Skip to main content

Tag: Life Sciences

Why do Corals Glow?

Written by AUFTAU on . Posted in Newsroom.

For centuries, nature lovers and scientists have been fascinated by the fact that creatures in the sea are able to glow. The phenomenon is very common in reef-building corals, but its biological role has been the subject of constant debate. Numerous hypotheses have been tested over the years. Some suggested that this phenomenon protect against radiation. Or perhaps it contributed to the optimization of the photosynthesis? Maybe the glowing property helped protect the coral against herbivores or to attract symbiotic algae to the corals?

 

A new Tel Aviv University study, in collaboration with the Steinhardt Museum of Natural History, and the Interuniversity Institute for Marine Sciences in Eilat, has proven for the first time that the magical phenomenon – whereby corals in deep reefs display glowing colors (fluorescence) – is intended to serve as a mechanism for attracting prey.

 

The study was led by Dr. Or Ben-Zvi, in collaboration with Yoav Lindemann and Dr. Gal Eyal, under the supervision of Prof. Yossi Loya from the School of Zoology and the Steinhardt Museum of Natural History at Tel Aviv University.

 

Chasing the Glow

The researchers first sought to determine whether plankton (small organisms that drift in the sea along with the current) are attracted to fluorescence, both in the laboratory and at sea. Then, in the lab, the researchers quantified the predatory capabilities of mesophotic corals (corals that live between the shallow coral reef area and the deep, completely dark zone of ​​the ocean), which exhibit different fluorescent appearances.

 

To test the planktons’ potential attraction to fluorescence, the researchers used, among other things, the crustacean Artemia salina, which is used in many experiments as well as for food for corals. The researchers noted that when the crustaceans were given a choice between a green or orange, fluorescent target versus a clear ‘control’ target, they showed a significant preference for the fluorescent target.

 

Moreover, when the crustaceans were given a choice between two clear targets, its choices were observed to be randomly distributed in the experimental setup. In all of the laboratory experiments, the crustaceans vastly exhibited a preferred attraction toward a fluorescent signal. Similar results were presented when using a native crustacean from the Red Sea. However, unlike the crustaceans, fish that are not considered coral prey did not exhibit these trends, and rather avoided the fluorescent targets.

 

 

Fluorescent Traps

The second phase of the study was carried out about 40 meters deep in the sea, where the fluorescent traps (both green and orange) attracted twice as many plankton as the clear trap.

 

“We conducted an experiment in the depths of the sea to examine the possible attraction of diverse and natural collections of plankton to fluorescence, under the natural currents and light conditions that exist in deep water,” says Dr. Or Ben-Zvi. “Since fluorescence is ‘activated’ principally by blue light (the light of the depths of the sea), at these depths the fluorescence is naturally illuminated, and the data that emerged from the experiment were unequivocal, similar to the laboratory experiment.”

 

“This phenomenon may play a greater role in marine ecosystems than previously thought.”

 

 

The “Light Trap Hypothesis”

In the last part of the study, the researchers examined the predation rates of mesophotic corals that were collected at 45 m depth in the Gulf of Eilat. They found that corals that displayed green fluorescence enjoyed predation rates that were 25 percent higher than corals exhibiting yellow fluorescence.

 

Prof. Loya: “Many corals display a fluorescent color pattern that highlights their mouths or tentacle tips, a fact that supports the idea that fluorescence, like bioluminescence (the production of light by a chemical reaction), acts as a mechanism to attract prey. The study proves that the glowing and colorful appearance of corals can act as a lure to attract swimming plankton to ground-dwelling predators, such as corals, and especially in habitats where corals require other energy sources in addition or as a substitute for photosynthesis (sugar production by symbiotic algae inside the coral tissue using light energy).”

 

Dr. Ben-Zvi concludes: “Despite the gaps in the existing knowledge regarding the visual perception of fluorescence signals by plankton, the current study presents experimental evidence for the prey-luring role of fluorescence in corals. We suggest that this hypothesis, which we term the ‘light trap hypothesis’, may also apply to other fluorescent organisms in the sea, and that this phenomenon may play a greater role in marine ecosystems than previously thought.”

CRISPR Therapeutics can Damage the Genome

Written by AUFTAU on . Posted in Newsroom.

TAU Researchers caution that while the genome editing method is very effective, it is not always safe and can promote cancer.

A new study from TAU identifies risks in the use of CRISPR therapeutics – an innovative, Nobel-prize-winning method that involves cleaving and editing DNA, already employed for the treatment of conditions like cancer, liver and intestinal diseases, and genetic syndromes.

