have access to safe drinking water, and some 2.5 billion people live in precariously unsanitary conditions, according to the Centers for Disease Control and Prevention. Together, unsafe drinking water and the inadequate supply of water for hygiene purposes contribute to almost 90% of all deaths from diarrheal diseases — and effective water sanitation interventions are still challenging scientists and engineers.

A new study published in Nature Nanotechnology proposes a novel nanotechnology-based strategy to improve water filtration. The research project involves the minute vibrations of carbon nanotubes called "phonons," which greatly enhance the diffusion of water through sanitation filters. The project was the joint effort of a Tsinghua University-Tel Aviv University research team and was led by Prof. Quanshui Zheng of the Tsinghua Center for Nano and Micro Mechanics and Prof. Michael Urbakh of the TAU School of Chemistry, both of the TAU-Tsinghua XIN Center, in collaboration with Prof. Francois Grey of the University of Geneva.

Shake, rattle, and roll

"We've discovered that very small vibrations help materials, whether wet or dry, slide more smoothly past each other," said Prof. Urbakh. "Through phonon oscillations — vibrations of water-carrying nanotubes — water transport can be enhanced, and sanitation and desalination improved. Water filtration systems require a lot of energy due to friction at the nano-level. With these oscillations, however, we witnessed three times the efficiency of water transport, and, of course, a great deal of energy saved."

The research team managed to demonstrate how, under the right conditions, such vibrations produce a 300% improvement in the rate of water diffusion by using computers to simulate the flow of water molecules flowing through nanotubes. The results have important implications for desalination processes and energy conservation, e.g. improving the energy efficiency for desalination using reverse osmosis membranes with pores at the nanoscale level, or energy conservation, e.g. membranes with boron nitride nanotubes.

Crowdsourcing the solution

The project, initiated by IBM's World Community Grid, was an experiment in crowdsourced computing — carried out by over 150,000 volunteers who contributed their own computing power to the research.

"Our project won the privilege of using IBM's world community grid, an open platform of users from all around the world, to run our program and obtain precise results," said Prof. Urbakh. "This was the first project of this kind in Israel, and we could never have managed with just four students in the lab. We would have required the equivalent of nearly 40,000 years of processing power on a single computer. Instead we had the benefit of some 150,000 computing volunteers from all around the world, who downloaded and ran the project on their laptops and desktop computers.

"Crowdsourced computing is playing an increasingly major role in scientific breakthroughs," Prof. Urbakh continued. "As our research shows, the range of questions that can benefit from public participation is growing all the time."

The computer simulations were designed by Ming Ma, who graduated from Tsinghua University and is doing his postdoctoral research in Prof. Urbakh's group at TAU. Ming catalyzed the international collaboration. "The students from Tsinghua are remarkable. The project represents the very positive cooperation between the two universities, which is taking place at XIN and because of XIN," said Prof. Urbakh.

Other partners in this international project include researchers at the London Centre for Nanotechnology of University College London; the University of Geneva; the University of Sydney and Monash University in Australia; and the Xi'an Jiaotong University in China. The researchers are currently in discussions with companies interested in harnessing the oscillation knowhow for various commercial projects.

Fresh Milk, Off the Grid
5/19/2015

TAU researcher harnesses energy-efficient pulsed electric fields to preserve milk

Even though much of the population in developing countries is involved in agriculture, food security is virtually out of reach. Often the only resort is to purchase a cow, buffalo, or sheep, to provide a steady supply of fresh milk, a nutritious staple of a daily diet. But how to preserve it safely? Refrigeration and boiling are costly — and often impossible due to sporadic electricity.

The answers may lie in new Tel Aviv University research published in Technology, which finds that short pulsed electric fields can be used to kill milk-contaminating bacteria. Through a process called electroporation, bacterial cell membranes are selectively damaged. According to lead investigator Dr. Alexander Golberg, of TAU's Porter School of Environmental Studies, applying this process intermittently prevents bacteria proliferation in stored milk, potentially increasing its shelf life.

According to the study, pulsed electric fields, an emerging technology in the food industry that has been shown to effectively kill multiple food-born microorganisms, could provide an alternative, non-thermal pasteurization process. The stored milk is periodically exposed to high-voltage, short pulsed electric fields that kill the bacteria. The energy required can come from conventional sources or from the sun. The technology is three times more energy-efficient than boiling and almost twice as energy efficient as refrigeration.

An alternative for poorer countries

"We are on a constant hunt for new, low-cost, chemical-free technologies for milk preservation, especially for small farmers in low-income countries," said Dr. Golberg. "For 1.5 billion people without adequate access to electricity, refrigeration is simply not a possibility and boiling does not preserve milk's freshness over time."

In developed countries, bacterial growth in milk is managed with refrigeration. But certain pathogens like listeria monocytogenes are less sensitive to low temperature so can proliferate during transportation and in storage. "Refrigeration slows the bacteria's metabolism, but pulsed electric fields kill them," said Dr. Golberg. "They are a fundamentally different approach to controlling microorganisms during storage.

"Our model shows that pulsed electric fields preservation technology does not require a constant electricity supply; it can be powered for only 5.5 hours a day using small, family scale solar panels," said Dr. Golberg. "I believe that this technology can provide a robust, simple, and energy-efficient milk preservation system that would decrease the amount of wasted milk, thus increasing the income of small farmers in developing countries."

Dr. Golberg is currently exploring partnerships with interested agencies to develop an affordable device to reduce food waste and increase small farmers' incomes.

Predicting Which African Storms Will Intensify into Hurricanes
3/12/2015

TAU researcher finds hurricanes ravaging U.S. and Canada originate as disturbances in western Africa's atmosphere

Hurricanes require moisture, the rotation of the earth, and warm ocean temperatures to grow from a mere atmospheric disturbance into a tropical storm. But where do these storm cells originate, and exactly what makes an atmospheric disturbance amp up full throttle?

A new study published in Geophysical Research Letters by Tel Aviv University's Prof. Colin Price and his graduate student Naama Reicher of the Department of Geosciences at TAU's Faculty of Exact Sciences finds most hurricanes over the Atlantic that eventually make landfall in North America actually start as intense thunderstorms in Western Africa.

"85 percent of the most intense hurricanes affecting the U.S. and Canada start off as disturbances in the atmosphere over Western Africa," says Prof. Price. "We found that the larger the area covered by the disturbances, the higher the chance they would develop into hurricanes only one to two weeks later."

Watching the clouds gather

Using data covering 2005-2010, Prof. Price analyzed images of cloud cover taken by geostationary satellites, which orbit the Earth at the precise speed of the earth's rotation and take pictures of cloud cover every 15 minutes. This enabled Prof. Price to track the variability in cloud cover blocking the earth's surface in West Africa between the months of June and November — hurricane season.

The coverage of clouds acts as an indication of atmospheric disturbances. The more clouds in an area, the larger the disturbance. Using infrared cloud-top temperature data gathered from satellites, Prof. Price assessed the temperatures of the cloud tops, which grow colder the higher they rise. He then compared his cloud data with hurricane statistics — intensity, date of generation, location, and maximum winds — from the same period using the National Hurricane Center data base.

"We first showed that the areal coverage of the cold cloud tops in tropical Africa was a good indicator of the monthly number of atmospheric disturbances — or waves — leaving the west coast of tropical Africa," said Prof. Price. "The disturbances that developed into tropical storms had a significantly larger area covered by cold cloud tops compared with non-developing waves."

What makes them special

According to Prof. Price, only 10 percent of the 60 disturbances originating in Africa every year turn into hurricanes. And while there are around 90 hurricanes globally every year, only 10 develop in the Atlantic Ocean.

"We wanted to know what was so special about these 10% of disturbances that develop into hurricanes. Was there something different about these storms at their genesis?" said Prof. Price. "By looking at each of these storms individually, we found again that the larger the cloud coverage originally in West Africa, the higher the value of the accumulated cyclone energy in a future hurricane. The conclusion, then, is that the spatial coverage of thunderstorms in West Africa can foretell the intensity of a hurricane a week later.

"If we can predict a hurricane one or two weeks in advance — the entire lifespan of a hurricane — imagine how much better prepared cities and towns can be to meet these phenomena head on," Prof. Price says. He is currently examining the thunderstorm clusters around the eyes of hurricanes to study the intensification process of those destructive phenomena.

The Future Is Looking Less Cloudy
2/25/2015

TAU researchers discover cellular networks can be used to detect dangerous fog

When warm air comes into contact with a cool surface and chills to saturation, fog materializes. It blankets open roads and runways and dramatically reduces visibility — often causing devastating accidents.

A new study published in the Bulletin of the American Meteorological Society, by Tel Aviv University's Prof. Pinhas Alpert and Dr. Noam David of the Department of Geosciences at TAU's Faculty of Exact Sciences, and by Prof. Hagit Messer and Omry Sendik of the Department of Electrical Engineering Systems at TAU's Faculty of Engineering, reports a practical solution to fog detection can be found in cellular communication networks already in place all over the world.

Present fog monitoring tools include satellite systems and in situ sensors, but they are costly to implement and suffer from lack of precision when measuring at ground levels — where the data is most crucial. Researchers found in previous studies that the transmission of wireless microwave links in cellular networks were able to detect only the densest fog, but new advances in higher cellular communication frequencies can facilitate the detection of even light fog.

Opening a window of opportunity

"The goal of the work presented here is to reveal the potential that exists in commercial microwave systems, where higher frequencies more sensitive to fog are starting to be used," said Prof. Alpert, who supervised the study together with Prof. Messer. "We are presenting a window of opportunity to monitor fog with high resolution using technology already in place."

Commercial wireless links that operate at frequencies of tens of gigahertz form the infrastructure for data transmission between cellular base stations. These links are widely deployed across countries by cellular communication providers and are situated at ground level altitudes. Because of this, they are affected by different atmospheric phenomena at surface level — particularly fog.

"These existing systems have the potential to be utilized as an efficient fog monitoring tool," said Dr. David, who conducted the research as part of his postdoctoral study. "However, many of these systems, in their current format, have the potential to monitor only relatively heavy fog — hence the need for emerging technology to acquire more accurate observations."

Current wireless microwave links typically operate between frequencies of about 6 to 40 gigahertz, and the signal loss induced by fog at these frequency bands is relatively low. In other words, such systems have the potential to monitor only relatively heavy fog. In order to satisfy the growing demand for higher data rates and wider bandwidth, higher frequencies of around 70/80 gigahertz are beginning to be employed. "Since these higher frequencies are highly sensitive to the effects of fog, a new opportunity to potentially acquire wide-scale, high resolution observations of fog in real time has emerged," said Dr. David.

A foggy evening in Tel Aviv

To prove their concept, the researchers used a map of existing microwave links in Israel and calculated the minimum liquid water content that could be detected using signal attenuation data at 20, 38, and 80 GHz. At 80 GHz, even light fog, with a visibility of up to 750 meters, had a measurable effect on the signal. And when the researchers analyzed actual 38-GHz signal data for an evening that was foggy in Tel Aviv but clear in Jerusalem, the visibilities and fog densities they calculated were consistent with recorded observations.

"While most studies of this kind are focused on rainfall, fog is no less hazardous to people and objects in motion," said Dr. David. "Current monitoring tools are insufficient. Our new approach exposes the potential that already exists in these communication systems to provide high-resolution spatial measurements of fog."

The researchers are continuing to explore the potential of wireless communication frequencies.

World Thunderstorm "Map" Key to Assessing Climate Change
2/9/2015

TAU researcher devises method to provide continuous coverage of thunderstorms all over the planet

The Doomsday Clock, which measures the likelihood of global catastrophe, last month ticked a minute closer to "midnight" — the apocalypse. The symbolic clock was set to 11:57 by a board of atomic scientists featuring 17 Nobel Laureates, who warned that the planet, beset by climate change and nuclear proliferation, faced extraordinary and undeniable threats to its continued existence.

New research by Prof. Colin Price of Tel Aviv University's Department of Geosciences and published in Environmental Research Letters will likely be crucial to measuring the impact of climate change on thunderstorms — one of the weather occurrences most problematic for human life on the planet. The varying frequency and intensity of thunderstorms have direct repercussions for the public, agriculture, and industry.

"To date, satellites have only provided snapshots of thunderstorm incidence," said Prof. Price, whose new map of thunderstorms around the world is the first of its kind. "We want to use our algorithm to determine how climate change will affect the frequency and intensity of thunderstorms. According to climate change predictions, every one percent rise in global temperature will lead to a 10 percent increase in thunderstorm activity. This means that we could see 25 percent more lightning by the end of the century."

Keeping track of lightning

To draft a global thunderstorm map, Prof. Price and TAU graduate student Keren Mezuman used a vast global lightning network of 70 weather stations capable of detecting radio waves produced by lightning — the main feature of a thunderstorm — from thousands of miles away. The World Wide Lightning Location Network (http://wwlln.net) is run by atmospheric scientists at universities and research institutes around the world. The TAU team harnessed this ground-based system to cluster individual lightning flashes into "thunderstorm cells."

Every hour the exact GPS time of every detected lightning pulse was registered. Prof. Price and his colleagues then calculated the difference in arrival times of signals, using data from four to five different stations to locate individual lightning strokes anywhere on the globe. Finally, the researchers grouped the detected flashes into clusters of thunderstorm cells.

The WWLLN station in Israel has the ability to detect lightning as far away as central Africa.

Climate change and thunderstorms

"When we clustered the lighting strikes into storm cells, we found that there were around 1,000 thunderstorms active at any time somewhere on the globe," said Prof. Price.

The researchers, pooling seven years of data analysis, found that every day lightning activity on earth peaked at 1900 GMT, with low activity at 0300 GMT every day. While previous studies had estimated that 90 percent of lightning flashes occurred over land areas, the TAU team found that only 50 percent of the thunderstorms cells existed over land areas, implying that land storms have much more lightning than ocean storms.

"How lightning will be distributed in storms, and how the number and intensity of storms will change in the future, are questions we are working on answering," Prof. Price said.

Partly Wrong with a Chance of Being Right
1/26/2015

TAU study pinpoints dominant factors informing erroneous forecasts of weather conditions around the world

The night before the Israel Defense Forces' 1976 mission rescuing over 200 hostages from hijackers in Entebbe, Uganda, Tel Aviv University's Prof. Pinhas Alpert, then head of an Israel Air Force base forecasting unit, provided intelligence that was critical to the success of the operation — the weather conditions commandos were likely to encounter en route and on the ground. Had his information been incorrect, the mission might have ended quite differently.

The inaccuracy of forecasts also has personal implications for people around the world, leaving them stranded without umbrellas, snowed in, or stuck in airports. But considering the technology available today, why do meteorologists continue to miss the mark?

New research published in the journal Land by Prof. Alpert and his PhD student Tali Hirsch-Eshkol of the Department of Geosciences at TAU's Faculty of Exact Sciences prioritizes, for the first time, reasons for forecast failures across different regions of the world. Using multi-regression-based statistics on data collected between 1979-1993 on tens of thousands of forecast points, Prof. Alpert and his team were able to quantify the causes — man-made and natural — for weather prediction inaccuracies.

The big picture

"Considering my background in forecasting, weather prediction fallacies bothered me for a long time," said Prof. Alpert. "Since joining TAU in 1982, I have been looking for a way to quantify the dominant factors that cause errors in forecasting. Until now, there has been no comprehensive analysis of these factors. They have been studied separately, but not in combination. I decided to quantify and prioritize the dominant factors for different regions, and provide this valuable information to the world scientific community."

Using statistical analysis of meteorological data over thousands of locations and the course of 15 years, Prof. Alpert identified unique factors affecting forecasts in Europe, North Africa, the Mediterranean, Asia, and East Asia. The researchers found the dominant factors clouding the accuracy of predictions comprised land-use changes (i.e. an area that had been covered in forest is suddenly bare), topography, particles in the atmosphere and population density.

"For example, when Israel's national water pipeline crossed the northern Negev in June 1964, it changed the lay of the land," said Prof. Alpert. "After a relatively short period of time, the desert was blooming, affecting the generation of clouds, precipitation, and temperature extremes. It is difficult for forecasters to incorporate changes like this. In effect, this single land-cover change altered the entire local climate over the Northern Negev, and existing forecast models had difficulty accommodating this, leading to erroneous predictions."

Gold, silver, and bronze

The researchers incorporated the dominant factors within a single equation and then monitored the model's ability to accurately predict monthly weather conditions in different regions over 15 years. Prof. Alpert and his team also created a table of "factor prioritization" — gold, silver, and bronze labels to identify dominant and less dominant factors for different regions in the world. For example, they found that in the eastern Mediterranean, particles in the atmosphere were the most important cause of forecast fallacies, followed by land cover change. They also found topography to be the most influential factor affecting weather around the world.

"The only tool the weather forecaster has is his model, and the only choice he or she has is to look at different models, each of which has strengths and weaknesses," said Prof. Alpert. "Several hundred research groups are trying to improve forecasting models all the time. These groups also seek to improve predictions of climate change and global warming. Our study provides them with information about the right topics of research to address for each region."

Prof. Alpert is continuing to investigate factors that damage the quality of forecasts, hoping to devise new methods of improving weather and climate models.

TAU's Porter Building Awarded Top LEED Distinction
1/5/2015

Environmental studies facility receives "Platinum" designation from U.S. Green Building Council

The capsule building at the Porter School of Environmental StudiesThe U.S. Green Building Council has awarded Tel Aviv University's Porter School of Environmental Studies its highest distinction, LEED (Leadership in Energy & Environmental Design) Platinum. The Porter Building is the first in Israel, and only one of a few dozen in the world, to receive this exceptionally high measure of its long-term sustainability and environmental consciousness.

The building scored 92 out of 110 points, making it only one of 17 other structures in the world to have garnered more than 90 points towards a LEED designation. Platinum, the highest distinction, is achieved by earning over 80 points. Buildings at only a very few other universities in the world, including Harvard and Yale, have received the coveted "Platinum" status.

The LEED scale is the most widely recognized and respected rating system for green building in the world. The "Platinum" rating constitutes an official, independent certification that environmental considerations were given the highest priority in planning and construction of a building.

The building is the vision of TAU benefactor and Governor Dame Shirley Porter, the Porter family of Israel and the UK, and the Porter Foundation, who have championed the project for the past 13 years. Dame Shirley founded the Porter School of Environmental Studies in 2000 to deepen knowledge and train a new environmental leadership in Israel. Since then, it has become Israel's leading school in Israel dedicated to research, teaching and policy studies in the environmental field.

The Porter Building was designed by Alexrod-Grobman Architects, Geotectura Studio, and NCArchitects and landscaped by Braudo-Maoz Landscape Architects. It provides an ultramodern space for teaching, multidisciplinary research, exhibitions, conferences, and demonstrations of environmental technologies. The innovative structure was designed to maximize the efficient use of energy, water, cool air, and materials.

For more, read the article in NoCamels: "TAU's Porter School Of Environment Awarded LEED Platinum Designation".

TAU Launches Institute to Advance Intelligent Transportation and Alternative Fuel Technologies
11/4/2014

High-tech accelerator program a "unique experiment" in academic and start-up cooperation

The capsule building at the Porter School of Environmental Studies
The "capsule building" at the Porter School of Environmental Studies

Tel Aviv University's National Research Institute for Transportation Innovation is poised to launch an accelerator program for budding entrepreneurs in the fields of intelligent transportation and alternative fuels. The new research institute, established in August in collaboration with the Alternative Fuels Administration of the Israeli Prime Minister's Office, will open the program in December.

The four-to-six-month program will be situated in the university's "capsule" building, the new home of TAU's Porter School of Environmental Studies.

"From the university's perspective, this is a unique experiment in joining hands with Israeli start-up industries, incorporating the best of the academic world with the best of hi-tech entrepreneurship," said Prof. Dan Rabinowitz, head of the Porter School and the Institute for Transportation Innovation.

The budget for the program is expected to reach NIS 1 million (about $263,000 US) annually, which will be partially funded by EcoMotion, an Israel-based community of entrepreneurs in the smart transportation industry. Each participating entrepreneurial team will receive about NIS 100,000 (about $26,000 US) in cash, as well as the consulting services of experts in business, technology, and the automotive industry. The goal is to guide entrepreneurs through the first stages of development and help them acquire their first investment at the end of the program.

"The accelerator is designed to try to cope with the lack of infrastructure supporting the realization of unique ideas in the field of intelligent transportation, and is a direct continuation of the community's activities," said EcoMotion director Boaz Mamo.

Read the story in The Jerusalem Post: "Tel Aviv University launches fuel substitutes accelerator"

Mediterranean, Semi-Arid Ecosystems Prove Resistant to Climate Change
10/20/2014

TAU discovers Middle Eastern vegetation is remarkably resilient to long-term drought

Climate change predictions for the Middle East, like other arid regions of the world, are alarming. In an area known for its water scarcity, rainfall is expected to decrease even further in the near future, spelling disaster for the functioning of unique ecosystems — hotspots of biodiversity and rich genetic fodder for essential crops.

To test these dire predictions, Prof. Marcelo Sternberg of the Department of Molecular Biology and Ecology of Plants at Tel Aviv University's Faculty of Life Sciences, together with ecologists from the University of Tübingen in Germany, subjected natural ecosystems to an experimental drought over the course of nine years, simulating predicted future climate scenarios.

In the course of their experiment, conducted in four different ecosystems ranging from desert (3.5 inches of annual rainfall) to moist Mediterranean woodland (30.7 inches of annual rainfall), the researchers found that, contrary to predictions, no measurable changes in annual vegetation could be seen. None of the crucial vegetation characteristics — neither species richness and composition, nor density and biomass (particularly important for ecosystems traditionally used as rangelands) — had changed appreciably in the course of the rainfall manipulations.

"Based on our study, the going hypothesis that all semiarid regions will react strongly to climate change needs to be revised," states Prof. Sternberg. The surprising results of the study were recently published in Nature Communications.

A natural comfort zone

The affected ecosystems proved resilient, likely due to the highly variable amounts of annual rainfall for which the regions are known. The experimental climate changes, which simulated a decrease of about 30 percent of current rainfall, seem to fall within the natural "comfort zone" of wild plants.

In their experiment, the scientists were intent on testing one of the basic assumptions of climate change — that an affected plant species will migrate to more hospitable areas in order to survive. The researchers tested for two possible alternatives: first, a species dying off due to its inability to migrate to new and more suitable areas, and second, other varieties of the same species adapting to the new conditions created by the climate change.

"This second option has been overlooked by most researchers," said Prof. Sternberg, who found local adaptation to be the primary course of action for the plant communities that were tested.

Broad and extensive study

"Our experiment is likely the most extensive climate change study ever done, because of the number of sites involved, the long duration of experimental manipulations, and the immense species richness," said Prof. Sternberg.

According to Prof. Sternberg, the Mediterranean and semi-arid annual plant communities would be little affected by climate change, at least in the short to medium term. However, it cannot be ruled out that species composition could change after 20-30 years, because natural short-term climatic variations impose a different selection regime on organisms than a long-term trend of changing climate conditions.

Prof. Sternberg is currently searching for a new collaboration and funding to maintain the long-term experiment and expand its breadth and scope.

Are Fish Near Extinction?
6/25/2014

TAU researcher discovers the biological flaw that dooms fish larvae's ability to feed

"An end to seafood by 2050?" "Fish to disappear by 2050?" These sensational media headlines were the result of a 2010 report by the United Nations Environment Program, declaring that over-fishing and pollution had nearly emptied the world's fish stocks. That scarcity portends disaster for over a billion people around the world who are dependent on fish for their main source of protein.

Now, a new study by Dr. Roi Holzman and Victor China of the Department of Zoology at Tel Aviv University's George S. Wise Faculty of Life Sciences has uncovered the reason why 90% fish larvae are biologically doomed to die mere days after hatching. With this understanding of the mechanism that kills off the majority of the world's fish larvae, leaving only a marginal proportion to populate the world's oceans, "We can help find a solution to the looming fish crisis in the world," said Dr. Holzman.

The research, published in PNASand conducted at the Inter-University Institute for Marine Sciences in Eilat, Israel, suggests that "hydrodynamic starvation," or the physical inability to feed due to environmental incompatibility, is the reason so many fish larvae perish.

Survival strategies

"By focusing on the constraints placed on larvae survival, we have a better chance of producing higher quality mariculture," a specialized branch of aquaculture involving the cultivation of marine organisms for food and other products in the open ocean, said Dr. Holzman. "If we can produce better fish, this will have huge implications for our ability to maintain fish populations."

Dr. Holzman based his study on the problematic nature of fish reproduction. Nearly all fish species reproduce externally — they release and abandon their sperm and eggs into the water, providing no parental care. The fertilized eggs then hatch in the water within a couple of days and the hatching larvae must sustain themselves. When attached to a yolk sac (a membranous sac attached to an embryo that provides early nourishment in the form of yolk), these premature organisms can survive for a period of two or three days, but once the larvae, with poorly developed fins and gills, open their mouths, they start dying in droves.

"We thought, something is going on during this period, in which the proportional number of larvae dying is greatest," said Dr. Holzman. "Our goal was to pinpoint the mechanism causing them to die. We saw that even under the best controlled conditions, 70% of fish larvae were dying within the two weeks known as the 'critical period,' when the larvae detach from the yolk sac and open their mouths to feed," said Dr. Holzman. "What was going on? We turned to physics as a source of the problem."

Eating soup with a fork

The physical structure of the larvae and their flawed interaction with the physical environment provided the answer Dr. Holzman was looking for. Over the course of two years, he and doctoral student Victor China observed fish larvae at three significant points in their development (at the beginning, middle, and end of that “critical period” — eight, 13, and 23 days old). They found that the "stickiness" of the water — the viscosity of the surrounding ocean water — was hampering the larvae's attempts to feed.

"All that determines the larvae's feeding ability is viscosity — not age, not development. Only their interaction with the surrounding water," said Dr. Holzman. "Because the water molecules around you have weak electrical bonds, only a thin layer sticks to your skin — a mere millimeter thick. If you're a large organism, you hardly feel it. But if you're a three-millimeter-sized larva, dragging a millimeter of water across your body will prevent you from propelling forward to feed. So really, it's all about larval size, and its ability to grow fast and escape the size where it feels the water as viscous fluid."

The researchers found that in less viscous water, the larvae improved their feeding ability. In theory, they can be expected to increase their survival rate. "We conclude that hydrodynamic starvation is the reason for their dying," said Dr. Holzman. "Imagine eating soup with a fork — that's what it's like for these larvae. They're not developed enough at the critical point to adopt the constrained feeding strategy of adult-sized, better-developed fish."

Armed with this knowledge of the larvae's biological flaw, the researchers are currently patenting a solution to maintain higher survival rates among fish larvae populations.

Can Coral Save Our Oceans?
6/24/2014

TAU researchers discover soft coral tissue may help protect reefs against the hazardous effects of climate change

Coral reefs are home to a rich and diverse ecosystem, providing a habitat for a wide range of marine animals. But the increasing acidification of ocean water is jeopardizing the calcified foundations of these reefs, endangering the survival of thousands upon thousands of resident species.

