REHOVOT, ISRAEL—July 27, 2010—A unique device based on sniffing—inhaling and exhaling through the nose—might enable numerous disabled people to navigate wheelchairs or communicate with their loved ones. Sniffing technology might even be used in the future to create a sort of “third hand” to assist healthy surgeons or pilots.

Developed by Prof. Noam Sobel, electronics engineers Dr. Anton Plotkin and Aharon Weissbrod, and research student Lee Sela in the Weizmann Institute of Science’s Department of Neurobiology, the new system identifies changes in air pressure inside the nostrils and translates these into electrical signals. The device was tested on healthy volunteers as well as quadriplegics, and the results showed that the method is easily mastered. Users were able to navigate a wheelchair around a complex path or play a computer game with nearly the speed and accuracy of a mouse or joystick.

Says Prof. Sobel, “The most stirring tests were those we did with locked-in syndrome patients. These are people with unimpaired cognitive function who are completely paralyzed—‘locked into’ their bodies. With the new system, they were able to communicate with family members, and even initiate communication with the outside. Some wrote poignant messages to their loved ones, sharing with them, for the first time in a very long time, their thoughts and feelings.” Four of those who participated in the experiments are already using the new writing system, and Yeda Research and Development Company, Ltd.—the technology transfer arm of the Weizmann Institute—is investigating the possibilities for developing and distributing the technology.

Sniffing is a precise motor skill that is controlled, in part, by the soft palate—the flexible divider that moves to direct air in or out through the mouth or nose. The soft palate is controlled by several nerves that connect to it directly through the braincase. This close link led Prof. Sobel and his scientific team to theorize that the ability to sniff—that is, to control soft palate movement—might be preserved even in the most acute cases of paralysis. Functional magnetic resonance imaging (fMRI) lent support to the idea, showing that a number of brain areas contribute to soft palate control. This imaging revealed a significant overlap between soft palate control and the language areas of the brain, hinting to the scientists that the use of sniffing to communicate might be learned intuitively.

To test their theory, the researchers created a device with a sensor that fits on a nostril’s opening and measures changes in air pressure. For patients on respirators, the team developed a passive version of the device, which diverts airflow to the patient’s nostrils. About 75 percent of the subjects on respirators were able to control their soft palate movement to operate the device. Initial tests, carried out with healthy volunteers, showed that the device compared favorably with a mouse or joystick for playing computer games. In the next stage, carried out in collaboration with Prof. Nachum Soroker of Loewenstein Hospital Rehabilitation Center in Raanana, Israel, quadriplegics and locked-in patients tested the device.

One patient who had been locked in for seven months following a stroke learned to use the device over a period of several days, writing her first message to her family. Another, who had been locked in since a traffic accident 18 years earlier, wrote that the new device was much easier to use than one based on blinking. Another 10 patients, all quadriplegics, succeeded in operating a computer and writing messages through sniffing.

In addition to communication, the device can function as a sort of steering mechanism for wheelchairs: Two successive sniffs in tell it to go forward, two out mean reverse, out and then in turn it left, and in and out turn it right. After 15 minutes of practice, a subject who is paralyzed from the neck down managed to navigate a wheelchair through a complex route—sharp turns and all—as deftly as a non-disabled volunteer.

Sniffs can be in or out, strong or shallow, long or short; and this gives the device’s developers the opportunity to create a complex “language” with multiple signals. The new system is relatively inexpensive to produce, and simple and quick to learn to operate in comparison with other brain-machine interfaces. Prof. Sobel believes that this invention may not only bring new hope to severely disabled people, but it could be useful in other areas; for instance, as a control for a “third arm” for surgeons and pilots.

To download videos on this research, click on the following link to the Proceedings of the National Academy of Sciences (PNAS) site: http://www.pnas.org/content/suppl/2010/07/14/1006746107.DCSupplemental

Prof. Noam Sobel’s research is supported by the Nella and Leon Benoziyo Center for Neurosciences; the J&R Foundation; and Regina Wachter, NY.

NEW YORK, NY—July 6, 2010—The Weizmann Institute of Science in Rehovot, Israel, was ranked second among the top international academic institutions on The Scientist magazine’s 8^th annual worldwide survey of “Best Places to Work in Academia.” In both 2005 and 2008, the Weizmann Institute was ranked as the top international academic institution (outside the United States) by survey respondents. The Institute has been ranked second two other times, including in 2009.

The Weizmann Institute of Science is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment. Weizmann scientists have been widely recognized for their research contributions. In 2009, Weizmann Institute Prof. Ada Yonath received the Nobel Prize in Chemistry, along with colleagues from the U.S.

The “Best Places to Work in Academia” survey, which will be published in the July issue of The Scientist, reviewed the entries of more than 2,000 respondents from 119 institutions in the U.S. and abroad. The respondents were asked to assess their working environment by indicating their level of agreement with 38 criteria in eight different areas, while also specifying how important each factor was to them. Job satisfaction, research resources, infrastructure and environment, and peers were among the eight categories included in the survey.

Princeton University was ranked the best place to work in academia in the U.S. for the second straight year. The University of Queensland, Australia, a first-timer to the survey, was ranked the top international academic institution.

The Scientist magazine provides coverage of the latest developments in the life sciences. This year’s survey results, full-color charts, methodology, and past survey results can be viewed at www.the-scientist.com/bptw/.

The American Committee for the Weizmann Institute of Science is a community of dedicated people who share a common vision in support of the Institute. The generous assistance the Institute receives from individuals, foundations, and corporations is vital for its future. Committee members show their devotion to the advancement of the Institute’s goals by becoming partners in the search for answers to the most difficult challenges facing humanity.

Not all explosions are created equal: It’s as true for film effects as it is for the stars. Yet, until now, scientists had only observed two basic kinds of exploding stars, known as supernovae. Now, scientists at the Weizmann Institute of Science, in collaboration with others around the world, have identified a third type of supernova. Their findings appeared this week in Nature.

The first two types of supernova are either hot, young giants that go out in a violent display as they collapse under their own weight, or old, dense, white dwarves that blow up in a thermonuclear explosion. The new supernova appeared in telescope images in early January 2005, and scientists, seeing that it had recently begun the process of exploding, started collecting and combining data from different telescope sites around the world, measuring both the amount of material thrown off in the explosion and its chemical makeup. But Dr. Avishay Gal-Yam, Hagai Perets (now at the Harvard-Smithsonian Center for Astrophysics), Iair Arcavi, and Michael Kiewe of the Weizmann Institute’s Faculty of Physics, together with Paolo Mazzali of the Max-Planck Institute for Astrophysics, Germany, the Scuola Normale Superiore, Pisa, and INAF/Padova Observatory in Italy, Prof. David Arnett from the University of Arizona, and researchers from across the US, Canada, Chile, and the UK, soon found that the new supernova did not fit either of the known patterns.

On the one hand, the amount of material hurled out from the supernova was too small for it to have come from an exploding giant. In addition, its location, distant from the busy hubs where new stars form, implied that it was an older star that had had time to wander off from its birthplace. On the other hand, its chemical makeup didn’t match that commonly seen in the second type. “It was clear,” says Dr. Perets, the paper’s lead author, “that we were seeing a new type of supernova.” The scientists turned to computer simulations to see what kind of process could have produced such a result.

The common type of exploding white dwarf (a type Ia supernova) is mainly made up of carbon and oxygen, and the chemical composition of the ejected material reflects this. The newly discovered supernova had unusually high levels of the elements calcium and titanium; these are the products of a nuclear reaction involving helium, rather than carbon and oxygen. “We’ve never before seen a spectrum like this one,” says Dr. Mazzali. “It was clear that the unique chemical composition of this explosion held an important key to understanding it.” Where did the helium come from? The simulations suggest that a pair of white dwarves are involved; one of them stealing helium from the other. When the thief star’s helium load rises past a certain point, the explosion occurs. “The donor star is probably completely destroyed in the process, but we’re not quite sure about the fate of the thief star,” says Dr. Gal-Yam.

The scientists believe that several other previously observed supernovae may fit this pattern. In fact, these relatively dim explosions might not be all that rare; if so, their occurrence could explain some puzzling phenomena in the universe. For example, almost all the elements heavier than hydrogen and helium have been created in, and dispersed by, supernovae; the new type could help explain the prevalence of calcium in both the universe and in our bodies. It might also account for observed concentrations of particles called positrons in the center of our galaxy. Positrons are identical to electrons, but with an opposite charge, and some have hypothesized that the decay of yet unseen “dark matter” particles may be responsible for their presence. But one of the products of the new supernova is a radioactive form of titanium that, as it decays, emits positrons. “Dark matter may or may not exist,” says Dr. Gal-Yam, “but these positrons are perhaps just as easily accounted for by the third type of supernova.”

A new type of explosion may explain the course of calcium. How does it work? Above is an illustration of a close-up view.

The exploding system is composed of two compact white dwarf stars—the dying embers left from the cores of stars similar to the sun. The more massive of the two (whose physical size is actually larger, a peculiar property of these objects), seen on the left side of panel A, is stealing mass from its less massive, but larger, companion, seen on the right. This mass is mostly helium gas.

Zooming closer to the mass thief (panel B), we can see that the helium mass streaming from the companion accumulates onto the surface of the heavier star, and is compressed by its huge gravitational force. The lighter star gradually loses most of its mass, and may eventually be totally destroyed by its gregarious neighbor.

When the mass of helium accumulated on the mass thief becomes very hot and dense, a nuclear explosion occurs (panel C). The helium explodes and is transformed into elements such as calcium and titanium, eventually producing the building blocks of life for future generations of stars.

The fate of the mass thief is unclear. It is known that the bulk of its mass does not undergo nuclear explosion. This tough star may actually survive the explosion (panel D1), or else the explosion may trigger its compression and collapse into an object even more dense and compact—a neutron star, no larger than the size of a big city on earth (shown, not to scale, in panel D2). Resolving  the ultimate fate of this star remains a mystery for future studies.

Image credits: Dr. Avishay Gal-Yam, Weizmann Institute of Science. (This image accompanies a paper by Perets et al. in Nature, May 20, 2010.)

Dr. Avishay Gal-Yam’s research is supported by the Nella and Leon Benoziyo Center for Astrophysics; the Yeda-Sela Center for Basic Research; the Peter and Patricia Gruber Awards; the Legacy Heritage Fund Program of the Israel Science Foundation; and Miel de Botton Aynsley ,UK.

REHOVOT, ISRAEL—April 19, 2010—The constant stress that many are exposed to in our modern society may be taking a heavy toll: Anxiety disorders and depression, as well as metabolic (substance exchange) disorders, including obesity, type 2 diabetes, and arteriosclerosis, have all been linked to stress. These problems are reaching epidemic proportions: Diabetes alone is expected to affect some 360 million people worldwide by the year 2030. While anyone who has ever gorged on chocolate before an important exam recognizes the tie between stress, changes in appetite, and anxiety-related behavior, the connection has lately been borne out by science, although the exact reasons for the connection aren't crystal clear. Dr. Alon Chen of the Weizmann Institute's Department of Neurobiology and his research team have now discovered that changes in the activity of a single gene in the brain not only cause mice to exhibit anxious behavior, but also lead to metabolic changes that cause them to develop symptoms associated with type 2 diabetes. These findings were published online this week in the Proceedings of the National Academy of Sciences (PNAS).

All of the body's systems are involved in the stress response, which evolved to deal with threats and danger. Behavioral changes tied to stress include heightened anxiety and concentration, while changes in the body include heat generation, changes in the metabolism of various substances, and even changes in food preferences. What ties all of these things together? The Weizmann team suspected that a protein known as Urocortin-3 (Ucn3) was involved. This protein is produced in certain brain cells—especially in times of stress—and it's known to play a role in regulating the body's stress response. These nerve cells have extensions that act as "highways" that speed Ucn3 on to two other sites in the brain: One, in the hypothalamus—the brain's center for hormonal regulation of basic bodily functions—oversees, among other things, substance exchange and feelings of hunger and satiety; the other is involved in regulating behavior, including levels of anxiety. Nerve cells in both these areas have special receptors for Ucn3 on their surfaces, and the protein binds to these receptors to initiate the stress response.

The researchers developed a new, finely tuned method for influencing the activity of a single gene in one area in the brain, using it to increase the amounts of Ucn3 produced in just that location. They found that heightened levels of the protein produced two different effects: The anxiety-related behavior of the mice increased, and their bodies underwent metabolic changes. With excess Ucn3, their bodies burned more sugar and fewer fatty acids, and their metabolic rates sped up. These mice began to show signs of the first stages of type 2 diabetes: A drop in muscle sensitivity to insulin delayed sugar uptake by the cells, resulting in raised sugar levels in the blood. Their pancreases then produced extra insulin to make up for the perceived deficit.

"We showed that the actions of a single gene in just one part of the brain can have profound effects on the metabolism of the whole body," says Dr. Chen. This mechanism, which appears to be a smoking gun tying stress levels to metabolic disease, might, in the future, point the way toward the treatment or prevention of a number of stress-related diseases.

Participating in the research were research students Yael Kuperman, Orna Issler, Limor Regev, Ifat Musseri, Inbal Navon, and Adi Neufeld-Cohen, along with Shosh Gil, all of the Weizmann Institute's Department of Neurobiology.

Dr. Alon Chen’s research is supported by the Nella and Leon Benoziyo Center for Neurosciences; the Carl and Micaela Einhorn-Dominic Brain Research Institute; the Croscill Home Fashions Charitable Trust; the Irwin Green Alzheimer’s Research Fund; Gerhard and Hannah Bacharach, Fort Lee, NJ; Mark Besen and the Pratt Foundation, Australia; Roberto and Renata Ruhman, Sao Paulo, Brazil; and Barry Wolfe, Woodland Hills, CA. Dr. Chen is the incumbent of the Philip Harris and Gerald Ronson Career Development Chair.

REHOVOT, ISRAEL—April 15, 2010—Weizmann Institute scientists have "trained" an electronic system to be able to predict the pleasantness of novel odors, just like a human would perceive them—turning on its head the popular notion that smell is completely personal. In research published in PLoS Computational Biology, the scientists argue that the perception of an odor's pleasantness is innately hard-wired to its molecular structure, and it is only within specific contexts that individual or cultural differences are made apparent.

These findings have important implications for automated environmental toxicity and malodor monitoring, as well as fast odor screening in the perfume industry. They also provide a critical building block for the Holy Grail of sense technology—transmitting scent digitally.

Over the last decade, electronic devices, commonly known as electronic noses, or "eNoses," have been developed to be able to detect and recognize odors. The main component of an eNose is an array of chemical sensors. As an odor passes through the eNose, its molecular features stimulate the sensors in such a way as to produce a unique electrical pattern—an "odor fingerprint"—that characterizes that specific odor. Like a sniffer dog, an eNose first needs to be trained with odor samples so as to build a database of reference. Then the instrument can recognize new samples of those odors by comparing the odor's fingerprint to those contained in its database.

But unlike humans, if eNoses are presented with a novel odor whose fingerprint has not already been recorded in their database, they are unable to classify or recognize it.

So a team of Weizmann scientists, led by Dr. Rafi Haddad, then a graduate student of Prof. Noam Sobel of the Department of Neurobiology and co-supervisor Prof. David Harel of the Department of Computer Science and Applied Mathematics, together with their colleague Abebe Medhanie of the Department of Neurobiology, and Dr. Yehudah Roth of the Edith Wolfson Medical Center in Holon, Israel, decided to approach this issue from a different perspective. Rather than train an eNose to recognize a particular odor, they trained it to estimate the odor along a particular perceptual axis. The axis they chose was odorant pleasantness. In other words, they trained their eNose to predict whether an odor would be perceived as pleasant or unpleasant, or anywhere in between.