Investigating the impact of this technology on T-cells (white blood cells of the immune system), the researchers detected a loss of genetic material in a significant percentage – up to 10% of the treated cells. They explain that such loss can lead to destabilization of the genome, which might cause cancer.

The study was led by Dr. Adi Barzel from the School of Neurobiology, Biochemistry and Biophysics at TAU’s George S. Wise Faculty of Life Sciences and Dotan Center for Advanced Therapies, a collaboration between the Tel Aviv Sourasky Medical Center (Ichilov) and Tel Aviv University, and by Dr. Asaf Madi and Dr. Uri Ben-David from TAU’s Sackler Faculty of Medicine and Edmond J. Safra Center for Bioinformatics. The findings were published in the leading scientific journal Nature Biotechnology.

Cleavage Risk

The researchers explain that CRISPR is a groundbreaking technology for editing DNA – cleaving DNA sequences at certain locations to delete unwanted segments, or alternately repair or insert beneficial segments. Developed about a decade ago, the technology has already proved impressively effective in treating a range of diseases – cancer, liver diseases, genetic syndromes, and more.

The first approved clinical trial ever to use CRISPR, was conducted in 2020 at the University of Pennsylvania, when researchers applied the method to T-cells – white blood cells of the immune system. Taking T-cells from a donor, they expressed an engineered receptor targeting cancer cells, while using CRISPR to destroy genes coding for the original receptor – which otherwise might have caused the T-cells to attack cells in the recipient’s body.  

 

“CRISPR therapeutics, in which DNA is cleaved intentionally as a means for treating cancer, might, in extreme scenarios, actually promote malignancies.”

 

In the present study, the researchers sought to examine whether the potential benefits of CRISPR therapeutics might be offset by risks resulting from the cleavage itself, assuming that broken DNA is not always able to recover.

Dr. Ben-David and his research associate Eli Reuveni explain, “The genome in our cells often breaks due to natural causes, but usually it is able to repair itself, with no harm done. Still, sometimes a certain chromosome is unable to bounce back, and large sections, or even the entire chromosome, are lost. Such chromosomal disruptions can destabilize the genome, and we often see this in cancer cells. Thus, CRISPR therapeutics, in which DNA is cleaved intentionally as a means for treating cancer, might, in extreme scenarios, actually promote malignancies.”

To examine the extent of potential damage, the researchers repeated mentioned 2020 Pennsylvania experiment, cleaving the T-cells’ genome in the same locations – chromosomes 2, 7, and 14 (of the human genome’s 23 pairs of chromosomes). Using a state-of-the-art technology called ‘single-cell RNA sequencing’ they analyzed each cell separately and measured the expression levels of each chromosome in every cell.

Significant Loss of Genetic Material

A significant loss of genetic material was detected in some of the cells. For example, when Chromosome 14 had been cleaved, about 5% of the cells showed little or no expression of this chromosome. When all chromosomes were cleaved simultaneously, the damage increased, with 9%, 10%, and 3% of the cells unable to repair the break in chromosomes 14, 7, and 2 respectively. The three chromosomes did differ, however, in the extent of the damage they sustained. 

“Single-cell RNA sequencing and computational analyses enabled us to obtain very precise results,” explain Dr. Madi and his student Ella Goldschmidt, adding: “We found that the cause for the difference in damage was the exact place of the cleaving on each of the three chromosomes. Altogether, our findings indicate that over 9% of the T-cells genetically edited with the CRISPR technique had lost a significant amount of genetic material. Such loss can lead to destabilization of the genome, which might promote cancer.”

 

“We advance this highly effective technology, while at the same time cautioning against its potential dangers. This may seem like a contradiction, but as scientists we are quite proud of our approach, because we believe that this is the very essence of science: we don’t ‘choose sides.'”

 

Researchers Not ‘Choosing Sides’

Based on their findings, the researchers caution that extra care should be taken when using CRISPR therapeutics. They also propose alternative, less risky, methods, for specific medical procedures, and recommend further research into two kinds of potential solutions: reducing the production of damaged cells or identifying damaged cells and removing them before the material is administered to the patient.

Dr. Barzel and his PhD student Alessio Nahmad conclude: “Our intention in this study was to shed light on potential risks in the use of CRISPR therapeutics. We did this even though we are aware of the technology’s substantial advantages. In fact, in other studies we have developed CRISPR-based treatments, including a promising therapy for AIDS. We have even established two companies – one using CRISPR and the other deliberately avoiding this technology. In other words, we advance this highly effective technology, while at the same time cautioning against its potential dangers. This may seem like a contradiction, but as scientists we are quite proud of our approach, because we believe that this is the very essence of science: we don’t ‘choose sides.’ We examine all aspects of an issue, both positive and negative, and look for answers.”