New research by Prof. Yehuda Benayahu, Dr. Zehava Barkay, Prof. Maoz Fine, and their jointly supervised graduate student Yasmin Gabay of Tel Aviv University's Department of Zoology, Wolfson Applied Materials Research Center and the Interuniversity Institute for Marine Sciences in Eilat has uncovered the protective properties of soft coral tissue, which proved resilient when exposed to declining oceanic pH levels. The study, published in PLOS One, provides insight into the changing face of coral reefs threatened by dropping oceanic pH levels and may provide a new approach toward preserving the harder, calcified reef foundations.

Reefs and environmental change

Acidification is caused by increased carbon dioxide emissions in the atmosphere due to global change, fossil fuel burning, and other pollution. These emissions dissolve in the ocean, resulting in a slight lowering of oceanic pH levels. This produces changes to ocean water's carbon content, destroying the calcification of reef-building stony coral.

"The rise in temperature and ocean acidification are the main concerns of environmental change," said Prof. Benayahu, the Israel Cohen Chair in Environmental Zoology, whose TAU laboratory is home to one of the world's only soft coral (octocoral) research centers. "We know the value of reefs, the massive calcium carbonate constructions that act as wave breakers, and protect against floods, erosion, hurricanes, and typhoons. While alive, they provide habitats for thousands of living organisms, from sea urchins to clams, algae to fish. Reefs are also economically important in regions like Eilat or the Caribbean."

At first, the researchers examined the effects of lowered pH levels on living colonies of soft corals. Observing no significant effects on their physiology, Gabay thought it would be interesting to consider the effects of acidification on the skeleton of these soft corals.

"We really wanted to know if something could survive dropping pH levels in the future," said Gabay. "I was curious as to whether coral tissue could protect the inner coral skeleton, which is of most use in terms of reef construction, so I conducted an experiment using live soft corals and soft coral skeletons, which were placed in tanks containing ocean water with manipulated pH levels."

Using state-of-the-art microscopy, Gabay then scanned the tissue-covered skeletons and bare skeletons of soft corals exposed to experimental acidic conditions, the same conditions the International Panel of Climate Change predicts will occur 100 years from now if carbon dioxide emissions continue to rise. She found that the bare soft coral skeletons exhibited acidic stressed symptoms — large pockets burned into their microscopic corpuscular subunits — whereas the tissue-covered skeleton revealed almost no damage to its microscopic subunits.

"We found that the soft coral's tissue may indeed protect the skeleton from declining pH levels," said Yasmin Gabay. "The organism's internal environment apparently has a mechanism that protects against the acidic conditions."

The future of "the orchestra"

According to Prof. Benayahu, the future of soft-coral reefs is still unclear. Soft corals are not primary reef builders, because their skeletons are slow to calcify. Stony corals provide the massive skeletons that create reefs. Soft corals are replacing these reef builders, because they are somehow able to survive and live under extreme environmental conditions.

"A reef is like an orchestra. Many organisms interact to create harmony," said Prof. Benayahu. "Thousands of species live together and create life together. It is hard to predict what will happen if only soft corals survive, because they simply do not calcify at same rate as stony corals."

The researchers are currently studying the potential effects of soft coral displacement of stony coral species and the subsequent ramifications for reefs.

Radio Waves Carry News of Climate Change
7/30/2013

The ionosphere, one of the regions of the upper atmosphere, plays an important role in global communications. Ionized by solar radiation, this electricity-rich region is used for the transmission of long wave communications, such as radio waves. Now Prof. Colin Price of Tel Aviv University's Department of Geophysical, Atmospheric and Planetary Sciences, working alongside PhD candidate Israel Silber, has discovered that the radio waves reflecting back to Earth from the ionosphere offer valuable news on climate change as well.

Their research shows that the strength of radio signals on the ground is a reliable indicator of temperature change above. Prof. Price and his team used simple radio antennae on the ground to measure radio waves broadcast by navigational transmitters around the globe, then compared information on the strength of these radio signals with data on temperature fluctuations in the upper atmosphere. They discovered that climate change in the upper atmosphere — caused by an abundance of greenhouse gases — may lead to a greater absorption of radio waves. Weaker signals could therefore be indicative of greater climate change.

Detailed in the Journal of Geophysical Research, this simple, cost-effective measurement can be a valuable contribution to the ongoing effort to track climate change, says Prof. Price, adding to measurements of ground and lower atmospheric temperatures to create a more holistic picture.

Global warming, upper atmospheric cooling

On the Earth's surface and in the lower atmosphere, an increase of greenhouse gases has a warming effect, the gases acting as a "blanket" and keeping heat from escaping from the Earth into space. But these gases, including carbon dioxide, are increasing in the upper atmosphere as well, where they have a cooling effect.

When cooled, the ionosphere contracts and descends into the atmosphere to where air is denser — leading to a higher absorption of radio waves, Prof. Price explains. By examining satellite-gathered data on the temperature in the upper atmosphere and comparing results to measurements of radio wave amplitudes collected on the ground, the researchers were able to uncover a clear correlation, consistent over time. As the upper atmosphere gets colder, radio signals lose their strength.

While the sun is certainly the driving force behind changes in temperature in this region, it accounts for only 60 to 70 percent of temperature variations, says Prof. Price. The remaining variability could not be systematically measured until now. By adding measurements of radio waves taken on the ground to solar radiation estimates, researchers can now explain approximately 95 percent of temperature changes in the upper atmosphere.

Degrees of change

According to Prof. Price, this new technique will be a valuable addition to current methods of monitoring climate change, such as the measurement of ground temperatures. Without the need for expensive equipment like satellites, monitoring the upper atmosphere can be done inexpensively and continuously. And because temperatures in the upper atmosphere fluctuate more dramatically than those on the ground — for every one degree of warming in the lower atmosphere, there is a corresponding ten degree cooling in the upper atmosphere — changes are far easier to monitor.

Using this system might reveal more about the ionosphere than ever before. The region is notoriously difficult to monitor; there are no weather balloons or airplanes that can go high enough, and it is too low for orbiting satellites. But with this method, it could be possible to study long and short term changes in the ionosphere, such as the impact of solar storms or thunderstorms on the upper atmosphere.

TAU Researchers Save a Dying Tadpole Species
5/28/2013

Rare amphibians recovered from development site

Tel Aviv University researchers have rescued some 800 tadpoles of a rare species of toad — the Syrian spadefoot — from one of the last remaining winter ponds in the Haifa area. The land is slated for the development of a new shopping center, with construction to begin in just a few short weeks.

When they learned that the pool was about to be built over, the researchers, led by Prof. Noga Kronfeld-Schor of TAU's Department of Zoology, approached Israel's Nature and Parks Authority and offered to conduct a rescue mission to save the pool's inhabitants. In addition to those of the spadefoot toads, tadpoles of several other endangered species were saved, including a rare salamander and the southern banded newt.

Though there were once hundreds of such pools along the Israeli coastline, a vast majority were either drained for agricultural use or construction, putting a variety of amphibian species in danger of extinction. Previous research has shown that the population of spadefoot toads in the Haifa pond was unique, says Prof. Kronfeld-Schor.

The toads have been transferred to the university and are now being cared for at TAU’s Zoological Gardens. The researchers hope to return them to the wild as soon as possible, and the Nature Authority is preparing a new site with artificial seasonal ponds for the toads in the Haifa area.

Israel Prize Awarded to TAU Scientist for Innovations in Water Research
1/18/2013

TAU's Prof. Emeritus Gideon Dagan wins Israel's top honor

Prof. Emeritus Gideon Dagan of Tel Aviv University's School of Mechanical Engineering is the recipient of the 2012 Israel Prize for Earth Science. The prize, which will be awarded at a April 2013 ceremony on the eve of Israel's Independence Day, honors his outstanding career and groundbreaking research in the field of hydraulics.

The Israel Prize Committee called Prof. Dagan one of the forefathers of the discipline of Stochastic Hydrology, which uses statistical methods to analyze and predict various field scale processes including groundwater pollution.

Education Minister Gideon Sa'ar praised Prof. Dagan's scientific contributions, saying that his work aids in Israel's understanding of available groundwater resources. Prof. Dagan's research will help scientists develop models to better manage Israel's precious groundwater in the years to come.

The future of water security

Prof. Dagan's stochastic models and analysis aid in the understanding of how groundwater moves across the Earth's topsoil layer. This data can be used to prevent groundwater contamination as well as contribute to water conservation efforts in Israel and across the globe. The situation is especially dire in the Middle East, says Israel's Energy and Water Minister Uzi Landau, who predicts that water in the region will become more valuable than oil considering the rapid population growth.

A prolific author, Prof. Dagan has published over 165 scientific articles over his career and has more than 6,000 citations. He has also lectured at top academic institutions worldwide.

Tel Aviv University is proud to number 73 recipients of the Israel Prize among its faculty. The prizes are given every year by the state of Israel to those who have displayed excellence in their fields of study or made a strong contribution to Israeli culture.

Tracking Pollution from Outer Space
11/27/2012

TAU team uses NASA satellites to measure pollution hovering over world's megacities

The thickest layers of global smog — caused by traffic, industry, and natural minerals, among other factors — are found over the world's megacities. But getting an accurate measurement of pollution is no easy task. On-the-ground monitoring stations do not always provide the most accurate picture — monitoring stations depend heavily on local positioning and some cities put stations in urban centers, while others build on the edge of a city.

Now Prof. Pinhas Alpert of Tel Aviv University's Department of Geophysics and Planetary Sciences and head of the Porter School of Environmental Studies, with graduate student Olga Shvainshteinand and Dr. Pavel Kishcha, is turning to three of NASA's high-tech satellites for a comprehensive view of pollutants in the atmosphere. Using eight years' worth of data collected by the satellites, the researchers tracked pollution trends for 189 megacities — metropolitan hotspots where the population exceeds 2 million. 58 of these megacities, including New York City, Tokyo, and Mumbai, have populations that exceed 5 million.

Their method, published in the American Journal of Climate Change, is the first to provide standardized global testing of pollution levels. Beyond uncovering reliable data about pollution trends, Prof. Alpert believes that this monitoring method will also hold countries accountable for their emissions and encourage more environmentally friendly practices.

A "three judge" panel

The smog which often covers megacities is actually a thick atmospheric layer several hundred meters above the Earth's surface, comprised of particles of pollutants. It's an environmental hazard and a severe health risk for those living below, who breathe in the particulates.

To accurately analyze the level of pollution over each megacity, the researchers used data gathered by three aerosol-monitoring satellites, called MODIS-Terra, MODIS-Aqua, and MISR, which NASA launched from 2000 through 2002. The combined data these satellites provide constitute an accurate survey of aerosol concentrations a few hundred meters above Earth.

Prof. Alpert likens the use of three satellites to the traditional Jewish idea of the three-judge panel. "In the Jewish tradition, individual judges don't decide cases. There must be a minimum of three. You need a majority opinion," he says. "By merging the data from three imperfect sensors, their flaws are mostly counterbalanced. In cases where the three sensors show differing signs of pollution levels, more research is required."

Winners and losers

Northeast China, India, the Middle East, and Central Africa are currently leading in pollution increase, including Bangalore, India, with a 34 percent average increase in aerosol concentration between 2002 and 2010. Ibdan, Nigeria, was also part of that group. Europe and Northeast and Central North America are seeing the largest decreases in aerosol concentrations overall. Among the cleanest cities were Houston, with a 31 percent decrease over the time period; Curitiba, Brazil, with a 26 percent decrease; and Stockholm, Sweden, with a 23 percent decrease.

Some American cities were on the list of increased pollution levels, including Portland with a 53 percent average increase and Seattle with a 32 percent average increase, but Prof. Alpert believes these numbers reflect the multiple wildfires that have been happening in the region in the second half of the period examined. In the future, he hopes to develop a method for separating such natural causes of pollution from man-made pollutants for more accurate data.

An honest view of emissions

A standardized approach to smog analysis is made difficult by often unreliable data from monitoring stations, the reluctance of politicians or government ministries to offer accurate numbers on pollution, and even a complete lack of monitoring in major parts of the world, says Prof. Alpert. When it comes to international treaties aimed at reducing pollution, this measurement method could help to keep all countries accountable for their promises by tracking compliance in an equitable way. Cities that successfully decrease pollution could be applauded for their efforts and stand as a positive example to follow, he suggests.

TAU Researchers Use Satellite Technology to Identify Potential Dead Sea Sinkhole Sites
10/16/2012

Advanced prediction techniques boost safety in the region

Sinkholes that form along the shores of the Dead Sea are a severe danger to visitors and residents of this popular region of Israel. Falling into one of these caverns, which measure up to 39 feet in diameter and 65 feet deep, can lead to injury and even death. With several hundred sinkholes forming every year in the region, the risk continues to rise.

Now a team of Israeli researchers including Dr. Alon Ziv of Tel Aviv University's Department of Geophysics and Planetary Sciences is reducing the dangers posed by the Dead Sea's sinkholes by improving prediction techniques. Knowing when a sinkhole will appear will allow authorities to plan ahead.

Using an earth-observation satellite system known as Cosmo-Skymed, the researchers expect to have a few months' warning before a sinkhole actually appears. The satellite data, which is received by scientists once every 16 days, allows the researchers to measure changes in the ground's surfaces. When the team sees the ground sink in a particular way, they flag the spot as a potential sinkhole site.

Radar waves broadcast by the satellite show even the smallest changes on the Earth's surface within inches. These methods have been used in the past to detect changes in the surface in areas where earthquakes occur and volcanoes erupt.

For the full story on this advanced prediction method for Dead Sea sinkholes, see the Ha'aretz story:
Israeli researchers find new way to predict formation of dangerous Dead Sea sinkholes

Predicting Wave Power Could Double Marine-Based Energy
9/10/2012

Forecasting wave height one second in advance optimizes energy collection, says a TAU researcher

In the search for alternative energy, scientists have focused on the sun and the wind. There is also tremendous potential in harnessing the power of the ocean's waves, but marine energy presents specific challenges that have made it a less promising resource.

It's a challenge to tune Wave Energy Converters (WECs) so that they are able to harvest the maximum energy from waves, which differ in terms of their size and force. This unpredictability leads to intermittent energy collection. WECs also need to withstand the harsh winds and storms to which they are subjected in the open sea — storms which can destroy the devices.

Now, working with a team at the University of Exeter in the UK, Prof. George Weiss of Tel Aviv University's School of Electrical Engineering and Center for Renewable Energy has developed a control algorithm that, when used in conjunction with previously-developed wave prediction technology, helps WECs calculate the correct amount of force needed to collect the maximum energy possible, allowing the device to respond to each wave individually. The system, which was recently published in the journal Renewable Energy, doubles the energy previously collected by WECs.

Calculating force

WECs, Prof. Weiss explains, have two parts — a fixed or weighted lower part, possibly attached to the ocean floor, and an upper section that moves up and down based on the motion of the water. The device collects energy generated by the resistance force between the parts. Unlike wind turbines or solar panels, which collect as much or as little energy as comes their way, WECs need to adjust themselves to each oncoming wave to function properly, which requires knowledge of the characteristics of the incoming wave.

If there is zero resistance between the two parts of the WEC, the upper part moves freely with the waves, and no electricity is generated, Prof. Weiss explains. On the other hand, where there is so much resistance that it suppresses movement, the device turns rigid. At both of these extremes, no energy is produced. The ideal is a happy medium based on measurements of the incoming wave.

Prof. Weiss and his fellow researchers developed a control algorithm that is responsible for setting the correct resistance force for the WEC based on the predicted wave information. A processor attached to the WEC runs the algorithm five times per second in order to determine and then implement an optimal mechanical response to the coming waves.

In the lab, the researchers have run simulations using wave data gathered from the ocean. Combining prediction technology with their new algorithm, energy collection was improved by 100 percent — double the amount of energy that WECs had collected previously.

One second warning

The most important piece of information is the height of the wave, says Prof. Weiss, which the WEC needs to know in advance in order to prepare. "You would think that the longer the WEC knows the wave height in advance, the better, but in a surprising finding, it turns out that a one-second prediction horizon is enough," he says, noting that a longer prediction time does not actually improve the energy harvest.

Their findings could not only help to improve the functioning of the WECs that are already in use in places such as the East Coast of the US and the Atlantic Coast of Spain, but could help the technology become more competitive. Currently, marine energy is fifty times more expensive to collect than the market price for the energy itself — as solar and wind energy were in their infancy, says Prof. Weiss. But with the improvement of WEC structure, performance, and mass production, it could become commercially viable. "There is a lot of untapped energy in the ocean," he adds.

Viruses Could be the Key to Healthy Corals
8/30/2012

TAU develops treatment for deadly coral bacteria based on human medicine

Corals are an invaluable part of the marine ecosystem, fostering biodiversity and protecting coastlines. But they're also increasingly endangered. Pathogenic bacteria, along with pollution and harmful fishing practices, are one of the biggest threats to the world's coral populations today.

One of the solutions to the crisis may lie in human medicine. Prof. Eugene Rosenberg of Tel Aviv University's Department of Molecular Microbiology and Biotechnology, working in collaboration with Dr. Ilil Atad of his own laboratory and Prof. Yossi Loya of TAU's Department of Zoology, has developed a treatment for coral infected by Thalassomonas loyana, otherwise known as White Plague disease. This deadly bacterium infects 9 percent of Favia favus corals on the Eilat coral reef in the Red Sea and readily transmits the disease to nearby healthy corals.

Their treatment uses viruses that infect bacteria by injecting genetic material into the bacteria, a therapy originally developed to treat bacterial infections in humans. In this case, the researchers isolated a virus called BA3, one of a category of viruses known as phages. After laboratory experiments showed that BA3 had the ability to kill off White Plague disease, field experiments in the Gulf of Eilat demonstrated that the treatment stopped the progression of the disease in infected corals and prevented the spread of the disease to surrounding healthy corals as well.

These findings were presented at the American Society for Microbiology's general meeting in June.

From human to marine medicine

Treating bacterial infections in corals is no easy task. Because corals don't produce antibodies like humans, they can't be immunized. And pharmaceutical antibiotics are not a viable option because the treatment releases the drugs into the sea, harming the marine environment.

The researchers applied their treatment to two groups of diseased coral, each surrounded by a circle of healthy corals. In the test group, the researchers injected the virus into the area at a concentration of 1000 per milliliter. The control group did not receive the virus.

After 24 hours, the difference in the outcome was highly significant, says Prof. Rosenberg. In the test group, the infection of the diseased coral ceased its progression, and the disease did not spread to the surrounding healthy corals. In the control group, however, the White Plague disease progressed rapidly in the original infected coral and spread to seven out of ten of the surrounding healthy corals.

Amplifying a natural process

One of the most surprising discoveries during the course of their research, says Prof. Rosenberg, was that some corals naturally posses the beneficial virus and are already resistant to infection by the pathogen. When the researchers tested the three corals in the control group that remained uninfected, they discovered that the virus was already present in their biological composition. "We found that this is a natural process that goes on all the time. What we are doing is only shifting the situation in favor of the virus," he explains.

This method of developing an antidote to specific pathogenic coral bacteria is a crucial breakthrough, Prof. Rosenberg says. Corals in different regions of the world are infected with different pathogens. For each location, it is necessary to isolate the appropriate virus. But microbiologists should be able to develop regionalized treatments based on the methods used by Prof. Rosenberg and his fellow researchers.

The next step is to develop an effective way to spread the viruses over large areas of an infected coral reef. Sufficient amounts of these viruses can be easily manufactured in the laboratory. After that, it's a question of technology and funding, Prof. Rosenberg adds.


More Gold -- and Other Minerals -- in Them Thar Hills?
7/24/2012

TAU researcher's new method uncovers half-million ton mineral deposit in rough mountain terrain

Though technology has taken much of the guesswork out of mining, mountain ranges are still notoriously difficult environments in which to hunt for valuable minerals. Various methods used to draw a picture of the underground environment, including the measurement of gravitational and magnetic fields, are easily thrown off by factors such as changes in topography height, surrounding temperature, and barometric pressure.

Now Prof. Lev Eppelbaum of Tel Aviv University's Department of Geophysics and Planetary Sciences has developed a new method for processing and analysing complex environments in the face of these challenges. Combining new physical-mathematical approaches with their own advanced software — which brings together all available analysis in the same three-dimensional image — the researchers were able to overcome the difficulties posed by mountainous regions, successfully uncovering new mineral reserves.

Prof. Eppelbaum began working on his methodology with the late Prof. Boris Khesin of Ben Gurion University. Presented at the European Geosciences Conference in Vienna in April 2012 and in their book Geophysical Studies in the Caucasus, the method has already uncovered a previously unknown polymetallic reserve on the southern slope of the Caucasus, part of a vast mountain range between Europe and Asia that stretches from the Black to the Caspian Seas. The reserves include copper, zinc, lead, aluminium, and a mixture of gold and silver, Prof. Eppelbaum says.

A mountain range in three dimensions

In the hunt for underground metals or other resources like oil, gas, or water, geophysical fields such as gravity, magnetics, temperature, polarization, and electromagnetism play crucial roles. For example, the density of polymetallic ore —which consists of more than one metal — exceeds that of the surrounding rocks, creating a gravity anomaly. Although a 3D gravity analysis may then be used to decode these environmental cues, reserves do not reveal themselves that easily.

"After the environmental analysis, you must calculate the different types of background 'noise,' "Prof. Eppelbaum observes, such as the complexity of the topography, environmental characteristics, and more. Mountain ranges present particularly difficult terrain for this kind of calculation.

In order to circumvent these issues, Profs. Eppelbaum and Khesin improved current methods of geophysical analysis. They developed new mathematical approaches to process the information gathered from already-existing technology and from their own specially-designed software which allows the user to interpret all the information in a cohesive 3D image. "This 3D combined modelling software, which we programmed ourselves, enables scientists to see the buried targets more clearly," says Prof. Eppelbaum.

Prof. Eppelbaum believes they have discovered more than 500,000 tons of previously undiscovered polymetallic ore in the Caucasus mountainside in a single ore deposit. Other zones that could contain ore reserves have also been identified by the new methodology.

Caucasus and beyond

An expert in the Caucasus Mountains, Prof. Eppelbaum says that this technique can be applied to any region of the world, but most effectively in mountainous regions such as the Appalachian Mountains in the US and Canada or the Alps in Europe. Dr. Eppelbaum plans to develop collaborations with international geophysicists in an effort to discover new reserves around the world. "These reserves are very valuable resources for countries to discover," he says.


Climate Change May Lead to Fewer -- But More Violent -- Thunderstorms
7/10/2012

Number of flash floods and forest fires could increase with temperature, says TAU researcher

Researchers are working to identify exactly how a changing climate will impact specific elements of weather, such as clouds, rainfall, and lightning. A Tel Aviv University researcher has predicted that for every one degree Celsius of warming, there will be approximately a 10 percent increase in lightning activity.

This could have negative consequences in the form of flash floods, wild fires, or damage to power lines and other infrastructure, says Prof. Colin Price, Head of the Department of Geophysics, Atmospheric and Planetary Sciences at Tel Aviv University. In an ongoing project to determine the impact of climate change on the world's lightning and thunderstorm patterns, he and his colleagues have run computer climate models and studied real-life examples of climate change, such as the El Nino cycle in Indonesia and Southeast Asia, to determine how changing weather conditions impact storms.

An increase in lightning activity will have particular impact in areas that become warmer and drier as global warming progresses, including the Mediterranean and the Southern United States, according to the 2007 United Nations report on climate change. This research has been reported in the Journal of Geophysical Research and Atmospheric Research, and has been presented at the International Conference on Lightning Protection.

From the computer screen to the real world

When running their state-of-the-art computer models, Prof. Price and his fellow researchers assess climate conditions in a variety of real environments. First, the models are run with current atmospheric conditions to see how accurately they are able to depict the frequency and severity of thunderstorms and lightning in today's environment. Then, the researchers input changes to the model atmosphere, including the amount of carbon dioxide in the atmosphere (a major cause of global warming) to see how storms are impacted.

To test the lightning activity findings, Prof. Price compared their results with vastly differing real-world climates, such as dry Africa and the wet Amazon, and regions where climate change occurs naturally, such as Indonesia and Southeast Asia, where El Nino causes the air to become warmer and drier. The El Nino phenomenon is an optimal tool for measuring the impact of climate change on storms because the climate oscillates radically between years, while everything else in the environment remains constant.

"During El Nino years, which occur in the Pacific Ocean or Basin, Southeast Asia gets warmer and drier. There are fewer thunderstorms, but we found fifty percent more lightning activity," says Prof. Price. Typically, he says,we would expect drier conditions to produce less lightning. However, researchers also found that while there were fewer thunderstorms, the ones that did occur were more intense.

Fire and flood warning

An increase in lightning and intense thunderstorms can have severe implications for the environment, says Prof. Price. More frequent and intense wildfires could result in parts of the US, such as the Rockies, in which many fires are started by lightning. A drier environment could also lead fires to spread more widely and quickly, making them more devastating than ever before. These fires would also release far more smoke into the air than before.

Researchers predict fewer but more intense rainstorms in other regions, a change that could result in flash-flooding, says Prof. Price. In Italy and Spain, heavier storms are already causing increased run-off to rivers and the sea, and a lack of water being retained in groundwater and lakes. The same is true in the Middle East, where small periods of intense rain are threatening already scarce water resources.


Steel-Strength Plastics -- and Green, Too!
6/7/2012

As landfills overflow with discarded plastics, scientists have been working to produce a biodegradable alternative that will reduce pollution. Now a Tel Aviv University researcher is giving the quest for environmentally friendly plastics an entirely new dimension — by making them tougher than ever before.

Prof. Moshe Kol of TAU's School of Chemistry is developing a super-strength polypropylene — one of the world's most commonly used plastics — that has the potential to replace steel and other materials used in everyday products. This could have a long-term impact on many industries, including car manufacturing, in which plastic parts could replace metallic car parts.

Durable plastics consume less energy during the production process, explains Prof. Kol. And there are additional benefits as well. If polypropylene car parts replaced traditional steel, cars would be lighter overall and consume less fuel, for example. And because the material is cheap, plastic could provide a much more affordable manufacturing alternative.

His research has been published in the journal Angewandte Chemie.

Better building blocks

Although a promising field of research, biodegradable plastics have not yet been able to mimic the durability and resilience of common, non-biodegradable plastics like polypropylene. Prof. Kol believes that the answer could lie in the catalysts, the chemicals that enable their production.

Plastics consist of very long chains called polymers, made of simple building blocks assembled in a repeating pattern. Polymerization catalysts are responsible for connecting these building blocks and create a polymer chain. The better the catalyst, the more orderly and well-defined the chain — leading to a plastic with a higher melting point and greater strength and durability. This is why the catalyst is a crucial part of the plastic production process.

Prof. Kol and his team of researchers have succeeded in developing a new catalyst for the polypropylene production process, ultimately producing the strongest version of the plastic that has been created to date. "Everyone is using the same building blocks, so the key is to use different machinery," he explains. With their catalyst, the researchers have produced the most accurate or "regular" polypropylene ever made, reaching the highest melting point to date.