To achieve this, the scientists first asked a group of native Israelis to rate the pleasantness of a selection of odors according to a 30-point scale ranging from "very pleasant" to "very unpleasant." From this data set, they developed an "odor pleasantness" algorithm, which they then programmed into the eNose. The scientists then got the eNose to predict the pleasantness of a completely new set of odors not contained in their database against the ratings provided by a completely different group of native Israelis. The scientists found that the eNose was able to generalize and rate the pleasantness of novel odors it never smelled before, and these ratings were about 80 percent similar to those of naive human raters who had not participated in the eNose training phase. Moreover, if the odors were simply categorized as either "pleasant" or "unpleasant," as opposed to being rated on a scale, it achieved an accuracy of 99 percent.

But these findings still don’t determine whether olfactory perception is culture-specific or not.  With this in mind, the scientists decided to test eNose predictions against a group of recent immigrants to Israel from Ethiopia. The results showed that the eNose's ability to predict the pleasantness of novel odors against the native Ethiopians' ratings was just as good, even though it was "tuned" to the pleasantness of odors as perceived by native Israelis. In other words, even though different odors may have different meanings across cultures, the eNose performed equally well across these populations. This suggests a fundamental cross-cultural similarity in odorant pleasantness.

Says Prof. Sobel: "Being able to predict whether a person who we never tested before would like a specific odorant, no matter their cultural background, provides evidence that odor pleasantness is a fundamental biological property, and that certain aspects of molecular structure are what determine whether an odor is pleasant or not." So how are cultural differences accounted for? "We believe that culture influences the perception of olfactory pleasantness mostly in particular contexts. To stress this point, some may wonder how the French can like the smell of local cheese, when many find the smell repulsive. We believe that it is not that the French think the smell is pleasant per se, they merely think it is a sign of good cheese. However, if the smell was presented out of context in a jar, then the French would probably rate the odor just as unpleasant as anyone else would."

The scientists' findings that odor perception is hard-wired to molecular structure and their design of an eNose that is able to classify new odors could provide new methods for odor screening and environmental monitoring, and may, in the future, allow for the digital transmission of smell to scent-enable movies, games, and music to provide a more immersive and captivating experience.

Prof. Noam Sobel’s research is supported by the Nella and Leon Benoziyo Center for Neurosciences; the J&R Foundation; and Regina Wachter, New York.

This research was funded by an FP7 grant from the European Research Council awarded to Noam Sobel.

REHOVOT, ISRAEL—April 6, 2010—Darwin's finches—some 14 related species of songbirds found on the Galapagos and Cocos Islands—will forever be enshrined in history for having planted the seeds of the theory of evolution through natural selection. Today, 150 years after Darwin's famous book, finches can still teach us a lesson about evolution. A large, international group of researchers, among them Prof. Doron Lancet and Dr. Tsviya Olender of the Department of Molecular Genetics at the Weizmann Institute of Science, recently produced the full genome of the zebra finch and analyzed it in detail. The report on the zebra finch genome, which appeared April 6 in Nature, is especially significant for what it reveals about learning processes for language and speech. For Prof. Lancet and Dr. Olender, however, the findings have provided an interesting twist on the evolution of the sense of smell.

Songbirds—like humans and a small number of other animals—are capable of complex, rich communication through sounds. The similarity between birdsong and human language makes birds a useful scientific model for probing how this ability developed, what neuronal mechanisms are required, and which genes encode them. Significantly, the scientific team found that a large percentage of the genes expressed in the finch brain are devoted to vocal communication. They also found that the expression levels of a number of genes, specifically those belonging to the important class of microRNAs, change after the bird is exposed to song. This implies that such genes might be involved in the birds' ability to learn new tunes.

"The senses are sophisticated means of interacting with the environment, and this is why they are so fascinating. In our lab, we are primarily interested in smell," says Dr. Olender, who joined the project, along with Prof. Lancet, in order to map the genes encoding smell receptors in the finch. In doing so, the scientists were entering the fray on a long-standing debate over whether odor sensation is active and important for birds. Some positive evidence exists: homing pigeons have been shown to use smell to help them navigate back to their coops. In contrast, a computer-aided analysis of the chicken genome had shown that out of 500 genes encoding smell receptors, a mere 70 produce active proteins. Prof. Lancet and Dr. Olender have now conducted a similar analysis of the zebra finch genome. Their findings revealed that while the finch has the same total number of smell genes as the chicken, it possesses three times as many that are active: around 200 of the finch's genes can potentially produce functional smell receptors. This figure supports the claim that some birds do rely on the sense of smell.

A comparison of the zebra finch genome to those of other bird species sheds some light on how this sense evolved in the birds: unlike mammals, in which all the different species share most of their smell receptor gene families, 95 percent of the receptors in the finches appeared to belong to families unique to them. In other words, it is possible that each bird species evolved its own array of smell receptors separately, rather than using ones passed down from a common ancestor. Says Prof. Lancet, "This finding suggests that smells may be involved in the unique communications among individuals within the species, on top of the messages they send through their songs."

Prof. Doron Lancet’s research is supported by the Helen and Martin Kimmel Center for Molecular Design and the Estate of Joe Gurwin. Prof. Lancet is the incumbent of the Ralph and Lois Silver Professorial Chair in Human Genomics.

The Weizmann Institute of Science in Rehovot, Israel, is one of the world’s top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.

REHOVOT, ISRAEL—February 4, 2010—The best way to track a moving object with a flashlight might be to aim it to one side, catching the object in the edge of the beam rather than the center. New research from the Weizmann Institute of Science reveals that bats, which "see" with beams of sound waves, skew their beams off-center when they want to locate an object. The research, which recently appeared in Science, shows that this strategy is the most efficient for locating objects.

Dr. Nachum Ulanovsky and postdoctoral fellow Dr. Yossi Yovel of the Institute's Department of Neurobiology knew that bat sonar (or echolocation) obeys the same physical laws as the sonar on a submarine: the bats (or ships) emit a sound and listen for the echo, accurately judging the type and location of objects around them by the changes in the sound waves as they are reflected back. But there's a tradeoff between detection and localization. The beam is most intense in the center, returning more information, which is good for detection; but localization is better done on the slope, where the intensity drops off as the signal spreads out, making it easier to follow movement across the beam.

Are bats able to choose the best echolocation strategy? Drs. Ulanovsky and Yovel, in collaboration with Dr. Cynthia Moss and research student Ben Falk from the University of Maryland, trained bats to locate and land—using echolocation alone—on a black sphere placed randomly in a completely dark room. A string of special microphones arrayed around the room's walls traced the bats' sound waves, while two infrared video cameras tracked their flight patterns.

The Egyptian fruit bats in Dr. Ulanovsky's lab produce their signals in pairs of clicks. The researchers identified a pattern: the first set of double clicks was aimed left, and then right, and the next set was aimed right, and then left. As the bats closed in for a landing, they continued to throw their sound beams to alternate sides of the sphere, just where a mathematical formula for sonar sensing predicted they would be most effective. As the sphere was easily detectable, the bats' optimal strategy was one of localization. To test a situation in which detection was needed as well as localization, the scientists installed a large panel behind the sphere that echoed the sound waves back to the bats' ears. Now they had to find the sphere's echo amidst conflicting signals. This time, as the bats approached their target, they began to narrow their sweep and aim the beams more or less directly toward the sphere.

Many types of sensation, from echolocation in dolphins to sniffing in dogs to movements in the human eye, are based on some sort of active sensing. Drs. Ulanovsky and Yovel believe that what works for bats may well work for other animals: "sensing on the slope" could play a role in all of these and others.

Dr. Nachum Ulanovsky’s research is supported by the Nella and Leon Benoziyo Center for Neurological Diseases; the Carl and Micaela Einhorn-Dominic Brain Research Institute; the J&R Foundation; and the A.M.N. Fund for the Promotion of Science, Culture and Arts in Israel.

REHOVOT, ISRAEL—January 21, 2010—The simple formula we’ve learned in recent years—forests remove the greenhouse gas carbon dioxide (CO₂) from the atmosphere; therefore forests prevent global warming—may not be quite as simple as we thought. Forests can directly absorb and retain heat, and, in at least one type of forest, these effects may be strong enough to cancel out a good part of the benefit in lowered CO₂. This is a conclusion of a paper that will be published January 22 in Science by scientists in the Weizmann Institute’s Faculty of Chemistry.

For the past 10 years, the Weizmann Institute has been operating a research station in the semi-arid Yatir Forest, a pine forest at the edge of the Negev Desert. This station is part of a world-wide project composed of over 400 stations, called FLUXNET, which investigates the relationship between forests, the atmosphere, and climate around the globe. The contribution of the Yatir station, says Prof. Dan Yakir of the Department of Environmental Sciences and Energy Research, is unique as it “is one of very few in the semi-arid zone, which covers over 17% of the Earth’s land surface, and it has the longest record of the processes taking place in semi-arid forests.”

Forests counteract the greenhouse effect by removing heat-trapping CO₂ from the atmosphere and storing it in living trees. Over the years of measurement, Prof. Yakir’s group has found that the semi-arid forest, even though it’s not as luxuriant as the temperate forests farther north, is a surprisingly good carbon sink — better than most European pine forests and about on par with the global average. This was unexpected news for a forest sitting at the edge of a desert, and it indicated that there is real hope for the more temperate forests if things heat up under future global climate change scenarios.

But forests do more than just store CO₂, and Prof. Yakir, together with Dr. Eyal Rotenberg, decided to look at the larger picture—the total energy budget of a semi-arid forest. The first hint they had that other processes might be counteracting the cooling effect of CO₂—how much sunlight is reflected from its surface back into space—with that of the nearby open shrub land. They found that the dark-colored forest canopy had a much lower albedo, absorbing quite a bit more of the sun’s energy than the pale, reflective surface of the surrounding areas. In a cloudless environment with high levels of solar radiation, albedo becomes an important factor in surface heating. uptake came when they compared the forest’s albedo

Next, the researchers looked at the mechanisms for “air conditioning” within the forest itself. To cool down, trees in wetter areas of the globe use water-cooled systems: They open pores in their leaves and simply let some of the water evaporate, drawing heat away in the process. But the semi-arid pine forest, with its limited water supply, is not built for evaporation. The scientists found that it uses an alternative, efficient, air-cooling system instead. As semi-arid forests are not as dense as their temperate counterparts, the air in the open spaces between the trees comes into contact with a large surface area, and heat can be easily transferred from the leaves to the air currents. This semi-arid air cooling system is quite efficient at cooling the treetops, and this cooling, in turn, leads to a reduction in infrared (thermal) radiation out into space. In other words, while the semi-arid forest can cool itself well enough to survive and take up carbon, it both absorbs more solar radiation energy (through the albedo effect) and retains more of this energy (by suppressing the emission of infrared radiation). Together, these effects turned out to be stronger than the scientists had expected. “Although the numbers vary with location and conditions,” says Prof. Yakir, “we now know it will take decades of forest growth before the ‘cooling’ CO₂ sequestration can overtake these opposing ‘warming’ processes.”

Prof. Yakir and Dr. Rotenberg then asked one more question: If planting semi-arid forests can in fact lead to warming over a good part of the forests’ life cycles, what happens when the opposite process— desertification—takes place? By applying what they had learned to existing data on areas that have turned to desert, they found that desertification, instead of hastening global warming, as is commonly thought, has actually mitigated it, at least in the short term. By reflecting sunlight and releasing infrared radiation, desertification of semi-arid lands over the past 35 years has slowed down global warming by as much as 20%, compared with the expected effect of the CO₂ rise over the same period. And in a world in which desertification is continuing at a rate of about six million hectares a year, that news might have a significant effect on how we estimate the rates and magnitude of climate change. Says Prof. Yakir, “Overall, forests remain hugely important climate stabilizers, not to mention the other ecological services they provide, but there are tradeoffs, such as those between carbon sequestration and surface radiation budgets, and we need to take these into consideration when predicting the future.”

Prof. Dan Yakir’s research is supported by the Avron-Wilstaetter Minerva Center for Research in Photosynthesis; the Sussman Family Center for the Study of Environmental Sciences; the Angel Faivovich Foundation for Ecological Research; and the Cathy Wills and Robert Lewis Program in Environmental Science.

The Weizmann Institute of Science in Rehovot, Israel, is one of the world’s top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.

REHOVOT, ISRAEL—December 7, 2009—Although bone marrow transplants have long been standard for acute leukemia, current treatments still rely on exact matches between donor and patient. Now, scientists at the University of Perugia, Italy, and the Weizmann Institute of Science have improved on a method of transplanting bone marrow-based stem cells from a mismatched donor, making it safer for use when no exact match exists. They were invited to present their findings at the recent annual American Society of Hematology conference in New Orleans.

More than a decade ago, Prof. Yair Reisner of the Weizmann Institute’s Department of Immunology pioneered a method for transplanting stem cells from family members who are a partial match. Based on these studies (in mice), he joined forces with Prof. Massimo F. Martelli, Head of the Hematology and Clinical Immunology Section at the University of Perugia, to demonstrate in more than 300 patients that the cure rate of these “mega dose” transplants is similar to that of transplants from matched, unrelated donors picked from international bone marrow donor registries. To combat the body’s tendency to reject the foreign cells, these stem cells are stripped of immune cells called T cells and given in high doses that overwhelm the host’s own immune system. Although removing donor T cells from the bone marrow reduces the risk of graft-versus-host disease – caused when the T cells attack the recipient’s tissues – the immune system is slow to recover after the transplant, leaving the patient at risk of serious infection. Doctors are faced with a difficult choice: Either remove the T cells from the bone marrow, increasing the risk of infection, or leave the T cells in the graft, putting the patient at risk for lethal graft-versus-host disease.

Prof. Martelli, working with Prof. Reisner, has now found a way to facilitate the recovery of the immune responses in recipients of T-cell-depleted bone marrow transplants. In a clinical trial, 25 of 26 leukemia and lymphoma patients who received mismatched mega-dose T-cell-depleted stem cell transplants from relatives showed prompt immune recovery, and their immune systems were functioning well several months later.

The scientists knew that certain regulatory T cells (T regs), rather than causing graft-versus-host disease, could actually help to prevent it in mice. T regs have also been shown to keep other immune responses in check, including preventing autoimmune attacks on the body’s own cells. In the present study, after purifying T regs from the donor’s blood, the cells were infused intravenously into the cancer patients, who had previously undergone standard radiation and chemotherapy treatments. Three days later, the patients received the donor stem cells, along with another kind of T cell – those that fight disease.

The patients who underwent this procedure showed quick, lasting improvements in immune activity, and most experienced no symptoms even though they received large doses of the T cells that are generally associated with lethal graft-versus-host disease.

Further follow-up on these patients and additional clinical trials will be needed before the procedure can be widely adopted, but these results strongly suggest that T regs used in mega-dose stem cells will further enhance the cure rate for bone marrow transplant patients without a matched donor in the family.

Prof. Yair Reisner’s research is supported by the M.D. Moross Institute for Cancer Research; the Kirk Center for Childhood Cancer and Immunological Disorders; the Mario Negri Institute for Pharmacological Research–Weizmann Institute of Science Exchange Program; the Gabrielle Rich Center for Transplantation Biology Research; the Russell Berrie Foundation; and Mr. and Mrs. Seymour Spira, Palm Beach Gardens, FL. Prof. Reisner is the incumbent of the Henry H. Drake Professorial Chair in Immunology.

The Weizmann Institute of Science in Rehovot, Israel, is one of the world’s top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.

REHOVOT, ISRAEL—December 3, 2009—What happens when a really gargantuan star—one hundreds of times bigger than our sun—blows up? Although a theory developed years ago describes what the explosion of such an enormous star should look like, no one had actually observed one—until now. An international team, led by scientists in Israel and including researchers from Germany, the US, the UK, and China, tracked a supernova—an exploding star—for over a year and a half, and found that it neatly fits the predictions for the explosion of a star greater than 150 times the sun's mass. Their findings, which could influence our understanding of everything from natural limits on star size to the evolution of the universe, appeared recently in Nature.