Two New Planets Found in Milky Way

Written by AUFTAU on . Posted in Newsroom.

TAU team leads discovery of giant planets, similar in size to Jupiter, in remote corner of the galaxy.

Tel Aviv University researchers led the recent discovery of two new planets in remote solar systems within the Milky Way galaxy. They identified the giant planets, named Gaia-1b and Gaia-2b, as part of a study in collaboration with teams from the European Space Agency (ESA) and the body’s Gaia spacecraft.

The development marks the first time that the Gaia spacecraft successfully detected new planets. Gaia is a star-surveying satellite on a mission to chart a 3D map of the Milky Way with unprecedented accuracy comparable to standing on Earth and identifying a 10-shekel coin (roughly the size of a U.S. nickel) on the Moon.  

TAU’s Prof. Shay Zucker, Head of the Porter School of the Environment and Earth Sciences, and doctoral student Aviad Panhi from the Raymond and Beverly Sackler School of Physics & Astronomy led the initiative. The findings were published in the scientific journal Astronomy & Astrophysics. 

More Discoveries on the Horizon

“The discovery of the two new planets was made in the wake of precise searches, using methods of artificial intelligence,” said Prof. Zucker. “We have also published 40 more candidates we detected by Gaia. The astronomical community will now have to try to corroborate their planetary nature, like we did for the first two candidates.”

The two new planets are referred to as “Hot Jupiters” due to their size and proximity to their host star: “The measurements we made with the telescope in the U.S. confirmed that these were in fact two giant planets, similar in size to the planet Jupiter in our solar system, and located so close to their suns that they complete an orbit in less than four days, meaning that each Earth year is comparable to 90 years of that planet,” he adds.  

Giant Leaps for Astronomy 

There are eight planets in our solar system. Less known are the hundreds of thousands of other planets in the Milky Way, which contains an untold number of solar systems. Planets in remote solar systems were first discovered in 1995 and have been an ongoing subject of astronomers’ research ever since, in hopes of using them to learn more about our own solar system.  

To fulfill its mission, Gaia scans the skies while rotating around an axis, tracking the locations of about 2 billion suns, stars at the center of a solar system, in our galaxy with precision of up to a millionth of a degree. While tracking the location of the stars, Gaia also measures their brightness — an incomparably important feature in observational astronomy, since it relays significant information about the physical characteristics of celestial bodies around them. Changes documented in the brightness of the two remote stars were what led to the discovery. Aviad Panhi explains: “The planets were discovered thanks to the fact that they partially hide their suns every time they complete an orbit, and thus cause a cyclical drop in the intensity of the light reaching us from that distant sun.”

To confirm that the celestial bodies were in fact planets, the researchers performed tracking measurements with the Large Binocular Telescope, in Arizona, one of the largest telescopes in the world today. The telescope makes it possible to track small fluctuations in a star’s movement which are caused by the presence of an orbiting planet.

The discovery marks another milestone in the scientific contribution of the Gaia spacecraft’s mission, which has already been credited with a true revolution in the world of astronomy. Gaia’s ability to discover planets via the partial occultation method, which generally requires continuous monitoring over a long period of time, has been doubted up to now. The research team charged with this mission developed an algorithm specially adapted to Gaia’s characteristics, and searched for years for these signals in the cumulative databases from the spaceship.  

Signs of Life?

What about the possibility of life on the surface of those remote new planets? “The new planets are very close to their suns, and therefore the temperature there is extremely high, about 1,000 degrees Celsius, so there is zero chance of life developing there,” explains Panhi. Still, he says, “I’m convinced that there are countless others that do have life on them, and it’s reasonable to assume that in the next few years we will discover signs of organic molecules in the atmospheres of remote planets. Most likely we will not get to visit those distant worlds any time soon, but we’re just starting the journey, and it’s very exciting to be part of the search.” 

Diagnosing Diseases in Space

Written by AUFTAU on . Posted in Newsroom.

TAU researchers successfully test genetic diagnosis under microgravity conditions.

If pursuing the unknown in space is on your bucket list, you can take comfort in knowing that TAU researchers recently conducted a unique experiment at the International Space Station to test genetic diagnosis under microgravity conditions. The researchers launched a kit together with Israeli astronaut Eytan Stibbe to space and proved that an existing technology based on a bacterial immune system against viruses, ‘CRISPR’, can be used to identify viruses and bacteria infecting crew members during space missions.