Using resources more efficiently

By 2020, the consumption of plastics is estimated to reach 200 million tons a year. Prof. Kol says that because traditional plastics aren't considered green, it's important to think creatively to develop this material, which has become a staple of daily life, with the least amount of harm to the environment. Cheaper and more efficient to produce in terms of energy consumption, as well as non-toxic, Prof. Kol's polypropylene is good news for green manufacturing and could revolutionize the industry. The durability of the plastic results in products that require less maintenance — and a much longer life for parts made from the plastic.

Beyond car parts, Prof. Kol envisions a number of uses for this and related plastics, including water pipes, which he says could ultimately conserve water use. Drinking water for the home has been traditionally carried by steel and cement pipes. These pipes are susceptible to leakage, leading to waste and therefore higher water bills. But they are also very heavy, so replacing them can be a major, expensive operation.

"Plastic pipes require far fewer raw materials, weighing ten times less than steel and a hundred times less than cement. Reduced leaking means more efficient water use and better water quality," Prof. Kol explains. The replacement of steel water pipes by those made of plastic is becoming more common, and the production of plastics with even greater strength and durability will make this transition even more environmentally-friendly.

Prof. Kol holds the Bruno Landesberg Chair in Green Chemistry at TAU.


"Dip Chip" Technology Tests Toxicity On-the-Go
5/14/2012

Biosensor warns of toxicity in real time, says TAU researcher

From man-made toxic chemicals such as industrial by-products to poisons that occur naturally, a water or food supply can be easily contaminated. And for every level of toxic material ingested, there is some level of bodily response, ranging from minor illness to painful certain death.

Biosensors have long been used to safeguard against exposure to toxic chemicals. Food tasters employed by the ancients acted as early versions of biosensors, determining if a meal had been poisoned. More modern examples include the use of fish, which may alter their swimming characteristics if a toxic material is introduced into to the water. But although current warning systems are more sophisticated, they require equipment and time that a soldier in the field or an adventurer in the wilderness do not have.

Now Prof. Yosi Shacham-Diamand, Vice Dean of Tel Aviv University's Faculty of Engineering, along with Prof. Shimshon Belkin of the Institute of Life Sciences at the Hebrew University of Jerusalem, has married biology and engineering to produce a biosensor device called the "Dip Chip," which detects toxicity quickly and accurately, generating low false positive and false negative readings. The Dip Chip contains microbes designed to exhibit a biological reaction to toxic chemicals, emulating the biological responses of humans or animals.

Converting biological response to electricity

The biological reaction is converted into an electronic signal that can be read by the user. When perfected for commercial applications, the chip might be easily plugged into a mobile device to determine toxicity, says Prof. Shacham-Diamand.

The new chips are based on genetically modified microbes developed in Prof. Belkin's lab. When the modified microbes are exposed to toxic or poisonous materials, they produce a measurable biochemical reaction — and this is where Prof. Shacham-Diamand's work begins.

"In my lab, we developed a method for communicating with the microbes, converting this biological response to electrical signals," he explains. The device, which looks like a dip stick, immobilizes these specially-produced microbes next to the sensing electrodes. Once the microbes come into contact with a questionable substance they produce a chemical signal that is converted to an electrical current by an device that can interpret the signals, producing a binary "toxic" or "not toxic" diagnosis.

In the future, Prof. Shacham-Diamand hopes that smaller versions of the Dip Chips might be plugged into existing mobile electronic devices, such as cell phones or tablets, to give the user a toxicity reading. This would make it an economically feasible and easy-to-use technology for people such as campers or for military purposes.

Reading any toxic material

One of the chip's advantages is its ability to identify toxicity as a biological quality instead of specific toxic chemicals. There are already excellent detectors to identify specific toxic materials, says Prof. Shacham-Diamand. The Dip Chip, however, is designed to alert the user to overall toxicity. And because the chip measures general toxicity, it will pick up on any and all toxic materials — even those that have not been discovered or invented yet.

Beyond their ability to find toxic chemicals in the field, these chips can also be put to use in the cosmetics or pharmaceuticals industries, says Prof. Shacham-Diamand. They could be used to detect the toxicity of new compounds, minimizing the controversial use of lab animals. Using the same technology, the researchers have also developed a larger-scale device which allows water to flow continuously over the sensor, making it appropriate for online, real-time monitoring of water supplies.

The results of their research have been published in a number of journals, including Electrochimica Acta and Sensors and Actuators B: Chemical.


Israel Names TAU's Renewable Energy Center a "Center of Research Excellence"
4/18/2012

With 55 senior researchers spanning seven faculties, the Renewable Energy Center at Tel Aviv University has made a commitment. A multi-disciplinary and innovative hub in a crucial area of research, its mission is to preserve the world's natural resources while advancing Israel's economy and security. Now the Center has been recognized by the state and named an National Research Center for Petroleum Alternatives for Transportation by Promoting Electrical Propulsion and Electric Vehicles.

Prof. Yossi Rosenwaks, head of the Renewable Energy Center, says he and his colleagues are honored to have won a position as a National Research Center, a new initiative by the Israeli government to promote Israel's intellectual creativity and foster fruitful collaborations between leading research institutions throughout the country. The designation provides grant money to support the return of outstanding Israeli researchers from abroad, build state-of-the-art laboratories and work spaces, and fund research efforts.

"This is a very prestigious honor, and reflects the excellence of the research groups involved. It will enable us to do much more work and to progress much faster toward the goal of developing a power source for electric vehicles," says Prof. Emanuel Peled, who will be leading the center at TAU along with Prof. Dina Golodnitsky. "We are in search of a breakthrough in science and technology to achieve this."

Supporting new facilities and talent

The funding will help elevate the university's Fuel Cell Laboratory to a world class facility, financing the purchase of state-of-the-art technological equipment and providing funds for scholarships and new faculty positions. The researchers' aim is to develop new materials, novel components, and devices for fuses and batteries in Lithium Air and Sodium Air systems. Prof. Peled hopes to develop electric vehicles with a 310-mile range at an affordable cost, ultimately reducing Israel's — and the world's — dependence on foreign oil.

One of the major benefits of the designation is that it will help TAU attract the best minds in energy research. With this new funding, they will be able to provide support for Ph.D. and post-doctoral students and two new faculty positions — one in the Faculty of Engineering and another in the School of Chemistry. TAU hopes to recruit leading Israeli researchers who might otherwise have sought positions abroad.

"Naturally, TAU needs to have the ability to attract the top minds in the field of renewable energy. The most organic way to do that is to direct talented Ph.D. students to this field, and then have faculty positions available for them when they're ready," says Prof. Rosenwaks.

In addition to the new funding, the university has pledged to establish President's Scholarships to meet their goals. The scholarships will provide students with sufficient economic support through their studies, so they can devote their time to research and to becoming leaders in the field, Prof. Rosenwaks adds.

A home for research excellence

Beyond the research group that is part of the designation, the Renewable Energy Center is home to a number of outstanding research groups that are working towards ending dependence on fossil fuels, Prof. Rosenwaks says. "TAU and the Renewable Energy Center bring together the world’s leaders in renewable energy research, supplying the laboratories and equipment necessary for scientific and technological breakthroughs," he says. "It's an exemplary model of interdisciplinary co-operation."

The Center promotes advanced research in renewable energy based in a variety of sources, including solar, wind, and biomass, along with the technologies for storing and managing the energy. Some of the leading fields of research at TAU include nano antennas to revolutionize solar energy, optimized electricity grids, and energy harvested through photosynthesis. In another highlight for the Center this year, faculty member Prof. Nathan Nelson, a world-renowend biologist, was awarded a prestigious European Research Council (ERC) grant for his research on photosynthetic hydrogen production.

For more information on the Renewable Energy Center, visit the Center's webpage at:
http://energy.tau.ac.il/


Swifts Return to the Holy City
4/16/2012

TAU researcher hosts ceremony to welcome migrating swifts back to Western Wall nesting site

Alongside the notes and prayers lodged in its ancient crevices, the Western Wall in Jerusalem has also long been home to the migrating swift, a highly aerial bird similar to swallows that can fly at an average speed of 30 miles an hour. According to Dr. Yossi Leshem of Tel Aviv University's Department of Zoology and Israel's foremost ornithologist, this holy site is one of the birds' oldest nesting colonies. In recent years, approximately 40 pairs of birds have been spotted nesting among the 2,000-year-old stones.

In a recent ceremony attended by Dr. Leshem and Jerusalem Mayor Nir Barkat, the swifts were welcomed back to their nesting site from their winter home in Africa. Dr. Leshem hopes to make the swift's annual pilgrimage a draw for bird lovers from all over the globe.

During their 100-day nesting period, these master aerialists fly high above the city, eating, sleeping, and even mating in the air. The swifts, which weigh in at a tiny 1.2-1.6 ounces apiece, arrive in mid-February and return to Africa in June.

TAU, along with the Friends of the Swifts Association and the Society for the Protection of Nature in Israel, are working to protect the swifts, who prefer to nest in man-made structures. The organizations hope to safeguard current nesting sites and build additional sites.

"Ever since humans started building cities, the common swift has found our buildings perfect for nesting sites, including ancient holy sites such as churches, synagogues, mosques, and temples, and has become dependent on us," says Dr. Leshem. To preserve this habitat, the birds' 88 nesting sites have been taken into account during work to strengthen the masonry of the Western Wall.

For the full story on the returning swifts, see the Jerusalem Post story:
http://www.jpost.com/InJerusalem/CityFront/Article.aspx?id=261026


Endangered Bats Find Sanctuary in Israeli "Ghost Bunkers"
4/12/2012

Abandoned army bunkers along the Jordan River have become a habitat for 12 indigenous bat species, three of which are already designated as endangered and two that are on the critical list. The bats were recently identified by a group of Tel Aviv University researchers who were granted access to the bunkers, spread out along a 60-mile-long stretch of land between the Sea of Galilee in the north of Israel to the Dead Sea's northern edge.

According to Ph.D. student Eran Levin of TAU's Department of Zoology, the local bat population is estimated to be in the thousands. "There is no doubt that, by being in a closed military zone that has prevented human interference, the bat habitat allows these delicate creatures to thrive," he said. The underground forts have been empty since a peace treaty was signed with Jordan in 1994.

The researchers are now working to make the bunkers a more hospitable place for the bats by "roughing up" the steel and concrete walls — suspending mesh sheets and wooden pallets and spraying insulating foam and stuck stones to surfaces to provide a better grip. Night cameras have also been installed to keep an eye on the bats' movement and behavior.

The bats are earning their lodging by serving as an asset to the environment. They each eat a few grams of insects every night, reducing the need for pesticides.

For the full story on the bats' new habitat, see the ynetnews.com story:
http://www.ynetnews.com/articles/0,7340,L-4181656,00.html


Has the Dead Sea Used Up its Nine Lives?
4/10/2012

Rapidly dropping water levels of the Dead Sea, the lowest point on the earth's surface heralded for its medicinal properties, has been a source of ecological concern for years. Now a drilling project led by researchers from Tel Aviv University and Hebrew University reveals that water levels have risen and fallen by hundreds of meters over the last 200,000 years.

Directed by Prof. Zvi Ben-Avraham of TAU's Minerva Dead Sea Research Center and Prof. Mordechai Stein of the Geological Survey of Israel, researchers drilled 460 meters beneath the sea floor and extracted sediments spanning 200,000 years. The material recovered revealed the region's past climatic conditions and may allow researchers to forecast future changes.

Layers of salt indicated several periods of dryness and very little rainfall, causing water to recede and salt to gather at the center of the lake. During the last interglacial period, approximately 120,000 years ago, the sea came close to drying up entirely, the researchers found, with another period of extreme dryness taking place about 13,000 years ago.

Today, the Dead Sea lies 426 meters below sea level and is receding rapidly. Despite this historical precedent, there is still cause for concern, says Prof. Ben-Avraham. In the past the change was climate-driven, the result of natural conditions; today, the lake is threatened by human activity.

"What we see happening in the Middle East is something that mimics a severe dry period, but this is not climate-enforced, this is a man-made phenomenon," he warns, caused by increasing amounts of water being taken from rivers for irrigation before it reaches the Dead Sea. Ultimately, this prevents the refilling of the sea by the waters of the Jordan River.

For the full story on the Dead Sea drilling project, see the CBS News story:
http://www.cbsnews.com/8301-205_162-57337425/after-it-died-once-will-dead-sea-die-again/


Is Seaweed the Future of Biofuel?
3/5/2012

TAU scientist takes the search for alternative energy sources to the sea


As scientists continue the hunt for energy sources that are safer, cleaner alternatives to fossil fuel, an ever-increasing amount of valuable farmland is being used to produce bioethanol, a source of transportation fuel. And while land-bound sources are renewable, economists and ecologists fear that diverting crops to produce fuel will limit food resources and drive up costs.

Now, Prof. Avigdor Abelson of Tel Aviv University's Department of Zoology and the new Renewable Energy Center, and his colleagues Dr. Alvaro Israel of the Israel Oceanography Institute, Prof. Aharon Gedanken of Bar-Ilan University, Dr. Ariel Kushmaro of Ben-Gurion University, and their Ph.D. student Leor Korzen, have gone to the seas in the quest for a renewable energy source that doesn't endanger natural habitats, biodiversity, or human food sources.He says that marine macroalgae — common seaweed — can be grown more quickly than land-based crops and harvested as fuel without sacrificing usable land. It's a promising source of bioethanol that has remained virtually unexplored until now.

The researchers are now developing methods for growing and harvesting seaweed as a source of renewable energy. Not only can the macroalgae be grown unobtrusively along coastlines, Prof. Abelson notes, they can also clear the water of excessive nutrients — caused by human waste or aquaculture — which disturb the marine environment.

A man-made "ecosystem"

While biomasses grown on land have the potential to inflict damage on the environment, the researchers believe that producing biofuel from seaweed-based sources could even solve problems that already exist within the marine environment. Many coastal regions, including the Red Sea in the south of Israel, have suffered from eutrophication — pollution caused by human waste and fish farming, which leads to excessive amounts of nutrients and detrimental algae, ultimately harming endangered coral reefs.

Encouraging the growth of seaweed for eventual conversion into biofuel could solve these environmental problems. The system that the researchers are developing, called the "Combined Aquaculture Multi-Use Systems" (CAMUS), takes into account the realities of the marine environment and human activity in it. Ultimately, all of these factors function together to create a synthetic "man-made ecosystem," explains Prof. Abelson.

Man-made fish feeders, which produce pollution in the form of excess nutrients and are generally considered harmful to the marine environment, would become a positive link in this chain. Used alongside an increased population of filter feeders such as oysters, which suck in extra particles and convert them food that the microalgae can consume, this "pollution" could be used to sustain a much greater yield of seaweed, which is needed for seaweed to become a sustainable source of fuel.

"By employing multiple species, CAMUS can turn waste into productive resources such as biofuel, at the same time reducing pollution's impact on the local ecosystem," he says.

Turning waste into opportunity

The researchers are now working to increase the carbohydrate and sugar contents of the seaweed for efficient fermentation into bioethanol, and they believe that macroalgae will be a major source for biofuel in the future. The CAMUS system could turn seaweed into a sustainable bioethanol source that is productive, efficient, and cost-effective.

Saving Lives and Aircraft on the Bird Superhighway
2/6/2012

TAU technology tracks bird migration in real time to avoid collision in the skies

When an airplane collides with birds, the result can be devastating. The now-famous US Airways emergency landing on the Hudson River was set in motion when the plane struck a flock of Canadian geese. That incident enjoyed a rare happy ending — but now Dr.Yossi Leshem of Tel Aviv University's Department of Zoology has developed a digitized system with the ability to track migrating birds in real-time, significantly reducing the threat of a collision.

Adapted from weather radar technology, Dr. Leshem's system has been implemented throughout Israel. The system tracks the movements of birds, then reports details of their coming and going, including the height at which they are flying, and which route they are taking. Based on this information, the Israel Air Force (IAF), which funds the research along with Israel’s Ministry of Defence, can alter flight plans accordingly.

With the third and final radar installed in the north of Israel two years ago, a flock can be followed 40 miles into Lebanon, Syria, or Jordan, and the Air Force given a two-hour advanced warning of the arrival of a flock. Since the beginning of the program, there has been a 76 percent drop in collisions — saving $800 million and countless lives since 1984.

Keeping an eye on the sky

Israel, on a flight path between Europe and Africa, is a superhighway of bird migration. Approximately 500 million birds fly through the country's airspace twice a year. Before Dr. Leshem’s project began, the Israeli Air Force lost ten aircrafts which collided with birds, and experienced about 75 collisions costing approximately $1 million in damages each, which also resulted in the deaths of three pilots. But for the past 32 years, Dr. Leshem and his fellow researchers have been tracking migrating birds across the skies of Israel to help avoid these costly collisions.

To start tracking migration patterns, the researchers flew motorized gliders from the Egyptian border in the south of Israel to the Lebanese border in the north. This was the first time, Dr. Leshem notes, that drones were employed for a non-military purpose. More recently, the system was updated, providing minute-to-minute updates on the whereabouts of migrating flocks as well as information on migration patterns.

Using weather radar originally designed to identify clouds, the radar can monitor birds as far as 62 miles away. Updates are provided in real time as information is received, says Dr. Leshem, who still serves in the reserves as a Lieutenant Colonel in the Air Force.

Bird-lovers flock to watch migration

Securing the airways has been a project of passion for Dr. Leshem, who is widely acknowledged as Israel’s foremost bird expert. His other projects, often undertaken in collaboration with Jordan and the Palestinian Authority, are efforts towards peace, education, and the health of the environment. One such regional effort is a project that helps farmers install nesting boxes for barn owls, providing natural pest control.

Dr. Leshem is also helping develop the region's potential for eco-tourism. The millions of birds who pass through the country each year are an opportunity to bring bird-lovers from all over the world to Israel, he says. Along with the Israeli government and the Society for the Protection of Nature in Israel, the country's oldest and largest environmental organization, Dr. Leshem is building a network of 15 bird watching stations all over the country. In addition to the existing stations in Jerusalem and at the Yarkon River close to the TAU campus, stations will be built in the desert at Sde Boker and the oasis of Ein Gedi adjacent to the Dead Sea, and elsewhere.

"Israel is well known in the world for history and archaeology, but it is also one of the hot spots for bird migration," Dr. Leshem says, issuing an open invitation to the world's bird-lovers, including an estimated 46 million bird enthusiasts in the U.S. Open to researchers, school trips, and other visitors, the centers will be a place for scientific study as well as tourism.


Reclaiming the Land After a Forest Fire
12/22/2011

TAU researchers use organic polymer to protect scorched soil from erosion

Wildfires cause tragic losses to life, property, and the environment. But even after the fire rages, the damage is far from done. Without vegetation, bare, burnt soil lies vulnerable to erosion, which can impede efforts towards natural forest regeneration.

Now Assaf Inbar, a graduate student at Tel Aviv University's Porter School of Environmental Studies, together with his supervisors Prof. Marcelo Sternberg of the Department of Molecular Biology and Ecology of Plants, Dr.Meni Ben-Hur of the Volcani Center and Dr. Marcos Lado of the University of La Coruña, Spain, have studied a new soil protection procedure that may significantly reduce erosion in areas ravaged by forest fires. Working with an organic polymer originally used in agriculture, Inbar and his supervisors have tested their method in the lab and also in Birya forest in Israel, large parts of which have been burnt by fire.

Protecting the soil from erosion, says Inbar, is vital for the quick restoration of the vegetation. And this method can be cheaper than current solutions, such as creating log barriers or mulching, a process in which the ground is covered with woody chips or straw.

The research was presented at the Israel Society of Ecology & Environmental Sciences Annual Conference in 2010 and at a COST–European Cooperation in Science and Technology Conference in 2009.

Holding on to the soil

Following a wildfire, soil often erodes because vegetation is burnt and the soil remains bare. Deprived of the protection from the elements that vegetation provides, soil can't absorb intense rains, causing run-off. "If water cannot penetrate the soil, it flows on top — taking the soil with it," says Inbar. The danger is especially great in forests with steep slopes and shallow soil. Once significant amounts of soil wash away, it is difficult to reforest the area.

The researchers turned to the anionic polymer Polyacrylamide (PAM), widely used in agriculture to prevent soil erosion. They tested the polymer on samples of burnt soils both in the lab, using a rainfall simulator, and out in the field under natural rainfall, using run-off plots in an area of Birya Forest that had been exposed to a moderate wildfire. The run-off plots were placed on a 40-degree slope and outfitted with a funnel at the bottom to collect run-off and sediments, measured after every rainstorm.

In both simulated and natural rainstorms, the burnt soils remained much more stable with the addition of the PAM than without, reports Inbar. With the addition of the polymer, applied in granules of about 110 pounds every 2.5 acres, soil erosion was reduced by 50 percent.

Helping the forest to bloom again

At just under $1.50 dollars per pound, PAM granules can be an affordable alternative to mulching, which sometimes requires application by helicopter, and to log barriers, which requires the effort of many workers and heavy machinery. What's more, the non-toxic PAM is safe for existing vegetation.

The researchers have tested the soil's ability to nurture vegetation with the addition of the polymer, and saw encouraging results. They used wheat as a model for annual plants that sprout during the rainy season in areas that had been affected by fire. The polymer had no negative impact on the growth of the wheat, concludes Inbar, who says the researchers' next step is to test different soils, the interaction between the polymer and ash, and the effectiveness of this treatment in larger areas.


A Light Wave of Innovation to Advance Solar Energy
11/10/2011

Some solar devices, like calculators, only need a small panel of solar cells to function. But supplying enough power to meet all our daily needs would require enormous solar panels. And solar-powered energy collected by panels made of silicon, a semiconductor material, is limited — contemporary panel technology can only convert approximately seven percent of optical solar waves into electric current.

Profs. Koby Scheuer, Yael Hanin and Amir Boag of Tel Aviv University's Department of Physical Electronics and its innovative new Renewable Energy Center are now developing a solar panel composed of nano-antennas instead of semiconductors. By adapting classic metallic antennas to absorb light waves at optical frequencies, a much higher conversion rate from light into useable energy could be achieved. Such efficiency, combined with a lower material cost, would mean a cost-effective way to harvest and utilize "green" energy.

The technology was recently presented at Photonics West in San Francisco and published in the conference proceedings.

Receiving and transmitting green energy

Both radio and optical waves are electromagnetic energy, Prof. Scheuer explains. When these waves are harvested, electrons are generated that can be converted into electric current. Traditionally, detectors based on semiconducting materials like silicon are used to interface with light, while radio waves are captured by antenna.

For optimal absorption, the antenna dimensions must correspond to the light's very short wavelength — a challenge in optical frequencies that plagued engineers in the past, but now we are able to fabricate antennas less than a micron in length. To test the efficacy of their antennas, Prof. Scheuer and his colleagues measured their ability to absorb and remit energy. "In order to function, an antenna must form a circuit, receiving and transmitting," says Prof. Scheuer, who points to the example of a cell phone, whose small, hidden antenna both receives and transmits radio waves in order to complete a call or send a message.

By illuminating the antennas, the researchers were able to measure the antennas' ability to re-emit radiation efficiently, and determine how much power is lost in the circuit — a simple matter of measuring the wattage going in and coming back out. Initial tests indicate that 95 percent of the wattage going into the antenna comes out, meaning that only five percent is wasted.

According to Prof. Scheuer, these "old school" antennas also have greater potential for solar energy because they can collect wavelengths across a much broader spectrum of light. The solar spectrum is very broad, he explains, with UV or infrared rays ranging from ten microns to less than two hundred nanometers. No semiconductor can handle this broad a spectrum, and they absorb only a fraction of the available energy. A group of antennas, however, can be manufactured in different lengths with the same materials and process, exploiting the entire available spectrum of light.

When finished, the team's new solar panels will be large sheets of plastic which, with the use of a nano-imprinting lithography machine, will be imprinted with varying lengths and shapes of metallic antennas.

Improving solar power's bottom line

The researchers have already constructed a model of a possible solar panel. The next step, says Prof. Scheuer, is to focus on the conversion process — how electromagnetic energy becomes electric current, and how the process can be improved.

The goal is not only to improve the efficiency of solar panels, but also to make the technology a viable option in terms of cost. Silicon is a relatively inexpensive semiconductor, but in order to obtain sufficient power from antennas, you need a very large panel — which becomes expensive. Green energy sources need to be evaluated not only by what they can contribute environmentally, but also the return on every dollar invested, Prof. Scheuer notes. "Our antenna is based on metal — aluminium and gold — in very small quantities. It has the potential to be more efficient and less expensive."


Carbon Monoxide -- The Silent Calmer?
11/8/2011

Inhaling low levels of CO reduces the impact of environmental stress, TAU researcher finds

According to scientists, carbon monoxide (CO), a tasteless, colorless and odorless gas, is not only a danger to the environment but also highly toxic to human beings. Found in the exhaust of vehicles and generators, CO has been dubbed the "silent killer" because excessive inhalation is lethal, poisoning the nervous system and heart.

Now, in a surprising twist, Prof. Itzhak Schnell of Tel Aviv University's Department of Geography and the Human Environment has discovered that low levels of the poisonous gas can have a narcotic effect that helps citydwellers cope with other harmful environmental factors of an urban environment, such as off-the-chart noise levels. This finding indicates that CO, in small doses, is a boon to the well-being of urbanites, better equipping them to deal with environmental stress.

The research has been published in the journal Environmental Monitoring and Assessment.

Gas combats noise pollution

The discovery was made in the context of a wider project designed to study the impact of environmental stressors on the human body. Most environmental observation stations, explains Prof. Schnell, are located outside stressful city centers, where pollutants such as vehicular and human traffic are significantly decreased, resulting in distorted data.

Instead, Prof. Schnell and his fellow researchers wanted to measure how people living in an urban environment confronted stressors in their daily lives. They asked 36 healthy individuals between the ages of 20 to 40 to spend two days in Tel Aviv, Israel's busiest city. The test subjects travelled various routes to sites such as busy streets, restaurants, malls and markets, by public and private transportation or by foot. Researchers monitored the impact of four different environmental stressors: thermal load (heat and cold), noise pollution, carbon monoxide levels, and social load (the impact of crowds).

Participants reported to what extent their experiences were stressful, and their input was corroborated with data taken from sensors that measured heart rate and pollutant levels. Noise pollution emerged as the most significant cause of stress.

The most surprising find of the study, says Prof. Schnell, was in looking at levels of CO that the participants inhaled during their time in the city. Not only were the levels much lower than the researchers predicted — approximately 1-15 parts per million every half hour — but the presence of the gas appeared to have a narcotic effect on the participants, counteracting the stress caused by noise and crowd density.

Turn down the volume

The results showed that living in a major city might not have as negative a health impact as the researchers were expecting. Though participants exhibited rising stress levels throughout the day, CO had a mitigating influence, and extended exposure to the chemical had no lasting effects.

The study's next step is to investigate how environmental loads impact the more vulnerable segments of the population, such as infants, the elderly, and those with medical conditions such as asthma. "We would be able to tell more accurately under what conditions vulnerable people shouldn't go out, and more importantly, identify areas that are still safe, helping to increase freedom of movement," notes Prof. Schnell.

But for now, urban dwellers can all contribute to making their environment a less stressful one by turning down the noise, he suggests. The findings indicate that most of the noise in an urban landscape is generated by human activity, and if individuals made an effort to reduce the noise they were making, they could help to reduce the environmental load placed on their neighbors.