"It’s all about balance," says team leader Dr. Avishay Gal-Yam of the Weizmann Institute of Science's Department of Particle Physics and Astrophysics. "During a star's lifetime, there's a balance between the gravity that pulls its material inward and the heat produced in the nuclear reaction at its core, pushing it out. In a supernova we're familiar with, of a star 10 to 100 times the size of the sun, the nuclear reaction begins with the fusion of hydrogen into helium, as in our sun. But the fusion keeps going, producing heavier and heavier elements, until the core turns to iron. Since iron doesn't fuse easily, the reaction burns out, and the balance is lost. Gravity takes over and the star collapses inward, throwing off its outer layers in the ensuing shockwaves."

The balance in a super-giant star is different. Here, the photons (light particles) are so hot and energetic, they interact to produce pairs of particles: electrons and their opposites, positrons. In the process, particles with mass are created from the massless photons, and this consumes the star's energy. Again, things are thrown out of balance, but this time, when the star collapses, it falls in on a core of volatile oxygen, rather than iron. The hot, compressed oxygen explodes in a runaway thermonuclear reaction that obliterates the star's core, leaving behind little but glowing stardust. "Models of 'pair supernovae' had been calculated decades ago," says Dr. Gal-Yam, "but no one was sure these huge explosions really occur in nature. The new supernova we discovered fits these models very well."

An analysis of the new supernova data led the scientists to estimate the star's size at around 200 times the mass of the sun. This in itself is unusual, as observers had noted that the stars in our part of the universe seem to have a size limit of about 150 suns; some had even wondered if there was a physical constraint on a star's girth. The new findings suggest that hyper-giant stars, while rare, do exist, and that even larger stars, up to 1,000 times the size of the sun, may have existed in the early universe. "This is the first time we've been able to analyze observations of such a massive exploding star," says Dr. Paolo Mazzali of the Max Planck Institute for Astrophysics in Germany, who led the theoretical study of this object. "We were able to measure the amounts of new elements created in this explosion, including approximately five times the mass of our sun in highly radioactive, freshly synthesized nickel. Such explosions may be important factories for heavy metals in the universe."

This massive supernova was found in a tiny galaxy only a hundredth the size of our own, and the scientists think that such dwarf galaxies could be natural harbors for the giant stars, somehow enabling them to surpass the 150-sun limit.

"Our discovery and analysis of this unique explosion has given us new insights into just how massive stars can get and how these stellar giants contribute to the makeup of our universe," says Dr. Gal-Yam. "We hope to understand even more when we find additional examples from new surveys that we have recently begun to carry out, covering large, previously unexplored areas of the universe."

Dr. Avishay Gal-Yam’s research is supported by the Nella and Leon Benoziyo Center for Astrophysics; the Peter and Patricia Gruber Awards; the William Z. & Eda Bess Novick New Scientists Fund; the Legacy Heritage Fund Program of the Israel Science Foundation; and Miel de Botton Aynsley, UK.

The Weizmann Institute of Science in Rehovot, Israel, is one of the world’s top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.

NEW YORK, NY—December 1, 2009—Richard L. Stone, dedicated advocate of the American Committee for the Weizmann Institute of Science (ACWIS), has been appointed Chair of the American Committee's Palm Beach Region. In this role, Mr. Stone will spearhead efforts to recruit new supporters and increase the visibility of the Weizmann Institute of Science in Rehovot, Israel, one of the world's top-ranking multidisciplinary research institutions.

Mr. Stone succeeds Dr. Albert Willner, whose leadership over many years engendered a strong, committed presence for Weizmann in Palm Beach. In his new role as Chair, Mr. Stone will strive to heighten awareness of the important work of the Weizmann Institute. As part of this campaign, he will further involve Institute supporters in the greater Palm Beach area.

Mr. Stone, a prominent litigator, is an attorney of counsel at Kirby McInerney, LLP, in New York. Joining the firm in 1997, he has been lead counsel on several major consumer and securities class actions.  Since earning his J.D. from Columbia Law School, Mr. Stone has amassed extensive legal expertise, dating back to his earliest experience as a law clerk for the Honorable Charles P. Sifton of the United States District Court for the Eastern District of New York. In addition to practicing law, Mr. Stone teaches at the Florida State University School of Law and the Nova Southeastern School of Law.

"The American Committee is fortunate to have Richard Stone in this important leadership role," said Larry Blumberg, national Chairman, adding, "the Palm Beach Region represents a major source of support for the Weizmann Institute. Consequently, we are delighted that Richard will be leading this growing region to even greater achievements and recruiting new participants to the Weizmann Institute family."

Mr. Stone's appointment to the Chairmanship reflects his steadfast support of the Weizmann Institute of Science. He is a member of ACWIS' Executive Committee and Board of Directors and has been an American Committee Regional Board member and served as a Co-Chair of both the 2008 and 2009 annual Palm Beach Region "Focus on the Future" dinners. Earlier this year, Mr. Stone and his family visited the Weizmann Institute.

In addition to his involvement with the Weizmann Institute, Mr. Stone is a member of the Board of Trustees of Junior Achievement of the Palm Beaches and founder of Supporters for the Pre-law Magnet, a non-profit that supports and teaches pre-law programs at local high schools. Mr. Stone has also served on the board of numerous Jewish charities in Palm Beach County.

The American Committee for the Weizmann Institute of Science is a community of dedicated people who share a common vision in support of the Institute. The generous assistance the Institute receives from individuals, foundations, and corporations is vital for its future. Committee members show their devotion to the advancement of the Institute’s goals by becoming partners in the search for answers to the most difficult challenges facing humanity.

October 7, 2009—The American Committee for the Weizmann Institute of Science congratulates Prof. Ada Yonath on receiving the 2009 Nobel Prize in Chemistry and is proud of her scientific achievements. We are delighted that the Nobel Committee for Chemistry has recognized the significance of Prof. Yonath's scientific research and awarded her this important prize.

Prof. Yonath's research is driven by curiosity and ambition to better understand the world and our place within it. This research aims high: to understand one of the most complicated "machines" of the biological system.

The announcement of the award is especially meaningful to and joyous for the American Committee for the Weizmann Institute. One of the Committee's most prominent leaders, Mrs. Helen Kimmel, together with her late husband, Martin, provided major funding for Prof. Yonath's research for more than 20 years. Prof. Yonath is the Martin S. and Helen Kimmel Professor of Structural Biology; her research is supported by the Helen and Milton A. Kimmelman Center for Biomolecular Structure and Assembly. The special friendship developed between Prof. Yonath and Mrs. Kimmel over the years symbolizes the Weizmann partnership between science and philanthropy.

In the late 1970s, Prof. Yonath decided, when she was a young student at the Weizmann Institute, to take on the challenge of answering one of the key questions concerning the activities of live cells: to decipher the structure and mechanism of action of ribosomes—the cell's protein factories. This was the beginning of a long scientific journey that has lasted decades, and required courage and devotion from the start. The journey began in a modest laboratory with a modest budget, and over the years increased to tens of researchers working under Prof. Yonath's guidance.

This basic research, which began in an attempt to understand one of the principles of nature, eventually led to an understanding of how a number of antibiotics function, something that is likely to aid in the development of more advanced and effective antibiotics. This discovery will hopefully also help in the struggle against antibiotic-resistant bacteria, a problem recognized as one of the most central medical challenges of the 21st century.

Prof. Yonath can be considered a model of scientific vision for her courage in choosing a significant scientific question and devotion in realizing the goal to its end, which will hopefully broaden knowledge for the benefit of humanity.

BEYOND THE BASICS
"People called me a dreamer," says Prof. Ada Yonath of the Structural Biology Department, recalling her decision to undertake research on ribosomes—the cell's protein factories. Solving the ribosome's structure would give scientists unprecedented insight into how the genetic code is translated into proteins; by the late 1970s, however, top scientific teams around the world had already tried and failed to get these complex structures of protein and RNA to take on a crystalline form that could be studied. Dreamer or not, it was hard work that brought results: Prof. Yonath and her colleagues made a staggering 25,000 attempts before they succeeded in creating the first ribosome crystals in 1980.

And their work was just beginning. Over the next 20 years, Prof. Yonath and her colleagues would continue to improve their technique. In 2000, teams at the Weizmann Institute and the Max Planck Institute in Hamburg, Germany—both headed by Prof. Yonath—solved, for the first time, the complete spatial structure of both subunits of a bacterial ribosome. Science magazine counted this achievement among the ten most important scientific developments of that year. The next year, Prof. Yonath's teams revealed exactly how certain antibiotics are able to eliminate pathogenic bacteria by binding to their ribosomes, preventing them from producing crucial proteins.

Prof. Yonath's studies, which have stimulated intensive research worldwide, have now gone beyond the basic structure. She has revealed in detail how the genetic information is decoded, how the ribosome's inherent flexibility contributes to antibiotic selectivity, and the secrets of cross-resistance to various antibiotic families. Her findings are crucial for developing advanced antibiotics.

Prof. Ada Yonath's research is supported by the Helen and Milton A. Kimmelman Center for Biomolecular Structure and Assembly. Prof. Yonath is the Martin S. and Helen Kimmel Professor of Structural Biology.

The Weizmann Institute of Science in Rehovot, Israel, is one of the world’s top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.

REHOVOT, ISRAEL—November 9, 2009—From Proust’s madeleines to the overbearing food critic in the movie Ratatouille who is transported back to his childhood at the aroma of stew, artists have long been aware that some odors can spontaneously evoke strong memories. Scientists at the Weizmann Institute of Science have now revealed the scientific basis of this connection. Their research appears in the latest issue of Current Biology.

Graduate student Yaara Yeshurun, together with Profs. Noam Sobel and Yadin Dudai of the Institute’s Department of Neurobiology, thought that the key might not necessarily lie in childhood, but rather in the first time a smell is encountered in the context of a particular object or event. In other words, the initial association of a smell with an experience will somehow leave a unique and lasting impression in the brain.

To test this idea, the scientists devised an experiment: First, in a special smell laboratory, subjects viewed images of 60 objects, each presented simultaneously with either a pleasant or an unpleasant odor generated in a machine called an olfactometer. Next, the subjects were put in a functional magnetic resonance imaging (fMRI) scanner to measure their brain activity as they reviewed the images they’d seen and attempted to remember which odor was associated with each. Then, the whole test was repeated—images, odors, and fMRI—with the same images, but different odors accompanying each. Finally, the subjects came back one week later, to be scanned in the fMRI again. They viewed the objects one more time and were asked to recall the odors they associated with them.

The scientists found that after one week, even if the subject recalled both odors equally, the first association revealed a distinctive pattern of brain activity. The effect was seen whether the smell was pleasant or unpleasant. This unique representation showed up in the hippocampus, a brain structure involved in memory, and in the amygdala, a brain structure involved in emotion. The pattern was so profound, it enabled the scientists to predict which associations would be remembered just by looking at the brain activity within these regions following the initial exposure. The scientists could look at the fMRI data on the first day of the experiment and predict which associations would come up a week later. To see if other sensory experiences might share this tendency, the scientists repeated the entire experiment using sounds rather than smells; they found that sounds did not arouse a similar distinctive first-time pattern of activity. In other words, these results were specific to the sense of smell. “For some reason, the first association with smell gets etched into memory,” says Prof. Sobel, “and this phenomenon allowed us to predict what would be remembered one week later based on brain activity alone.”

Adds Ms. Yeshurun: “As far as we know, this phenomenon is unique to smell. Childhood olfactory memories may be special not because childhood is special, but simply because those years may be the first time we associate something with an odor.”

Prof. Noam Sobel’s research is supported by the Nella and Leon Benoziyo Center for Neurosciences; the J&R Foundation; the Eisenberg-Keefer Fund for New Scientists; and Regina Wachter, New York, NY.

The Weizmann Institute of Science in Rehovot, Israel, is one of the world’s top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.

November 6, 2009—The Weizmann Institute of Science in Rehovot, Israel, ranked second among the top international academic institutions on The Scientist magazine’s annual survey of “Best Places to Work in Academia.” In both 2005 and 2008, the Weizmann Institute of Science was ranked as the top international academic institution (outside the United States) by survey respondents.

The survey, published in the November issue of The Scientist, reviewed the entries of more than 2,350 qualified respondents. Survey respondents represented 119 institutions: 94 from the U.S. and 25 from abroad. The respondents were asked to assess their working environment by indicating their level of agreement with 38 criteria in eight different areas, while also specifying how important each factor was to them. Research resources, pay, peers, job satisfaction, and tenure and promotion were among the eight categories included in the survey.

Princeton University was ranked the best place to work in academia in the U.S. and the Max Planck Institute of Molecular Cell Biology and Genetics was ranked the top international academic institution. The magazine determined that, overall, respondents focused on collaboration, team building, and unique funding opportunities as important work environment factors.

The Scientist magazine provides coverage of the latest developments in the life sciences. This year’s survey results, as well as in-depth analysis, full-color charts, methodology, and past survey results can be viewed at www.the-scientist.com/bptw.

The Weizmann Institute of Science, noted for its wide-ranging exploration of the natural and exact sciences, is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.

The American Committee for the Weizmann Institute of Science is a community of dedicated people who share a common vision in support of the Institute. The generous assistance the Institute receives from individuals, foundations, and corporations is vital for its future. Committee members show their devotion to the advancement of the Institute’s goals by becoming partners in the search for answers to the most difficult challenges facing humanity.

NEW YORK, NY—September 17, 2009—Ellen Merlo of New York has been appointed Chair of the New York Region’s Executive Committee of the American Committee for the Weizmann Institute of Science. Ms. Merlo has been a longtime supporter and advocate of the Weizmann Institute of Science–one of the world’s top-ranking multidisciplinary research institutions, located in Rehovot, Israel.

As part of her philanthropic leadership appointment, Ms. Merlo will direct efforts to raise awareness and expand the reach of the Weizmann Institute of Science, while also championing the Institute’s crucial work to address the biggest challenges facing humanity. She will aim to further involve current New York supporters and recruit new supporters. Ms. Merlo will succeed Bruce Pollack, who served as Chair of the New York Region’s Executive Committee for four years.

Throughout her 33 years of employment with Philip Morris USA (PMUSA), Ms. Merlo held a variety of positions, including Vice President of Marketing Services, where she was responsible for Marketing Programs such as Event Sponsorship and Database Development. She also served as a Director of Brand Management.

Prior to her retirement in 2003, Ms. Merlo was Senior Vice President of Corporate Affairs at PMUSA. She directed internal and external communications; public affairs activities; corporate responsibility planning and programs; and consumer affairs and community relations, including charitable grants on behalf of the company. She also served as senior spokesperson.

"Ellen Merlo is among the American Committee’s most devoted and active leaders," Larry Blumberg, national Chairman of the organization, said. "I am delighted that she has agreed to lead the New York Region. Ellen’s passion for the Weizmann Institute is contagious, and her ability to communicate the importance of our mission is so valuable as we seek to expand our circle of supporters in New York and beyond."

Her appointment to the leadership position recognizes Ms. Merlo’s long-standing dedication to the Weizmann Institute of Science. She has been a New York Regional Executive Committee member, a member of the American Committee’s Board of Directors and its Executive Committee, and has been nominated as a member of the International Board of Governors of the Weizmann Institute of Science. Ms. Merlo also recently chaired a national task force for the American Committee on positioning and visibility, and at the 2009 Global Gathering in Los Angeles, she was inducted into the prestigious President’s Circle. Since her retirement, Ms. Merlo has taken on active roles in other philanthropic organizations as well, including serving as Vice President of the Baron de Hirsch Fund, and heading up her own charitable foundation, the Pearl Welinsky Merlo Foundation.

The American Committee for the Weizmann Institute of Science (ACWIS), founded in 1944, develops philanthropic support for the Weizmann Institute of Science in Rehovot, Israel, one of the world's premier scientific research institutions. The Weizmann Institute is a center of multidisciplinary scientific research and graduate study, addressing crucial problems in medicine and health, technology, energy, agriculture, and the environment. For additional information, please visit www.weizmann-usa.org.