The study was led by Dr. Dudu Burstein from the Shmunis School of Biomedicine and Cancer Research, Tel Aviv University and Dr. Gur Pines from the Volcani Institute. The experiment was conducted by Stibbe as part of the “Rakia” mission in April, under the leadership of the Ramon Foundation and the Israel Space Agency.

Suited for Astronauts

CRISPR systems are the immune systems of bacteria from viruses. Bacteria use the CRISPR-Cas systems as a sort of molecular ‘search engine’ to locate viral sequences and cleave them to disable viruses.

As part of their scientific vision, the researchers hypothesized that genetic diagnostics using this method, which requires minimal and easily operated equipment, could be suitable for long space missions: “Conditions in space are extremely problematic,” explains Burstein. “Treatment methods are limited, so it is essential to identify pathogens [= a microorganism that can cause disease] in a rapid, reliable, and straightforward method.” The method stands in contrast to tests like PCR (which we are now all familiar with due to Covid-19), which Burstein notes require trained personnel and relatively complex equipment.”

 

Researchers discussing the experimental design. From left to right: Dan Alon, Dr. David Burstein, Dr. Gur Pines (Photo: Ella Rannon)

Burstein outlines the process: “First, the DNA is amplified: each targeted DNA molecule is repeatedly duplicated many times. Then the CRISPR-Cas goes into action: If it identifies the target DNA, it activates a fluorescent molecular marker. The fluorescence lets us know whether the bacteria or viruses of interest are indeed present in the sample. This whole process can be conducted in one tiny test tube, so it is well suited for the astronauts’ needs.”

Zero Gravity? No problem!

Dr. Burstein describes the preparation for the space experiment: “Doctoral student Dan Alon and Dr. Karin Mittelman planned the experiment in detail and conducted it countless times in the lab under various conditions. After reaching the desired result, they prepared a kit, including the CRISPR-Cas system and the other components required for detection. Eventually, the kit was launched with Eytan Stibbe to the International Space Station.”

The experiments conducted by Stibbe were very successful, and proved that it is indeed possible to perform precise and sensitive CRISPR-based diagnosis – even in an environment with virtually no gravity.

What now? “This is the first step towards the simple and rapid diagnosis of diseases and pathogens on space missions,” says Burstein, adding that there is still some work to do on the next stages, including, “simple extraction of DNA from samples, making the system more efficient, so that it will be able to test a variety of organisms in one test tube, and diagnosis of more complex samples.”

“It was inspiring to see our test kit in Eytan’s hands at the Space Station, and we’re even more excited by the possibility that such kits will help future astronauts on their extraterrestrial missions,” he concludes.

 

Eytan Stibbe executing the experiment on the International Space Station (Photo: the Ramon Foundation and the Israel Space Agency)

Featured image: International space station on orbit of planet Earth 

If We Let Them Go, They Won’t Come Crawling Back

Written by AUFTAU on . Posted in Newsroom.

One in every five species of reptiles is facing extinction.

There are over 12,000 species of reptiles crawling our planet, but according to a new international study, involving researchers from Tel Aviv University and Ben-Gurion University of the Negev, 21% of these, or a total of about 2,000 species, are threatened with extinction. How can we save them? Or is it too late?

15.6B Years of Evolution Down the Drain?

The comprehensive study, the first of its kind in history, was conducted by the International Union for Conservation of Nature (IUCN) and included 52 researchers from around the world, including Prof. Shai Meiri of Tel Aviv University’s School of Zoology, The George S. Wise Faculty of Life Sciences and the Steinhardt Museum of Natural History, and Dr. Uri Roll of Ben-Gurion University of the Negev. The study was published in the prestigious journal Nature.

The findings of the study show that 30% of forest-dwelling reptiles and about 14% of those living in arid areas are threatened, and that 58% of all turtle species and 50% of all crocodile species are in danger of becoming extinct. The researchers sadly point out that if all of the 1,829 species of turtles, crocodiles, lizards, and snakes that have been found to be threatened do indeed become extinct in the coming years, the world will lose a cumulative wealth of 15.6 billion years of evolution.

Fortunately, no species of reptile has become extinct in Israel in the last decade, but there are many species that are endangered, such as the Hermon Gecko, the Be’er Sheva fringe-fingered lizard and several more.

 

50% of all crocodile species are in danger of becoming extinct

Mapping Out the Threats

The IUCN is an international body whose role is, among other things, to assess the threat of extinction posed to various species. Each species of animal or plant receives a score on a five-point scale. The purpose of this ranking is to define those species that are the most endangered, thereby enabling decision makers and various bodies, such the Israel Nature and Parks Authority, to outline policies accordingly.