This research was carried out in cooperation with Dr. Oded Potchter and Yaron Yaakov from the Department of Geography and the Human Environment, Prof. Haggai Hermesh from the Sackler Faculty of Medicine, Prof. Yoram Epstein from the Heller Institute of Medical Research, and Dr. Shmuel Brenner from the Arava Institute for Environmental Studies.


Hybrid Power Plants Can Help Industry Go Green
11/3/2011

TAU researchers develop affordable solar option for power plants

Hybrid cars, powered by a mixture of gas and electricity, have become a practical way to "go green" on the roads. Now researchers at Tel Aviv University are applying the term "hybrid" to power plants as well.

Most power plants, explains Prof. Avi Kribus of TAU's School of Mechanical Engineering and its innovative new Renewable Energy Center, create power using fuel. And solar thermal power plants — which use high temperatures and pressure generated by sunlight to produce turbine movement — are currently the industry's environmentally-friendly alternative. But it's an expensive option, especially when it comes to equipment made from expensive metals and the solar high-accuracy concentrator technology used to harvest solar energy.

Now, a new technology Prof. Kribus has developed combines the use of conventional fuel with the lower pressures and temperatures of steam produced by solar power, allowing plants to be hybrid, replacing 25 to 50 percent of their fuel use with green energy. His method, which will be reported in a future issue of the Solar Energy Journal, presents a potentially cost-effective and realistic way to integrate solar technology into today's power plants.

Taking down the temperature for savings

In a solar thermal power plant, sunlight is harvested to create hot high-pressure steam, approximately 400 to 500 degrees centigrade. This solar-produced steam is then used to rotate the turbines that generate electricity.

Though the environmental benefits over traditional power plants are undeniable, Prof. Kribus cautions that it is somewhat unrealistic economically for the current industry. "It's complex solar technology," he explains. The materials alone, which include pipes made from expensive metals designed to handle high pressures and temperatures, as well as fields of large mirrors needed to harvest and concentrate enough light, make the venture too costly to be widely implemented.

Instead, with his graduate student Maya Livshits, Prof. Kribus is developing an alternative technology, called a steam-injection gas turbine. "We combine a gas turbine, which works on hot air and not steam, and inject the solar-produced steam into the process," he explains. "We still need to burn fuel to heat the air, but we add steam from low-temperature solar energy, approximately 200 degrees centigrade." This hybrid cycle is not only highly efficient in terms of energy production, but the lowered pressure and heat requirements allow the solar part of the technology to use more cost-effective materials, such as common metals and low-cost solar collectors.

A bridge to green energy

The hybrid fuel and solar power system may not be entirely green, says Prof. Kribus, but it does offer a more realistic option for the short and medium term. Electricity from solar thermal power plants currently costs twice as much as electricity from traditional power plants, he notes. If this doesn't change, the technology may never be widely adopted. The researchers hope that a hybrid plant will have a comparable cost to a fuel-based power plant, making the option of replacing a large fraction of fuel with solar energy competitive and viable.

The researchers are starting a collaboration with a university in India to develop this method in more detail, and are looking for corporate partnerships that are willing to put hybrid technology into use. It's a stepping stone that will help introduce solar energy into the industry in an accessible and affordable way, Prof. Kribus says.


Thousand-Color Sensor Reveals Contaminants in Earth and Sea
11/2/2011

TAU technology spots environmental hazards from inches to light-years away

The world may seem painted with endless color, but physiologically the human eye sees only three bands of light — red, green, and blue. Now a Tel Aviv University-developed technology is using colors invisible to the naked eye to analyze the world we live in. With the ability to detect more than 1,000 colors, the "hyperspectral" (HSR) camera, like Mr. Spock's sci-fi "Tricorder," is being used to "diagnose" contaminants and other environmental hazards in real time.

Prof. Eyal Ben-Dor of TAU's Department of Geography and the Human Environment says that reading this extensive spectrum of color allows the sensor to analyze 300 times more information than the human brain can process. Small and easy to use, the sensor can provide immediate, cost-effective, and accurate monitoring of forests, urban areas, agricultural lands, harbors, or marinas — areas which are often endangered by contaminants and phenomena such as soil erosion or sediment dust. Using the hyperspectral camera will ultimately lead to better protection and treatment of the environment.

The HSR sensor, detailed in the journal Remote Sensing of Environment, has both commercial and scientific applications, says Prof. Ben-Dor, who has consulted for local and foreign space agencies in their use of the technology. These applications can include anything from helping companies adhere to regulations on environmental contamination to measuring the extent of environmental damage caused by forest fires.

From far and wide

The sensor interprets reflected sunlight radiation that bounces off an object, material, or environment. Each reflected color represents a different chemical reaction between two compounds. "A combination of absorption or reflection of energy creates the color that the HSR sensor sees," explains Prof. Ben-Dor. The sensor's extensive range — reading information from as close as 0.4 inches and as far as 500 miles away — means it can be placed anywhere from the ground itself to unmanned aircraft, satellites or weather balloons. The camera can also be pointed towards the stars to help astronomers gain insight into the make-up of a planet's atmosphere.

Most recently, Prof. Ben-Dor has used the technology to survey different environments, including soil and sea, seeking to identify problem areas. The area around gas pipelines is one site of environmental contamination, he says. Leaks can be particularly damaging to the surrounding earth, so the sensors can be used to test along a pipeline for water content, organic matter, and toxins alike. In agricultural areas, the sensor can be used to determine levels of salt in the soil to save crops before they are destroyed.

The technique is also effective in marinas, which are highly contaminated by gasoline and sealants from the undersides of sea vessels. "This toxic material sinks, and becomes concentrated on the sediment of the marina, which also contaminates nearby beaches," Prof. Ben-Dor explains.

The color of possibility

Before the HSR technology was developed, samples of potentially contaminated or endangered soil, sediment or water would have to be taken to the lab for lengthy analysis. With the use of a hyperspectral sensor, real-time analysis allows immediate action to better environmental conditions. The sensor can also be used to determine levels of indoor pollution caused by dust, analyze the strength of concrete being used for buildings in earthquake zones, or scan the environment around an open mine to look at the impact on human health.

According to Prof. Ben-Dor, this technology's potential is endless and can be used in disciplines such as medicine, pharmacology, textile industry, and civil engineering. Without so much as a touch, the sensor can provide in-depth analysis on environmental composition. It's a method that can map and monitor the earth from "microscope to telescope," he says.


Relief from "Parking Wars"
10/31/2011

TAU researcher develops computer software to revamp city parking

For those who live or work in cities, parking is a major source of stress and frustration. Researchers estimate that for every 110 vehicles circulating on the roads looking for spaces, there are 100 available spots, both in lots and on the street.

Now Nadav Levy, a Ph.D. student at Tel Aviv University's Porter School of Environmental Studies, along with his supervisors Prof. Itzhak Benenson of the Department of Geography and the Human Environment and Dr. Karel Martens of Holland's Radboud University, are answering the need for a more efficient way to park. They have developed a computer simulator that models the real-life parking challenges of a particular district or city, identifying different strategies for improvement and testing the impact of new policies before they are implemented on the roads.

The simulator, called PARKAGENT, takes into account real parking policies, drivers, and parking inspectors for an exact replication of any given city, including roads, buildings, and parking lots. Recently published in the journal Computers, Environment and Urban Systems, the software has already been put to the test, evaluating the potential impact of parking policy changes in Israel and Europe.

Predicting policy outcomes

When considering issues such as where to place parking lots or how to establish the routes of the parking inspectors, city officials have few resources to measure the success of their choices. Their decisions, though seemingly mundane, have a high impact on a city's traffic flow. Up to 30 percent of cars driving in the center of the city at peak hours are looking for parking, says Levy, wasting gas and creating congestion, pollution, and noise.

The simulator tests a new parking policy by implementing it into the PARKAGENT environment, gathering information on how these policies impact the drivers, who have individualized parking needs. The software takes into account their probable destinations, how long they require parking, and how much they are willing to pay. Policies could include a change in the amount of time permitted in a public parking space, the construction or closing of a parking lot, or the construction of a new building in the environment — all of which alter parking demand.

The software assesses key values such as the drivers' cruising time, how long they park for, and the distance from the parking space to their destination. Levy analyzes the resulting data to determine whether a policy would decrease the time the drivers would spend to find a parking place near the destination. The software can also be used to determine which routes parking inspectors should travel for optimal distribution of parking tickets.

Levy and his supervisors have already completed an analysis to determine the impact of an additional multi-story parking garage in the Israeli city of Ramat Gan, and they are now working in collaboration with the city of Antwerp, Belgium, to predict the outcome of a plan to replace a parking lot with a boardwalk along a river.

Solving the parking woes of urban living

According to Levy, urban parking policies can use a major overhaul. Until now, he says, city officials have not dealt with these issues scientifically, working more on "hunches" about where they suspect parking is required, and for how long. PARKAGENT removes the guesswork.

Many major cities make two main mistakes with their parking policies, he adds. In North America and Israel, on-street parking is typically cheaper than off-street. Drivers then aim to find cheap parking in the city, and drive around more than necessary just to "check," explains Levy. City traffic would move more efficiently if drivers had incentive to park in lots straightaway. The second error is not enforcing a strict time limit for high-demand parking areas. Increased turnover, caused by time restrictions, will benefit both businesses and drivers, making the quest for a parking spot much easier.

Nonetheless, Levy predicts that the future of urban transportation lies in alternatives to private cars, such as mass transportation systems, bicycles, and car-sharing systems. As cities get denser, private cars will become inefficient, hindering urban mobility, he says.


Growing Something out of Nothing
10/26/2011

TAU researchers nurture innovative biofuel crops to reduce our carbon footprint

Fears of global warming and its impact on our environment have left scientists scrambling to decrease levels of atmospheric carbon we humans produce. Now, Tel Aviv University researchers are doing their part to reduce humanity's carbon footprint by successfully growing forests in the most unlikely place — deep in Israel's Aravah Desert.

With environmental "extras" such as a local plant species, recycled sewage water unsuitable for agriculture, and arid lands unusable for crops, a group of researchers including Profs. Amram Eshel and Aviah Zilberstein of TAU's Department of Molecular Biology and Ecology of Plants at the George S. Wise Faculty of Life Sciences and the university's new Renewable Energy Center have discovered a winning combination.

In many parts of the world, including areas of India, central Asia and the Sahara desert, their new crop of plants would be not only viable in difficult terrain, but valuable in terms of carbon reduction. These standing crops, grown on land once considered barren, can soak up carbon dioxide from the atmosphere and convert it into oxygen. Their research is soon to be published in the European Journal of Plant Science and Biotechnology.

Making the desert bloom

Though maintaining our current forests is a necessary initiative, Prof. Eshel says, it is not enough to off-set human carbon output. In their quest to create forests that diminish carbon dioxide in the atmosphere, many countries have been converting fertile agricultural lands into forests. But TAU researchers believed that encouraging growth on a piece of land that was traditionally barren, such as desert land, was a step in a better direction.

"When you take the overall carbon balance of converting agricultural land and freshwater into energy products, you may not gain that much," says Prof. Eshel. "You're investing a lot of energy in the process itself, thus releasing a lot of carbon into the atmosphere."

To conserve fresh water, the researchers used water considered of low quality, such as recycled sewage water and salt water that was the by-product of inland desalination plants. The final piece of the puzzle was to find a plant hearty enough to successfully grow in the desert. The researchers turned to Tamarix, a botanical genus that includes salt cedar trees and is indigenous to the old-world deserts. Some 150 different varieties of the botanical genus were used, grown in both a common garden setting and in densities that mimicked commercial crops.

With the first harvest of trees just last summer, researchers have much to process, including analyzing the amount of carbon dioxide the crops have successfully captured from the atmosphere. The answers will determine how much carbon such a crop can offset.

A source for biofuel?

The cut trees themselves might also be used as a source of renewable energy. These "biomass" or "biofuel" crops, derived from natural crops, could help to reduce dependence on traditional fossil fuels such as coal. But the question of where to grow crops dedicated to fuel production had to be addressed, since converting agricultural land could have the side effect of creating food shortages.

Arid and previously unused desert lands provide an ideal solution, Prof. Eshel says. To make his approach economically feasible, much more land would be needed than Israel can provide. But similar tracts of land, such as the Sahara Desert, are big enough to grow these types of crops on a larger scale. He adds that what has been done in the Israeli desert can be replicated elsewhere to great effect.

This research is a collaboration between TAU's Porter School of Environmental Science, the University of Tuscia in Viterbo, Italy, and the Hebrew University in Jerusalem. Funds for the study were provided by the Italian Ministry for the Environment, Land and Sea.


Soft Coral Builds Strong Reefs
8/16/2011

TAU researcher discovers that endangered soft corals are also building blocks of coral reefs

Scientists have long believed soft corals, one of the many endangered elements of marine life, are only minor contributors to the structure of coral reefs. But that's not true, says new research from Tel Aviv University — and the preservation of soft corals is essential to the health of our seas.

Joint research by Tel Aviv University and the Academia Sinica, the National Museum of Natural Science of Taiwan, and National Taiwan University has revealed that soft corals, like stony corals, are one of the central building blocks of a reef, says Prof. Yehuda Benayahu of TAU's Department of Zoology at the George S. Wise Faculty of Life Sciences. A new in-depth analysis of reefs in the South China Sea has revealed that massive parts of the reefs are actually made from cemented microscopic skeletal elements of soft corals termed sclerites.

The finding, which recently appeared in the journal Coral Reefs, challenges conventional knowledge about soft corals and makes their conservation a priority. Like whales, dolphins, and stony corals, soft corals are a critically important component of the marine environment, Prof. Benayahu insists.

Building a home from flesh and bone

Reefs are ecosystems derived from biological organisms. They predominantly consist of cemented stony corals made of calcium carbonate. In contrast, the tissues of soft corals contain sclerites, which look like tiny pins or porcupine needles. In the reefs of Kenting National Park, located in South Taiwan, the researchers discovered that large structures originally believed to be comprised of stony corals were actually deposits of sclerites that been cemented to each other by calcium carbonate over time.

Soft corals were once considered a mere veneer of reefs, says Prof. Benayahu, not unlike a living ocean carpet. Once a soft coral colony disintegrates, the sclerites, each less than 1 millimeter in size, were thought to scatter and simply accumulate on the sea bed along with shells, sea urchin spines, and other smaller materials. But in fact, they are integral throughout the reef ecosystem and provide a home for creatures such as fish, snails, algae and many others.

Outside of the marine environment, soft corals also work to protect our human habitat. Boulders and reef structures made of cemented soft coral sclerites that form near shores act as natural wave breakers, Prof. Benayahu says, protecting land against erosion by the sea or ocean during typhoons or cyclones.

Carbon dioxide burning through our oceans

Not only is soft coral widespread, especially throughout the Indo-Pacific reefs, but it is also extremely rich in biodiversity. The genus Sinularia, the soft coral used in reef building, is composed of about 170 species worldwide. This is more than any stony coral genus, including 130 species of staghorn corals, the most populous. Given its spread and diversity, the group is certainly understudied, Prof. Benayahu says.

Soft coral is in danger of being wiped out of the marine environment. One major culprit is the rising acidity of our oceans, caused by heightened levels of carbon dioxide, says Prof. Benayahu. "As burning oil dissolves into the sea water, the water becomes more acidic, which then dissolves calcareous materials," he warns, including corals whose skeletons are made of calcite.

Soft corals need not only to be protected, but also further studied to understand their role in the entire ecosystem. Questions such as the rate at which soft corals can form reefs, especially as they face environmental challenges such as temperature changes, water acidity, and rising sea levels, still linger.

This investigation was led by Dr. Ming-Shiou Jeng of the Academia Sinica's Biodiversity Research Center, along with colleagues from the National Museum of Natural Science in Taichung and National Taiwan University, Taipei.


Raptor Usurpers in Neighboring Habitats Reshape the Conventional Wisdom
8/3/2011

Environmental assessments need to examine a broader reach, says TAU researcher

When we make plans that will change a natural environment — whether it's building a new shopping mall or planting a new forest — surveyors dutifully assess the environmental risks to plant and animal life in the region. But what's environmentally good for one area may be an environmental disaster for an adjacent one, a Tel Aviv University researcher cautions.

When displaced by these projects, indigenous species migrate to neighboring habitats, says Guilad Friedemann, a PhD student at TAU's Department of Zoology in the George S. Wise Faculty of Life Sciences. This has a significant impact on the species and resources that were already there. With a new species moving in and demanding its share of existing space and food, competition becomes fierce.

Based on a study of two raptor species in the Judean Foothills, the long-legged buzzard and the short-toed eagle, Friedemann has determined that human interference in natural habitats has a reach beyond the specific region under assessment. Pursued under the supervision of TAU's Prof. Yossi Leshem and Prof. Ido Izhaki from the University of Haifa, and in collaboration with the KKL-JNF, Smolar – Vinnikov Foundation, NPA and Kfar Etzion Field School, this ongoing research has been published in the journal Biological Conservation.

A turf war revealed by GPS

When a species is forced from its habitat, it has to go somewhere — and that has an effect on neighboring environments. The long-legged buzzard had always made its home in the open spaces of the Judean Mountains, explains Friedemann, using the mountain cliffs for nesting and hunting. But because environmentalists have been planting a new forest in the area in a process known as "afforestation," the buzzard needed to migrate elsewhere. They now make their nests in the trees of the Judean Foothills, threatening the nesting ground and food source of the short-toed eagle, its established inhabitants.

Through extensive field research, including the placement of advanced GPS systems on the adult nesting birds, Friedemann and his fellow researchers tracked the movements of both species throughout breeding season by tagging four buzzards and three eagles. They found 31 buzzard nests and 60 eagle nests in the Judean Foothills. The researchers continue to examine each nest twice a season, tracking the growth of new chicks and analyzing food remains to determine the extent of competition for food sources between the two raptor species.

The results, say Friedemann, will indicate that the buzzards have started to muscle in on the eagles' habitat — taking over their nests and diminishing the common food supply of snakes, lizards and rodents. "Every time you have strong competition between two species, one is more successful," he explains. "There is a negative impact on the weaker species."

The next step, says Friedemann, is to extend research done with the GPS transmitters, and to assess the rising levels of aggression in both buzzards and eagles, which arise from the heightened competition for food and space. By playing recorded bird calls near nesting sites of the opposite species, the researchers can measure how aggressive the response becomes.

Living side-by-side

In this case, afforestation, usually considered a positive contribution to the sustainability of our environment, was the cause of habitat destruction. This should serve as a cautionary lesson for any project that serves to alter the natural environment, the researchers conclude.

"There needs to be a broader consideration not just of the directly affected area, but of neighboring areas as well — especially if there is a species that will be forced to abandon the original area and seek out a new place to live," Friedemann says. In this instance, harm might have been avoided by setting aside a track of open space where the buzzards could continue to nest and hunt, a conclusion that would have broad implications for landscape planning and policy.

We must take more responsibility for the assessment of neighboring habitats, Friedemann cautions, because what helps one environment might harm the next.


Environmental Pollutants Lurk Long After They "Disappear"
7/20/2011

The health implications of polluting the environment weigh increasingly on our public consciousness, and pharmaceutical wastes continue to be a main culprit. Now a Tel Aviv University researcher says that current testing for these dangerous contaminants isn't going far enough.

Dr. Dror Avisar, head of the Hydro-Chemistry Laboratory at TAU's Department of Geography and the Human Environment, says that, when our environment doesn't test positive for the presence of a specific drug, we assume it's not there. But through biological or chemical processes such as sun exposure or oxidization, drugs break down, or degrade, into different forms — and could still be lurking in our water or soil.

In his lab, Dr. Avisar is doing extensive testing to determine how drugs degrade and identify the many forms they take in the environment. He has published his findings in Environmental Chemistry and the Journal of Environmental Science and Health.

Replicating nature

Drug products have been in our environment for years, whether they derive from domestic wastewater, hospitals, industry or agriculture. But those who are searching for these drugs in the environment are typically looking for known compounds — parent drugs — such as antibiotics, pain killers, lipid controllers, anti-psychotic medications and many more.

"If we don't find a particular compound, we don't see contamination — but that's not true," Dr. Avisar explains. "We may have several degradation products with even higher levels of bioactivity." Not only do environmental scientists need to identify the degraded products, but they must also understand the biological-chemical processes that produce them in natural environments. When they degrade, compounds form new chemicals entirely, he cautions.

For the first time, Dr. Avisar and his research group have been working to simulate environmental conditions identical to our natural environment, down to the last molecule, in order to identify the conditions under which compounds degrade, how they degrade, and the resulting chemical products. Among the factors they consider are sun exposure, water composition, temperatures, pH levels and organic content.

Currently using amoxicillin, a common antibiotic prescribed for bacterial infections such as strep throat, as a test case, Dr. Avisar has successfully identified nine degradation products with different levels of stability. Two may even be toxic, he notes.

Classifying compounds with a fine-tooth comb

According to Dr. Avisar, who will soon expand his research to include the degraded products of chemotherapy drugs, his research is breaking new ground, extending past research. And while the attempt to catalogue the degraded products of common compounds in our environment may feel like looking for needles in haystacks, it's research that the world can't afford to ignore.

"It's important to talk about the new chemicals in our environment, derived from parent drugs. They are part of the mixture," Dr. Avisar warns. "Chemicals do not simply disappear — we must understand what they've turned into. We are dealing with a whole new range of contaminants."

"Fault-Finding" Coral Reefs Can Predict the Site of Coming Earthquakes
3/21/2011

In the wake of the devastating loss of life in Japan, the urgent question is where the next big earthquake will hit. To answer it, geologist Prof. Zvi Ben-Avraham and his doctoral student Gal Hartman of Tel Aviv University's Department of Physics and Planetary Sciences in the Raymond and Beverly Sackler Faculty of Exact Sciences are examining coral reefs and submarine canyons to detect earthquake fault zones.

Working with an international team of Israelis, Americans and Jordanians, Prof. Ben-Avraham and his team are developing a new method to determine what areas in a fault zone region are most at risk. Using a marine vessel, he and his colleagues are surveying  a unique geological phenomenon of the Red Sea, near the coastal cities of Eilat and Aqaba — but their research could be applied anywhere, including Japan and the west coast of the U.S.

Recently published in the journal Geo-Marine Letters, the research details a "mass wasting" of large detached blocks and collapsed walls of submarine canyons along the gulf region of the Red Sea. They believe the geological changes were triggered by earthquake activity.

What’s next for San Andreas?

The team has created the first underwater map of the Red Sea floor at the head of the Gulf of Aqaba, and more importantly, identified deformations on the sea floor indicating fault-line activity. They not only pinpointed the known fault lines along the Syrian-African rift, but located new ones that city engineers in Israel and Jordan should be alert to.

"Studying fossil coral reefs and how they've split apart over time, we've developed a new way to survey active faults offshore by looking at the movement of sediment and fossil structures across them," says Hartman. "What we can't say is exactly when the next major earthquake will hit. But we can tell city engineers where the most likely epicenter will be." According to Hartman, the tourist area in the city of Eilat is particularly vulnerable.

While geologists have been tracking underwater faults for decades, the new research uniquely tracks lateral movements across a fault line (a "transform fault") and how they impact the sediment around them. This is a significant predictive tool for studying the San Andreas Fault in California as well, says Hartman.

The research is supported by a USAID grant through the Middle East Regional Cooperation (MERC) program.

Marching orders for city engineers

Aboard a marine vessel that traversed the waters of Israel and Jordan and peering at depths as deep as 700 meters, the researchers analyzed the structure of the seabed and discovered active submarine canyons, mass wasting, landslides, and sediment slumps related to tectonic processes and earthquake activity.

"There are several indicators of seismic activity. The most significant is the location of the fault. Looking at and beneath the seafloor, we saw that the faults deform the upper sediments. The faults of the Red Sea are active. We managed to find some other faults too and now know just how many active faults are in the region. This should help make authorities aware of where the next big earthquake will strike," says Hartman.

What made their study particularly unique is that they used the offset along linear structures, of fossil coral fringing-reefs to measure what they call "lateral slip across active faults." With this knowledge, researchers were able to calculate total slip and slip-rates and how active the fault has become.

"We can now identify high-risk locations with more certainty, and this is a boon to city planners. It's just a matter of time before we'll need to test how well cities will withstand the force of the next earthquake. It's a matter of proper planning," concludes Hartman.


A Seismograph for Ancient Earthquakes
3/14/2011

Earthquakes are one of the world's biggest enigmas — impossible to predict and able to wreak untold damage within seconds. Now, a new tool from Tel Aviv University may be able to learn from earthquakes of the ancient past to better predict earthquakes of the future.

Prof. Shmuel Marco of Tel Aviv University's Department of Geophysics and Planetary Sciences in the Raymond and Beverly Sackler Faculty of Exact Sciences and his colleagues have invented a new tool which he describes as a "fossil seismograph," to help geophysicists and other researchers understand patterns of seismic activity in the past.

Inspired by a strange "wave" phenomenon he studied in disturbed sediment in the Dead Sea region, Prof. Marco says the new tool, developed with input from geologists and physicists, is relevant to areas where earthquakes affect bodies of water, like the West Coast of the United States. It also can help engineers understand what's at risk when they plan new hydroelectric power plants. The new research was published in the journal Geology.

A geophysical yardstick for centuries past

"Current seismographical data on earthquakes only reaches back a century or so," says Prof. Marco. "Our new approach investigates wave patterns of heavy sediment that penetrates into the light sediments that lie directly on top of them. This helps us to understand the intensity of earthquakes in bygone eras — it's a yardstick for measuring the impact factor of earthquakes from the past."

Prof. Marco, his departmental colleague Prof. Eyal Hefetz, and doctoral student Nadav Wetzer took a highly technical look at layers of mud at the Dead Sea. The layers were originally stratified in a very stable manner, but now heavier sediment appears to have been pulled up into the lighter sediment.

The researchers propose that the physics governing the sediment patterns is similar to a phenomenon found in clouds and sea waves but in the case of rocks it was the earthquake shaking (rather than wind) that triggered the formation of waves. The scientists call it the "Kelvin-Helmholtz Instability," which describes a theory of turbulence in fluids. The Tel Aviv University team applied this theory to analyze the deformation of sediment caused by past earthquakes.

Earthquakes cause deformation in rocks and sediment. Using the basic principles of friction, the researchers considered the geometry of the shapes they found in the Dead Sea sediment and combined it with a number of other parameters found in physical science to calculate how earthquakes from the past were distributed in scale, time and place.

The bigger geological picture

Prof. Marco and his colleagues found that the deformation begins as moderate wave-like folds, evolves into complex recumbent folds, and finally exhibit instability and fragmentation. The deformation process advances depending on the earthquake size — the stronger the earthquake, the more intense the deformation.

The seismological record for fault lines like those near Jerusalem and Los Angeles simply isn't old enough to predict when the next quake might strike. "We've expanded the window of observation beyond 100 years, to create, if you will, a 'fossil seismograph,'" says Prof. Marco. He adds that the tool is only relevant in earthquake zones that intersect with bodies of water such as lakes or the sea.