REHOVOT, ISRAEL—September 10, 2009—Why are some pediatric cancers able to spontaneously regress? Prof. Michael Fainzilber and his team in the Weizmann Institute’s Biological Chemistry Department seem to have unexpectedly found part of the answer. Further research toward a better understanding of the mechanism of action might hopefully lead, in the future, to the development of drugs that will be able to induce regression of certain tumors.

TrkA is a particular cell receptor well known for its "pro-life advocacies": when nerve growth factor proteins bind to TrkA receptors, it activates the receptors into promoting the growth and survival of neurons.

So when Fainzilber, together with Ph.D. student Liraz Harel, postdoctoral student Dr. Barbara Costa, technician Zehava Levy, and former Ph.D. student Dr. Marianna Tcherpakov carried out screening tests to identify other molecules involved in this signaling cascade, it took them by surprise to learn that TrkA may not be who it seems. They found that if TrkA teams up with another molecule called CCM2 — the newly identified player in this signaling cascade — they become "partners in crime," with TrkA turning into a cell killer.

However, though paradoxical, this atypical behavior may actually be rooting for life after all. This idea comes from findings concerning pediatric tumors of neural origin; specifically, medulloblastoma — the most common malignant brain tumor and the second most common malignancy among children less than 20 years of age, and neuroblastoma — the most common extracranial solid cancer in childhood.

Neuroblastoma displays unusual behavior, being one of the few human malignancies known to demonstrate spontaneous regression in some cases, but nobody knows how or why. Studies have shown that the tumors with positive prognosis usually express TrkA, while aggressive forms of the tumor do not. However, how TrkA induces tumor regression is yet unknown and the mechanism was an enigma.

What if CCM2 was the missing piece to the tumor regression puzzle? Together with a group of scientists in Germany who were conducting a large-scale gene expression study in tumors from neuroblastoma patients, they checked the expression levels of CCM2 and TrkA from the patient samples collected. The results were clear-cut: TrkA and CCM2 were always expressed together in certain tumors — those that showed the highest incidences of regression and patient survival.

The scientists confirmed their results by blocking the expression of either TrkA or CCM2 in some cells, which resulted in cell survival. On the other hand, by introducing CCM2 to cells lacking it, cell death was induced if TrkA was also present, suggesting that this mechanism could lead to tumor regression.

This research, recently published in Neuron, is one of the first to elucidate this paradoxical "pro-cell death" behavior of TrkA and the first to identify CCM2 as a crucial accessory in this particular pathway, as well as describing in detail just how these two molecules interact.

Prof. Michael Fainzilber’s research is supported by the M.D. Moross Institute for Cancer Research; the Dr. Miriam and Sheldon G. Adelson Medical Research Foundation; the Helen and Martin Kimmel Institute for Stem Cell Research; the Irving B. Harris Foundation; and Mr. and Mrs. Michael Salzberg, Bethesda, MD. Prof. Fainzilber is the incumbent of the Chaya Professorial Chair for Molecular Neuroscience.

The Weizmann Institute of Science in Rehovot, Israel, is one of the world’s top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.

REHOVOT, ISRAEL—September 7, 2009—Eleven young women scientists, who completed their Ph.D. studies with honors at various academic institutions throughout Israel, will each receive an award of between $15–25,000 a year, for two years.

The award ceremony will take place on September 14, 2009, in the Schmidt Lecture Hall at the Weizmann Institute of Science. These awards, which have been granted within the framework of the Weizmann Institute’s National Postdoctoral Award Program for Advancing Women in Science, is intended to help young women conduct postdoctoral studies at leading universities abroad, assisting them in pursuing a career in the sciences: natural (physics, chemistry, and the life sciences) or exact (mathematics and computer science). The goal of the program is to begin closing the gap between the numbers of male and female scientists in the highest ranks of academia.

Recipients of the awards are selected by a special Feinberg Graduate School committee, headed by the Weizmann Institute President’s Adviser for Advancing Women in Science, Prof. Adi Kimchi.

Five of this year’s recipients completed their doctoral studies at the Hebrew University of Jerusalem, three at the Weizmann Institute of Science, two at the Technion – Israel Institute of Technology, and one at Tel Aviv University.

The program, now in its third year, is aimed at helping young women scientists to overcome the main bottleneck in their professional advancement – conducting postdoctoral studies abroad. The award provides various incentives – economic, as well as social and professional – and helps to alleviate the pressure on women, especially those who are married with young children, by financing their studies abroad for two years.

The ultimate goal of the award is to encourage women who are interested in pursuing a scientific career in Israel, with the intention of producing a future cadre of women leaders within Israeli research establishments.

The program is supported by the Clore Israel Foundation; the Feder Family Philanthropic Fund; the Pearl Welinsky Merlo Foundation; the Charles H. Revson Foundation; the Mike Rosenbloom Foundation; the Rueff-Wormser Postdoctoral Award; the Rowland and Sylvia Schaefer Foundation; the Fredda Weiss Foundation; Janine Gordon, New York, NY; Arlyn Imberman, New York, NY; Meryl Jaffe and Adam Hurwich, New York, NY; and Karen Siem, London.

The Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.

REHOVOT, ISRAEL—August 3, 2009—Biomolecular computers, made of DNA and other biological molecules, only exist today in a few specialized labs, remote from the regular computer user. Nonetheless, Tom Ran and Shai Kaplan, research students in the lab of Prof. Ehud Shapiro of the Weizmann Institute’s Biological Chemistry, and Computer Science and Applied Mathematics Departments have found a way to make these microscopic computing devices “user friendly,” even while performing complex computations and answering complicated queries.

Shapiro and his team at Weizmann introduced the first autonomous programmable DNA computing device in 2001. So small that a trillion fit in a drop of water, that device was able to perform such simple calculations as checking a list of 0s and 1s to determine if there was an even number of 1s. A newer version of the device, created in 2004, detected cancer in a test tube and released a molecule to destroy it. Besides the tantalizing possibility that such biology-based devices could one day be injected into the body - a sort of "doctor in a cell" locating disease and preventing its spread - biomolecular computers could conceivably perform millions of calculations in parallel.

Now, Shapiro and his team, in a paper published online today in Nature Nanotechnology, have devised an advanced program for biomolecular computers that enables them to “think” logically. The train of deduction used by this futuristic device is remarkably familiar. It was first proposed by Aristotle over 2000 years ago as a simple if…then proposition: “All men are mortal. Socrates is a man. Therefore, Socrates is mortal.” When fed a rule (All men are mortal) and a fact (Socrates is a man), the computer answered the question “Is Socrates Mortal?” correctly. The team went on to set up more complicated queries involving multiple rules and facts, and the DNA computing devices were able to deduce the correct answers every time.

At the same time, the team created a compiler - a program for bridging between a high-level computer programming language and DNA computing code. Upon compiling, the query could be typed in something like this: Mortal(Socrates)?. To compute the answer, various strands of DNA representing the rules, facts and queries were assembled by a robotic system and searched for a fit in a hierarchical process. The answer was encoded in a flash of green light: Some of the strands had a biological version of a flashlight signal - they were equipped with a naturally glowing fluorescent molecule bound to a second protein which keeps the light covered. A specialized enzyme, attracted to the site of the correct answer, removed the “cover” and let the light shine. The tiny water drops containing the biomolecular data-bases were able to answer very intricate queries, and they lit up in a combination of colors representing the complex answers.

Prof. Ehud Shapiro’s research is supported by the Clore Center for Biological Physics; the Arie and Ida Crown Memorial Charitable Fund; the Phyllis and Joseph Gurwin Fund for Scientific Advancement; Sally Leafman Appelbaum, Scottsdale, AZ; the Carolito Stiftung, Switzerland; the Louis Chor Memorial Trust Fund; and Miel de Botton Aynsley, UK. Prof. Shapiro is the incumbent of the Harry Weinrebe Chair of Computer Science and Biology.

The Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.

REHOVOT, ISRAEL— July 6, 2009—Baroness Ariane de Rothschild was at the Weizmann Institute yesterday to get a first-hand report on a one-of-a-kind program for promoting excellence in science and math education, which is supported by the Rothschild-Caesarea Foundation. She first met with Institute President Prof. Daniel Zajfman, who filled her in on the history of the Weizmann Institute and the vision of its founder, Dr. Chaim Weizmann, the first President of the State of Israel and of the Weizmann Institute, as well as on the Israel’s present-day place on the forefront of global science. Vice President for Resource Development and Dean for Educational Activities Prof. Israel Bar-Joseph then spoke to her on the Rothschild-Weizmann Program for Excellence in Science Teaching and its goal of creating an elite corps of science teachers to lead the way in transforming the field. The Baroness de Rothschild expressed particular interest in the criteria for acceptance to the program and the quality of the teachers participating, pointing out that the educational ills the program was designed to address are worldwide problems. She then met with the scientific directors of the program, head of the Weizmann Institute’s Science Teaching Department Prof. Bat-Sheva Eylon and Prof. Shimon Levit, as well as five of the program’s participants.

Born in San Salvador and raised in Latin America and Africa, Baroness Ariane de Rothschild, a French and German citizen, has over 20 years of finance and banking experience. She now holds various board positions in Geneva and in Paris with the LCF Rothschild Group, as well as serving as chairwoman of BeCitizen, an advisory company in structured finance and fund management for the environment sector. In addition, she devotes much of her time to the Edmond and Benjamin de Rothschild Foundations, in which her personal interests mesh with the family’s commitment to education and philanthropic innovation in the arts and culture, medical research, environment, women’s empowerment, intercultural dialogue, and social entrepreneurship.

The Rothschild-Weizmann Program for Excellence in Science Teaching, which began operating at the Weizmann Institute last year, grants master’s degrees to outstanding science and math teachers in middle and high schools. For those who already have advanced science degrees, the program also offers a track in developing educational initiatives, which combines practical experience with scientific research. The prestigious Rothschild-Weizmann Program deepens and broadens the teachers’ scientific knowledge, familiarizes them with the newest approaches to science education, introduces them to research in the field of science teaching, and provides them with experience in leading original educational initiatives. Participants in the program receive study grants and an exemption from tuition, and they continue to teach in parallel to their studies. The first 50 teachers to join the program are now finishing their first year of studies.

The Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.

NEW YORK, NY—June 25, 2009—Dedicated advocate of the American Committee for the Weizmann Institute of Science, John L. Schwartz, M.D., has been appointed Chair of the Southern California Region’s Board of Directors. In his new philanthropic leadership role, Dr. Schwartz will head efforts to enlist new supporters and raise awareness of the Weizmann Institute of Science — one of the world’s foremost centers of science and technology research, located in Rehovot, Israel.

Dr. Schwartz will promote the important work of the Weizmann Institute. He seeks to further engage the vibrant Southern California area, one of the American Committee’s most active and key regions in the U.S. He succeeds Lon Morton of Calabasas.

Dr. Schwartz is a board-certified physician and “serial” entrepreneur. He was founder and CEO of Continuing Medical Education (CME) Inc., and it was under his stewardship that the company became the largest proprietary provider of clinical information for U.S. healthcare providers. In 2004, five years after selling CME, he co-founded the Value Investing Congress, which provides high-quality, practical information on investing to hedge fund managers and ultra high-net-worth investors.

“We are delighted to have Dr. Schwartz at the helm of one of the most important regional areas for the American Committee,” Larry Blumberg, National Chairman, said. “Working closely with the Southern California volunteer leadership and with Janis Rabin, Executive Director of the region, we know that his passionate commitment to the Weizmann Institute will help us reach even greater heights of success in Los Angeles and beyond.”

Dr. Schwartz’s appointment to the chairmanship follows years of support of the Weizmann Institute of Science: a member of the American Committee Board of Directors, Executive Committee, and the Weizmann Institute’s International Board of Governors, he served as Chair of the Global Gathering Gala — the highlight of the American Committee’s yearly national event. He and his wife, Vera, are also members of the prestigious President’s Circle. Dr. Schwartz is a devoted husband, father, and grandfather. He resides in Pacific Palisades.

The American Committee for the Weizmann Institute of Science (ACWIS), founded in 1944, develops philanthropic support for the Weizmann Institute of Science in Rehovot, Israel, one of the world's premier scientific research institutions. The Weizmann Institute is a center of multidisciplinary scientific research and graduate study, addressing crucial problems in medicine and health, technology, energy, agriculture, and the environment. For additional information, please visit www.weizmann-usa.org.

REHOVOT, ISRAEL—June 17, 2009—Bacteria can anticipate a future event and prepare for it, according to new research at the Weizmann Institute of Science. In a paper that appeared in the June 17, 2009 issue of Nature, Prof. Yitzhak Pilpel, doctoral student Amir Mitchell, and research associate Dr. Orna Dahan of the Institute’s Molecular Genetics Department, together with Prof. Martin Kupiec and Gal Romano of Tel Aviv University, examined microorganisms living in environments that change in predictable ways. Their findings show that these microorganisms’ genetic networks are hard-wired to “foresee” what comes next in the sequence of events and begin responding to the new state of affairs before its onset.

E. coli bacteria, for instance, which normally cruise harmlessly down the digestive tract, encounter a number of different environments on their way. In particular, they find that one type of sugar — lactose — is invariably followed by a second sugar — maltose — soon afterward. Pilpel and his team in the Molecular Genetics Department checked the bacteria’s genetic response to lactose and found that, in addition to the genes that enable it to digest lactose, the gene network for utilizing maltose was partially activated. When they switched the order of the sugars, giving the bacteria maltose first, there was no corresponding activation of lactose genes, implying that bacteria have naturally “learned” to get ready for a serving of maltose after a lactose appetizer.

Another microorganism that experiences consistent changes is wine yeast. As fermentation progresses, sugar and acidity levels change, alcohol levels rise, and the yeast’s environment heats up. Although the system was somewhat more complicated than that of E. coli, the scientists found that when the wine yeast feel the heat, they begin activating genes for dealing with the stresses of the next stage. Further analysis showed that this anticipation and early response is an evolutionary adaptation that increases the organism’s chances of survival.

Ivan Pavlov first demonstrated this type of adaptive anticipation, known as a conditioned response, in dogs in the 1890s. He trained the dogs to salivate in response to a stimulus by repeatedly ringing a bell before giving them food. In the microorganisms, says Pilpel, “evolution over many generations replaces conditioned learning, but the end result is similar.” “In both evolution and learning,” says Mitchell, “the organism adapts its responses to environmental cues, improving its ability to survive.” Romano: “This is not a generalized stress response, but one that is precisely geared to an anticipated event.” To see whether the microorganisms were truly exhibiting a conditioned response, Pilpel and Mitchell devised a further test for the E. coli based on another of Pavlov’s experiments. When Pavlov stopped giving the dogs food after ringing the bell, the conditioned response faded until they eventually ceased salivating at its sound. The scientists did something similar, using bacteria grown by Dr. Erez Dekel, in the lab of Prof. Uri Alon of the Weizmann Institute’s Molecular Cell Biology Department, in an environment containing the first sugar, lactose, but not following it up with maltose. After several months, the bacteria had evolved to stop activating their maltose genes at the taste of lactose, only turning them on when maltose was actually available.

“This showed us that there is a cost to advanced preparation, but that the benefits to the organism outweigh the costs in the right circumstances,” says Pilpel. What are those circumstances? Based on the experimental evidence, the research team created a sort of cost/benefit model to predict the types of situations in which an organism could increase its chances of survival by evolving to anticipate future events. The researchers are already planning a number of new tests for their model, as well as different avenues of experimentation based on the insights they have gained.

Pilpel and his team believe that genetic conditioned response may be a widespread means of evolutionary adaptation that enhances survival in many organisms — one that may also take place in the cells of higher organisms, including humans. These findings could have practical implications, as well. Genetically engineered microorganisms for fermenting plant materials to produce biofuels, for example, might work more efficiently if they gained the genetic ability to prepare themselves for the next step in the process.

Prof. Yitzhak Pilpel’s research is supported by the Ben May Charitable Trust and Madame Huguette Nazez, Paris, France.

The Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.

REHOVOT, ISRAEL—May 31, 2009—Prof. Katzir passed away yesterday, Saturday, May 30, 2009, at his home in the Weizmann Institute of Science. He was 93.

Professor Ephraim Katzir, fourth President of Israel and one of the founding faculty members of the Weizmann Institute of Science, was born in Kiev, the Ukraine, in 1916. His parents, Yehuda and Tsila Katchalski, brought him to British-ruled Palestine in 1922. Following high school in Jerusalem, he enrolled in the Hebrew University of Jerusalem where he studied botany, zoology and bacteriology before finally concentrating on biochemistry and organic chemistry. In 1941, he completed his Ph.D. thesis on simple synthetic polymers of amino acids and continued his education at the Polytechnic Institute of Brooklyn, Columbia University and Harvard University.

While studying in Jerusalem he participated in the first non-commissioned officers’ course given by the underground Haganah. Later, Katzir became deeply involved in the Israel Army’s Science Corps, Hemed, founded at the start of the 1948 War of Independence, and for a time commanded it as a lieutenant colonel.

At the war’s end, in 1949, Katzir and his brother Aharon, also a scientist, joined the Weizmann Institute. Ephraim founded and headed the Biophysics Department, while Aharon headed the Polymer Research Department until his tragic death at the hands of terrorists at Ben-Gurion Airport in 1972.

Ephraim Katzir’s initial research centered on polyamino acids – synthetic models that facilitate the study of proteins. His pioneering studies contributed to the deciphering of the genetic code, the production of synthetic antigens and the clarification of the various steps of immune responses. The understanding of polyamino acid properties led, among other things, to Weizmann scientists’ development of Copaxone, a drug used worldwide for the treatment of multiple sclerosis.

Another major success was in immobilizing enzymes. Katzir developed a method for binding enzymes, which speed up numerous chemical processes, to a variety of surfaces and molecules. The method laid the foundations for what is now called enzyme engineering, which plays an important part in the food and pharmaceutical industries. For example, it is used to produce fructose-enriched corn syrup and semi-synthetic penicillins.

Along with his scientific research, Professor Katzir was profoundly involved in the social and educational aspects of science. He headed a governmental committee for the formulation of a national scientific policy, trained a generation of younger scientists, translated important material into Hebrew and helped to establish a popular science magazine. He served as Chief Scientist of the Israel Defense Ministry and Chairman of the Society for the Advancement of Science in Israel, the Israel Biochemical Society, the National Council for Research and Development and the Council for the Advancement of Science Education. He headed the National Biotechnology Council and was President of the World ORT Union.

In 1973, Katzir was elected fourth President of the State of Israel, a position he held until 1978. (It was upon becoming President that he changed his last name from Katchalski to Katzir.) During his term he paid special attention to the problems of society and education and was consistently concerned with learning more about all sectors of the population.

Upon completing his term of office, he returned to research at the Weizmann Institute and was named Institute Professor, a prestigious title awarded by Weizmann faculty and administration to outstanding scientists who made significant and meaningful contributions to science or to the State of Israel. He also devoted himself to the promotion of biotechnological research in Israel and founded the Department of Biotechnology at Tel Aviv University. The creation of this department was a continuation of his previous efforts to establish science-based industries in Israel: he had helped create several companies based on the fruits of scientific research.

In the later years of his scientific career Prof. Katzir turned to new areas of research. In one project, he headed a team of Weizmann scientists that won an international contest for computer modeling of proteins. In another study, he was part of an interdisciplinary Institute team that revealed an important aspect of snake venom’s effects on the body.

Katzir authored hundreds of scientific papers and served on the editorial and advisory boards of numerous scientific journals. International scientific symposia were held in Rehovot and Jerusalem to celebrate his 60th, 70th and 80th birthdays.

Prof. Katzir was a member of the Israeli Academy of Sciences and Humanities and of numerous other learned bodies in Israel and abroad, including The Royal Institution of Great Britain, The Royal Society of London, the National Academy of Sciences of the United States, the Academie des Sciences in France, the Scientific Academy of Argentine and the World Academy of Art and Science. He was visiting professor at Harvard University, Rockefeller University, University of California at Los Angeles and Battelle Seattle Research Center.

In addition, Katzir was awarded the Rothschild and Israel Prizes in Natural Sciences, the Weizmann Prize, the Linderstrom Land Gold Medal, the Hans Krebs Medal, the Tchernikhovski Prize for scientific translations, the Alpha Omega Achievement Medal and the Engineering Foundation’s International Award in Enzyme Engineering. He was the first recipient of the Japan Prize and was appointed to France’s Order of Legion of Honor. He received honorary doctorates from more than a dozen institutions of higher learning in Israel and around the world, including Harvard University, Northwestern University, McGill University, University of Oxford and the Technion-Israel Institute of Technology.

The magazine Annual Reviews quoted Katzir thus: “I have had the opportunity to devote much of my life to science. Yet my participation over the years in activities outside science has taught me there is life beyond the laboratory. I have come to understand that if we hope to build a better world, we must be guided by the universal human values that emphasize the kinship of the human race: the sanctity of human life and freedom, peace between nations, honesty and truthfulness, regard for the rights of others, and love of one’s fellows.”

The Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.

NEW YORK, NY—May 19, 2009—The American Committee for the Weizmann Institute of Science was recognized as a Bronze Winner by the 29th Annual Telly Awards. This is the second Telly, one of the most recognized awards for video and film productions, won by the American Committee in the past three years. The award was presented to a film shown at the 2008 New York Gala entitled, Dor L’ Dor: Honoring the Generations. The film pays tribute to and serves as a lasting legacy for three families’ multigenerational philanthropic support of the Weizmann Institute of Science. Funding for this film, in addition to previous ones, was granted to the American Committee by Arlyn Imberman, who served as producer.

Ms. Imberman, a member of the Weizmann President’s Circle and a renowned graphologist, has provided funding to the American Committee for the past three years to support the production of films that accentuate the significance and benevolence of supporting research at the Weizmann Institute. The films have been screened annually at the New York Region Gala dinner, and are also viewed by Weizmann Institute supporters across the country.

“We are proud that Arlyn Imberman’s creative vision has been recognized with two prestigious Telly awards,” Marshall S. Levin, Executive Vice President and CEO of the American Committee, said. “It was Arlyn’s goal to share the core philanthropic values and beliefs of Weizmann Institute supporters with a larger audience, and we have achieved that by producing these poignant videos. We are grateful for her generous support and creative guidance.”

The Dor L’ Dor film is a 7-minute discourse with three families who have made supporting the Weizmann Institute a priority over several generations. In the film, the Blumberg, Pickman, and Gurwin families explain their enthusiasm for the Weizmann Institute’s cutting-edge multidisciplinary research, talented scientists, and pursuit to solve some of the most difficult challenges facing humanity. Each family also addresses the value of philanthropy and the importance of passing down the dedication to philanthropic activities, including a commitment to supporting Weizmann, from one generation to the next.

A similar film, also produced by Ms. Imberman, was previously recognized with a Silver Telly, the top honor. The 29th Annual Telly Awards was one of the most competitive thus far, with 13,500 entries from all 50 states and countries around the world. The Telly Awards is the premier award honoring outstanding local, regional, and cable TV commercials and programs; the finest film and video productions; and groundbreaking web commercials, video, and film. More than 40 accomplished industry professionals, each a past Silver Winner, compose the prestigious Telly Awards judging panel. Entries do not compete against each other; instead, each entry is individually judged against a high standard of merit.

The winning films were created for the American Committee by Twenty-Two Productions, an award-winning New York City-based film production company, led by Dean Silvers and Marlen Hecht.

The American Committee for the Weizmann Institute of Science (ACWIS), founded in 1944, develops philanthropic support for the Weizmann Institute of Science in Rehovot, Israel, one of the world's premier scientific research institutions. The Weizmann Institute is a center of multidisciplinary scientific research and graduate study, addressing crucial problems in medicine and health, technology, energy, agriculture, and the environment. For additional information, please visit www.weizmann-usa.org.

Stopgap DNA Repair Needs a Second Step

One can have a dream, two can make that dream so real, goes a popular song. Now a Weizmann Institute study has revealed that it takes two to perform an essential form of DNA repair.

Prof. Zvi Livneh of the Weizmann Institute’s Biological Chemistry Department has been studying DNA repair for some two decades: “Considering that the DNA of each cell is damaged about 20,000 times a day by radiation, pollutants, and harmful chemicals produced within the body, it’s obvious that without effective DNA repair, life as we know it could not exist. Most types of damage result in individual mutations – genetic ‘spelling mistakes’ – that are corrected by precise, error-free repair enzymes. Sometimes, however, damage results in more than a mere spelling mistake; it can cause gaps in the DNA, which prevent the DNA molecule from being copied when the cell divides, much like an ink blot or a hole on a book page interferes with reading. So dangerous are these gaps that the cell resorts to a sloppy but efficient repair technique to avoid them: it fills in the missing DNA in an inaccurate fashion. Such repair can save the cell from dying, but it comes at a price: this error-prone mechanism, discovered at the Weizmann Institute and elsewhere about a decade ago, is a major source of mutations.”

In a recent study he conducted with graduate students Sigal Shachar and Omer Ziv, as well as researchers from the US and Germany, Livneh revealed how the error-prone repair works. The team found that such repair proceeds in two steps and requires two types of enzymes, belonging to the family of enzymes called DNA polymerases, which synthesize DNA. First, one repair enzyme, “the inserter,” does its best to fit a genetic “letter” into the gap, opposite the damaged site in the DNA molecule; several enzymes can perform this initial step, which often results in the insertion of an incorrect genetic letter. Next, another enzyme, “the extender,” helps to restore regular copying of DNA by attaching additional DNA letters after the damaged site; only one repair enzyme is capable of performing this vital second step. These findings were published recently in the EMBO Journal.

Understanding how this major form of DNA repair works can have significant clinical implications. Since defects in this process increase the risk of cancer, clarifying its nuts and bolts might one day make it possible to enhance it in people whose natural DNA repair is deficient. In addition, manipulating this mechanism can improve the effectiveness of cancer drugs. Cancer cells can resist chemotherapy by exploiting their natural repair mechanisms, and blocking these mechanisms may help overcome this resistance, leading to a targeted destruction of the cancerous tumor.

Prof. Zvi Livneh’s research is supported by the Helen and Martin Kimmel Institute for Stem Cell Research; the estate of Lore F. Leder; and Esther Smidof, Geneva, Switzerland. Prof. Livneh is the incumbent of the Maxwell Ellis Professorial Chair in Biomedical Research.

True Grit

Sea Urchins' Digging Teeth Are Designed to Stay Sharp

Sea urchins dig themselves hiding holes in the limestone of the ocean floor using teeth that don’t go blunt. Weizmann Institute scientists have now revealed their secrets, which might give engineers insights into creating ever-sharp tools or mechanical parts.

The urchins dig holes to fit their globular bodies using their five teeth, which, like those of rodents, are ground down at the tip but continue to grow on the other end throughout the animals’ lives. The amazing part, however, is that the urchins’ teeth, which need to be harder and stronger than the rocky limestone being dug out, are themselves made almost entirely of calcite – the same calcite that makes up much of the limestone. How is this possible? In a series of studies spanning more than a decade, Profs. Steve Weiner and Lia Addadi of Weizmann’s Structural Biology Department have discovered that the urchins’ secret lies in a combination of ingenious design strategies. The latest of these studies, conducted with postdoctoral fellow Yurong Ma and graduate student Yael Politi and in collaboration with Prof. Pupa Gilbert and Dr. Rebecca Metzler of the University of Wisconsin; Drs. Barbara Aichmayer, Oskar Paris, and Peter Fratzl from the Max Planck Institute of Colloids and Interfaces in Potsdam, Germany; and Dr. Anders Meibom from the Muséum National D’Histoire Naturelle in Paris, France, was reported recently in the Proceedings of the National Academy of Sciences (PNAS).

The scientists found that the sea urchins’ teeth contain crystals of magnesium calcite, which are smaller, harder, and denser than those of pure calcite; they are concentrated at the grinding tip of the tooth, particularly in the tip’s center, where the most force is being exerted in the course of grinding. What holds these crystals at the center of the tip is a matrix of larger and softer calcite crystals. While in most such materials a matrix of hard fibers contains a softer filling, the reverse is true for the urchins’ tooth: a matrix of relatively soft calcite fibers holds the harder magnesium calcite crystals, which allows these crystals to spread over the entire surface of the tooth. The presence of magnesium calcite crystals acts like sandpaper that helps to grind the rock down.

In the latest study, the researchers used x-ray photoelectron emission spectromicroscopy and other high-resolution imaging methods to uncover yet another amazing structural feature of sea urchin tooth design. They found that all the crystalline elements that make up the tooth are aligned in two different arrays, and that these arrays are “interdigitated,” or interlocked like the fingers of folded hands, just at the tip of the tooth, where most of the wear occurs. The scientists believe that interlocking produces a notched, serrated ridge resembling that of a carpenter’s file. This ridge is self-sharpening: as the tooth is being ground down, the crystalline layers break in such a way that the ridge always stays corrugated.

Prof. Lia Addadi’s research is supported by the Clore Center for Biological Physics; the Ilse Katz Institute for Material Sciences and Magnetic Resonance Research; the Helen and Martin Kimmel Center for Nanoscale Science; the Helen and Milton A. Kimmelman Center for Biomolecular Structure and Assembly; and the Carolito Stiftung. Prof. Addadi is the incumbent of the Dorothy and Patrick Gorman Professorial Chair.

Prof. Stephen Weiner’s research is supported by the Kekst Family Center for Medical Genetics; the Helen and Martin Kimmel Center for Archaeological Science; the Helen and Milton A. Kimmelman Center for Biomolecular Structure and Assembly; and the estate of George Schwartzman. Prof. Weiner is the incumbent of the Dr. Walter and Dr. Trude Borchardt Professorial Chair in Structural Biology.

For the scientific paper, please see: www.pnas.org/content/106/15/6048.full?sid=39c9feb7-911b-4679-bc95-f752b74e0dcd

Weizmann Institute Scientists Show White Blood Cells Move Like Millipedes

How do white blood cells – immune system “soldiers” – get to the site of infection or injury? To do so, they must crawl swiftly along the lining of the blood vessel – gripping it tightly to avoid being swept away in the blood flow – all the while searching for temporary “road signs” made of special adhesion molecules that let them know where to cross the blood vessel barrier so they can get to the damaged tissue.

In research recently published in the journal Immunity, Prof. Ronen Alon and his research student Ziv Shulman of the Weizmann Institute’s Immunology Department show how white blood cells advance along the length of the endothelial cells lining the blood vessels. Current opinion maintains that immune cells advance like inchworms, but Alon’s new findings show that the rapid movement of the white blood cells is more like that of millipedes. Rather than sticking front and back, folding and extending to push itself forward, the cell creates numerous tiny “legs” no more than a micron in length – adhesion points, rich in adhesion molecules (named LFA-1) that bind to partner adhesion molecules present on the surface of the blood vessels. Tens of these legs attach and detach in sequence within seconds – allowing them to move rapidly while keeping a good grip on the vessels’ sides.

Next, the scientists turned to the Institute’s Electron Microscopy Unit. Images produced by transmission and scanning electron microscopes, taken by Drs. Eugenia Klein and Vera Shinder, showed that upon attaching to the blood vessel wall, the white blood cell legs “dig” themselves into the endothelium, pressing down on its surface. The fact that these legs – which had been thought to appear only when the cells leave the blood vessels – are used in crawling the vessel lining suggests that they may serve as probes to sense exit signals. The researchers found that the shear force created by the blood flow was necessary for the legs to embed themselves. Without the thrust of the rushing blood, the white blood cells couldn’t sense the exit signals or get to the site of the injury. These results explain Alon’s previous findings that the blood’s shear force is essential for the white blood cells to exit the blood vessel wall. The present study suggests that shear forces cause their adhesion molecules to enter highly active states. The scientists believe that the tiny legs are trifunctional: used for gripping, moving, and sensing distress signals from the damaged tissue.