In 2004, the IUCN released a comprehensive report on amphibians, and a few years later it issued reports on birds and mammals. The IUCN has been working on the reptile report for the past 18 years, having invited experts on this taxonomic group from all over the world to participate.

“In general, the state of reptiles in the world is bad,” says Prof. Meiri. “It’s worse than that of birds and mammals, though not as bad as that of the amphibians. And of course there are a lot of nuances. We see that turtles are in a worse position than lizards and snakes, but that may be because we know more about turtles. Perhaps if we knew more about snakes, we would see that they, too, are in big trouble.”

“The biggest threat to reptiles is the destruction of their habitats due to agriculture, deforestation, and urban development, and less because of direct hunting, which mainly affects turtles and crocodiles. We created detailed maps of these threats. For example, if a particular species is highly threatened in the Israel’s Arava desert, but not in the rest of its habitat range that may span the entire Arabian Peninsula, then globally it is not considered a threatened species. The new assessments, for more than 10,000 species of reptiles, will allow us to understand their conservation needs, and hopefully enable us to find far more intelligent solutions for them than we have been able to so far.”

 

Prof. Shai Meiri

Dr. Uri Roll adds, “This is important work that forms the initial basis for risk assessment among various reptiles around the world, but is certainly not the end of the story. We still lack a lot of information about the various risks facing reptiles. For example, climate change is expected to have significant effects on reptiles. The current assessment that has just been published does not yet include these future threats in its reptile risk assessments. We still have a lot of work ahead of us.”

When asked whether it is still possible to stop the wheels from turning, Prof. Meiri says that “There’s room for optimism, but not overly so. It is finally possible, thanks in part to this study, to plan dedicated nature conservations for reptiles as well – there is more awareness and there are ways in which we can help them. In Israel, great efforts are made to protect various kinds of turtles. Less attention is paid to most species of lizards and snakes, however, which make up the vast majority.”

Featured image: Endangered: Egyptian mastigure (Photo: Alex slavenko)

The Ultimate Solution to Global Warming?

Written by AUFTAU on . Posted in Newsroom.

Breakthrough TAU discovery may accelerate an industrial transition to sustainable energy.

Hydrogen-powered bicycles and cars have been in serial production for years. In these vehicles, the regular polluting lithium battery has been replaced by a fuel cell that converts hydrogen, a non-polluting fuel, to electricity. Most of today’s hydrogen is, however, still produced from natural gas in a highly polluting process and is therefore referred to as gray hydrogen. Not only is natural gas a non-renewable source of energy, but it also creates carbon dioxide gas when burned, damaging our environment and contributing to global warming.

Enter a new TAU discovery, which may boost the industrial transition from using polluting gray hydrogen to environmentally friendly green hydrogen: Researchers identified a mutant of a known strain of microscopic algae that allows, for the first time, the production of green hydrogen gas via photosynthesis on a scale suited to industrial requirements. Hydrogen gas can thus be produced solely through renewable energy and in a climate-neutral manner, reducing our carbon footprint and greenhouse gas emissions dramatically to stabilize global temperatures. 

Humanity’s transition to the use of green hydrogen may be the ultimate solution to the problem of global warming.

The microscopic algae

Continuous Production Achieved

The study was led by doctoral student Tamar Elman, under the supervision of Prof. Iftach Yacoby from the Renewable Energy Laboratory of The George S. Wise Faculty of Life Sciences at Tel Aviv University. The study was recently published in the prestigious journal Cell Reports Physical Science. 

While production of green hydrogen is possible through solar panels wired to devices that perform water breakdown into hydrogen and oxygen (electrolysers), the researchers explain that this is an expensive process, requiring precious metals and distilled water. In nature, hydrogen is produced as a by-product of photosynthesis for periods of minutes by micro-algae, unicellular algae found in every water reservoir and even in the soil. For this biological process to become a sustainable source of energy, however, humanity must engineer micro-algae strains that produce hydrogen for days and weeks.

Prof. Yacoby explains that as part of the laboratory tests, the researchers identified a new mutant in microscopic algae that prevents oxygen from accumulating at any lighting intensity, and therefore hypothesized that continuous hydrogen production could be achieved from it. With the help of bioreactor measurements in liter volumes, they were indeed able to prove that hydrogen can be produced continuously for more than 12 days.

According to Prof. Yacoby, the new mutant overcomes two major barriers that have so far hindered continuous production of hydrogen:

  1. Accumulation of oxygen in the process of photosynthesis – As a rule, oxygen poisons the enzyme that produces hydrogen in algae, but in the mutation, increased respiration eliminates the oxygen and allows favorable conditions for continuous hydrogen production.
  1. Loss of energy to competing processes – And this includes carbon dioxide fixation into sugar. This, too, has been solved in the mutant and most of the energy is being channeled for continuous hydrogen production.