But it could be very relevant to geologists studying earthquake patterns in areas like the Salton Sea. The Salton Sea, only 100 years old, is located directly on the San Andreas Fault in California's Border Region.


Debunking Solar Energy Efficiency Measurements
1/10/2011

In recent years, developers have been investigating light-harvesting thin film solar panels made from nanotechnology — and promoting efficiency metrics to make the technology marketable. Now a Tel Aviv University researcher is providing new evidence to challenge recent "charge" measurements for increasing solar panel efficiency.

Offering a less expensive, smaller solution than traditional panels, Prof. Eran Rabani of Tel Aviv University's School of Chemistry at the Raymond and Beverly Sackler Faculty of Exact Sciences puts a lid on some current hype that promises to increase efficiencies in thin film panels. His research, published recently in the journals Nano Letters and Chemical Physics Letters, may bring the development of new solar energy technologies more down to earth.

Prof. Rabani combines a new theoretical approach with computer simulations. "Our theory shows that current predictions to increase efficiencies won't work. The increase in efficiencies cannot be achieved yet through Multiexciton Generation, a process by which several charge carriers (electrons and holes) are generated from one photon," he says.

Inefficient as "charged"

But both new and existing theories bode well for the development of other strategies in future solar energy technology, he points out. Newer approaches published in journals such as Science may provide means for increasing the efficiencies of solar technology, and perhaps would also be useful in storage of solar energy, Prof. Rabani and his team of researchers believe.

A chemical physicist, Prof. Rabani investigates how to separate charges from the sun efficiently. In 2004, physicists suggested that more than one electron-hole pair could be pulled from one photon in a complicated process in semiconductor nanocrystals. If this were possible, the charge would be doubled, and so the solar energy efficiency would increase. "We've shown that this idea doesn't work," Prof. Rabani says.

One step closer to marketing the sun

The development of more efficient and less expensive devices to make use of solar energy is one of the greatest challenges in science today. Billions of dollars are being spent to find the best methods to collect electron "charges" from the sun.

Typically, one photon from the sun absorbed in a thin film solar panel can excite one electron-hole pair, which is then converted to electricity. Currently there are claims that if more electron-hole pairs can be excited after the photon is absorbed, a larger fraction of the photon energy can successfully be converted into electricity, thus increasing device efficiency.

The theory that Prof. Rabani developed with his Israeli colleagues shows why this process is not as efficient as originally conceived. It's bad news for panel producers looking to create more efficient solar panels, but good news for researchers who are now free to look to the next realistic step for developing a technology that works.

Prof. Rabani is now on sabbatical at the University of California, Berkeley as a Miller Visiting Professor.


After the Fire, a "Bottle Tree" Brings Christmas to Haifa
12/23/2010

This year, Christians living in Haifa are having trouble finding a real Christmas tree — earlier in 2010 a devastating forest fire that killed 43 people also wiped out more than 5 million trees in the nearby Carmel Mountain range, making it harder for them to justify using "real" trees to celebrate the holidays.

Coincidentally, on the day the fire started to rage out of control, Hadas Itzcovitch, a young Tel Aviv University lecturer who teaches at a special science program for gifted high school students at the school, was putting the finishing touches on a Christmas tree commissioned by the City of Haifa. Developed with her father Ernest, an artist, the tree was built on a metal frame and included thousands of light-filled water bottles hanging down as branches. The bottles were collected in the community, and energy-conserving LED lights lit the boughs of the "tree."

But on the day when the tree was to be erected, she could smell the smoke from the fire, and saw its flames burning on the mountain. "I thought that it might be bad taste to erect a Christmas tree when all around us the fires were burning out of control," says Itzcovitch, who instructs students in novel ways to use recycled materials and conserve energy.

A message for the environment

But the City of Haifa urged her to continue, so the important holiday symbol dedicated to the city's three monotheistic religions would not be lost. They had commissioned the tree from Itzcovitch more than a month before the fire for the city's "Festival of Festivals," which celebrates the Muslim Eid, Christian Christmas and Jewish Hanukkah holidays.

At the meeting, city officials asked for a tree that was 6.5 yards high, to be erected at a busy intersection. Itzcovitch told them that for the same budget she could build the tree twice as high if she did it with recycled materials. City officials were delighted with the idea and the important environmental message the tree would send to the residents of Haifa, a coastal city along the Mediterranean Sea in Israel. The multicultural city would not only see the tree as a sign of peace between the religions that live there, but also would teach he importance of recycling and living in harmony with nature.

Exposing youth to more than a holiday tradition

It was coincidental and ironic, says Itzcovitch, that the fire started burning out of control just as the "bottle-tree" was being raised. She does not discount the environmental message of protecting our world's resources, which she also spreads through her design work — and teaching at local colleges and universities.

Itzcovitch lectures at the Unit for Science Oriented Youth of Tel Aviv University's Joan and Jaime Constantiner School of Education. It provides a variety of courses for the fostering of excellence to a wide range of populations, including gifted students.

"I am working with gifted kids that want to learn about science," says Itzcovitch. "We teach them about energy-saving science projects, and how to 'upcycle' materials. It opens their minds to environmental issues just before they head to university," she says.

Although Itzcovitch herself is Jewish, she likes the message her Christmas tree sends for peace, and because it's made of recycled materials, it can be used every year. If the City of Haifa agrees, she proposes to keep adding a yard's worth of height to the tree each year — to celebrate the holidays, and remind city residents about the importance of environmental preservation.


Back to the Dead (Sea, That Is)
12/20/2010

They'll drill through four ice ages, epic sandstorms, mankind's migration from Africa to the New World, and the biggest droughts in history. Tel Aviv University is heading an international study that for the first time will dig deep beneath the Dead Sea, 500 meters (about a third of a mile) down under 300 meters (about a fifth of a mile) of water. Drilling with a special rig, the researchers will look back in time to collect a massive amount of information about climate change and earthquake patterns.

The study, led by Prof. Zvi Ben-Avraham of Tel Aviv University's Minerva Dead Sea Research Center, "aims to get a complete record in unprecedented resolution — at one year intervals — of the last 500 thousand years,” says Prof. Ben-Avraham.

A crazy sandstorm 365,250 years ago?

Looking at the core sample to be dug about five miles offshore near Ein Gedi, the researchers hope to pinpoint particular years in Earth history to discover the planet's condition. They'll be able to see what the climate was like 365,250 years ago, for instance, or determine the year of a catastrophic earthquake.

This is by far the largest Earth sciences study of its kind in Israel. The evidence will help the world's climatologists calibrate what they know about climate change from other geological samples — and may lead to better predictions of what's in store for Middle East weather. For example, are currently increasing dry and hot periods in the region something new, or are they part of some larger cyclical pattern? What they find should also shed light on earthquake patterns — important information for Israelis, Jordanians and Palestinians who live on or around the fault line that passes through the Dead Sea region.

Slicing through a geological cake

"The sediments provide an 'archive' of the environmental conditions that existed in the area in its geological past," Prof. Ben-Avraham says. While the sample being collected isn't as deep as oil explorers drill to look for oil, the core will be something special: it will be kept in an unbroken piece so that records can be traced more accurately.

The study is being supported by the Israel Sciences Academy and includes dozens of scientists from America, Germany, Switzerland, Norway, Japan, and Israel. Scientists from Jordan and the Palestinian Authority are also cooperating on this unique event. The researchers come from a variety of disciplines, from environmental science to chemistry, and each will get different parts of the core to analyze.

Prof. Ben-Avraham himself is particularly interested in chemical changes to the sediment in the Dead Sea over the last half million years. The study, he adds, will shed light on human migration patterns through the region.

At 423 meters, or a quarter of a mile, below sea level, the Dead Sea is the lowest place on earth. Today it draws millions of tourists from around the world to enjoy its legendarily healing properties.

For coverage of this research in The New York Times, please see:
http://www.nytimes.com/2010/12/18/world/middleeast/18deadsea.html


The Sweetness of Biodegradable Plastics
12/14/2010

Environmentalists around the world agree — plastic bags are choking our landfills and polluting our seas. Now a Tel Aviv University researcher is developing new laboratory methods using corn starch and sugar to help sustainable plastics — those that biodegrade and are even tougher than those made from petrochemicals — compete in the industry.

The answer to the problem, Prof. Moshe Kol of Tel Aviv University's School of Chemistry says, is a new variety of catalysts — substances that initiate or sustain chemical reactions in other substances. His team has already developed several of these new catalysts, and it's currently expanding its activities in partnership with the University of Aachen in Germany and the University of Bath in England.

Prof. Kol is improving the process of making these "green" plastics stronger and more heat-resistant, allowing them to be used in a variety of ways, from the automotive industry to Starbucks coffee cups. The type of plastic the partners are working on, polylactic acid or PLA, is a kind of biodegradable plastic made from renewable plant sources such as corn, wheat or sugarcane. It's already used in bottles, bags, and film, and like polyester can even be woven into clothes.

Making stronger and biodegradable "Lego blocks"

The new catalysts enable the polymerization of lactide, which is the building block of a corn-based plastic. Conventional catalysts have limited control of the way in which these building blocks — the corn-based molecules — are assembled — and they may be toxic. But Prof. Kol's catalysts can be used more safely and efficiently, making "green" plastics more commercially feasible.

"The structure of these corn-based plastics depends on several parameters. The most important is the character of the building blocks, like Lego blocks, that hold the material together," says Prof. Kol. He aims to make sustainable corn-based plastics complement or replace the petroleum-based plastics which can take a millenium to degrade, leaving harmful pollutants in the soil and in water. Corn-based plastic wouldn't cause any adverse health effects and would be expected to biodegrade in a compost bin in a matter of months.

Lord of the plastic ring

Plastics won't be going away any time soon, Prof. Kol suggests, pointing to the movement from concrete or stainless steel to plastic in a variety of industries. Replacing the steel manifold of a car with a plastic substitute would cut down on fuel consumption, and replacing a water pipe made of concrete or metal with one made of corrosion- and crack-resistant plastic may improve the quality of our drinking water.

For disposable items, a perfect plastic material would be a polymer made from renewable resources, that degrades to its original non-toxic form. Plastics made from corn sugar are the most desirable in the industry at the moment.

The preliminary results of Prof. Kol's efforts are in, and the plastics that he and his team produce in the lab look and feel like polystyrene, which could be used for making drinking cups, for example. Rigid and transparent, the drinking cups currently only work for liquids under 122 degrees Fahrenheit, but they represent a first big step into greening plastics and the chemical industry.


Israel's Top Eco-Friend Is for the Birds
12/8/2010

From brokering bird preservation projects with Jordanian generals to showing former U.S. President Jimmy Carter the ecological elements of peace making, Dr. Yossi Leshem of Tel Aviv University's Department of Zoology is now recognized as one of Israel's top 10 environmentalists.

In fact, a recent Israel21c report puts him in the #1 spot. "When Israelis mention birds, the name Yossi Leshem is never far off," Israel21c notes. "A world renowned ornithologist, Leshem has been involved in many aspects of nature conservation, with an emphasis on bird research, for close to 38 years. … They don't call him the 'bird man' for nothing."

Dr. Leshem earned his Ph.D. on migrating birds in 1989, and the 63-year-old researcher has been on a quest ever since to ensure that there are fewer collisions between aircraft and birds. Israeli skies are a major flyway for birds transiting from continental Africa to Europe, and some half-billion birds are particularly vulnerable as they pass through the region twice a year via the Syrian-African rift.

"Whenever I ask someone what they know about Israel, they always say the same three things: history, archaeology and the conflict we have with the Palestinians. But you know, our story with bird migration is no less significant," says Dr. Leshem. "We have 500 million birds passing through Israel twice each year, and we are creating special facilities in the Hula Valley and at 15 birding stations across Israel to study and educate young and old about the importance of preserving these birds.

"My goal right now is to turn Israel into a birding hotspot, to access some of the 100 million birders who travel the world looking for their favorite flying friends. This has implications beyond eco-tourism and bird watching. Through developing bird stations, we are creating a network for study and research for the next generation."

In his doctoral research on "Migrating Birds Know No Boundaries," Dr. Leshem demonstrated a decrease of 76 percent in the number of collisions with aircraft caused by birds, saving the government 800 million dollars.

In 2008, during Israel's 60th anniversary celebrations, Dr. Leshem received a Lifetime Achievement Award for Environmental Protection in Israel. With the Palestinian Authority and Jordan, he is involved in educational activities regarding bird life and is developing a grassroots project so that farmers can use owl nesting boxes instead of pesticides on their farms.

A past general director at the Society for the Protection of Nature in Israel (SPNI), Dr. Leshem now works as a senior researcher at the Department of Zoology in the Faculty of Life Sciences at Tel Aviv University.

For the story on Israel's eco-heroes and Tel Aviv University's Dr. Leshem:
http://www.israel21c.org/201010248441/environment/the-top-10-environmentalists-helping-green-israel


Time for a Rain Dance?
11/1/2010

In many areas of the world, including California's Mojave Desert, rain is a precious and rare resource. To encourage rainfall, scientists use "cloud seeding," a weather modification process designed to increase precipitation amounts by dispersing chemicals into the clouds.

But research now reveals that the common practice of cloud seeding with materials such as silver iodide and frozen carbon dioxide may not be as effective as it had been hoped.

In the most comprehensive reassessment of the effects of cloud seeding over the past fifty years, new findings from Prof. Zev Levin, Dr. Noam Halfon and Prof. Pinhas Alpert of Tel Aviv University's Department of Geophysics and Planetary Sciences have dispelled the myth that, at least in Israel, cloud seeding is an effective mechanism for precipitation enhancement.

The findings were recently reported in Atmospheric Research.

Throwing seeds into the wind

During the course of his study, Prof. Levin and his colleagues looked over fifty years' worth of data on cloud seeding, with an emphasis on the effects of seeding on rainfall amounts in a target area over the Sea of Galilee in the north of Israel. The research team used a comprehensive rainfall database and compared statistics from periods of seeding and non-seeding, as well as the amounts of precipitation in adjacent non-seeded areas.

By comparing rainfall statistics with periods of seeding they were able to show that increments of rainfall happened by chance. For the first time, they were able to explain the increases in rainfall through changing weather patterns instead of the use of cloud seeding.

Most notable was a six-year period of increased rainfall, originally thought to be a product of successful cloud seeding. Prof. Levin and his fellow researchers showed that this increase corresponded with a specific type of cyclone which is consistent with increased rainfall over the mountainous regions. They observed a similarly significant rain enhancement over the Judean Mountains, an area which was not the subject of seeding.

The researchers concluded that changing weather patterns were responsible for the higher amount of precipitation during these years. Their research method may be useful in the investigation of cloud seeding in the U.S. and other regions.

Considering the alternatives

Despite being relatively expensive, there are more than 80 cloud seeding projects around the world, according to a recent World Meteorological Organization report. Unfortunately, most are operational projects with no scientific evaluation of success or failure.

In Beijing, China, for example, a large amount of chemical particles were introduced to the clouds to inhibit precipitation — a process called "overseeding" — to limit rainfall during the 2008 Olympics. Seeding is also used in the Sierra Mountains of California and in Wyoming to try to increase precipitation in the mountains, thus increasing water levels in reservoirs.

However, Prof. Levin notes thus far there is no proof that this method is successful. It is important to understand that in order to determine that cloud seeding enhances rainfall, a complicated statistical evaluation needs to be conducted and comparison needs to be made with similar areas that are not seeded.

One could take an analogy from the testing of new drugs. For a drug to be approved a comprehensive test needs to be conducted in which part of the sampled population is given a placebo. The same is with cloud seeding, for comparison; some of the sampled clouds need to be unseeded.

The only probable place where cloud seeding could be successful, Levin says, is when seeding is performed on orographic clouds, which develop over mountains and have a short lifespan. In this type of cloud, seeding could serve to accelerate the formation of precipitation.


The Dual Nature of Dew
9/28/2010

When the scientific and spiritual worlds collide, they do so in the most surprising ways. Classical meteorological and plant science has, in the last century, insisted that dew negatively affects plant life, leading to rot and fungus. But in the Judeo-Christian tradition, dew is most welcomed as an important source of vegetative and plant life, celebrated in poetry and prayer.

Now Prof. Pinhas Alpert of Tel Aviv University's Department of Geophysics and Planetary Sciences has developed an explanation for the perplexing paradox with his colleagues. According to scientific literature, he says, dew that accumulates through the night has a negative effect on vegetation and fruits because it creates a "spongy" effect. But in a recent issue of the Water Resources Journal, Prof. Alpert demonstrates that dew is an important water source for plant life in climates such as those in the Eastern Mediterranean, where the Judeo-Christian tradition originated, and parts of the U.S. Great Basin Desert.

"Semi-arid zones are dry for over half the year," he explains. "Dew is therefore an important source of moisture in the air. It surrounds the plant leaves nearly every morning for approximately two to three hours past sunrise." This finding, he says, explains why dew is such an important part of Judaeo-Christian traditions. In Judaism, blessings are offered to rain and dew in daily prayer, and there are many references to dew throughout the Bible, including the Old Testament books of Genesis and Isaiah.

Creating the ideal conditions for growth

A plant's growth is based on photosynthesis, employing stomata, the small openings in vegetation and fruit leaves that absorb carbon dioxide. The combination of water, carbon dioxide in the air and sunlight help a plant to produce sugars which allow it to grow. In temperate zones, most of a plant's growth occurs in the middle of the day, when the most sunlight is available.

But there are climatic influences as well. According to Prof. Alpert, plants in a semi-arid zone close these stomatic openings in the midday as a defence mechanism, to avoid losing moisture, or in other words water, when the weather is at its driest. When this happens, photosynthesis and plant growth cannot take place.

For these reasons, the early-morning hours — and not those of midday — are the period of maximum growth for plants in the Eastern Mediterranean region, Prof. Alpert says. And it's all due to the dew. "In the early morning, dew surrounds the leaves of a plant with moisture, and the plant does not close its stomata. Therefore, it can grow."

Biblical dew

In order to research the effect of dew on plant life, Prof. Alpert and his fellow scientists studied the interaction between the leaves of a plant and the air. They measured how much moisture departs from the leaves and how much carbon dioxide enters them at various times of the day.

These findings explain a very old paradox, says Prof. Alpert. Despite its negative reputation in other climates, dew is idealized in the Bible for its ability to help fruits and vegetables grow in a dry and inhospitable region — like the Eastern Mediterranean, where the books of the Bible were first collected.


Getting a Tail Up on Conservation?
9/1/2010

Lizards are an important indicator species for understanding the condition of specific ecosystems. Their body weight is a crucial index for evaluating species health, but lizards are seldom weighed, perhaps due in part to the recurring problem of spontaneous tail loss when lizards are in stress.

Now ecological researchers have a better way of evaluating these lizards. Dr. Shai Meiri of Tel Aviv University's Department of Zoology has developed an improved tool for translating lizard body lengths to weights. Dr. Meiri's new equations calculate this valuable morphological feature to estimate the weight of a lizard species in a variety of different ecosystems.

"Body shape and body size are hugely important for the understanding of multiple ecological phenomena, but there is a need for a common metric to compare a multitude of different species," he says.

Building a lizard data bank

In a study published recently in the Journal of Zoology, Dr. Meiri evaluated hundreds of lizard species: long-bodied, legless species as well as stout, long-legged species; some that sit and wait for prey, others that are active foragers. Based on empirical evidence, such as well-established behavioral traits, he built a statistical model that could predict weights of lizards in a reliable, standardized manner, for use in the field or at the lab.

For the study, Dr. Meiri looked at a large sample of lizards — 900 species in 28 different families — and generated a dataset of lizard weights, using this dataset to develop formulae that derive body weights from the most commonly used size index for lizards (the length of the head and body, or "snout–vent length"). He then applied a species-level evolutionary hypothesis to examine the ecological factors that affect variation in weight–length relationships between different species.

Predicting post-disaster damage to the environment

How can this standardized metric protect our environment? "It can help answer how lizard species may react if there were major shifts in the availability of food due to climactic changes," he says.

In the future, zoologists will be able to use Dr. Meiri's method to better predict which communities of animals will shrink, grow or adapt to changing conditions, even after massive environmental disasters like the recent Gulf of Mexico oil spill.


A Nemesis for Oil Spills
8/3/2010

It's taken millions of dollars to cap it, and it could take billions more to clean it up. BP's oil spill in the Gulf of Mexico is acknowledged the environmental catastrophe of the century. But Tel Aviv University has a solution that may help "bioremediate" the remaining problems.

Prof. Eugene Rosenberg and Prof. Eliora Ron of Tel Aviv University's Department of Molecular Microbiology and Biotechnology are using naturally occurring oil-munching bacteria, grown at the TAU lab, to clean the hard-to-reach oil pockets that occur when oil mixes with sand and organic matter on beaches and forms a thin layer on the Gulf's precious waterways.

"It's worked to clean up an oil spill on the coast of Haifa, Israel, so we've already got good evidence it could work in Florida too," says Prof. Ron. Details of their decades of research appear in The Handbook of Hydrocarbon and Lipid Microbiology, published this year by Springer Verlag.

Using nature itself to fight contamination

The researchers identified a naturally occurring variety of sea-borne bacteria that digests oil. By studying the bacteria's genetic background, developing methods of growing the bacteria, and increasing their capacity to ingest the oil, the scientists have developed a solution that could clean up the residual oil that can't be removed by mechanical means.

Prof. Ron says that sucking up surface oil pools and containing the oil are important and necessary first-step actions. But her solution addresses the smaller amounts of oil left behind — that which isn't easily removed from sand and water. It is this small percentage of oil that sits under rocks and forms a thin film on the water's surface. Her bacterial solution can remove this oil, which is necessary to protect the sea's wildlife.

"We see sad pictures of birds covered in oil and people with good intentions cleaning bird wings," says Prof. Ron. "But by the time the oil is on their wings, it's too late. Birds die because oil gets into their lungs."

Going the last mile

"The problem is huge and even with just a little bit in your lungs, oil is bad. Even when cleanup crews reduce the amount of oil at sea, there will probably be enough left behind to kill birds and wildlife." At this level of oil removal, the researcher says, the only solution is bioremediation — using nature itself to do the final cleanup.

Featured in Time magazine in the 1970s, the bacterial bioremediation solution developed at Tel Aviv University has been applied to clean out the bilges of oil tankers at sea and is used around the world.


The Wisdom of Tel Aviv University's Owls
6/24/2010

Known for his work with birds and other feathery friends, Prof. Yossi Leshem of Tel Aviv University's Department of Zoology is showing how nature can provide the best medicine — not only for pest problems, but also for diplomacy.

For decades, Prof. Leshem has been pioneering environmentally-friendly techniques in pest control, using owls and birds to keep populations of predatory mice at bay in farmer's fields in Israel. Over the years, his projects have extended to Europe, North America and more locally in the Middle East.

This year, farmers from Jordan and the Palestinian Authority were joined in the project by 50 Israeli-Arab farmers — showing that natural pesticide control is not just good for the environment, it’s good for peace as well.

Today, through Webcams trained on owl nests, thousands of nature enthusiasts can track the progress of owl and predatory bird nesting boxes Prof. Leshem and his colleagues have set up in various locations, tools to reduce the use of dangerous pesticides. Owls, if given good homes and the right conditions, can control the damage caused by mice and other small mammals to farmer's fields, he says.

"We were pleasantly surprised by the birds at the Tirat Tzvi kibbutz. The barn owls that nested in the water tower successfully raised four nestlings," he says. "We noted the abundance of rodents in the kibbutz fields and decided to raise another brood. They can be seen on the Internet site, where the nestlings can be seen with their first feathers.

"This has been an exceptionally successful year for the barn owls," Prof. Leshem concludes.

Almost 1,900 nesting boxes have been placed all over the country, about 600 of them in the Bet Shean Valley and the Jezreel Valley in Israel. Barn owls have occupied almost 80% of the nesting boxes, and many farmers are now enjoying the services of these "unique pest controllers," he says.

Watch live coverage of Tel Aviv University's ecologically-friendly and bridge-building owls in Israel:
http://video.tau.ac.il/General/birds/2010/

Watch a YouTube video on the project here:
http://www.youtube.com/watch?v=ZJDVohcnfHQ

 


Protein Power for Jack and the Beanstalk
5/17/2010

Plant geneticists are on a determined quest — to control auxin, a powerful plant growth hormone. Auxin tells plants how to grow, where to lay down roots, how to make tissues, and how to respond to light and gravity. Knowing how to manipulate auxin could thus have enormous implications for the production of biofuel, making plants grow faster and better.

A recent publication in the journal PLoS Biology from the laboratory of Prof. Shaul Yalovsky of Tel Aviv University's Molecular Biology and Ecology of Plants Department describes a special protein, the ICR1, found to control the way auxin moves throughout a plant affecting its development. When this protein is genetically engineered into valuable biofuel crops such as corn, sugarcane or experimentals like switchgrass, farmers can expect to get a far larger yield than what they harvest today, Prof. Yalovsky has found.

In short, much more biofuel for the buck.

"We've found a mechanism that helps the shoot and root talk to each other," says Prof. Yalovsky. "Somehow both parts of the plant need to speak to each other to say: 'Hey down there, I'm up here and there's lots of sun,' or 'I'm down here in the roots and it's too dry." The plant's shoots need to respond to its environment. We've discovered the mechanism that helps auxin do its job."

Putting energy into sugar

Auxin is considered the most important plant hormone for plant growth and root growth. Prof. Yalovsky explains that knowing how to manipulate it can lead to much bigger yields of non-food crops, like those needed for biofuel. Efficiency is now a limiting factor in biofuel production, and scientists are looking for anything that can produce biofuel in the same amounts as the production of traditional fossil-based fuels.

The ICR1 protein that Prof. Yalovsky has isolated works together with a group of proteins called ROPs, which his lab also isolated in previous research. Together, this system of work in harmony to manipulate the composition and vascular tissues of plant cell walls. The researchers found specifically that ICR1 can be manipulated and, as a consequence, influence auxin distribution in plants. Plant scientists now have a tool that allows breeders to grow certain plant organs of choice, with the possibility of manipulating plant cell wall composition — the kinds of tissues needed in making biofuel.

In the PLoS Biology report published recently, the researchers spell out the links between the mechanisms that regulate cell structure and the development of the whole plant. The ICR1, they explain, influences the way the hormone auxin moves around the plant.

Breaking down the walls

Plant tissue is made of cells engulfed in a tough cell wall that helps it retain shape and rigidity. It's composed of cellulose, a polysaccharide, and lignin, which is the woody material in a plant. Current methods for removing the unwanted lignin in the cell wall — which must be removed to produce biofuel — amounts to about a 50% loss cellulosic material which could be used for biofuel.

Ideally crop growers want to maximize the amount of cellulose in the plant, which can be broken down to make sugar for ethanol. The new system found in proteins and developed at Tel Aviv University has the potential to increase crop yield and make fuel production more cost-effective. His approach could mean less lignin, more cellulose and ultimately more biofuel, says Prof. Yalovsky.