In future studies, the scientists plan to check whether it is possible to regulate aggressive immune reactions (such as in autoimmune diseases) by interrupting the “digging” of immune cell legs into the endothelium. They also plan to investigate whether cancerous blood cells metastasize through the blood stream using similar mechanisms in order to exit the blood vessels and enter different tissues.

Prof. Ronen Alon’s research is supported by the De Benedetti Foundation-Cherasco 1547. Prof. Alon is the incumbent of the Linda Jacobs Chair in Immune and Stem Cell Research.

The American Committee for the Weizmann Institute of Science (ACWIS), founded in 1944, develops philanthropic support for the Weizmann Institute of Science in Rehovot, Israel, one of the world's premier scientific research institutions. The Weizmann Institute is a center of multidisciplinary scientific research and graduate study, addressing crucial problems in medicine and health, technology, energy, agriculture, and the environment. For additional information, please visit www.weizmann-usa.org.

REHOVOT, ISRAEL—April 22, 2009—The Israel Presidents and Prime Ministers Memorial Prize was awarded to the Weizmann Institute of Science by President Shimon Peres for preserving the heritage of Israel’s first president, Dr. Chaim Weizmann. The Institute was honored for initiating a program that brings outstanding young scientists living abroad back to Israel.

Dr. Maya Schuldiner of the Weizmann Institute’s Department of Molecular Genetics, one of the 34 scientists who joined the Institute faculty during the past three years, said: “Six months ago, my husband Oren (who has also become a senior scientist at the Weizmann Institute) and I returned to Israel after our postdoctoral studies in San Francisco. Even though we enjoyed living in this beautiful city which has some of the best universities in the world, not a day went by that we didn’t miss Israel. Other Israelis we met there also missed home. To my disappointment, and to theirs, many of them will not return home, as this would jeopardize their job satisfaction, their standard of living, and the level of education for their children. The Weizmann Institute enables us to engage in world-class science—with the same equipment and under the same conditions as those available at the best universities in the world—without giving up on our identities, without losing the possibility of raising our children as Israelis, and without having to miss our country. If only as many young Israeli scientists as possible could be as lucky as we are, and be able to return home.”

The Weizmann Institute of Science, named after Dr. Chaim Weizmann, has invested substantial resources and effort in providing young scientists the ability to conduct research in Israel, in an attempt to counteract the phenomenon known as “brain drain”: young Israeli scientists going abroad to do their postdoctoral research and deciding to remain overseas after receiving attractive job offers. The Weizmann Institute has spent some $30 million offering positions to 34 outstanding young Israeli scientists and financing their absorption into the Institute: establishing a laboratory, purchasing research equipment, and generating salaries for several laboratory workers and students. The Institute also funded each scientist’s move back to Israel, including transportation home for his or her entire family. Most scientists were offered on-campus housing—a particularly important component for those spending long hours in the lab. A kindergarten run by a steering committee comprising mainly scientist mothers was built on the Institute campus for the benefit of the many young scientists who are parents of preschool-age children. The kindergarten serves meals to the children and provides them with care till the late afternoon.

The Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.

REHOVOT, ISRAEL—April 6, 2009—The design of efficient systems, driven by sunlight, for splitting water into hydrogen and oxygen is among the most important challenges facing science today, underpinning the long-term potential of hydrogen as a clean, sustainable fuel. But manmade systems that exist today are very inefficient and often require additional use of sacrificial chemical agents. In this context, it is important to establish new mechanisms by which water splitting can take place.

Now, a unique approach developed by Prof. David Milstein and colleagues in the Weizmann Institute’s Organic Chemistry Department provides important steps in overcoming this challenge. The team has demonstrated a new mode of bond generation between oxygen atoms, and even defined the mechanism by which it takes place. In fact, it is the generation of oxygen gas by the formation of a bond between two oxygen atoms originating from water molecules that proves to be the bottleneck in the water splitting process. Their results have recently been published in Science.

Nature, by taking a different path, has evolved a very efficient process: photosynthesis—carried out by plants—the source of all oxygen on Earth. Although there has been significant progress towards the understanding of photosynthesis, just how this system functions remains unclear; vast worldwide efforts have been devoted to the development of artificial photosynthetic systems based on metal complexes that serve as catalysts, with little success. (A catalyst is a substance that is able to increase the rate of a chemical reaction without getting used up.)

The new approach devised by the Weizmann team is divided into a sequence of reactions, which leads to the liberation of hydrogen and oxygen in consecutive thermal- and light-driven steps, mediated by a unique ingredient—a special metal complex that Prof. Milstein’s team designed in previous studies. Moreover, the one that they designed—a metal complex of the element ruthenium is a “smart” complex in which the metal center and the organic part attached to it cooperate in the cleavage of the water molecule.

The team found that, upon mixing this complex with water, the bonds between the hydrogen and oxygen atoms break, with one hydrogen atom binding to its organic part, while the remaining hydrogen and oxygen atoms (OH group) bind to its metal center.

This modified version of the complex provides the basis for the next stage of the process: the “heat stage.” When the water solution is heated to 100˚C, hydrogen gas is released from the complex—a potential source of clean fuel—and another OH group is added to the metal center.

“But the most interesting part is the third ‘light stage,’” says Prof. Milstein. “When we exposed this third complex to light at room temperature, not only was oxygen gas produced, but the metal complex also reverted back to its original state, which could be recycled for use in further reactions.”

These results are even more remarkable considering that the generation of a bond between two oxygen atoms promoted by a manmade metal complex is a very rare event, and it has been unclear how it can take place. Yet Prof. Milstein and his team have also succeeded in identifying an unprecedented mechanism for such a process. Additional experiments have indicated that during the third stage, light provides the energy required to cause the two OH groups to get together to form hydrogen peroxide (H₂O₂), which quickly breaks up into oxygen and water. “Because hydrogen peroxide is considered a relatively unstable molecule, scientists have always disregarded this step, deeming it implausible; but we have shown otherwise,” says Prof. Milstein. Moreover, the team has provided evidence showing that the bond between the two oxygen atoms is generated within a single molecule—not between oxygen atoms residing on separate molecules, as commonly believed—and it comes from a single metal center.

Discovery of an efficient artificial catalyst for the sunlight-driven splitting of water into oxygen and hydrogen is a major goal of renewable clean energy research. So far, Prof. Milstein’s team has demonstrated a mechanism for the formation of hydrogen and oxygen from water, without the need for sacrificial chemical agents, through individual steps, using light. For their next study, they plan to combine these stages to create an efficient catalytic system, bringing those in the field of alternative energy an important step closer to realizing this goal.

Participating in the research were former postdoctoral student Stephan Kohl, Ph.D. student Leonid Schwartsburd, and technician Yehoshoa Ben-David, all of the Organic Chemistry Department, together with staff scientists Lev Weiner, Leonid Konstantinovski, Linda Shimon, and Mark Iron of the Chemical Research Support Department.

Prof. David Milstein’s research is supported by the Mary and Tom Beck–Canadian Center for Alternative Energy Research and the Helen and Martin Kimmel Center for Molecular Design. Prof. Milstein is the incumbent of the Israel Matz Professorial Chair of Organic Chemistry.

The American Committee for the Weizmann Institute of Science (ACWIS), founded in 1944, develops philanthropic support for the Weizmann Institute of Science in Rehovot, Israel, one of the world's premier scientific research institutions. The Weizmann Institute is a center of multidisciplinary scientific research and graduate study, addressing crucial problems in medicine and health, technology, energy, agriculture, and the environment. For additional information, please visit www.weizmann-usa.org.

REHOVOT, ISRAEL—March 23, 2009—In the first observation if its kind, scientists at the Weizmann Institute of Science and San Diego State University were able to watch what happens when a star the size of 50 suns explodes. As they continued to track the spectacular event, they found that most of the star’s mass collapsed in on itself, resulting in a large black hole.

While exploding stars — supernovae — have been viewed with everything from the naked eye to high-tech research satellites, no one had directly observed what happens when a really huge star blows up. Dr. Avishay Gal-Yam of the Weizmann Institute’s Faculty of Physics and Prof. Douglas Leonard of San Diego State University recently located and calculated the mass of a gigantic star on the verge of exploding, following through with observations of the blast and its aftermath. Their findings have lent support to the reigning theory that stars ranging from tens to hundreds of times the mass of our sun all end up as black holes.

A star’s end is predetermined from birth by its size and by the “power plant” that keeps it shining during its lifetime. Stars, among them our sun, are fueled by hydrogen nuclei fusing together into helium in the intense heat and pressure of their inner cores. A helium nucleus is a bit lighter than the sum of the masses of the four hydrogen nuclei that went into making it and, from Einstein’s theory of relativity (E=MC²), we know that the missing mass is released as energy.

When stars like our sun finish off their hydrogen fuel, they burn out relatively quietly in a puff of expansion. But a star that’s eight or more times larger than the sun makes a much more dramatic exit. Nuclear fusion continues after the hydrogen is exhausted, producing heavier elements in the star’s different layers. When this process progresses to the point that the core of the star has turned to iron, another phenomenon takes over: In the enormous heat and pressure in the star’s center, the iron nuclei break apart into their component protons and neutrons. At some point, this causes the core and the layer above it to collapse inward, firing the rest of the star’s material rapidly out into space in a supernova flash.

A supernova releases more energy in a few days than our sun will release over its entire lifetime, and the explosion is so bright that one occurring hundreds of light years away can be seen from Earth even in the daytime. While a supernova’s outer layers are lighting up the universe with dazzling fireworks, the star’s core collapses further and further inward. The gravity created in this collapse becomes so strong that the protons and electrons are squeezed together to form neutrons, and the star’s core is reduced from a sphere 10,000 kilometers around to one with a circumference of a mere 10 kilometers. Just a crate-full of this star’s material weighs as much as our entire Earth. But when the exploding star is 20 times the mass of our sun or more, say the scientists, its gravitational pull becomes so powerful that even light waves are held in place. Such a star — a black hole — is invisible for all intents and purposes.

Until now, none of the supernovae stars that scientists had managed to measure had exceeded a mass of 20 suns. Dr. Gal-Yam and Prof. Leonard were looking at a specific region in space using the Keck Telescope on Mauna Kea in Hawaii and the Hubble Space Telescope. Identifying the about-to-explode star, they calculated its mass to be equal to 50-100 suns. Continued observation revealed that only a small part of the star’s mass was flung off in the explosion. Most of the material, says Dr. Gal-Yam, was drawn into the collapsing core as its gravitational pull mounted. Indeed, in subsequent telescope images of that section of the sky, the star seems to have disappeared. In other words, the star has now become a black hole — so dense that light can’t escape.

Dr. Avishay Gal-Yam’s research is supported by the Nella and Leon Benoziyo Center for Astrophysics; the Peter and Patricia Gruber Award; the Legacy Heritage Fund; and the William Z. and Eda Bess Novick Young Scientist Fund.

The Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.

Weizmann Institute research shows our brain's sense centers are continuously active. In the absence of a stimulus, however, their electrical activity remains in 'screen saver' mode.

Even when our eyes are closed, the visual centers in our brain are humming with activity. Weizmann Institute scientists and others have shown in the last few years that the magnitude of sense-related activity in a brain that’s disengaged from seeing, touching, etc., is quite similar to that of one exposed to a stimulus. New research at the Institute has now revealed details of that activity, explaining why, even though our sense centers are working, we don’t experience sights or sounds when there’s nothing coming in through our sensory organs.

The previous studies of Prof. Rafael Malach and research student Yuval Nir of the Neurobiology Department used functional magnetic resonance imaging (fMRI) to measure brain activity in active and resting states. But fMRI is an indirect measurement of brain activity; it can’t catch the nuances of the pulses of electricity that characterize neuron activity.

Together with Prof. Itzhak Fried of the University of California at Los Angeles and a team at the EEG unit of the Tel Aviv Sourasky Medical Center, the researchers found a unique source of direct measurement of electrical activity in the brain: data collected from epilepsy patients who underwent extensive testing, including measurement of neuronal pulses in various parts of their brain, in the course of diagnosis and treatment.

An analysis of this data showed conclusively that electrical activity does, indeed, take place even in the absence of stimuli. But the nature of the electrical activity differs if a person is experiencing a sensory event or undergoing its absence. In results that appeared recently in Nature Neuroscience, the scientists showed that during rest, brain activity consists of extremely slow fluctuations, as opposed to the short, quick bursts that typify a response associated with a sensory percept. This difference appears to be the reason we don’t experience hallucinations or hear voices that aren’t there during rest. The resting oscillations appear to be strongest when we sense nothing at all – during dream-free sleep.

The slow fluctuation pattern can be compared to a computer screen-saver. Though its function is still unclear, the researchers have a number of hypotheses. One possibility is that neurons, like certain philosophers, must ‘think’ in order to be. Survival, therefore, is dependant on a constant state of activity. Another suggestion is that the minimal level of activity enables a quick start when a stimulus eventually presents itself, something like a getaway car with the engine running. Nir: ‘In the old approach, the senses are ‘turned on’ by the switch of an outside stimulus. This is giving way to a new paradigm in which the brain is constantly active, and stimuli change and shape that activity.’

Malach: ‘The use of clinical data enabled us to solve a riddle of basic science in a way that would have been impossible with conventional methods. These findings could, in the future, become the basis of advanced diagnostic techniques.’ Such techniques might not necessarily require the cooperation of the patient, allowing them to be used, for instance on people in a coma or on young children.

For the scientific paper, please see:  http://www.nature.com/neuro/journal/v11/n9/full/nn.2177.html

Prof. Rafael Malach’s research is supported by the Nella and Leon Benoziyo Center for Neurological Diseases; the Carl and Micaela Einhorn-Dominic Brain Research Institute; Ms. Vera Benedek, Israel; Benjamin and Seema Pulier Charitable Foundation, Inc.; and Ms. Mary Helen Rowen, New York, NY. Prof. Malach is the incumbent of the Barbara and Morris Levinson Professorial Chair in Brain Research.

The Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.

Behind Closed Eyes

Even when our eyes are closed, the visual centers in our brain are humming with activity. Weizmann Institute scientists and others have shown in the last few years that the magnitude of sense-related activity in a brain that’s disengaged from seeing, touching, etc., is quite similar to that of one exposed to a stimulus. New research at the Institute has now revealed details of that activity, explaining why, even though our sense centers are working, we don’t experience sights or sounds when there’s nothing coming in through our sensory organs.

The previous studies of Prof. Rafael Malach and research student Yuval Nir of the Neurobiology Department used functional magnetic resonance imaging (fMRI) to measure brain activity in active and resting states. But fMRI is an indirect measurement of brain activity; it can’t catch the nuances of the pulses of electricity that characterize neuron activity.

Together with Prof. Itzhak Fried of the University of California at Los Angeles and a team at the EEG unit of the Tel Aviv Sourasky Medical Center, the researchers found a unique source of direct measurement of electrical activity in the brain: data collected from epilepsy patients who underwent extensive testing, including measurement of neuronal pulses in various parts of their brain, in the course of diagnosis and treatment.

An analysis of this data showed conclusively that electrical activity does indeed take place, even in the absence of stimuli. But the nature of the electrical activity differs if a person is experiencing a sensory event or undergoing its absence. In results that appeared recently in Nature Neuroscience, the scientists showed that during rest, brain activity consists of extremely slow fluctuations, as opposed to the short, quick bursts that typify a response associated with a sensory percept. This difference appears to be the reason we don’t experience hallucinations or hear voices that aren’t there during rest. The resting oscillations appear to be strongest when we sense nothing at all — during dream-free sleep.

The slow fluctuation pattern can be compared to a computer screensaver. Though its function is still unclear, the researchers have a number of hypotheses. One possibility is that neurons, like certain philosophers, must “think” in order to be. Survival, therefore, is dependant on a constant state of activity. Another suggestion is that the minimal level of activity enables a quick start when a stimulus eventually presents itself, something like a getaway car with the engine running. Nir: “In the old approach, the senses are ‘turned on’ by the switch of an outside stimulus. This is giving way to a new paradigm in which the brain is constantly active, and stimuli change and shape that activity.”