To industrialize these results, the research team led by Prof. Yacoby is working on a pilot program of larger volumes and the development of methods that will allow the time of hydrogen harvest to be extended, in order to reduce its cost to competitive levels. “The rate of hydrogen production from the new mutant reaches one-tenth of the possible theoretical rate, and with the help of additional research it is possible to improve it even further,” concludes Prof. Yacoby.

 

Tamar Elman and Prof. Iftach Yacoby in the lab

Featured image: Tamar Elman and the microscopic algae

How are the Birds Coping with Climate Change?

Written by AUFTAU on . Posted in Newsroom.

Researchers detect changes in birds’ bodies, probably caused by global warming.

Researchers at Tel Aviv University have found changes in the morphology of many birds in Israel over the past 70 years, which they interpret to be a response to climate change. The body mass of some species decreased, while in others body length increased – in both cases increasing the ratio between surface area and volume. The researchers contend that these are strategies to facilitate heat loss to the environment: “The birds evidently changed in response to the changing climate. However, this solution may not be fully adequate, especially as temperatures continue to rise.”

Relying on the vast bird collection preserved by The Steinhardt Museum of Natural History at TAU, the researchers looked for changes in bird morphology over the past 70 years in Israel. They examined approximately 8,000 adult specimens of 106 different species – including migratory birds that annually pass through Israel (such as the common chiffchaff, white stork, and black buzzard), resident wild birds (like the Eurasian jay, Eurasian eagle-owl, and rock partridge), and commensal birds, that live near humans. They built a complex statistical model consisting of various parameters to assess morphological changes – in the birds’ body mass, body length and wing length – during the relevant period.

The study was led by Prof. Shai Meiri and PhD student Shahar Dubiner of the School of Zoology, The George S. Wise Faculty of Life Sciences, and the Steinhardt Museum of Natural History at Tel Aviv University. The paper was published in the scientific journal Global Ecology and Biogeography.

Cooling Down

Prof. Meiri explains that according to Bergmann’s rule, formulated in the 19th century, members of bird and mammal species living in a cold climate tend to be larger than members of the same species living in a warmer climate. This is because the ratio of surface area to volume is higher in smaller animals, permitting more heat loss (an advantage in warm regions), and lower in larger bodies, minimizing heat loss (a benefit in colder climates). Based on this rule, scientists have recently predicted that global warming will lead to a reduction in animal size, with a possible exception: birds living in the human environment (such as pigeons, house sparrows, and the hooded crow) may gain size due to increased food availability, a phenomenon already witnessed in mammals such as jackals and wolves.

Either Long or Slender

Shahar Dubiner: “Our findings revealed a complicated picture. We identified two different types of morphological changes: some species had become lighter – their mass had decreased while their body length remained unchanged; while others had become longer – their body length had increased, while their mass remained unchanged. These together represent more than half of the species examined, but there was practically no overlap between the two groups – almost none of the birds had become both lighter and longer. We think that these are two different strategies for coping with the same problem, namely the rising temperatures. In both cases, the surface area to volume ratio is increased (by either increasing the numerator or reducing the denominator) – which helps the body lose heat to its environment. The opposite, namely a decrease in this ratio, was not observed in any of the species.”

 

The researchers (from left to right): Shahar Dubiner and Prof. Shai Meiri

Global Phenomenon

Sadly, flying away from global warming is not an option. These findings were observed across the country, regardless of nutrition, and in all types of species: resident birds; commensal species living in the human environment – which, contrary to predictions, exhibited changes similar to those of other birds; and migrants.

A difference was identified, however, between the two strategies: changes in body length tended to occur more in migrants, while changes in body mass were more typical of non-migratory birds. The very fact that such changes were found in migratory birds coming from Asia, Europe, and Africa, suggests that we are witnessing a global phenomenon.

The study also found that the impact of climate change over time on bird morphology (the birds’ change in either weight or length over time, relative to the actual temperature change during that time) is ten times greater than the impact of similar differences in temperature between geographical areas (the birds’ differences in weight or length in different geographical areas, relative to the temperature differences between those areas).

What is the Limit of Evolutionary Flexibility?