Where There's Smoke ...
4/22/2010

Native Americans used smoke signals to indicate danger, and a white plume is sent up by the Vatican when a new Pope is chosen. Now, a new research project by Tel Aviv University researchers and their colleagues shows that where there's "smoke" there may be significant consequences for local weather patterns, rainfall and thunderstorms.

In a new study, Prof. Colin Price, head of Tel Aviv University's Department of Geophysics and Planetary Science, researched data on lightning patterns in the Amazon to show how clouds are affected by particulate matter emitted by the fires used for slash-and-burn foresting practices. His findings, recently published in the journal Geophysical Research Letters, could be used by climate change researchers trying to understand the impact of pollution on global weather patterns.

Along with colleagues at the Weizmann Institute and the Open University in Israel, Prof. Price demonstrated how pollution's effects on cloud development could negatively impact our environment. While low levels of particulate matter actually help the development of thunderstorms, the reverse is true once a certain concentration is reached — the particles then inhibit the formation of clouds and thunderstorms.

"The clouds just dry up," he says.

Lightning strikes to the center of the issue

Scientists have known for some time that man-made aerosols affect cloud formation, but specific scientific findings have been inconclusive. How clouds and storms change in response to air pollution is central to the debate about climate change and global warming, since clouds have a general cooling effect on the Earth's climate.

But how man-made pollution impacts clouds, rainfall and weather patterns remains poorly understood, and natural particulates, such as those generated by Iceland's recent volcano eruptions may add to this effect. The thick volcanic ash cloud absorbs solar radiation, heating the upper atmosphere, similar to the forest fire smoke, and can hence also impact the development of clouds and rainfall, Price said.

While studying the climatology of the Amazon forest during its annual dry season, the researchers noticed how thousands of man-made forest fires injected smoke into the atmosphere. Since thunderstorms still occur during the dry season, it was the perfect opportunity for studying the effects of these particulates on thundercloud development.

Cloud droplets form on small particles called "cloud condensation nuclei" (CCN). As the number of CCN increase due to the fire activity, the lightning activity increased in the storms ingesting the smoke. More CCN implies more small droplets that can be carried aloft into the upper parts of the cloud where lightning is generated. Increased lightning activity generally also implies increasing rainfall over the Amazon. But when particulate matter became too dense, they observed, clouds didn't form, and the lightning activity in thunderstorms diminished dramatically.

Seeking answers to vital questions

These results may have significant implications for polluted regions of the world that rely on rainfall for agriculture and human consumption. "One of the most debated topics related to future climate change is what will happen to clouds, and rainfall, if the earth warms up," says Prof. Price, "and how will clouds react to more air pollution in the atmosphere?"

Clouds deflect the sun's rays, cooling the Earth's climate.  If we change the duration of cloud cover, the aerial coverage of clouds, or the brightness of clouds, we can significantly impact the climate, Prof. Price and his colleagues explain. And too many aerosols may have disastrous impacts on rainfall patterns as well.

Air pollution from car exhausts and smokestacks at power plants and factories contribute to increasing particulate matter in our atmosphere. This is the first study of its kind that uses lightning as a quantitative way to measure the impact of air pollution on cloud development over a large area, and across a number of years.

"Lightning is a sensitive index to the inner workings of polluted clouds over the Amazon Basin," concludes Prof. Price.


A New Energy Source from the Common Pea
3/4/2010

If harnessing the unlimited solar power of the sun were easy, we wouldn't still have the greenhouse gas problem that results from the use of fossil fuel. And while solar energy systems work moderately well in hot desert climates, they are still inefficient and contribute only a small percentage of the general energy demand. A new solution may be coming from an unexpected source — a source that may be on your dinner plate tonight.

"Looking at the most complicated membrane structure found in a plant, we deciphered a complex membrane protein structure which is the core of our new proposed model for developing 'green' energy," says structural biologist Prof. Nathan Nelson of Tel Aviv University's Department of Biochemistry. Isolating the minute crystals of the PSI super complex from the pea plant, Prof. Nelson suggests these crystals can be illuminated and used as small battery chargers or form the core of more efficient man-made solar cells.

Nanoscience is the science of small particles of materials and is one of the most important research frontiers in modern technology. In nature, positioning of molecules with sub-nanometer precision is routine, and crucial to the operation of biological complexes such as photosynthetic complexes. Prof. Nelson's research concentrates on this aspect.

The mighty PSI

To generate useful energy, plants have evolved very sophisticated "nano-machinery" which operates with light as its energy source and gives a perfect quantum yield of 100%. Called the Photosystem I (PSI) complex, this complex was isolated from pea leaves, crystalized and its crystal structure determined by Prof. Nelson to high resolution, which enabled him to describe in detail its intricate structure.

"My research aims to come close to achieving the energy production that plants can obtain when converting sun to sugars in their green leaves," explains Prof. Nelson.

Described in 1905 by Albert Einstein, quantum physics and photons explained the basic principles of how light energy works. Once light is absorbed in plant leaves, it energizes an electron which is subsequently used to support a biochemical reaction, like sugar production.

"If we could come even close to how plants are manufacturing their sugar energy, we'd have a breakthrough. It's therefore important to solve the structure of this nano-machine to understand its function," says Prof. Nelson, whose lab is laying the foundations for this possibility.

Since the PSI reaction center is a pigment-protein complex responsible for the photosynthetic conversion of light energy to another form of energy like chemical energy, these reaction centers, thousands of which are precisely packed in the crystals, may be used to convert light energy to electricity and serve as electronic components in a variety of different devices.

"One can imagine our amazement and joy when, upon illumination of those crystals placed on gold covered plates, we were able to generate a voltage of 10 volts. This won't solve our world's energy problem, but this could be assembled in power switches for low-power solar needs, for example," he concludes.


Bunkers for Bats
3/2/2010

The song lyrics ask, "War — what's it good for?" Well, conflicts between peoples may create new opportunities for displaced and endangered animals.

Haaretz newspaper reports that Ph.D. student Eran Levin of Tel Aviv University's Department of Zoology has discovered one of the most species-rich bat populations in the world — and they're hiding out in unused army bunkers in the Jordan Valley.

The bunkers, originally set up by the Israel Defense Forces, have been abandoned since the 1994 peace accord with Jordan. Since then, they have become the bats' preferred haunt. Levin is making sure that the bats — some of them endangered — get adequate "hanging" space to encourage breeding and long-term survival.

"Thanks to Bat Conservation International and the Ford Foundation, we were able to begin making the bunkers a better home for the bats," said Levin. "We've used planks, whitewashed surfacing mixed with gravel, plastic nets and ropes to make the ceilings more accessible for them. It turns out that every species has a preference in terms of materials and location, so we were able to encourage rarer bats to come as well as supporting the more widespread species."

As many as 12 different species are now residents in about 20 old army bunkers. The scientists believe that the bats come from Israel, Jordan and Palestinian-controlled areas. The buildings are now providing crucial living space for some of the most endangered bat species in the region, including the Mediterranean Horseshoe Bat and Geoffroy's Bat.

To read more about how Tel Aviv University researchers are providing a suprising house and home to an important nocturnal mammal, read the article in Haaretz:

http://www.haaretz.com/hasen/spages/1146631.html


Animals Cope with Climate Change at the Dinner Table
2/8/2010

Some animals, it seems, are going on a diet, while others have expanding waistlines.

It's likely these are reactions to rapidly rising temperatures due to global climate change, speculates Prof. Yoram Yom-Tov of Tel Aviv University's Department of Zoology, who has been measuring the evolving body sizes of birds and animals in areas where climate change is most extreme.

Changes are happening primarily in higher latitudes, where Prof. Yom-Tov has identified a pattern of birds getting smaller and mammals getting bigger, according to most of the species he's examined. The change, he hypothesizes, is likely a strategy for survival. Prof. Yom-Tov, who has spent decades measuring and monitoring the body sizes of mammals and small birds, says that these changes have been happening more rapidly.

His most recent paper on the topic, focused on the declining body sizes of arctic foxes in Iceland, appeared in Global Change Biology.

Radical changes in body size

Animal populations in a wide variety of geographical areas — birds in the UK, small mammals in the arctic, and most recently foxes, lynx and otters in cold Scandinavian regions — are adapting to a shift in rising temperatures. Where temperature changes are most radical, such as those at higher latitudes, Prof. Yom-Tov has measured the most radical changes of these animals' body size over time.

"This change can be seen as an early indicator of climate change," says Prof. Yom-Tov. "There is a steady increase of temperatures at higher latitudes, and this effect — whether it's man-made or natural — is having an impact on the animals living in these zones."

In his most recent paper, Prof. Yom-Tov and his Tel Aviv University colleague Prof. Eli Geffen report that arctic foxes are being influenced by changing water currents in the oceans. These changes, likely a result of climate change, affects the foxes' food supplies. Hydrologists are confounded as to why the shifts in currents are happening, but the effect in foxes is evident: their bodies are changing along with the changing currents.

Scientists are finding changes in animals' bodies across the whole animal kingdom. "Climate change is affecting migration patterns and the behavior and growth of birds, mammals, insects, flowers — you name it," says Prof. Yom-Tov. "The global warming phenomenon is a fact." What we do with this information may change our world.

Adapting to survive

Whether or not human beings are primarily responsible for climate change, Prof. Yom-Tov says, science shows that plants and animals are rapidly evolving in response to these changes. Smaller bodies allow mammals, for example, to cope with warmer temperatures, since a smaller body size gives the body a proportionally increased surface area for the dissipation of heat, he says.

"These animals need to adapt themselves to changing temperatures. In some regions the changes are as large as 3 or 4 degrees centigrade," says Prof. Yom-Tov. "If they don't adapt, their numbers may decline. If they do, their numbers remain stable or even increase."

Prof. Yom-Tov's method accesses many years' worth of data, comparing bones and skulls that natural history museums and individuals have collected over decades. He measures body sizes by studying various features (cranial size, for example) and then statistically analyzes how they have evolved.


A Deadly Scorpion Provides a Safe Pesticide
1/11/2010

Scorpions deliver a powerful, paralyzing venom — a complex cocktail of poisonous peptides — that immobilize animal prey on the spot. Some of the toxins in this cocktail damage only insects, which is why a Tel Aviv University researcher is harnessing them to create a safe and ecologically sound pesticide.

Prof. Michael Gurevitz of Tel Aviv University's Department of Plant Sciences has isolated the genetic sequences for important neurotoxins in the scorpion venom. He's also developed methods to produce and manipulate toxins to restrict their toxicity in certain insects or mammals.

"Two decades ago I realized that scorpion venom is a goldmine for possible insecticidal and therapeutic agents. This raised the question of how to use them as ecologically-safe agents against insects in a farmer's fields, or in medicinal disorders," he says.

In his study of the toxins and the evolution of their genes he recently published a paper in the journal Molecular Biology and Evolution that demonstrates how computational analyses at the gene sequence level leads to better understanding of how to manipulate toxin activity.

A venom factory in the lab

Rather than isolating the venom constituents of the Israeli yellow scorpion, known to be among the world's most poisonous scorpions, Prof. Gurevitz developed genetic methods for producing and manipulating the desired toxins in bacteria. He then investigated how they act against insects and mammals, paving the way for potential use in the agriculture industry.

He went in this direction because attempts to insert a certain neurotoxin gene into a plant genome hoping for the plant to produce the toxin and kill infesting insects has failed. As a peptide, the toxin was metabolized in the insect guts, which evidently seems to require that it first be engineered to be able to penetrate into the insect blood stream to have its impact on the nervous system.

Prof. Gurevitz says that some neurotoxins in the scorpion are highly active against some insects — leaf-eating moths, locusts, flies and beetles — but have no effect on beneficial insects like honeybees or on mammals like humans. He continues to pursue an effective mode of delivery for what could be a new insecticide.

Prof. Gurevitz is considered one of the world's pioneers in this field, having published numerous papers on this subject. He spent six years as a research fellow at Washington University in St. Louis and Michigan State University, beginning his scorpion studies while an M.Sc. student in Jerusalem 35 years ago. Since then, he's developed methods of toxin gene cloning, production and modification in his lab, paving the way for an entirely new molecular field based on the venom of the deadly insect.

A "Trojan crop" to hide a deadly poison

Since scorpion toxins must be modified to be able to penetrate the blood stream of an infesting insect, it is important to study the toxins and the way they interact with the insect nervous system. Only then would it be possible to modify them in such a way as to reach their target tissues in insects, he says. This is the direction he is working on now.

The agriculture industry already uses mostly pyrethroids, which also penetrate into insects and attack their nervous systems, leading to paralysis and death. Their main drawback, however, is the lack of specificity and the danger these compounds pose to the environment, livestock and humans.

"Why not harness potent natural compounds that venomous animals developed during millions of years of evolution?" asks Prof. Gurevitz. "I am developing the science so we can learn how to use them, and to learn how to produce agents to mimic their effect yet maintain specificity to certain kinds of insects."


Corals Fight Back -- Fish Beware!
12/9/2009

Corals are known to eat plankton and tiny jellyfish, but for the first time ever, a Tel Aviv University Ph.D. student, Omri Bronstein, has discovered a coral devouring a large adult jellyfish, the BBC reports.

"During a survey we were amazed to see some mushroom corals actively feeding on moon jellyfish," says Ada Alamaru, another member of the research team working under Prof. Yossi Loya of TAU's Department of Zoology. "We couldn't believe our eyes."

The researchers suggest that the coral may be responding to changes in their underwater climate. As an "indicator species," sensitive coral have been among the first to die as the marine environment heats up. They may be fighting back by radically changing their diets — to the dismay, perhaps, of their jellyfish neighbors.

Read the BBC story for the mouth-watering details:
http://news.bbc.co.uk/earth/hi/earth_news/newsid_8350000/8350972.stm


Calling Off Disaster
11/12/2009

Popular Science has bestowed their 2009 "Invention of the Year" award in the field of safety to new Tel Aviv University research into flood forecasting, Haaretz reports in this story. The magazine will publish a full feature on the research in next month's issue.

Prof. Pinhas Alpert, a geophysicist and head of TAU's Porter School for Environmental Studies, and his co-researchers Prof. Hagit Messer Yaron and doctoral fellow Noam David developed a way to predict the intensity of major floods. Their model, which analyzes cell phone signals, adds a component to weather forecasting never before available.

"By monitoring the specific and fluctuating atmospheric moisture around cell phone towers throughout America, we can cheaply, effectively and reliably provide a more accurate 'critical moisture distribution' level for fine-tuning model predictions of big floods," says Prof. Alpert.

Read more about this creative and potentially life-saving technology.

The university has a tradition of creative leadership in science. In 2008, Scientific American named researchers Prof. Eshel Ben-Jacob, Dr. Itay Baruchi, and Dr. Beka Solomon among the world's top innovators.


Sensing Disasters from Space
10/22/2009

One small step for mankind is now a leap for averting natural and man-made disasters on earth.

New Tel Aviv University technology combines sophisticated sensors in orbit with sensors on the ground and in the air to create a “Hyperspectral Remote Sensor” (HRS).  It can give advance warnings about water contamination after a forest fire, alert authorities of a pollution spill long before a red flag is raised on earth, or tell people in China where a monsoon will strike.

Prof. Eyal Ben-Dor of TAU's Department of Geography describes his team’s HRS technology as a combination of physical, chemical and optical disciplines.  “When a devastating forest fire hits the Hollywood Hills, for example, we can see from space how the mineralogy of the soil has changed,” he explains.  “Because of these changes, the next rainstorm may wash out all the buildings or leach contaminants into the soil.  With our new tool, we can advise on how to contain the pollutants after the fire, and warn if there is a risk for landslides.”

Details on new applications of this technology were presented recently in several leading journals including Soil Science Society of America Journals, Soil Science Journal and the International Journal of Remote Sensing.

Putting a price on dirt

HRS provides information useful to property developers as well. It can offer a soil profile map with detailed information for contractors, farmers or vintners interested in making major land purchase deals or managing existing ones. It can also indicate where water runoff should be directed and what minerals may be lacking in a given parcel of land.

“Water is an expensive commodity today,” says Prof. Ben Dor. “Knowing how to better manage water resources is a top priority for states like California, and our new tool could help them do that.”

Today, it can take years before authorities can detect chemicals that can compromise our health. For example, about 90% of all gas stations leak contaminants into the soil, says Prof. Ben-Dor. His new HRS can monitor gas stations and identify problematic areas. “Our space sensors combined with ground measurements and GPS data will be able to detect and map hydrocarbon contamination in real time.  Within a year, we’ll be able to identify these problematic areas far more quickly than with traditional methods,” he says.

Seeing where Earth takes the heat

The HRS simultaneously acquires hundreds of optical images, each from a different frequency, that enable a “spectral assessment” from distances high in the air via airplanes and in orbit using satellites.  This raw data is then processed by Prof. Ben Dor and his team to yield sophisticated thematic maps. “These are not regular maps at all,” says Prof. Ben-Dor. “We are combining properties from the physical, chemical and optical worlds, using all the latest technologies available from these fields. Ours is one of a few leading teams in the world exploring this novel way of mapping earth.”

These “soil maps” supply a bigger picture. Water bodies and sediment runoff in California.  A small soil patch in a California forest after a fire.  Impending monsoons and floods in China.  Contaminants surrounding a factory.  All these can literally be “seen” from space with the HRS.

Previous research by Prof. Ben-Dor, which focused on mapping urban heat islands from space, is now regularly used by cities and urban planners to develop projects such as “green” roofs or new parks.


A Thermometer for the Earth
10/1/2009

According to climate change experts, our planet has a fever — melting glaciers are just one stark sign of the radical changes we can expect. But global warming's effects on farming and water resources is still a mystery. A new Tel Aviv University invention, a real-time "Optical Soil Dipstick" (OSD), may help solve the mystery and provide a new diagnostic tool for assessing the health of our planet.

According to Prof. Eyal Ben-Dor of TAU's Department of Geography, his soil dipstick will help scientists, urban planners and farmers understand the changing health of the soil, as well as its agricultural potential and other associated concerns. "I was always attracted to drug development and diagnostics, which spurred the development of this OSD device," he says. "It's like a diagnostic device that measures soil health. Through a small hole in the surface of the earth, we can assess what lies beneath it."

As climate change alters our planet radically, Prof. Ben-Dor explains, this dipstick could instantly tell geographers what parts of the U.S. are best — or worst — for farming. For authorities in California, it is already providing proof that organic farms are chemical-free, and it could be used as a whistle-blower to catch environmental industrial polluters.

The efficacy of the OSD was recently reported in the Soil Science Society of America Journal.

"Precision agriculture"

Today, there is no simple and inexpensive way to test for soil health in the field. Soil maps of individual states are only compiled every 10 or 20 years, and each one costs millions. One testing process even requires the use of a bulldozer, which dredges up large tracts of land to be sampled and analyzed in a laboratory.

Testing can be much simpler with Prof. Ben-Dor's dipstick, which can be used by non-professionals. The thin catheter-like device is inserted into a small hole in the soil to give real-time, immediately accurate and reliable information on pollution and the all-round health of the soil. Analyzing chemical and physical properties, the dipstick outputs its data to a handheld device or computer. "To optimize production and save costs, farmers need to know if their crops are getting the right blend of minerals. This tool could permit them to pursue 'precision agriculture,'" says Prof. Ben-Dor.

The OSD, which is expected to cost about $10,000 per unit per application, allows technicians to determine if the soil needs water or is contaminated. It also provides information about the condition of root zones where crops are growing. And the quality of information, the researchers explain, is identical to that provided by large government laboratories. Prof. Ben-Dor says that these dipsticks can also be remotely and wirelessly networked to airplanes and satellites, providing the most detailed, comprehensive and reliable soil map of the U.S.

Saving money and avoiding headaches

Soil maps are important tools of the trade for land developers, city planners, farmers and environmental prosecutors. Those employed today tend to be outdated, rendering them useless for many applications, and only about 30% of the planet has been mapped in this way. Soil maps for the Far East, the Arctic, and Africa, which can be more readily developed with Prof. Ben-Dor's dipstick, will better tell scientists, researchers and government agencies how climate change and population growth are affecting our planet and its resources.

"Soil mapping is a national undertaking," Prof. Ben-Dor observes. "It takes years and millions of dollars worth of manual labor and laboratory analysis, not to mention exhausting headaches with government authorities and ministries. For a fraction of that energy and money, and with a staff that has minimal training, the OSD could do the same job, and could continue doing it on a yearly, monthly, and possibly even a daily basis. The headaches would be gone, and we would finally get an accurate picture of the earth's crust in these environmentally critical years."

The OSD is currently in a prototype stage and is set for commercialization. If the right strategic partner is found, a new device could be on the shelves, and in the ground, within the year.


TAU Invention Busts Dust
9/22/2009

Worried that dust from a nearby construction zone will harm your family's health? A new Tel Aviv University tool could either confirm your suspicions or better yet, set your mind at rest.

Prof. Eyal Ben-Dor and his Ph.D. student Dr. Sandra Chudnovsky, of TAU's Department of Geography have developed a sensor called "Dust Alert" — the first of its kind — to help families and authorities monitor the quality of the air they breathe. Like an ozone gas or carbon monoxide meter, it measures the concentration of small particles that may contaminate the air in your home. Scientific studies on "Dust Alert" appeared recently in the journal Science of the Total Environment, Urban Air Pollution: Problems, Control Technologies and Management Practices.

"It works just like an ozone meter would," says Prof. Ben-Dor. "You put it in your home or office for three weeks, and it can give you real-time contamination levels in terms of dust, pollen and toxins." Functioning like a tiny chemistry lab, the device can precisely determine the chemical composition of the toxins, so homeowners, office managers and factories can act to improve air quality.

Using the measurements, Prof. Ben-Dor can sometimes find a quick remedy for a dusty or pollen-filled home. The solution could be as easy as keeping a window open, he says. "We've found through our ongoing research that some simple actions at home can have a profound effect on the quality of air we breathe."

Instant results

Based on a portable chemical analyzer called a spectrophotometer, the invention can be installed and begin to collect data within minutes, although several weeks' worth of samples produces the best assessment of air quality. The longer period allows for fluctuations in both internal and external environments, such as changing weather patterns.

The "Dust Alert" fills an important need. Polluted air, breathed in for weeks, months and sometimes years, can have fatal consequences, leading to asthma, bronchitis and lung cancer. With findings from Prof. Ben-Dor's invention, urban planners can provide better solutions and mitigate risks. "We can certainly give an accurate forecast about the health of a home or apartment for prospective home owners. If somebody in your family has an allergy, poor air quality can be a deal breaker," says Prof. Ben-Dor.

Prof. Ben-Dor's device may be most useful in the aftermath of disasters, such as chemical fires, heavy dust storms, hurricanes or tragedies like 9/11. Survivors of these situations are usually unaware of the lingering environmental problems, and the government can't do enough to protect them because no accurate tools exist to define the risk. Using a Dust Alert, residents could be advised to vacate their homes and offices until the dust has cleared, or to take simple precautions such as aerating hazardous rooms in a flat, suggests Prof. Ben-Dor.

Putting dust on the map

According to Prof. Ben-Dor, the Dust Alert could also be used by cities and counties to develop "dust maps" that provide detailed environmental information about streets and neighborhoods, permitting government authorities like the EPA to more successfully identify and prosecute offenders. Currently, for example, there is no system for demonstrating how construction sites compromise people's health.

"Until now, people have had to grin and bear the polluted air they breathe," says Prof. Ben-Dor. "The Dust Alert could provide crucial reliable evidence of pollution, so that society at large can breathe easier. We can see the dust on the furniture and on the windows, but most of us can't see the dust we breathe. For the first time, we are able to detect it and measure its more dangerous components."

With their dust maps, TAU scientists have already correlated urban heat islands with high levels of particulate matter, giving urban planners crucial information for the development of green spaces and city parks. Prof. Ben-Dor also plans to develop his prototype into a home-and-office unit, while offering customized services that can help people decode what's left in the dust.


Hurricane Katrina: Phone Home
7/6/2009

Though New Orleans residents were told to evacuate days before the arrival of Hurricane Katrina, no one could have predicted the real extent of the devastation.

Now researchers from Tel Aviv University say they have found a novel and reliable way to help predict the intensity of the next big flood, using common cell phone towers across the United States. Their model, which analyzes cell phone signals, adds a critical component to weather forecasting never before available.

"By monitoring the specific and fluctuating atmospheric moisture around cell phone towers throughout America, we can cheaply, effectively and reliably provide a more accurate 'critical moisture distribution' level for fine-tuning model predictions of big floods," says Prof. Pinhas Alpert, a geophysicist and head of Tel Aviv University's Porter School for Environmental Education.

Prof. Alpert and his co-researchers Prof. Hagit Messer Yaron and doctoral fellow Noam David reported on their research in the April 2009 Atmospheric Chemistry and Physics.

Information the weather girl can use

Cell phone towers emit radio waves that are diminished by moisture in the air, a factor that can be used to improve model warnings on flood levels. In addition, the researchers measured the rainfall distributions and were able to accurately estimate the size of impending floods before they struck. This was demonstrated in post-analysis of two case-studies of floods in the Judean Desert in Israel, where cell phone towers — and flash floods — are abundant.

Using real data measurements collected from the towers, the researchers demonstrated how microwave links in a cellular network correlated with surface station humidity measurements. The data provided by cell phone towers is the missing link weather forecasters need to improve the accuracy of flood forecasting. The microwave data used in this study was supplied by two cellular providers Cellcom and Pelephone in Israel.

Can texting save lives?

"Our method provides reliable measurement of moisture fields near the flood zone for the first time," notes Prof. Alpert, who also works with NASA on developing models to study global warming weather patterns. This new tool, he says, can add to the bigger picture of understanding climate change patterns in general.

"Accurate predictions of flooding were difficult before because there haven't been enough reliable measurements of moisture fields in remote locations," Prof. Alpert adds. Using the signals collected from cell phone towers as they communicate with base stations and our handsets, weather forecasters will now have a crucial missing piece of information for flood prediction that they never had before. It will permit forecasters and residents alike to more accurately gauge the danger they face from an impending flood.

Because hundreds of thousands of cell phone towers are already in place, the Tel Aviv University invention can be adopted quickly. And cell phone companies are already collecting the data anyway, as Americans continue to ramp up their minutes of call time every month.


Monitoring Water Through a Snake's Eyes
5/11/2009

Although most Americans take the safety of their drinking water for granted, that ordinary tap water could become deadly within minutes, says Prof. Abraham Katzir of Tel Aviv University's School of Physics and Astronomy.

To combat the threat of contamination due to industrial spillage, natural disaster or sabotage, the physicist has developed a new system to monitor the safety of a building or community's water supply in real time.

Modifying special fibers developed in his Tel Aviv University lab, Prof. Katzir can detect "colors" in the infrared spectrum which distinguish between pure and contaminated water. Not visible to the naked eye, this spectrum is normally only seen by certain animals, like snakes or vampire bats, to track down prey. Connected to a commercial infrared spectrometer, the fibers serve as sensors that can detect and notify authorities immediately if a contaminant has entered a water reservoir, system, building or pipeline.

In the lab, the fiberoptic system detected poisons such as pesticides in amounts well below the World Health Organization safety threshold. Preliminary field experiments have already been done at several European sites, and the results were reported recently in the Journal of Applied Spectroscopy.