Malach: “The use of clinical data enabled us to solve a riddle of basic science in a way that would have been impossible with conventional methods. These findings could, in the future, become the basis of advanced diagnostic techniques.” Such techniques might not necessarily require the cooperation of the patient, allowing them to be used, for instance, on people in a coma or on young children.

Prof. Rafael Malach’s research is supported by the Nella and Leon Benoziyo Center for Neurological Diseases; the Carl and Micaela Einhorn-Dominic Brain Research Institute; Ms. Vera Benedek, Israel; Benjamin and Seema Pulier Charitable Foundation, Inc.; and Ms. Mary Helen Rowen, New York, NY. Prof. Malach is the incumbent of the Barbara and Morris Levinson Professorial Chair in Brain Research.

For the scientific paper, please see: www.nature.com/neuro/journal/v11/n9/full/nn.2177.html

Bacteria Are Models of Efficiency

The bacterium Escherichia coli, one of the best-studied single-celled organisms around, is a master of industrial efficiency. This bacterium can be thought of as a factory with just one product: itself. It exists to make copies of itself, and its business model is to make them at the lowest possible cost, with the greatest possible efficiency. Efficiency, in the case of a bacterium, can be defined by the energy and resources it uses to maintain its plant and produce new cells, versus the time it expends on the task.

Dr. Tsvi Tlusty and research student Arbel Tadmor of the Weizmann Institute of Science’s Physics of Complex Systems Department developed a mathematical model for evaluating the efficiency of these microscopic production plants. Their model, which appeared in the online journal PLoS Computational Biology, uses only five remarkably simple equations to check the efficiency of these complex factory systems.

The equations look at two components of the protein production process: ribosomes (the machinery in which proteins are produced) and RNA polymerase (an enzyme that copies the genetic code for protein production onto strands of messenger RNA for further translation into proteins). RNA polymerase is thus a sort of work “supervisor” that keeps protein production running smoothly, checks the specs, and sets the pace. The first equation assesses the production rate of the ribosomes themselves; the second, the protein output of the ribosomes; the third, the production of RNA polymerase. The last two equations deal with how the cell assigns the available ribosomes and polymerases to the various tasks of creating other proteins, more ribosomes, or more polymerases.

The theoretical model was tested in real bacteria. Do bacteria “weigh” the costs of constructing and maintaining their protein production machinery against the gains to be had from being able to produce more proteins in less time? What happens when a critical piece of equipment is in short supply — say, a main ribosome protein? Tlusty and Tadmor found that their model was able to accurately predict how an E. coli would change its production strategy to maximize efficiency following disruptions in the work flow caused by experimental changes to genes with important cellular functions.

What’s the optimum? The model predicts that a bacterium, for instance, should have seven genes for ribosome production. It turns out that that’s exactly the number an average E. coli cell has. Bacteria having five or nine get a much lower efficiency rating. Evolution, in other words, is a master efficiency expert for living factories, meeting any challenges that arise as production conditions change.

Dr. Tsvi Tlusty’s research is supported by the Clore Center for Biological Physics.

For the scientific paper, please see: www.ploscompbiol.org/article/info%3Adoi%2F10.1371%2Fjournal.pcbi.1000038

Weizmann Institute Scientists Show Extra Copies of a Gene Carry Extra Risk

Is more of a good thing better? A gene known as LIS1 is crucial for ensuring the proper placement of neurons in the developing brain. When an LIS1 gene is missing, brains fail to develop their characteristic folds; babies with lissencephaly, or “smooth brain,” are born severely mentally retarded. But new research by Prof. Orly Reiner of the Institute’s Molecular Genetics Department, which recently appeared in Nature Genetics, shows that having extra LIS1 genes can cause problems as well.

Reiner was the first to discover LIS1’s tie to lissencephaly, in 1993. Her latest study shows that LIS1 works by helping to determine polarity in the cell — how the various organelles are arranged inside the cell, as well as where it connects to neighboring cells. Neurons alter their polarity several times during development, especially when they take on an elongated shape and migrate to new locations in the brain.

But what if, rather than too little, the body has too much LIS1? One of the surprises to come out of the recent spate of post-human-genome research is the number of genes that can be repeated or deleted in an individual’s genome. Most extra copies of genes may be no more harmful than a computer backup disk, but scientists have been finding that some repeats can cause disease.

Research associate Dr. Tamar Sapir and lab technician Talia Levy, working in Reiner’s lab, developed a mouse model in which additional LIS1 protein was produced in the brain. The scientists found that the brains of these mice were a bit smaller than average. On closer inspection, they discovered a range of subtle changes in cell polarity and movement: nuclei within the proliferating zone tended to move faster, but with less control; rates of cell death were higher; and various factors in the cell became more disordered.

Reiner then asked whether their findings might apply to humans. Together with Jim Lupski and Drs. Weimin Bi and Oleg A. Shchelochkov of the Baylor College of Medicine in Houston, Texas, they searched through blood samples using a technique that matches a patient’s DNA with control DNA to identify additions or deletions in its sequence. They identified seven individuals with extra copies of either LIS1 or adjacent genes that are also involved in brain development. All suffered developmental abnormalities. Two of the patients — children with a second LIS1 gene — had previously been diagnosed with failure to thrive and delayed development, and were found to have small brain sizes. A third, who had three copies of the gene, was mentally retarded and suffered from bone deformation as well.

Reiner: “Several brain diseases, including schizophrenia, epilepsy, and autism, have been linked to faulty neuron migration, and recent research has hinted that some of these may involve variations in gene number. Our study is the first to demonstrate the effects of the duplication of a single gene in a mouse model and tie it to a new ‘copy number variation’ human disease.”

Prof. Orly Reiner’s research is supported by the Nella and Leon Benoziyo Center for Neurological Diseases; the Kekst Family Center for Medical Genetics; the David and Fela Shapell Family Center for Genetic Disorders Research; the PW-Iris Foundation; and the PW-Jani.M Research Fund. Prof. Reiner is the incumbent of the Bernstein-Mason Chair of Neurochemistry.

For the scientific paper, please see: www.nature.com/ng/journal/v41/n2/pdf/ng.302.pdf

The Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.

Positive Results

Even when the results of the basic research at the Weizmann Institute are translated directly to medical application, it may take years to reach patients. But, once in a while, a finding can change lives almost immediately.

In 2006, Prof. Nava Dekel of the Institute’s Biological Regulation Department, together with doctors in the in vitro fertilization (IVF) unit of the Kaplan Medical Center, made the surprising discovery that performing a uterine biopsy — causing a slight injury to the lining of the uterus just before a woman undergoes IVF doubles the chances of a successful pregnancy. Although the mechanism was not completely clear, Dekel and her team assumed that the injury provokes a response in the uterus that makes it more receptive to the embryo’s implantation.

The next year, Prof. Dekel was in Toronto, Canada, giving a lecture in the framework of the Weizmann Women and Science series, organized by Weizmann Canada. That lecture was reported in detail in a local Jewish newspaper, where it caught the attention of Howard and Roslyn Kaman. After many years of undergoing unsuccessful fertility treatments, failed IVF, and miscarriages, the article gave the couple new hope. They contacted Prof. Dekel by e-mail, and she referred them to Drs. Amichai Barash and Irit Granot, who had participated in the original research along with Drs. Yael Kalma and Yulia Gnainsky of the Weizmann Institute.

The doctors in Rehovot sent, as requested, a detailed description of the procedure, which was then performed in a fertility clinic in Toronto. The result: A healthy baby girl, Hannah Esther Angel Kaman, was born this past October.

Prof. Nava Dekel’s research is supported by the Kirk Center for Childhood Cancer and Immunological Disorders. Prof. Dekel is the incumbent of the Philip M. Klutznick Professorial Chair of Developmental Biology.

Weizmann Institute Scientists Create Working Artificial Nerve Networks

Scientists have already hooked brains directly to computers by means of metal electrodes, in the hope of both measuring what goes on inside the brain and eventually healing conditions such as blindness or epilepsy. In the future, the interface between brain and artificial system might be based on nerve cells grown for that purpose. In research that was recently featured on the cover of Nature Physics, Prof. Elisha Moses of the Physics of Complex Systems Department and his former research students Drs. Ofer Feinerman and Assaf Rotem have taken the first step in this direction by creating circuits and logic gates made of live nerves grown in the lab.

When neurons — brain nerve cells — are grown in culture, they don’t form complex “thinking” networks. Moses, Feinerman, and Rotem wondered whether the physical structure of the nerve network could be designed to be more brain-like. To simplify things, they grew a model nerve network in one dimension only — by getting the neurons to grow along a groove etched in a glass plate. The scientists found they could stimulate these nerve cells using a magnetic field (as opposed to other systems of lab-grown neurons that only react to electricity).

Experimenting further with the linear setup, the group found that varying the width of the neuron stripe affected how well it would send signals. Nerve cells in the brain are connected to great numbers of other cells through their axons (long, thin extensions), and they must receive a minimum number of incoming signals before they fire one off in response. The researchers identified a threshold thickness, one that allowed the development of around 100 axons. Below this number, the chance of a response was iffy, while just a few over this number greatly raised the chance a signal would be passed on.

The scientists then took two thin stripes of around 100 axons each and created a logic gate similar to one in an electronic computer. Both of these “wires” were connected to a small number of nerve cells. When the cells received a signal along just one of the “wires,” the outcome was uncertain; but a signal sent along both “wires” simultaneously was assured of a response. This type of structure is known as an AND gate. The next structure the team created was slightly more complex: Triangles fashioned from the neuron stripes were lined up in a row, point to rib, in a way that forced the axons to develop and send signals in one direction only. Several of these segmented shapes were then attached together in a loop to create a closed circuit. The regular relay of nerve signals around the circuit turned it into a sort of biological clock or pacemaker.

Says Prof. Moses: “We have been able to enforce simplicity on an inherently complicated system. Now we can ask, ‘What do nerve cells grown in culture require in order to be able to carry out complex calculations?’ As we find answers, we get closer to understanding the conditions needed for creating a synthetic, many-neuron ‘thinking’ apparatus.”

For the scientific paper, please see: www.nature.com/nphys/journal/v4/n12/pdf/nphys1099.pdf

Weizmann Institute Scientists Discover How Cancer Cells Survive a Chemotherapy Drug

What separates the few cancer cells that survive chemotherapy — leaving the door open to recurrence from those that don’t? Weizmann Institute scientists developed an original method for imaging and analyzing many thousands of living cells to reveal exactly how a chemotherapy drug affects each one.

For research student Ariel Cohen, together with Naama Geva-Zatorsky and Eran Eden in the lab of Prof. Uri Alon of the Institute’s Molecular Cell Biology Department, the question posed an interesting challenge. To approach it, they needed a method that would allow them to cast a wide net on the one hand — to sift through the numerous cellular proteins that could conceivably affect survival — but that would let them zoom in on the activities of individual cells in detail, on the other. Letting the computer take over the painstaking work of searching for anomalies enabled the team to look at the behavior of over 1,000 different proteins. Even so, it took several years to complete the project, which entailed tagging the specific proteins in each group of cancer cells with a fluorescent gene and capturing a series of time-lapse images over 72 hours. A second, fainter fluorescent marker was added to outline the cells so the computer could identify them. A chemotherapy drug was introduced 24 hours into this period, after which the cells began the process of either dying or defending themselves against the drug.

The team’s efforts have produced a comprehensive library of tagged cells, images, and data on cancer-cell proteins — a virtual goldmine of ready material for further cancer research. And they succeeded in pinpointing two proteins that seem to play a role in cancer cell survival.

Although most of the proteins behaved similarly in all the cells, the researchers found that a small subset of them — around five percent — could act unpredictably, even when the cells and drug exposure were identical. The scientists called these proteins bimodal, as they acted in one of two ways.

The team then asked whether any of the bimodal proteins they identified were those that occasionally promote cell survival. They found two molecules that seemed to fit the bill. One of them, known by the letters DDX5, is a multitasking protein that, among other things, plays a role in initiating the production of other proteins. The other, RFC1, also plays varied roles, including directing the repair of damaged DNA. When the researchers blocked the production of these proteins in the cancer cells, the drug became much more efficient at wiping out the growth.

Says Prof. Cohen: “This method gave us tremendous insight into how a cell responds to a drug. By conducting an unbiased study — we started with no preconceived notions of which proteins were involved — we were able to pinpoint possible new drug targets and to see how certain activities might boost the effectiveness of current drugs.”

Prof. Uri Alon’s research is supported by the Kahn Family Foundation for Humanitarian Support and Keren Isra - Pa’amei Tikva.

For the scientific paper, please see: www.sciencemag.org/cgi/reprint/322/5907/1511.pdf

The Weizmann Institute of Science in Rehovot, Israel, is one of the world’s top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.

CHICAGO, IL—January 5, 2009—The American Committee for the Weizmann Institute of Science announced that Lee J. Brown will assume the office of Executive Director of its Midwest Region. The Weizmann Institute of Science is one of the world’s foremost centers of science and technology research; it is located in Rehovot, Israel. Its American Committee cultivates awareness of and support for the Institute in the United States.

Lee Brown brings to the position nearly three decades of experience in Chicago- and greater Midwest-area organizations focused on health, science, humanity, and personal development. As Vice President of Sinai Health System (encompassing Chicago’s Mt. Sinai Hospital, Schwab Rehabilitation Hospital, Mt. Sinai Children’s Hospital, Sinai Community Institute, and the Sinai Urban Health Institute), he was responsible for the structure and administration of the organization’s Department of Development, and also laid the groundwork for a $20 million capital campaign, its first in 20 years. Previously, Mr. Brown had been Director of Development for the Upper Midwest/Chicago Region of the Anti-Defamation League. He also worked for the American Cancer Society, The Salvation Army, and Boy Scouts of America.

In his role as Executive Director of the Midwest Region, Mr. Brown will advocate for the Weizmann Institute of Science and advance its mission of “Science for the Benefit of Humanity” in Chicago and the Midwestern United States. He will focus his efforts on enhancing and cultivating relationships with major donors in the area and recruiting new and diverse volunteer leadership in order to promote visibility of and support for the Weizmann Institute of Science.

Mr. Brown received his B.A. in Public Service from Northern Illinois University.

The American Committee for the Weizmann Institute of Science (ACWIS), founded in 1944, develops philanthropic support for the Weizmann Institute of Science in Rehovot, Israel, one of the world's premier scientific research institutions. The Weizmann Institute is a center of multidisciplinary scientific research and graduate study, addressing crucial problems in medicine and health, technology, energy, agriculture, and the environment. For additional information, please visit www.weizmann-usa.org.

REHOVOT, ISRAEL—January 5, 2009—The Weizmann Institute of Science and its Davidson Institute of Science Education have proposed a variety of free-of-charge scientific and educational activities to residents of southern Israel and those residing in settlements just outside the Gaza Strip. The activities include visits to the Weizmann Institute's Visitors' Center, the Chaim Weizmann House, and the Clore Garden of Science, as well as lectures, scientific experiments, presentations, and online quizzes and competitions. The activities are open to families and groups, and the visitors can stay in the Youth Village on the Institute campus.

In addition, the Science Mobile, a teaching lab-in-a-van, is available to residents of the south free of charge. Its team can be invited to conduct entertaining and enjoyable science activities in southern Israel, in facilities protected from rocket attacks.

Click here to link to a brief video describing the Institute's efforts to reach as many children as possible from the cities under attack, by bringing children to its Rehovot campus and also by dispatching a science mobile (a science lab-in-a-van) to locations in the south where children are spending innumerable hours in bomb shelters.

The Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.

REHOVOT, ISRAEL—December 18, 2008—Top-level research institutions in the UK and Israel will collaborate, thanks to a bold new initiative of Weizmann UK.