Shahar Dubiner: “Our findings indicate that global warming causes fast and significant changes in bird morphology. But what are the implications of these changes? Should we be concerned? Is this a problem, or rather an encouraging ability to adapt to a changing environment? Such morphological changes over a few decades probably do not represent an evolutionary adaptation, but rather certain phenotypic flexibility exhibited by the birds. We are concerned that over such a short period of time, there is a limit to the flexibility or evolutionary potential of these traits, and the birds might run out of effective solutions as temperatures continue to rise.”

Featured image: Israeli birds have become either longer or slenderer over the past 70 years

Work created by TAU-affiliated artists can’t exist on earth

Written by AUFTAU on . Posted in Newsroom.

Many think that physics is an exact science that requires the application of analytical and quantitative abilities, while art is based on emotion and creativity. A collaboration between the physicist Dr. Yasmine Meroz of Tel Aviv University (TAU) and the contemporary artist Liat Segal challenges the boundaries between the two fields. Their joint work, called “Impossible Object,” will be launched in April to the International Space Station (ISS), as part of the “Rakia” mission of the Israeli astronaut Eitan Stiva.

Dr. Meroz is a senior faculty member at the School of Plant Sciences and Food Security at TAU’s Wise Faculty of Life Sciences, whose lab studies the physics of plant systems. Segal studied Computer Science and Biology and worked in the hi-tech industry for several years, before shifting her career to arts. The special bond between the two was created when they were graduate students at the same lab at TAU.

“Impossible Object” is a sculpture made of water. The liquid’s three-dimensional form does not get its shape from any vessel and so cannot exist on earth, but only in outer space in the absence of gravity.

The sculpture is made of interconnected brass pipes and rods, through which water is flown. In the absence of gravity, the water adheres to the rods and forms a liquid layer shaped by water tension, which envelopes the brass structure, yielding a three-dimensional shape that changes over time. The underlying brass structure is reminiscent of a wavy and directionless staircase, raising questions about shape and form in the absence of gravity and directionality. In particular, what is the shape of water? What does a “slice of the sea” or a “handful of a wave” look like?

“There is much in common between art and scientific research: Both are the result of a thought process in which creativity plays a central role and are motivated by the desire to ask interesting questions,” Dr. Meroz says. “‘Impossible Object’ is a research-based artwork, where the medium is basically the physics underpinning water behavior in the absence of gravity. I learned a lot in the process, and I have no doubt it will contribute to research in my laboratory. In this respect, this work expresses the unrealized potential of the synergy between art and scientific research.”

“I am very happy about my collaboration with Yasmine,” Segal adds. “In this collaboration we not only shared knowledge and inspiration, but we were also able to bring about a true co-creation, which could not have been realized by each one of us individually. ‘Impossible Object’ is timely, weighing the role of culture and art at an era when humanity is experiencing accelerated scientific and technological developments. Following incredible technological and scientific achievements in space, and as space tourism becomes tangible, it is important to reflect on the place of culture and arts in our lives, on earth and beyond.”

This is their second collaboration; their previous artwork, “Tropism,” has been exhibited at TAU’s Genia Schreiber University Art Gallery.

TAU Welcomes Ukrainian Emergency Fellowship Students

Written by AUFTAU on . Posted in Newsroom.

Some “need time to unfreeze”, as they begin their studies on campus.

Tel Aviv University officially welcomed seven Ukrainian graduate students, who arrived within the framework of the Emergency Fellowship Fund recently announced by the University in light of Russia’s invasion of Ukraine and the ensuing refugee crisis.

The all-women group of students hail from different cities in Ukraine, stretching from Lviv and Kyiv to Mariupol and Mikolaiv, and will continue their studies in law, medicine, psychology, music and linguistics. 

“You are very much wanted here at TAU,” President Ariel Porat told the students at the introductory meeting, expressing hope that despite the unfortunate circumstances students will find “a home away from home” at the University that will enrich their academic and personal lives. 

Constant Worry

Most of the students left their families behind in Ukraine, and worry about their wellbeing around the clock. “I managed to speak to my family yesterday, but today the connection was severed and I was unable to reach them,” says Alisa, a graduate student in law, who will be studying Crisis Management at TAU. She comes from a small town near Mariupol, in Eastern Ukraine, which has suffered some of the heaviest blows in the fighting. Alisa heard about the Fellowship through her academic advisor, as did most of the other students. 

Marina, another law student, was enrolled at the Ukrainian State Pedagogical University in Kropyvnytskyi, a central town which she says is pretty safe for now. The University premises, however, have been converted into living quarters for people escaping from more dangerous areas. Lectures are only taking place online and are highly irregular. “I was supposed to graduate in June,” she tells us, “but for now, I’m just happy to be able to continue my studies here at TAU.”

