Newsroom – Page 48 – Australian Friends of Tel Aviv University

For the first time: The “God Particle” has been characterized in its decay into a pair of charm quarks

Written by AUFTAU on 8 August 2021. Posted in Newsroom, Press release.

Physicists worldwide have been captivated by the Higgs boson particle, also known as the “God Particle”. Its discovery a decade ago made waves in the physics community, and had researchers curious to learn more about its properties. TAU researchers have now succeeded, as part of a groundbreaking study, to describe a rare physical process through which the Higgs boson decays into a pair of rare elementary particles. The rate of this decay process can now be characterized more precisely and completely than before.

The new study was conducted as part of the ATLAS experiment at the Large Hadron Collider (LHC) at CERN (Geneva) by Prof. Erez Etzion and doctoral students Guy Koren, Hadar Cohen and David Reikher from the Raymond and Beverly Sackler School of Physics and Astronomy, Raymond and Beverly Sackler Faculty of Exact Sciences, at Tel Aviv University. It was a collaboration with the research team of Prof. Eilam Gross from the Weizmann Institute of Science and others.

Learning More About Forces in Nature

Over fifty years ago, physicists Prof. Peter Higgs and Prof. Francois Englert (who since 1984 has been a Sackler Fellow by special appointment in the TAU School of Physics and Astronomy) estimated that a new particle might exist whose field “provides the mass” to the elementary particles in our world.

In 2012, the end of a 30-year hunt for the Higgs boson was celebrated. Israeli researchers were senior partners in this discovery, and Prof. Halina Abramowicz, who was part of the TAU team, said “The discovery of the Higgs-like particle affirms the world view that the universe is made up of straightforward, symmetrical laws and that humans are the byproduct of disruptions in that symmetry.” Higgs and Englert won the Nobel Prize the following year.

The Challenge of Creating the Higgs boson

In the particle accelerator, pairs of protons are made to collide with each other at extremely high velocities. In such energetic collisions, various interesting processes can occur, from which, one can learn about the nature of our universe. The way in which these processes are investigated, is by means of a complex array of particle detectors placed around the points of collision, enabling reconstruction of the types of particles that are generated during the collision, as well as their features. A vast range of processes can occur during the collisions, and each has its own unique “signature” in the detector. In order to extract rare events and acquire new insights about the elementary particles and forces in nature, large amounts of statistical data must be collected (i.e. a very large number of collisions must be observed).

The Higgs boson is, as mentioned, a relatively heavy elementary particle, but can be created in collision between protons, as long as the accelerator’s energy is high enough. Immediately after its creation, it decays into lighter particles.

“It is interesting to investigate into which types of particles the Higgs decays, and with what frequency it decays into each type of particle,” says Guy Koren. “To help answer that question, our group is trying to measure the rate at which the Higgs boson decays into particles called ‘charm quarks’.” Quarks are a specific type of particles that share similar features. They compound, for instance, the protons and neutrons, which are in the nuclei of atoms. Koren continues to explain that measuring the decay of Higgs boson into ‘charm quarks’ is not a simple mission, for two reasons: 1. Only one out of billions of collisions [between protons] result in the creation of Higgs bosons. Furthermore, only three percent of the Higgs bosons that do emerge proceed to decay into charm quarks. 2. Five additional types of quarks exist, and they all leave similar signatures in the detectors. So, even when the process does take place, it is very hard to identify.

More Information About The Rate of Decay

Despite all the collisions that have been collected since 2012, the group from Tel Aviv has not yet identified enough decays of Higgs bosons into charm quarks to measure the rate of the process with the required statistical accuracy.

Nevertheless, sufficient data has been accumulated to state what the maximal rate of the process is with respect to the theoretical predictions. A rate of decay higher than the predicted rate would constitute a first important indicator for “new” physics or expansion of the currently accepted model – the standard model of elementary particles. From the current measurement, the researchers conclude (with a well-defined statistical certainty) that there is no chance that the rate of decay of the Higgs boson into charm quark is 8.5 (or more) times higher than the theoretical predictions, otherwise enough such decays would have been observed in order to measure it. “This is the first time that anyone has ever succeeded in saying something important about the rate of this specific decay based on a direct measurement of it, therefore it is a very important and significant statement in our field,” explains Koren

The research is not yet over, however. Higgs’ decays into quarks of smaller masses have yet to be observed. As a result, the researchers cannot be certain that the same ‘rules’ apply to quarks from those generations. “If it should appear that the Higgs boson decays at a rate that is not proportional to mass (squared) of the particles, there could be far-reaching implications for our understanding of the universe,” explains Prof. Etzion.