The program—entitled "Making Connections"—will bring together scientists from the Weizmann Institute of Science in Israel with their UK counterparts from the University of Oxford, the University of Cambridge, Imperial College London (ICL), and University College London (UCL).

The timing of the project's launch is significant, as it comes amid continuing attempts to impose an academic boycott on Israeli institutions. The UK University and College Union (UCU) has just announced that it is ending its academic boycott of Israel.

Since its inception in 1950, this is the first time that Weizmann UK has provided grants for such an initiative, which is funded entirely by UK philanthropists.

As soon as the program was launched, it received 29 applications from the Weizmann Institute—far more than had been anticipated. Of these, 10 projects were shortlisted and, with the help of Professors Benjamin Chain (UCL), David Klug (ICL), and Haim Garty (Weizmann Institute), five were selected for funding by Weizmann UK.

The five winning research programs will focus on brain processes involved in learning and memory; understanding the nature of dark energy in the universe; the physical principles that govern the basic processes of living cells; deciphering the molecular events that take place in living cells; and the self-assembly of advanced materials.

Lord Mitchell, Chairman of Weizmann UK, said: "This is a very important development in international scientific collaboration. Our first five projects deal with some of the most challenging areas at the forefront of modern scientific investigation and we are proud to be leading the way."

Weizmann Institute President Prof. Daniel Zajfman concurs: "Science knows no borders. Scientific ideas and discoveries, whether it be in the short- or long-term, benefit all humankind. Thus, it seems only natural that scientists worldwide should focus their efforts collectively in broadening the boundaries of human knowledge. Our vision is that this pioneering program will develop into a broad, prestigious, bi-national project, akin to existing programs that Israel has developed with the U.S. and Germany. It will be initiated on a competitive basis of quality assessment and will serve scientists from all universities and research institutions in the two countries."

Originally planned as two programs over a five-year period, initial response suggests a swift increase may be possible.

The Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.

NEW YORK, NY—November 5, 2008—The Weizmann Institute of Science in Rehovot, Israel was ranked the best international academic institution for which to work by The Scientist magazine. Participants in the magazine’s annual survey of “Best Places to Work in Academia” cited Weizmann’s research resources, infrastructure, and work environment as particular strengths.

The survey, published in The Scientist’s November issue, reviewed entries from over 2,300 qualified respondents. These respondents represented a total of 73 institutions: 54 from the U.S. and 19 from abroad. Survey respondents were asked to assess their work environments by indicating their level of agreement with 41 criteria, in eight different areas. Categories included the quality of mentoring, infrastructure and environment, pay, research resources, and tenure.

An analysis by the magazine determined that Australia is the best country overall in which to conduct scientific research. Runners-up were Israel, Belgium, the United States, and Canada. Readers ranked J. David Gladstone Institutes in San Francisco as the best academic environment in the United States.

Prof. Haim Garty, a Vice President of the Weizmann Institute, said in an interview with The Scientist, “What’s unique to us … is that the red tape is minimal. The Institute’s role is to provide the resources and stay out of the way.”

The Scientist, the magazine of life sciences, has been published for over 20 years. Details on the survey can be viewed at www.the-scientist.com.

The American Committee for the Weizmann Institute of Science (ACWIS), founded in 1944, develops philanthropic support for the Weizmann Institute of Science in Rehovot, Israel, one of the world's premier scientific research institutions. The Weizmann Institute is a center of multidisciplinary scientific research and graduate study, addressing crucial problems in medicine and health, technology, energy, agriculture, and the environment. For additional information, please visit www.weizmann-usa.org.

BOCA RATON, FL—September 18, 2008—The American Committee for the Weizmann Institute of Science announced that Mindy Ginsberg will assume the office of Executive Director of the American Committee's Palm Beach Region.

Mindy Ginsberg brings to the position a strong background in fundraising and marketing in the Palm Beach area. She served as Director of Institutional Advancement, Southeast Region, for Yeshiva University and the Albert Einstein College of Medicine from November 2002 to May 2008. Previously, Ms. Ginsberg had served as an independent fundraising consultant for the National United Jewish Communities, as well as the Adolph and Rose Levis Jewish Community Center and the Mount Zion Foundation, both in Boca Raton. Ms. Ginsberg had also worked in senior development capacities for the Southeast Regional Office of National Hadassah (1996–9) and the Jewish Federation of Palm Beach County (1990–6).

In her role as Executive Director of the Palm Beach Region, Ms. Ginsberg will advocate for the Weizmann Institute of Science and advance its mission of Science for the Benefit of Humanity in southeastern Florida. In particular, she will focus her efforts on representing the Weizmann Institute to major donors in the area and recruiting new and diverse lay leadership. She succeeds Alex Bruner.

Ms. Ginsberg received her B.A. from Brandeis University. Her husband, David, owns DMG Insurance and Financial Services, and together they have two sons: Brandon, 12, and Steven, 9.

The American Committee for the Weizmann Institute of Science (ACWIS), founded in 1944, develops philanthropic support for the Weizmann Institute of Science in Rehovot, Israel, one of the world's premier scientific research institutions. The Weizmann Institute is a center of multidisciplinary scientific research and graduate study, addressing crucial problems in medicine and health, technology, energy, agriculture, and the environment. For additional information, please visit www.weizmann-usa.org.

NEW YORK, NY—September 11, 2008—The New York Region of the American Committee for the Weizmann Institute of Science will hold its annual dinner at Cipriani 42nd Street in New York City on Thursday, September 25, 2008. The event will honor three families whose philanthropic activities with the American Committee for the Weizmann Institute of Science have been passed down from generation to generation: Rhoda and Gerald Blumberg and Robin Lynn and Lawrence Blumberg; Phyllis and Joseph Gurwin, Laura Flug, and Eric Gurwin; and Gladys and Morton Pickman and Ellen and Stephen Danetz.

Rhoda and Gerald Blumberg first established their ties to the Weizmann Institute 35 years ago, and have been devoted supporters ever since. Their enthusiasm was passed down to their son, Larry, who is currently the American Committee's Chairman and, like his father, worked his way through the ranks of leadership, serves in both legal and lay capacities. Larry is also an Institute Governor and the recipient of an honorary doctorate from the Institute. As experts in estate planning and charitable giving, Jerry and Larry have both lent their legal services to the American Committee. A former American Committee Vice President, today, at age 97, Jerry is an Honorary Vice Chairman and a Governor Emeritus of the Institute. Jerry, Rhoda, Larry, and Robin are all members of the President's Circle and pillars of the Weizmann family.

President's Circle members Joseph and Phyllis Gurwin have made philanthropy a priority, and Joseph's children, Laura Flug and Eric Gurwin, have inherited this dedication to Weizmann. Laura is a member of the American Committee's national Executive Committee and President's Circle, following in the footsteps of her father, who is a Board member, Institute Governor, and recipient of an honorary doctorate from the Institute. Joseph's wife, Phyllis, has recently been elected to the American Committee's Board as well.

Presenting Sponsors Gladys and Morton Pickman have set an impressive example of generosity for the next generation, inspiring Gladys's daughter and son-in-law, Ellen and Stephen Danetz, to become active supporters of the Weizmann Institute of Science. The philanthropic ethic cultivated by Gladys and Morton reflects the spirit of unity and history that characterize the Institute. Gladys and Ellen are descendants of one of the founding fathers of the Institute and the State of Israel, Harry Levine. Their close relationship with him inspired their fervent commitment to Israel and Weizmann, and Mac has led the way as a Board member, Institute Governor, and, along with Gladys, a member of the President's Circle.

The benefit will also commemorate the 60th birthday of the State of Israel, as well as the 60th anniversary of the naming of the Weizmann Institute (founded 15 years earlier as the Daniel Sieff Research Institute). Political analyst Jeff Greenfield will act as the master of ceremonies, and the evening will feature entertainment by Miri Ben-Ari, known as the "Hip-Hop Violinist."

All proceeds from the 2008 New York Gala will be applied to purchase a DNA Sequencing System—a critical piece of instrumentation required by Weizmann scientists working in a variety of research disciplines. The success of the Human Genome Project marked the beginning of a new era in genetics research, medical care, and technology: the era of individualized medicine. Thanks to advanced technology, the field of genomics is moving at an exponential rate, and reached another landmark in the fall of 2007 with the first-ever sequencing of the entire genome of an individual. Weizmann scientists include world-renowned genomics researchers, and the Institute was Israel's liaison to the Human Genome Project. This prestige and brainpower must be fully utilized in order to keep up with the fast-moving science of the future, and to fulfill the Institute's mission of "Science for the Benefit of Humanity."

Today, the Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.

The Dinner Chairs are Gershon Kekst, Ellen Merlo, Andrew R. Morse, Bruce G. Pollack, and Larry Simon.

The American Committee for the Weizmann Institute of Science (ACWIS), founded in 1944, develops philanthropic support for the Weizmann Institute of Science in Rehovot, Israel, one of the world's premier scientific research institutions. The Weizmann Institute is a center of multidisciplinary scientific research and graduate study, addressing crucial problems in medicine and health, technology, energy, agriculture, and the environment. For additional information, please visit www.weizmann-usa.org.

NEW YORK, NY—September 11, 2008—The New York Region of the American Committee for the Weizmann Institute of Science will hold its annual dinner at Cipriani 42nd Street in New York City on Thursday, September 25, 2008. The event will honor three families whose philanthropic activities with the American Committee for the Weizmann Institute of Science have been passed down from generation to generation: Rhoda and Gerald Blumberg and Robin Lynn and Lawrence Blumberg; Phyllis and Joseph Gurwin, Laura Flug, and Eric Gurwin; and Gladys and Morton Pickman and Ellen and Stephen Danetz.

Rhoda and Gerald Blumberg first established their ties to the Weizmann Institute 35 years ago, and have been devoted supporters ever since. Their enthusiasm was passed down to their son, Larry, who is currently the American Committee's Chairman and, like his father, worked his way through the ranks of leadership, serves in both legal and lay capacities. Larry is also an Institute Governor and the recipient of an honorary doctorate from the Institute. As experts in estate planning and charitable giving, Jerry and Larry have both lent their legal services to the American Committee. A former American Committee Vice President, today, at age 97, Jerry is an Honorary Vice Chairman and a Governor Emeritus of the Institute. Jerry, Rhoda, Larry, and Robin are all members of the President's Circle and pillars of the Weizmann family.

President's Circle members Joseph and Phyllis Gurwin have made philanthropy a priority, and Joseph's children, Laura Flug and Eric Gurwin, have inherited this dedication to Weizmann. Laura is a member of the American Committee's national Executive Committee and President's Circle, following in the footsteps of her father, who is a Board member, Institute Governor, and recipient of an honorary doctorate from the Institute. Joseph's wife, Phyllis, has recently been elected to the American Committee's Board as well.

Presenting Sponsors Gladys and Morton Pickman have set an impressive example of generosity for the next generation, inspiring Gladys's daughter and son-in-law, Ellen and Stephen Danetz, to become active supporters of the Weizmann Institute of Science. The philanthropic ethic cultivated by Gladys and Morton reflects the spirit of unity and history that characterize the Institute. Gladys and Ellen are descendants of one of the founding fathers of the Institute and the State of Israel, Harry Levine. Their close relationship with him inspired their fervent commitment to Israel and Weizmann, and Mac has led the way as a Board member, Institute Governor, and, along with Gladys, a member of the President's Circle.

The benefit will also commemorate the 60th birthday of the State of Israel, as well as the 60th anniversary of the naming of the Weizmann Institute (founded 15 years earlier as the Daniel Sieff Research Institute). Political analyst Jeff Greenfield will act as the master of ceremonies, and the evening will feature entertainment by Miri Ben-Ari, known as the "Hip-Hop Violinist."

All proceeds from the 2008 New York Gala will be applied to purchase a DNA Sequencing System—a critical piece of instrumentation required by Weizmann scientists working in a variety of research disciplines. The success of the Human Genome Project marked the beginning of a new era in genetics research, medical care, and technology: the era of individualized medicine. Thanks to advanced technology, the field of genomics is moving at an exponential rate, and reached another landmark in the fall of 2007 with the first-ever sequencing of the entire genome of an individual. Weizmann scientists include world-renowned genomics researchers, and the Institute was Israel's liaison to the Human Genome Project. This prestige and brainpower must be fully utilized in order to keep up with the fast-moving science of the future, and to fulfill the Institute's mission of "Science for the Benefit of Humanity."

Today, the Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.

The Dinner Chairs are Gershon Kekst, Ellen Merlo, Andrew R. Morse, Bruce G. Pollack, and Larry Simon.

The American Committee for the Weizmann Institute of Science (ACWIS), founded in 1944, develops philanthropic support for the Weizmann Institute of Science in Rehovot, Israel, one of the world's premier scientific research institutions. The Weizmann Institute is a center of multidisciplinary scientific research and graduate study, addressing crucial problems in medicine and health, technology, energy, agriculture, and the environment. For additional information, please visit www.weizmann-usa.org.

REHOVOT, ISRAEL—August 14, 2008—Tons of soot are released into the air annually as forest fires rage from California to the Amazon to Siberia and Indonesia. Climate scientists have generally assumed that the main effect of smoke on climate is cooling, as the floating particles can reflect some solar energy back to space as well as increasing cloud size and lifespan. But new research by scientists at the Weizmann Institute of Science; the University of Maryland, Baltimore County (UMBC); and NASA may cause them to rethink soot’s role in shaping the Earth’s climate.

Airborne particles such as soot — known collectively as aerosols — rise into the atmosphere where they interact with clouds. Understanding what happens when the two meet is extremely complicated, in part because clouds are highly dynamic systems that both reflect the sun’s energy back into space, cooling the upper atmosphere, and trap heat underneath, warming the lower atmosphere and the Earth’s surface. Aerosols, in turn, can have both heating and cooling effects on clouds. On the one hand, water droplets form around the aerosol particles, which may extend the cloud cover. On the other hand, particles, especially soot, absorb the sun’s radiation, stabilizing the atmosphere and thus reducing cloud formation.

Dr. Ilan Koren and Hila Afargan of the Weizmann Institute’s Environmental Sciences and Energy Research Department, together with colleagues from UMBC and NASA’s Goddard Space Flight Center in Maryland, have, for the first time, developed an analytical model that puts all of these factors together to show when aerosols rising into the clouds will heat things up and when they will cool them off. The scientists tested their model on data from the Amazon, finding it reflected the true situation on the ground so accurately they could rule out the possibility that random changes in cloud cover — rather than aerosols from burning forests — were at work.

Their findings, which appear in the August 15, 2008 issue of Science, reveal that adding small quantities of aerosols into a clean environment can indeed produce a net cooling effect. As more and more particles enter the cloud layer, however, the effect progressively switches from cooling to heating mode. The researchers also found that the extent of the original cloud cover is important. A completely overcast sky prevents the sun’s rays from reaching the aerosols, so the result may be additional cooling of the atmosphere and the Earth’s surface. But the larger the ratio of open sky to clouds, the more aerosol particles absorb radiation, thus hastening the heating of the remaining cloud cover, reducing cloud cover, and heating the system.

An accurate model of the intricate relationship between clouds and aerosols has been a key missing piece in the picture of human-induced climate change. The scientists believe their findings may help both climate modelers and policy makers to understand the true climatic consequences of burning trees or sooty industrial fuels.

Dr. Ilan Koren’s research is supported by the Sussman Family Center for the Study of Environmental Sciences; the Fusfeld Research Fund; and the Samuel M. Soref and Helene K. Soref Foundation.

The Weizmann Institute of Science in Rehovot, Israel, is one of the world's top-ranking multidisciplinary research institutions. Noted for its wide-ranging exploration of the natural and exact sciences, the Institute is home to 2,600 scientists, students, technicians, and supporting staff. Institute research efforts include the search for new ways of fighting disease and hunger, examining leading questions in mathematics and computer science, probing the physics of matter and the universe, creating novel materials, and developing new strategies for protecting the environment.