Kateryna from Kyiv studies psychology, and left immediate family members in Ukraine. “This is my first time in Israel and I know nothing about the local culture, but I’m very curious to learn,” she says, adding that the adjustment process helps her endure the constant concern about her family’s wellbeing. 

“We need some time to ‘unfreeze’, before we can start to take in and appreciate our surroundings,” adds Alisa. 

Here to Help

The students are being offered counseling and psychological services by TAU International, which has been taking full care of them since their arrival in Israel. “In light of the humanitarian situation in Ukraine, we are making a great effort to ensure that the Ukrainian students enjoy their campus experience and have a smooth transition to living in Tel Aviv, and that all their immediate needs are met,” says Michal Linder Zarankin, the School’s International Projects Coordinator.

Their tuition and living expenses are covered by TAU’s $1 million Emergency Fellowship Fund, which was swiftly raised by the University’s donors around the world over the last few weeks. 

Five more Ukrainian students are expected to arrive next week, as well as some faculty members. 

Out of the 30,000 students studying at TAU, over 300 hold dual Israeli-Ukrainian citizenship. In addition to these, there are many Israeli TAU students of Ukrainian and Russian descent. 

Featured image: Ukrainian graduate students are welcomed by TAU’s President Ariel Porat, Prof. Milette Shamir VP International and TAU International staffers

Prof. Ehud Gazit – First Israeli to Receive Prestigious International Recognition in Chemistry

Written by AUFTAU on . Posted in Newsroom.

Selected as International Solvay Chair in Chemistry for 2023.

Prof. Ehud Gazit from The Shmunis School of Biomedicine and Cancer Research at The George S. Wise Faculty of Life Sciences and The Department of Materials Science and Engineering at The Iby and Aladar Fleischman Faculty of Engineering, was selected as the International Solvay Chair in Chemistry for 2023. Prof. Gazit, who also heads TAU’s Blavatnik Center for Drug Discovery, is the first Israeli to receive this annually awarded honor and the first scientist to be appointed to the position outside of the United States and Europe. 

 Joining 15 Other World Top Scientists

The Solvay International Institute was founded in Belgium about a century ago and is designed to develop and support creative and groundbreaking research in physics, chemistry and related fields, in order to increase and deepen the understanding of natural phenomena. The Institute organizes annual conferences on physics and chemistry, as well as international workshops for the training of doctoral students and selected topics. 

As part of Gazit’s new appointment, he will spend a month or two in Brussels, the capital of Belgium, during which he will give lectures on his field of research. The prestigious nomination has previously been awarded to 15 of the world’s top scientists, including three Nobel laureates in chemistry, the Wolf Prize winner and laureates of other prestigious awards, all from leading institutions in the US and Europe, who are now joined by Gazit. 

Gazit is a biophysicist, biochemist and nanotechnologist. His main area of expertise is “Solid State Biology”, an innovative field of study that combines disciplines from physics, chemistry, synthetic and structural biology and materials engineering. He is a world-renowned expert in nanotechnology and biological chemistry, a highly cited researcher who has published more than 350 scientific articles and inventor of more than 100 patents.

Previously, he served as Vice President for Research and Development of the University, as the Chairman of Ramot, Tel Aviv University’s Tech Transfer Company, and as the Chief Scientist of Israel’s Ministry of Science and Technology. 

Over the years, Gazit has won a number of prestigious awards and prizes in Israel and around the world, including The Kadar Family Award for Outstanding Research, the Landau Prize in Science and Arts and the Rapaport Prize for Excellence in Biomedical Research. He is a Fellow of the Royal Society of Chemistry in the UK, a Foreign Fellow of the National Academy of Sciences in India and a Member of the European Organization for Molecular Biology.  

Gazit stated: “I thank the Solvay Institute for selecting me, a great honor and excitement for me. It is a great privilege for me to join such a prestigious and impressive list of leading researchers. Today I am reminded of the former President of Israel, Prof. Ephraim Katzir, one of Israel’s greatest scientists, and of whom I am one of his academic ‘great grandchildren’ and who organized the Solvay Institute’s Chemistry Conference about 40 years ago. Apart from the personal honor, I am happy and proud to represent Tel Aviv University and the State of Israel in this appointment.”

Victoria

Tok Corporate Centre, Level 1,
459 Toorak Road, Toorak VIC 3142
Phone: +61 3 9296 2065
Email: [email protected]

New South Wales

Level 22, Westfield Tower 2, 101 Grafton Street, Bondi Junction NSW 2022
Phone: +61 418 465 556
Email: [email protected]

Western Australia

P O Box 36, Claremont,
WA  6010
Phone: :+61 411 223 550
Email: [email protected]