The Colors of danger

Once in use, the sensor system would be one of the first real-time water monitors in the United States to provide protection from chemoterrorism attacks — a threat to which U.S. water supplies are particularly susceptible. "It's unlikely that someone will poison the water supply in Afghanistan," says Prof. Katzir, "but America is in grave danger and needs to arm itself against chemical threats to its drinking water.

"With our naked eyes we can't distinguish between pure water and water that contains a small amount of alcohol or acetone. They're all clear. We can't do it even with a spectrophotometer, which measures visible colors," explains Prof. Katzir. "But we can clearly distinguish between liquids using an infrared spectrometer which can distinguish between 'colors' in the invisible infrared spectrum."

Such an instrument can be used to detect hazardous chemicals, pollutants and threats in the water, "seeing" water in the same way as a snake does. The special fiber sensors make it possible to monitor the quality of water in a remote location, such as a lake, a river, or a pipeline, and detect trace amounts of contaminants in real time, adds Prof. Katzir. Water management executives in Florida's Everglades and officials in Germany are among those who have expressed an interest in using the technology.

Skyscrapers in New York City a likely point of attack

"Toxic materials are readily available as pesticides or herbicides in the agriculture industry, and can be harmful if consumed even in concentrations as low as few parts per million," says Prof. Katzir.

Cities like New York are especially susceptible to a chemoterrorist threat. With many skyscrapers holding water reserves on the top of the building, a terrorist only needs to introduce poison into a tank to wreak havoc. "A terrorist wouldn't have to kill tens of thousands of people. Only 50 deaths — as horrible as that would be — would cause nationwide panic."

Currently, water authorities in America test water reservoirs usually once every day or two, with no system in place to detect chemical threats instantaneously. "This new system can cut millions of dollars from the cost of testing water manually." The fiber sensors developed by Prof. Katzir are made of insoluble, non-toxic, and biocompatible materials. "You can eat them and nothing will happen to you," he notes.

Prof. Katzir's determination to fight terrorism through science has a personal side as well. His father, world-renowned scientist Prof. Aharon Katzir, was assassinated by the Japanese Red Army in a terror attack in 1972. "I am trying to walk in his footsteps by doing applied research that can be a practical tool in an important battle. This system can be ready for use in less than a year."


A Flash of Lightning in a Hurricane's Eye
4/20/2009

The intensity of lightning strikes that precede major storms might provide a clue to the ultimate strength of hurricanes, say Tel Aviv University researchers. They're providing a new tool to predict the power of these devastating storms — and save lives and property in the process.

In a new study appearing in Nature Geoscience, TAU's Prof. Colin Price and an Israeli team discovered a surprising connection between lightning activity and hurricane intensity. The scientists studied lightning activity that occurred in the early stages of 58 intense hurricanes, and found that 56 of these storms exhibited a significant correlation between hurricane intensity and lightning activity. Peak lightning activity generally appeared a day before the hurricane winds reached their greatest strength, providing up to 24 hours' advance notice of the most dangerous parts of the storms.

Since lightning activity can now be monitored continuously at any location around the globe, lightning data may lead to more accurate hurricane forecasts in the future, say the researchers.

"Until now hurricanes had been somewhat a mystery, due to their spending most of their lifetimes over tropical oceans, where few people live. There were few measurements available to study these monstrous storms," Prof. Price says. "However, recent advances in global lightning detection systems have allowed scientists to remotely measure the electrical 'pulse' of hurricanes from thousands of kilometers away."

To learn more about this new Tel Aviv University research, read the story as it appeared at the National Geographic Web site:

http://news.nationalgeographic.com/news/2009/04/090406-lightning-hurricanes.html


A Dirty Job But ...
4/13/2009

Byproducts from the electronics, fuel, chemical and defense industries can be far from benign. Toxic heavy metals like cadmium and lead can seep into our food chain and cause cancer. And if found in the soil, these dangerous materials can render parks off-limits and real estate worthless.

For environmental, health and financial reasons, new solutions are needed to help clean industrial chemicals from America's soil.

Now, an innovative Tel Aviv University soil-cleaning technique, which turns a cement truck into a giant mixer, may change things for industry and environmental specialists. Prof. Amos Ullmann and Prof. Neima Brauner of TAU's Faculty of Engineering and Prof. Eliora Ron of the Faculty of Life Sciences, in cooperation with Israeli researcher Dr. Zvi Ludmer, are working on a new cleaning agent that binds to and whisks dangerous materials away from the soil, leaving desirable minerals intact.

"My colleagues have developed a system that literally washes the soil," says Dr. Michael Gozin of TAU's School of Chemistry. Their top-secret formulation, now in the early stages of research and development, will make it possible for truckloads of contaminated earth to be cleaned in a cement mixer. The compound not only leaves life-sustaining nutrients in the soil, but it's also biodegradable and environmentally safe.

More than soap and water

"Heavy metals can't be removed from the soil with just soap and water," says Dr. Gozin. "Chemically-speaking, a cleaning agent of this nature is very difficult to develop." With the new technique, once a commercial partner is found, however, the product could be ready in as little as 3 years. It can also be customized to remove specific dangerous chemicals, which can then be transferred to suitable confinement facilities.

Soil, says Dr. Gozin, is a very complex material. "When we're designing chemicals of the future, we have to keep in mind the delicate balance in our environment. Micro-organisms, for example, are important to keep in the soil. We don't want to kill them or remove the beneficial minerals and metals. Our advanced solution keeps all these factors in mind," he says.

The special compound developed by the Tel Aviv University team relies on advanced chemical architecture: they've created molecular compounds with complex and highly specific functions. As well as being able to recognize and bind to certain metals such as cadmium, the compounds are also non-toxic and biodegradable.

Current solutions for cleaning the soil are very time-consuming, expensive and not completely effective. They strip the soil of all its basic compounds, leaving behind dead and useless sand. They also leave behind their own toxic byproducts and do not biodegrade. "These solutions solve one problem, but create others," says Dr. Gozin, who also works on research projects for the U.S. Department of Defense, and the U.S. Air Force.

Other applications

The new Tel Aviv University solution will give polluted soil a new lease on life and may affect business as well. Properties close to industrial parks are especially at risk and the value of that real estate remains low.

Technically-speaking, the solution could also be applied in the mining industry, to help mineralogists pull certain desired chemicals from the soil, like gold or the rare metals used in the high-tech industry.

The Tel Aviv University research is funded by the Israeli Science Foundation.


A Winged Alternative to Toxic Pesticides
4/2/2009

In the modern world, farmers use toxic chemicals to control voles, mice and other rodents that can destroy their crops. Unfortunately these chemicals may also cause illness in the humans that eat those crops.

Now Prof. Yossi Leshem from TAU’s Department of Zoology has developed a proven method to keep these pesticides out of our produce. According to a recent story in the Jerusalem Post, Prof. Leshem is leading a national project in Israel that uses barn owls and kestrels, two natural predators of rodents, to help farmers exterminate rodents without recourse to toxic pesticides.

Prof. Leshem and his colleagues built a series of nesting boxes to encourage kestrels and owls to set up their “homes” next to farm fields. He recently reported that the project is successful. “There are now 1,600 nesting boxes. One pair of barn owls can eat 2,000 mice per year when they feed at night, and the kestrels eat the voles during the day,” Prof. Leshem explained. “We may export the idea and teach it in African countries,” he adds.

For more information about TAU’s exciting new project to save valuable crops and protect the health of those who consume them, see the full story in the Jerusalem Post here.


"Reverse Ecology" Reveals Ancient Environmental Clues
3/16/2009

New methods pioneered by researchers at Tel Aviv University and Stanford University are looking at genomic data from bacteria and discovering a window into the ancient environments in which the bacteria used to live. The results could provide important clues about global warming.

Published in the February issue of the Journal of Computational Biology, this ground-breaking research, which is being called "reverse ecology," offers information about the complex evolutionary interplay between organisms such as parasites and hosts. "Looking at the cellular history of an organism gives us a way to predict the biochemical environment of organisms and learn ecology from the genomic data on a large scale," says lead author Dr. Elhanan Borenstein, a Tel Aviv University doctoral graduate and post-doctoral fellow now at Stanford.

"With 'reverse ecology,' you can look at the genome and metabolic network of a species of bacteria and recreate the past environment that organism lived in," Dr. Borenstein says.

To learn more about how Tel Aviv University is reading clues from the past to learn more about the present and the future, click here and read the full story from Science Daily.


Tiny "Lab-on-a-Chip" Can Detect Pollutants, Disease and Biological Weapons
2/17/2009

For centuries, animals have been our first line of defense against toxins. A canary in a coalmine served as a living monitor for poisonous gases. Scientists used fish to test for contaminants in our water. Even with modern advances, though, it can take days to detect a fatal chemical or organism.

Until now. Working in the miniaturized world of nanotechnology, Tel Aviv University researchers have made an enormous — and humane — leap forward in the detection of pollutants.

A team led by Prof. Yosi Shacham-Diamand, vice-dean of TAU’s Faculty of Engineering, has developed a nano-sized laboratory, complete with a microscopic workbench, to measure water quality in real time.  Their “lab on a chip” is a breakthrough in the effort to keep water safe from pollution and bioterrorist threats, pairing biology with the cutting-edge capabilities of nanotechnology.

“We’ve developed a platform — essentially a micro-sized, quarter-inch square 'lab' — employing genetically engineered bacteria that light up when presented with a stressor in water,” says Prof. Shacham-Diamand. Equipment on the little chip can work to help detect very tiny light levels produced by the bacteria.

Instead of using animals to help detect threats to a water supply, Prof. Shacham-Diamand says, “Our system is based on a plastic chip that is more humane, much faster, more sensitive and much cheaper.”

Tiny lab-on-chip boosts accuracy

“Basically, ours is an innovative advance in the ‘lab on a chip’ system,” says Prof. Shacham-Diamand. “It’s an ingenious nano-scale platform designed to get information out of biological events. Our solution can monitor water with never-before-achieved levels of accuracy. But as a platform, it can also be used for unlimited purposes, such as investigating stem cell therapies or treating cancer.”

According to published literature, Tel Aviv University is one of the top five universities in the world pioneering the “lab on a chip” concept. The nanolabs can be used to evaluate several biological processes with practical applications, such as microbes in water, stem cells, or breast cancer development. Prof. Shacham-Diamand’s active lab group publishes a major paper about once a month in this field, most recently in the journal Nano Letters.

Environmental, medical and defense uses for “mini-labs”

Partnering with other Israeli scientists, Tel Aviv University is currently building and commercializing its water-testing mini-labs to measure and monitor how genetically engineered bacteria respond to pollution such as E. coli in water. Cities across Israel have expressed interest in the technology, as has the state of Hawaii.

But other uses are being explored as well. Funded by a $3 million grant from the United States Department of Defense Projects Agency (DARPA), the new lab-on-a-chip could become a defensive weapon that protects America from biological warfare. His system, Prof. Shacham-Diamand says, can be also modified to react to chemical threats and pollution. With some tweaking here and there, it can be updated as new threats are detected.

Prof. Shacham-Diamond’s research has also attracted the interest of cancer researchers around the world. He recently addressed 400 physicians at a World Cancer Conference who are seeking new devices to measure and monitor cancer and pharmaceuticals. “They need sensors like Tel Aviv University’s lab on a chip. It’s a hot topic now,” says Prof. Shacham-Diamond.


Changing Sexes on the Sea Floor
2/11/2009

Trees do it. Bees do it. Even environmentally stressed fish do it. But Prof. Yossi Loya from Tel Aviv University’s Department of Zoology is the first in the world to discover that Japanese sea corals engage in “sex switching” too.

His research may provide the key to the survival of fragile sea corals -- essential to all life in the ocean -- currently threatened by global warming.

In times of stress like extreme hot spells, the female mushroom coral (known as a fungiid coral) switches its sex so that most of the population becomes male. The advantage of doing so, says the world-renowned coral reef researcher, is that male corals can more readily cope with stress when resources are limited. Apparently, when times get tough, nature sends in the boys.

“We believe, as with orchids and some trees, sex change in corals increases their overall fitness, reinforcing the important role of reproductive plasticity in determining their evolutionary success,” says Prof. Loya, whose findings recently appeared in the Proceedings of the Royal Society B.

The will to fight and survive

“One of the evolutionary strategies that some corals use to survive seems to be their ability to change from female to male,” says Prof. Loya. “As males, they can pass through the bad years, then, when circumstances become more favorable, change back to overt females. Being a female takes more energy. And having the ability to change gender periodically enables a species to maximize its reproductive effort.”

Corals, though a part of the animal kingdom, can act like plants. Both are sedentary life forms, unable to move when times get tough.

In stressful environmental conditions, male corals can “ride out the storm,” so to speak, says Prof. Loya. “Males are less expensive -- in the evolutionary sense -- to maintain. They are cheaper in terms of their gonads and the energy needed to maintain their bodies,” he adds.

He also notes that this theory probably doesn’t apply to humans, even those who have opted for a sex change.

While admired for their beauty by divers, coral reefs provide an essential habitat for thousands of species of underwater creatures. Without the reefs, much of the underwater wildlife in reef habitats would perish. And for millions of people in the tropical regions, coral reef sea life is a major source of daily protein.

Keeping the food chain and natural wonders alive

Coral reef destruction, however, is expected to continue as an effect of global warming. About one-quarter of coral reefs around the world have already been lost. Prof. Loya’s finding may give new insight to scientists into developing coral breeding strategies for the time when the massive climate changes predicted by scientists set in.

“This knowledge can help coral breeders. Fungiid corals are a hardy coral variety which can be grown in captivity. Once you know its mode of reproduction, we can grow hundreds of thousands of them,” says Prof. Loya, currently involved in coral rehabilitation projects in the Red Sea.

Prof. Yossi Loya has been studying coral reefs for over 35 years. He has also won the prestigious Darwin Medal, awarded once every four years by the International Society for Coral Reefs, for a lifetime contribution to the study of coral reefs.


The Flash Before the Flood
11/20/2008

Flash floods are the most common natural disaster in the United States, and because of their unpredictability they’re the leading weather-related cause of death for Americans. They usually arrive with little or no warning, but a Tel Aviv University researcher is trying to predict where and when they will occur ― using lightning.

Prof. Colin Price, coordinator of the international “Flash Project” and head of the Geophysics and Planetary Physics Department at Tel Aviv University, is studying the link between lightning and subsequent flash floods. The three-year study includes scientists from five European countries, and its results are expected to be adopted by weather forecasting agencies around the world.

The goal is to develop an early warning system for people in the path of a flood. “Flash floods are different from normal floods, which are often the product of melting snow. Flash floods are short-lived and dump a lot of rain,” says Prof. Price, a climate change specialist.  “Using the radiation emitted from lightning flashes, we’ve developed a system that can give adequate warning to the public ― and save lives.”

Eventually, the Flash system may be used to send messages to cell phones, RSS feeds, GPS units and other devices to warn people in the path of a flash flood and avert disaster.

“Nowcasting” for flood warnings

Unlike normal floods which arrive slowly and with more warning, flash floods are particularly dangerous because they happen so quickly, developing from thunderstorms that form in a matter of hours. By measuring the radiation emitted by lightning, researchers can pinpoint the most intense thunderstorms, and the resulting rainfall can be located and tracked.

This data has been used to predict both the path of a storm and where heavy rainfall will appear ― crucial predictions, since the impact of flash floods depends on ground topography, slope and vegetation cover. “Nowcasting,” which predicts what conditions will be in the next few hours, versus “forecasting” a day or two in advance of expected weather conditions, is critical.

Looking at real-time lightning data, Tel Aviv University researchers can see where storms will travel over a period of a few hours, and can warn people in the path of the flood of impending danger. Such a tool will become even more relevant as erratic weather patterns, predicted by climate-change scientists today, become a reality tomorrow.

A flood of warnings delivered in a flash

The research from the Flash program can be extrapolated for use anywhere in the world, including the flash flood-prone regions of the U.S.  For example, the U.S. National Lightning Detection Network could easily apply the results of the Flash research.

“This is a tool for the future,” says Prof. Price. “And it will be even more exciting in the next decade, when we’ll have continuous real-time detection of lightning activity from satellites. That data will be used to predict floods anywhere.” The U.S. will also have geostationary satellites with lightning trackers that will take a picture every 15 minutes from 36,000 kilometers above the earth.

In the meantime, end users and educational institutions can connect and learn about floods on the “Flash” website. By mid 2009, Prof. Price says, real-time maps will be available to predict floods in a flash.

Listen to the Scientific American podcast about Prof. Price's research here:

http://www.sciam.com/podcast/episode.cfm?id=predicting-floods-in-a-flash-08-11-21


TAU Announces New "Supercenter" for Renewable Energy at Conference Opened by Al Gore
6/13/2008

Natural resources are rapidly being depleted. Traditional energy sources, like oil, have become hostages to a weakening world economy. The future, it seems, may depend on renewable energy -- new technology that bridges scientific disciplines and commercial opportunities.

Tel Aviv University has just taken a big step toward making renewable energy a daily reality.

At Israel's international conference on renewable energy last month, Tel Aviv University announced it will create a new "Supercenter" to develop renewable energies. The Supercenter will conduct pioneering research in groundbreaking solar energy applications, wind energy, biofuels and energy storage, taking advantage of the transformational and incremental technologies already being explored by Tel Aviv University researchers.

Opening the conference, "Renewable Energy and Beyond," hosted at Tel Aviv University, keynote speaker Al Gore discussed the soaring price of oil and the continuing threat of greenhouse gases, warming the planet to what Gore said could be the "point of no return." Gore came to Tel Aviv University in May to accept a $1 million Dan David Prize for his work on "social responsibility with particular emphasis on the environment." The Supercenter is Tel Aviv University’s profound response to the serious environmental issues facing the world.

Robert Goldberg, Chairman of the Board of Governors of Tel Aviv University, announced the creation of the new Supercenter during the conference. Gore attended the conference along with other American energy luminaries, including Harvard University Prof. Michael B. McElroy and deputy assistant secretary Steven Chalk of the U.S. Office of Energy Efficiency and Renewable Energy.

A multi-disciplinary powerhouse

The proposed Supercenter "will be much more than a hatchery for new clean technologies," said Prof. Abraham Kribus, an engineer and solar energy expert. "It will be a multi-disciplinary powerhouse including all the non-technological aspects, such as economics, law, and public policy, for making clean technology a reality in Israel and beyond."

In his opening address, TAU President Prof. Zvi Galil called the mass adoption of renewable energy sources a matter of economics. "Our challenge is to develop technologies for higher yield, more cost-efficient production of energy from renewable sources -- another green revolution -- for a famine of energy rather than food. This is the key contribution that research universities can make," he said.

"It is here that the research is advanced, that green energy technology companies look to improve their products," he said, adding that "Tel Aviv University is well positioned to take a major part in this new green revolution. In fact, we already have multidisciplinary teams working on solar and wind energy and on bio-mass for bio-fuels." Such solutions, Prof. Galil pointed out, could lessen the increasing levels of greenhouse gas emissions now being produced by emerging economies such as China and India.

Linking innovation, academia and policy, Tel Aviv University is expected to be a top center in the world in the renewable energy field.

Small steps, then giant leaps

Tel Aviv University researchers believe that both incremental and transformational technologies can push the renewable energy market forward. Incremental technologies will produce more efficient solar panels, for example, while transformational technologies will change the very way we use energy -- like the hyper-efficient batteries being developed at Tel Aviv University for storing and transporting energy from intermittent sources such as wind and sun.

TAU Prof. Amram Eshel is growing desert plants for use as a renewable fuel, using marginal lands and reclaimed sewage and saline water -- a solution that doesn't compete with food crops. Prof. Kribus' own Solar Energy Laboratory is increasing the efficiency of solar cells by collecting both heat and electricity from solar panels. Borrowing the power of photosynthesis from bacteria, Prof. Chanoch Carmeli is developing "artificial leaves," a new breed of low-cost solar cells to convert sunlight to electricity (based on the natural process of photosynthesis which occurs in leaves), at Tel Aviv University laboratories.

Power the world over

Besides being in a strategic geographical location for providing immediate solutions to countries such as China and India, Tel Aviv Universit's Supercenter will advance multidisciplinary research to achieve viable renewable energy solutions for the global community. At the Supercenter's helm will be scientists, engineers, economists, sociologists and legal scholars, including 30 faculty members and dozens of TAU graduate students. Cross-institutional collaborations will all be part of the formula of the planned Supercenter, in order to nurture future generations of environmentalists, scientists, and businesspeople.


One Small Step for a Laboratory Science, One Green Leap for Mankind
5/27/2008

“Environmentally friendly” is not a phrase normally used to describe a chemistry lab. But thanks to a groundbreaking discovery at Tel Aviv University, the chemical industry is a step closer to being green.

Prof. Arkadi Vigalok from the School of Chemistry at Tel Aviv University has discovered a way to use water to make certain steps of a complicated chain of chemical reactions more environmentally-friendly.

Prof. Vigalok’s solution replaces chemical solvents, which can pollute the environment, with water.  Though chemists have long thought it possible, Prof. Vigalok’s approach has only rarely been even attempted.  His discovery was recently reported in the journal Angewandte Chemie, International Edition.

A natural solvent

“Ten to twenty chemical reactions may be done to make a single medicine, and in each step organic solvents are used,” Prof. Vigalok says. “If we can cut out their use by applying water instead, this could amount to a substantial advance.”  Prof. Vigalok noted that 100 kilograms (about 220 pounds) of solvents and materials might be used to produce 1 kilogram (about 2 pounds) of medicine.

In his new approach, water is mixed with organic compounds called aldehydes.  Prof. Vigalok discovered that an oxidation reaction needed to convert the materials to a new product, carboxylic acid, can be achieved without the use of solvents.  Moreover, the oxygen for this reaction is consumed directly from air.

Walking on water

Because aldehydes don’t mix with water, they effectively “float” on the surface, where the reaction takes place.  This method can be applied to a few key stages in the reaction process.  The used water can then be easily recycled.

Prof. Vigalok and his team at Tel Aviv University join a small but growing group of chemists around the world who are making the chemical industry less destructive to the environment.  The field is now known as “Green Chemistry.”

“The plastics industry, the oil refinery business, every drug we take — they’re all parts of the chemical industry, the biggest industry in the world by far.  In making certain steps of the chemical process greener, we may not have an enormous impact on the environment at present, but we certainly challenge chemists to rethink methods used in traditional chemistry,” says Prof. Vigalok.


Al Gore and Tom Stoppard Among 2008 Dan David Prize Winners Honored at TAU Ceremony
5/23/2008

The seven 2008 Dan David Prize laureates, including Al Gore and Sir Tom Stoppard, were recognized for their impact on the world at a ceremony held May 19 at Tel Aviv University. Israeli President Shimon Peres gave the keynote address.

Laureates were selected based on their activities in the three time dimensions of past, present and future.

Al Gore: our present responsibility to the environment

Gore received the $1 million prize for his present work in Social Responsibility with Particular Emphasis on the Environment, due to his contribution to creating greater worldwide awareness of global climate change. Accepting the prize, Gore called on those concerned about the environment to demand that politicians to make a change to renewable sources of energy, such as solar power. What we need, Gore said, is “sufficient political will. But as the people of Israel know, sufficient political will is a renewable resource.”

Honoring the “creative rendering of the past”

Sharing the $1 million prize in the field of Creative Rendering of the Past -- Literature, Theater, Film are filmmaker Atom Egoyan, author Amos Oz and playwright Stoppard.

  • Oz (Arad, Israel) was honored for his works emphasizing the individual and exploring conflicts between nations.
  • Stoppard (London) was recognized for his portrayal of the search for meaning while displaying dazzling theatricality and genius for laughter.
  • Egoyan (Toronto) was noted for his exploration of the human impact of historical events and the nature of truth and its representation through art.

 

Climate change and saving the future

Three geoscientists were recognized with the $1 million Dan David Prize for their research affecting the future:

  • Geoffrey Eglinton (University of Bristol, United Kingdom) for his studies of organic chemical fossils, which reveal the climates of ancient worlds and the implications for tomorrow.
  • Ellen Mosley-Thompson and Lonnie G. Thompson (Ohio State University, Columbus, Ohio) for their separate and joint efforts in studying the geological and environmental records in ice cores and how these records  assist in predicting future geological events.

 

“Climate change is one of today’s most pressing issues and recognizing four of the seven winners in this area helps bring additional focus on the crisis,” said Mr. Dan David, who founded the prize. “As we look toward saving our future, we cannot forget our past, and that past as portrayed in the arts is especially forceful thus our prize for the past focuses on this area.”

The Dan David Prize annually awards three prizes of $1 million each for achievements with an outstanding scientific, technological, cultural or social impact on our world. The Prize is headquartered at Tel Aviv University and is named after international entrepreneur and philanthropist Dan David.


Preventing the Big American Blackout
3/12/2008

With electricity rates soaring as much as 150% since 2001, and predictions of severe and regular blackouts in states such as Washington and Virginia, there's a clear need for new thinking about electricity.

A recipe for preventing a dark future comes by way of an Israeli and American team, who suggest effective and environmentally friendly ways to generate "healthy electricity" markets in the United States.

"There are no easy answers for solving America's energy demands," says Prof. Asher Tishler, Dean of the Faculty of Management at Tel Aviv University, and his American partner, Chi-Keung Woo of the San Francisco consulting firm Energy and Environmental Economics.

"But a smart formula for easing into the next decade would include a slower evolution towards deregulation of the electricity market, along with an aggressive investment in clean technology," they say. The two researchers have co-authored a number of economics papers in this field, most recently in the International Journal of Energy Sector Management and Utilities Policy.

Deregulate slowly, go green quickly

Tishler and Woo recommend that Americans "think greener" by channelling billions of investment dollars into research and development dedicated to creating sustainable and alternative energy solutions during a slow and steady transition to deregulation. "With aggressive R&D, in 10 to 15 years green technology will be a reality," says Tishler, "and we'll find that it is not more expensive than traditional sources of energy."

But what happens to rising electricity costs in the interim? Among the 20 American states that have deregulated utilities, prices for electricity remain higher than the ones that did not.  Hang in there, say the researchers.

"Prices in a private market will fluctuate like crazy," says Prof. Tishler, but "competition over time will reduce this volatility." He stresses that unlike other traditional commodities, electricity is not easy to control. Batteries cannot store electricity when demand is low, no major advances in technology to improve efficiency have been made recently, and labor costs remain high.

Social costs a factor

Easing consumers through the deregulation transition may not be easy on their pocketbooks. Tishler and Woo suggest, however, that if consumers are willing to fork out more for their electricity bills in the near future, it will encourage lower usage, thereby conserving power, helping to prevent blackouts, and benefiting the environment.

As the wealth of America's middle class grows, so does the demand for big screen TVs and all manner of power-hungry electronics and so do greenhouse gas-causing CO2 emissions, taxing the environment further. "Energy consumption is a social issue, not just an economic one," says Tishler.

An immediate way to cut down on use is by raising power prices even more, and by urging consumers to switch to clean energy. Alternatives such as solar power may be more costly in the short term, but the social benefits, though difficult to calculate, "are huge," conclude the researchers.

Prof. Asher Tishler holds a Ph.D. in Economics from the University of Pennsylvania, and has been a faculty member at Tel Aviv University since 1976. He was recently appointed dean of the Faculty of Management. Over the last two decades, his research has focused on the defense sector and on optimizing electricity markets.


TAU Professor Finds Global Warming Is Melting Soft Coral
10/18/2007

Tel Aviv University Professor (and alumnus) Hudi Benayahu, head of TAU's Porter School of Environmental Studies, has found that soft corals, an integral and important part of reef environments, are simply melting and wasting away. And Prof. Benayahu believes this could mean a global marine catastrophe.

Environmental stress, says Benayahu, is damaging the symbiotic relationship between soft corals and the microscopic symbiotic algae living in their tissues. There is no doubt that global warming is to blame, warns the marine biologist, explaining that this symbiotic relationship is key for the survival of most soft corals.

Soft corals help maintain the health and balance of reef ecosystems and provide protection to numerous animals such as “Nemo”, the famous clown fish from the Walt Disney movie. They are also a rich and promising source of life-saving drugs against cancer and deadly infectious diseases.

Says Prof. Benayahu, “It's too late. We have now actually missed the boat in finding some key pharmaceuticals. There is a huge gap in our knowledge of soft corals in the reef environment, and with the rate of extinction, we have lost certain species forever.”

We may never recover certain therapeutic drugs, and humans could not live with a wide-spread extinction of marine life, he points out. Life as we know it could not exist if the marine environment, an important producer of oxygen, continues to follow this course.

Unlike their harder brethren, soft corals have no stony calcified outer skeleton to protect them. When they die, they are gone for good, leaving no trace of their existence. Where soft corals were once found in about 50-60 percent of Prof. Benayahu’s study sites around the globe, a few years later he is finding that only about 5 percent remain.

Earlier this year, Prof. Benayahu observed of a Japanese soft coral reef, “There was a massive disappearance of soft corals. You can't imagine this was the same site. Just two years passed and the entire area was deserted, lifeless."

But there is still hope. Prof. Benayahu recently returned from Phuket, Thailand, where he gave a training workshop to international students on the biology of soft corals. Future marine biologists from countries such as Australia, China, India, Malaysia, Israel and Thailand participated. The workshop was intended to increase awareness of what could be a global environmental catastrophe.

“I am hoping that these young scientists will take what they learned to better understand how they can save soft corals back in their home countries,” says Prof. Benayahu, who is also a professor of marine biology in the Department of Zoology at Tel Aviv University.

With more than 35 years experience in the field, Prof. Benayahu is one of a handful of world experts who devotes his life to the taxonomy, ecology and biology of soft corals. He has discovered dozens of new soft coral species across the entire Indo-Pacific region, and he carefully studies with his students the role these species play in the reef environment. He has received numerous grants to support his work, including one from the National Geographic Society to study marine life and soft corals on shipwrecks.

Prof. Benayahu received both his Masters and Ph.D. degress in marine biology from Tel Aviv University. In 1982 he did post-doctoral training at natural history museums across Europe, as well as one year at Florida International University (Florida). Since 1987 he has been a Professor in the Department of Zoology at TAU and has published over 125 refereed papers.


Earthquake Experts at Tel Aviv University Turn to History for Guidance
10/2/2007

The best seismologists in the world don’t know when the next big earthquake will hit. But a Tel Aviv University geologist suggests that earthquake patterns recorded in historical documents of Middle Eastern countries indicate that the region’s next significant quake is long overdue.

A major quake of magnitude seven on the Richter scale in the politically-fragile region of the Middle East could have dire consequences for precious holy sites and even world peace, says Tel Aviv University geologist Dr. Shmulik Marco. In light of this imminent danger, Marco, from the school’s Department of Geophysics and Planetary Sciences, has taken an historical approach to earthquake forecasting by using ancient records from the Vatican and other religious sources in his assessment. The past holds the key to the future, he says.

“All of us in the region should be worried,” explains Marco, who dedicates his career to piecing together ancient clues.

Based on the translations of hundreds of documents -- some of the originals of which he assumes reside in Vatican vaults -- Marco has helped determine that a series of devastating earthquakes have hit the Holy Land over the last two thousand years. The major ones were recorded along the Jordan Valley in the years 31 B.C.E., 363 C.E., 749 C.E., and 1033 C.E. “So roughly,” warns Marco, “we are talking about an interval of every 400 years. If we follow the patterns of nature, a major quake should be expected any time because almost a whole millennium has passed since the last strong earthquake of 1033.”

Written by monks and clergy, the documents, which span about two millenia, can help determine the location and impact of future quakes on several fault planes cutting through Israel and its neighboring countries, Marco believes. “We use the records, written in churches and monasteries or by hermits in the desert, to find patterns,” he says. Marco credits the help of an international team of historians, who have deciphered the Latin, Greek, and Arabic of the original correspondence.

He continues, “Even if these papers were not ‘officially’ recording history, they hold a lot of information. ... Some are letters to Europe asking for funding of church repairs. And while many of these accounts are told in an archaic religious manner, they help us confirm the dates and location of major calamities. Following these patterns in the past can be a good predictor of the future.”

One of the most cited Christian chroniclers in history upon whom Marco bases some of his conclusions is a ninth-century Byzantine aristocratic monk named Theophanes, venerated today by Catholics. In one manuscript, Theophanes wrote, “A great earthquake in Palestine, by the Jordan and in all of Syria on 18 January in the 4th hour. Numberless multitudes perished, churches and monasteries collapsed especially in the desert of the Holy City.”

While Christian sources helped Marco confirm ancient catastrophes and cast light on future ones, Jewish sources from the Bible also gave him small pieces of the puzzle. A verse in Zechariah (Ch. 14) describes two instances of earthquakes, one of which split apart the Mount of Olives, he says. Muslim clergy have also collected ancient correspondence, which further broadens the picture.

”Earthquakes are a manifestation of deeper processes inside the earth,” Marco says. “My questions and analysis examine how often they occur and whether there is pattern to them, temporally or spatially. I am looking for patterns and I can say that based on ancient records, the pattern in Israel around the Dead Sea region is the most disturbing to us.

“When it strikes and it will  this quake will affect Amman, Jordan as well as Ramallah, Bethlehem, and Jerusalem. Earthquakes don’t care about religion or political boundaries,” Marco concludes.


Tel Aviv University Scientists Probe "Deep" Questions Aboard EcoOcean's Environmental Research Ship
9/7/2007

Did the great flood of Noah’s generation really occur thousands of years ago? Was the Roman city of Caesarea destroyed by an ancient tsunami? Will pollution levels in our deep seas remain forever a mystery?

These are just a few of the questions that are being addressed by a new environmental marine research team from Tel Aviv University and the non-profit research and education organization, EcoOcean.

The team, headed by EcoOcean's Andreas Weil and Prof. Sven Beer of Tel Aviv University, are working to uncover new secrets about civilization and climate change from the depths of the sea floor. They are also a conducting a large-scale study on the health of the Mediterranean Sea with Ph.D. students they sponsor. The work is being done aboard "Mediterranean Explorer", a floating marine vessel.

“When I was looking for a partner, I needed to find a team of marine scientists who were leaders in their fields,” says Weil, a Swedish environmental philanthropist who helped conceive and fund the idea of giving a free, floating marine research lab to any scientist who needed it. “I didn’t want us to be just another Greenpeace group of environmental activists. My dream was to build the foremost research vessel for high-level scientific marine research. I wanted to be able to help provide hard scientific data and education about the real state of affairs of our oceans.”

The first and only institution that came to mind was Tel Aviv University (TAU), internationally famous for its work in marine biology. “Besides being the only university in Israel that has a dedicated marine unit, its researchers are leaders not only in Israel, but the world,” says Weil, who brought a crew of TAU scientists on board as EcoOcean advisors. They include Professors Yossi Loya, Micha Ilan, Yehuda Benayahu, and Sven Beer, with Beer appointed as the chief partner and chief scientific advisor for EcoOcean.

Climate, the marine environment, and the health of humanity are inexorably intertwined, says Beer. “Marine research is more important for the future of humanity than some people realize. Marine plants provide most of the oxygen that we breathe and regulate the climate more than any other ecosystem on the planet. In the face of global warming, it is critical that we understand our seas in order to sustain life as we know it.”

Prof. Beer was part of the team on board "Mediterranean Explorer" that recently headed to the Black Sea off the coast of Turkey, the site where historians believe the great biblical flood occurred. EcoOcean and an international team believe they have found evidence to substantiate what is written in the Bible.

Says Weil, “We found that indeed a flood happened around that time. From core samples, we see that a flood broke through the natural barrier separating the Mediterranean Sea and the freshwater Black Sea, bringing with it seashells that only grow in a marine environment. There was no doubt that it was a fast flood one that covered an expanse four times the size of Israel. It might not have been Noah, as it is written in the Bible, but we believe people in that region had to build boats in order to save their animals from drowning. We think that the ones who survived were fishermen they already had the boats.”

The action and adventure never seem to stop aboard "Mediterranean Explorer", which often plays host to visiting scientists from institutions abroad, including New York's Columbia University, Woods Hole Oceanographic Institution near Boston, McMaster University in Canada, and Istanbul Technical University.

Next week the team will sail out to take underwater footage for evidence of an ancient tsunami thought to have destroyed the port city Caesarea generations ago. They will also be looking for deep-sea sea grasses, algae and sponges that had been observed earlier by researchers but were never properly investigated. “This is very interesting,” says Weil, "because sea grasses are normally not found at these depths. Maybe one day one of these organisms can provide us with a new drug.”

Dan Schaffer, the operations manager for EcoOcean and captain of the ship, has been working with EcoOcean for nearly four years. "I am doing a lot more than driving the boat," jokes Schaffer, who sums up the point of EcoOcean quite well. "The way I see it, we are working on three different venues. One is in education we are teaching children who will be our future environmental stewards. The second thing is that we have brought this research vessel to Israel and have created a platform that academics in Israel and abroad can use for maritime research. The third is that we have created a floating classroom for students in higher education. Not only can these students do science, but they learn how it is done properly in the field of oceanography."

Schaffer adds that EcoOcean is proving to be an important matchmaker to help scientists cross more than the great big seas. “Prof. Yehuda Benayahu from Tel Aviv University wanted to go to Eritrea to work on a joint project with Eritrea University," he relates. "We made that happen by bringing the know-how and encouraging USAID to supply the funding. It is a perfect story for how research between people and across continents should be done. We are looking forward to more international collaborations.”


Clues to Noah's Flood Found on Ocean Floor
9/7/2007

TAU scientists and Swedish environmental philanthropist Andreas Weil have formed a marine team aboard the "Mediterranean Explorer".  Together, they are unlocking environmental and historical mysteries secreted in the depths of the ocean for centuries.  This floating laboratory and educational facility is being used to discover more about global warming, climate change, and even biblical history.  Joining in on the adventure are students, professors and a diverse group of scientists from a variety of cultures and  backgrounds.


Man's Best Friend, the Bat
8/31/2007

Tel Aviv University, in partnership with the Ministry of the Environment and the city of Ramat Gan, is relocating mosquito-eating bats to work as pest exterminators.

The bats, which can eat up to 600 mosquitoes a night each, have been encouraged to nest in the area of Ramat Gan and will be observed by researchers over a period of several years.  The bats provide a natural way of controlling growing pest populations, often casued by human interference in the ecosystem.  In the past, mosquitoes have been associated with the transmission of diseases like malaria and the West Nile Virus in Israel.

http://www.treehugger.com/files/2007/08/like_a_bat_outt.php


First Frogs, Now Our Wheat?
8/13/2007

The catastrophic decline and extinction of our planet’s amphibians, some believe, is due to a virulent fungus spreading around the globe. Scientists now find another strain of fungus, called Ug99 (or stem rust), has claimed a new victim: Our global wheat crops. According to The Jerusalem Post, the wheat fungus first found in Uganda eight years ago, is moving like wildfire through Africa. It now threatens to destroy some 70% of the world’s wheat crops.

But this fungus, currently in Yemen and making its way north to Israel, may just get a dose of medicine: A native Israeli species of wheat, Sharon goatgrass (Aegilops sharonensis), found on Israel's coastal plain and in a few locations in Lebanon, is highly resistant to the fungus. 
Scientists from the University of Minnesota and Tel Aviv University are proposing that genetic engineers take the “resistance” from Israel’s Sharon goatgrass and transplant it to at-risk varieties of wheat.

Their research has been published in the American Phytopathological Society's journal, Plant Disease. Led by Prof. Brian Steffenson from Minnesota and Prof. Yehoshua Anikster of Tel Aviv University’s Institute for Cereal Crops Improvement the researchers believe they can offer hope to other scientists fighting the fungus.

Anikster says that Ug99 is "a very dangerous threat" to Israeli wheat, now cultivated on 850,000 dunams in the country. "The short-term solution for this disease is to apply fungicides to the wheat, but this comes with an economic and environmental cost." 



The Israeli and American scientists are now working on collecting species for long-term storage in a Tel Aviv University gene bank. Ultimately the plan would be to transfer Ug99 resistance from the Israeli wheat to other wheat varieties.

Researchers noted that even though Israel is a very small country, it has a wealth of genetic diversity in wild progenitors of wheat, barley, and oats. Anikster added that "the genes carried by these wild species are important for cereal production far beyond Israel's border."

This story first appeared on TreeHugger (August 13, 2007) and The Jerusalem Post (August 7, 2007).

 


Nature Takes Its Southerly Course
7/5/2007

A TAU-sponsored organization, the International Center for the Study of Bird Migration in Latrun, is easing the difficult migration of over 500 species of birds on their journeys from Europe and the Middle East to Africa. Because Israel is situated at the junction of these three continents, half a billion birds pass annually through the region on the way to their winter homes.
 
Read Ilana Teitelbaum’s article on the “Essence of Life” Web site:

http://www.eolife.org/article.php?aid=97228891f7383fb4fafb5db6b83e4686

 

 


Nature Is for the Birds, TAU Researchers Observe
6/28/2007

All of us have to cope with extremes of temperature. Birds are no exception and some are particularly clever at it, ornithologists from Tel Aviv University’s International Center for the Study of Bird Migration have found.

Scientists observing a family of storks in Israel’s Kibbutz Tirat Zvi have been concerned recently with a punishing heat wave. The kibbutz is home to a pair of white storks, apparently the most southerly-located examples of the species in the world. Researchers are especially worried that high temperatures in the region could lead to dehydration for two chicks recently hatched to the storks.

Photographer Ronen Vaturi, in documenting the birds’ nesting habits, noticed that, in addition to sprinkling water on the chicks during the daytime, the male stork had developed the habit of collecting straw for the nest and dipping it in a nearby puddle of water before placing it next to the chicks, thereby providing his children with much-needed moisture and preventing their dehydration. The father stork does this as often as four times an hour during the hottest part of the day.

(No sightings, as yet, of any storks bearing tiny nest-size air conditioners.)

A live Web camera directed at the stork’s nest is available online here:

http://www.birds.org.il/show_item.asp?levelId=1468


The Earth Has a Fever!
2/1/2007

The Earth has a fever! When we get a fever our body temperature rise by 1-2 degrees, and we feel pretty rotten. We stay at home, don’t want to talk to anyone, we are cranky, and we behave strangely. That fever is relative to our average body temperature of 36C (you will have to translate Celsius to Fahrenheit if you wish). Well, the Earth has a similar fever of 1 C at the moment, relative to its average temperature of 15 C. And similar to our bodies that start acting strange when we have a fever, the Earth is also starting to show signs of irritability, strange behaviour, which we are noticing through changes in the weather and climate.

The facts are that the temperatures observed today and during the last few decades are the highest they have been for at least 1000 years if not longer (we don’t have accurate data further than that). Furthermore, the concentration of greenhouse gases that are known to absorb heat emitted from the Earth’s surface are now the highest we have seen in at least 600 thousand years, and likely longer (we have no data going back further in time). If you don’t trust the temperature data, take a look outside. 95% of all mountain glaciers around the world are melting and receding. The Greenland ice sheet is dramatically losing mass (ice) due to melting, while the summer Arctic sea ice is continuously shrinking every year.

Okay, so things are getting warmer. But perhaps it is a natural cycle of the Earth? Perhaps, but lets look at the data again. Over the history of the Earth the population of humans on the planet was always below 500 million, until suddenly at the start of the Industrial Revolution around 1800, the population start increasing dramatically, to the present number of more than 6 billion people. Within 200 years the population shot up, and it continues today. Why did it increase so dramatically? Better standards of living, technology, medicine, agriculture, etc. resulted in longer life expectancy, lower infant mortality, possibilities to feed many people from a single farm, etc. It just so happens that as the population of the globe started shooting up, so did the concentrations of some gases in the atmosphere that we call greenhouse-gases. These gases are primarily CO2, CH4, N2O and more recently CFCs and O3. All these gases are produced by our burning of fossil fuels (coal, oil and natural gas), agricultural practices and industrial practices around the world. When we look back over the last 1000 years, we notice that the concentration of these greenhouse gases were very stable in the atmosphere, but they ALL shot up starting around 1800 and continue to increase rapidly today. 99% of all climate scientists will agree that the increase in these gases over the last 200 years in the atmosphere is due to anthropogenic activities on our planet.

Well, that still does not mean the warming we are observing is caused by the increasing greenhouse gases. But it can explain the warming. There is NO other way of explaining the present global warming of the Earth. Some scientists suggest the sun is responsible for the warming, others claim cosmic rays that change the amount of clouds, while others still deny the reliability of the data. However, we can use computer models to simulate the past and present climate to better understand the connections between the sun, greenhouse gases and the climate. All climate models manage to reproduce the present day warming only when they include the increasing trends of greenhouse gases into their models. Without the increasing greenhouse gases the models cannot reproduce the present day warming. Well, the models may not be good enough, or they may be missing something. Maybe. However, these same models manage to simulate the present day climate fairly well, and also manage to simulate past ice ages fairly well. So they strengthen the argument of cause-and-effect.

These climate models are also the crystal ball that allow us climate researchers to look into the future. Here we are less certain of what may happen in the next decades. All models predict warmer temperatures, increased sea level and changes in rainfall patters (some places drier with others wetter). The possibilities of future changes in the climate may results in many changes in our lives, although looking into the future is somewhat speculative. Some models predict increases in heat waves, droughts, forest fires in some regions of the globe, while in other regions we can expect increases in the frequency of flash floods and intense storms. Will hurricanes increase in intensity and number in a warmer world? Will malaria spread in third world countries? Will water scarcity result in regional conflicts in the future? What about mass evacuations of populations due to sea level rise?

Can something be done to stop the global warming? Well, if it really is caused by the increasing greenhouse gases, then the answer is YES. It is simply a matter of money, and who is going to pay. Nobody wants to decrease their own standard of living, but solving the problem of global warming means decreasing our standard of living. Whether it is paying more for gasoline to drive our cars, paying more for clean electricity, or paying more taxes so governments can invest in alternative renewable energy sources, we will all have to pay in the end. The only long term solution is to dramatically reduce the amount of greenhouse gases in the atmosphere, primarily CO2, but also CH4 and N2O. Wind energy, hydroelectric power, solar energy, geothermal, biomass and even nuclear energy are possible solutions that will dramatically reduce the amount of CO2 in the atmosphere. These sources of energy produce only a small fraction of the worlds energy needs today.

What we scientists are worried about now are surprises. It is much easier to melt the Greenland ice sheet than it is to rebuild it. The ice and snow around the planet have a cooling effect due to their white color that reflects large amounts of solar radiation back to space. Without this ice and snow, additional radiation will be absorbed at the surface and the Earth will warm even more. The thawing of the high latitude permafrost (frozen ground) may result in huge emissions of CH4 that will also accelerate the warming.

A few more degrees warming, and the Earth will need to be put in intensive care!

Colin Price
Professor
Department of Geophysics and Planetary Science
Tel Aviv University

Original article can be found at:
http://www.earthsky.org/blog/50992/the-earth-has-a-fever


Global Democracy
7/12/2006

Coral reefs are sick and dying. Global warming is mainly to blame, according to Tel Aviv University (TAU) Professors Yosi Loya and Eugene Rosenberg.

This dynamic duo is strapping on their flippers and getting ready to hit the sea: they have been assigned a lofty mission by the World Bank to turn around the spiral of destruction. In conjunction with about 60 other experts in the world, they are sharing a $21 million fund as part of the International Coral Reef Initiative, designed to research coral and build a plan of action that will be followed by ocean stewards around the world.

Rosenberg and Loya know that bacteria are killing corals. Global warming and pollution are exaggerating this effect at an unprecedented rate. Today, one-third of the world's coral reefs have died, says Loya, who explains that coral reefs are sensitive to the slightest amount of change in seawater temperature. Rosenberg adds that increased temperatures cause certain bacteria to become more virulent.

The World Bank chose the two TAU experts to form their international reef team, both because Loya and Rosenberg are leaders in their respective fields, coral biology and coral microbiology, and because they have a longstanding tradition of taking basic research, and combining it with environmental science to make real-world solutions that leap out of the laboratory.

Professor Loya, a zoologist at the George S. Wise Faculty of Life Sciences, has worked on the community structure and species diversity of Red Sea reefs. He formed the foundation for many modern reef studies and sampling methods that are used worldwide today. Loya has pioneered investigations of reef-communities from the native Red Sea corals in Israel to the Great Barrier Reef. More recently, he has contributed to understanding the effects of chronic pollution and how interactions between elevated sea temperature and bacterial disease affects Mediterranean corals.

Professor Rosenberg, from the Molecular Microbiology and Biotechnology Department, has made advances in environmental technologies, such commercializing bacteria that consumes crude oil. He has written numerous books on how to use microorganisms to combat pollution. In recent years he has demonstrated that certain bacteria are responsible for coral bleaching.

"The World Bank assigned five different groups of experts on different aspects of the problem from coral diseases, bleaching of coral reefs and restoration initiatives and they selected the best people in the world," said Loya, "There is power in producing better understanding in pure research on why the corals are dying."

Acting as underwater sleuths, the scientists are involved in figuring out an action plan that can take effect before Global warming damage is irreversible. To formulate the plan, they meet with their teams around the world and together devise a strategy for managers at the local level to follow. Whether it is the Philippines, India, or Israel, researchers are making sure both developed and developing countries have access to the same coral reef management tools.

"A coral reef is like an underwater rainforest and the world's most important indicator system," says Professor Loya. "I have been working on coral reefs for forty years and corals are the most complex and diverse system in the marine environment. The only terrestrial ecosystem that can come close to it in its complexity is a rainforest."

Coral health is valued as an important yardstick for assessing environmental degradation due to Global warming . Known as an indicator species, like amphibians are in terrestrial ecosystems, coral reefs are sensitive to environmental disturbances, man-made or natural, even before the extent of the damage can be fully known.

"You hear a lot about global change and the warming of planet earth," says Loya. "Coral reefs are sensitive to differences in temperature and are used to growing in a stable environment. When they don't have that, they die. Corals thrive within a temperature window of 20-26 degrees centigrade. Two degrees more in temperature is a disaster for coral reefs. In the last 10-15 years, there are more and more reports around the world of coral reefs, which are dying. They are the first to respond to change."

Coral reefs are colorful, rock-like structures built by ocean animals called corals. The living animals are about an inch long and live on the sea floor by attaching themselves to the limestone carcasses of their dead ancestors. Thousands and millions of years later, the layers of living and dead corals form a large coral structure called a reef which in turn becomes an attractive homestead for thousands of other ocean animals and plants.

"Everyone talks about sick corals and describes the number of infectious diseases that they are subjected to," says Rosenberg, who has decided to take a unique approach and looks at corals as though they are terrestrial animal. "In most animal systems, infectious disease is protected by various mechanisms," he explains. "If you sneeze, you cover your face or you clean up water a supply so the disease won't be transmitted.

"I am studying what to do when corals sneeze," he says, noting that a distinctive coral killer, a species bacterium he calls a pathogen, is becoming more virulent as the globe heats up. The bacteria prey on the algae living in the coral and since these algae are the primary nutrient source for corals, without them, corals die.

"If we stop the transmission of the bacteria to the algae, we can control the disease and coral death," affirms Rosenberg. It is a simple answer to a big problem, but like a drug-developer seeking a cure for a disease, he says, a practical solution to stopping the transmission is in the works.

Rosenberg is collaborating with five other top researchers from around the globe working specifically on coral disease. The funding gets channeled to TAU graduate students too: the Red Sea coral reefs' proximity to Tel Aviv University means that graduate students can make their country a classroom. The university is also an attractive hub for international students and visiting professors working in marine microbial ecology.

The Red Sea coral reef is arguably one of the most important reefs in the world in terms of species diversity and size; it is also one of the most northerly corals in the world. At a junction of three countries Israel, Egypt and Jordan, it is in peril: local pollution and the effects of global warming are taking its toll.

Coral health can be preserved only if some of the world's greatest polluters clean up their act, Loya believes, "Reefs can be restocked, the local pollution can be cleaned up, but the only long-lasting solution to saving the corals is to stop global warming through political action in all of the world's governments."

On the local side, one of Loya's battles is trying to get Israeli fish farms in Eilat to stop polluting the water. In the lab he is using contemporary and fossil corals to build predictive models concerned with global climate change.

The positive side to the coral story is that the World Bank, an influential force for change, is now involved in the fight against global warming. The international coral initiatives that TAU professors are spearheading are supported by similar efforts by top-notch scientists from other institutions such as Scripps and Harvard.

"There is power in producing better understanding of global warming ," says Loya, "But as for a real-world solution to dying reefs and global warming , we need to decrease the emission of greenhouse gases today."

Loya's commitment to saving the environment has had a great impact on his colleague Rosenberg. "Loya was my biggest influence," he says. The two have co-edited a book Coral Health and Disease.

Rosenberg doesn't have a diving license and only occasionally snorkels. His attitude is positive and directed to humanity's ability to change the current situation. "I only snorkel when I have to," says Rosenberg, "The last time was at the Great Barrier Reef and they had to throw me a life vest in the end. Today, I work mostly in the lab and my students dive and bring back the coral. I smoke cigars and I think," quips Rosenberg.

This original version of this article can be found at: http://www.israel21c.com/


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The Brain Mechanism Behind Multitasking

The brief reactivation of a learned memory can block interference from competing tasks, TAU researchers say.

DNA Delivery Technology Joins Battle Against Drug-Resistant Bacteria

New tool is major milestone against lethal condition, TAU researchers say.

Cardiac Stem Cells from Heart Disease Patients May Be Harmful

TAU researchers discover molecular pathway involved in toxic interaction between host cells and immune system.

Multispectral Imaging Reveals Ancient Hebrew Inscription Undetected for Over 50 Years

Military correspondence from the First Temple period discovered on reverse side of well-studied artifact at The Israel Museum, TAU researchers say.

Earliest Human Impact on the Environment Took Place 11,500 Years Ago

The earliest geological indication of humans' impact on the environment discovered in the Dead Sea, TAU researchers say.

IDEAS Immersion Program to Host Nine Female Entrepreneurs from TAU

Acceleration program partners with Cross Campus and Google to help budding women entrepreneurs incubate startups.

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