Featured image: Illustration: The European Organization for Nuclear Research (CERN)’s LHC accelerator, by which the Higgs boson was detected in 2012 in the ATLAS and CMS experiments

New Warning Sign for Breast Cancer

Written by AUFTAU on 6 August 2021. Posted in Newsroom.

A team led by Tel Aviv University identified a new indicator of metastatic breast cancer, laying the groundwork for preventive treatment that could save millions of lives.

Metastatic breast cancer, also known as Stage 4 breast cancer, occurs when cancer has spread, or “metastasized,” to other parts of the body. Mortality from breast cancer is almost exclusively a result of tumor metastasis, and lungs are one of the main metastatic sites. The five-year survival rate for women with metastatic breast cancer is estimated at 28%.

Investigating The “Black Box” of Breast Cancer

“Breast cancer patients, as well as patients with many other types of cancer, do not die from the primary tumor, but from distant metastases which have developed, sometimes after years, in essential organs such as the lungs and brain,” said the study’s lead researcher, Prof. Neta Erez, Chair of the Department of Pathology at TAU’s Sackler Faculty of Medicine. “Understanding the body’s preparation for the reception of metastases at an early stage may save millions of lives.”

The researchers explain that metastases can appear several years after the initial cases are treated. Today, methods used for follow-up screening identify metastases only when they are quite large–when the disease is at an advanced stage and unlikely to be cured.

For this reason, Erez’s research group is investigating the black box—the time period between apparent recovery and the appearance of metastases to understand the metastatic process and to find ways of blocking it in early stages. Their research in recent years has revealed that certain tissues, in organs where the metastases are set to arrive, “prepare the area” for reception and produce a hospitable environment for them, a long time before the appearance of the metastases themselves. In the present study, the research team searched for signs of these changes, which may be used in the future to identify the start of the process that predicts metastases. The researchers identified these changes in the area known as “the micro-environment” of the tumor, and specifically in connective tissue known as fibroblasts which are found in the lungs among other places.

“In a normal situation, fibroblasts play a central role in healing wounds and injury to the lungs, but recent studies revealed that cancer is successful in recruiting them and causing them to produce a supportive environment for it,” said Erez.

What is Happening in the Micro-environment of the Metastases?

The researchers compared genes sequenced from healthy lungs, from lungs with micro-metastases (very small metastases which cannot be identified using existing clinical tools) and from lungs with large metastases, in a state of advanced disease.

By identifying and comparing the respective development in the three different types of sample tissues, the researchers succeeded, for the first time, in characterizing the process that occurs in the micro-environment of the metastases. The findings provide valuable understanding about how cancer cells grow, which can then be leveraged for detection by existing imaging methods and treated to prevent metastasis.

The study’s leading research team from Erez’s laboratory included Dr. Ophir Shani and Dr. Yael Raz along with additional researchers from Tel Aviv University, Sheba Medical Center at Tel HaShomer, Tel Aviv Sourasky Medical Center (Ichilov Hospital), and the Weizmann Institute of Science. The findings were published in the prestigious peer-reviewed journal eLife.

Featured image: Prof. Neta Erez (Photo: Michal Kidron)

Diminishing at the Edges

Written by AUFTAU on 4 August 2021. Posted in Newsroom, Press release.

A new study by Tel Aviv University reveals significant ecological damage to many marine protected areas (MPAs) around the world. A strong “edge effect” was observed, resulting in a 60% reduction in the fish population living on their outer edges (1-1.5 km), compared to the core areas. The “edge effect” significantly diminishes the effective size of those areas, and largely stems from human pressures, first and foremost overfishing at their borders.

Marine protected areas were designed to preserve marine ecosystems, and help to conserve and restore fish populations and marine invertebrates whose numbers are increasingly dwindling due to overfishing. The effectiveness of the protected areas has been proven in thousands of studies conducted worldwide. At the same time, most studies sample only their “inside” and “outside”, and there still is a knowledge gap about what happens in the space between their core and areas around them that are open for fishing.

The study was conducted by Sarah Ohayon, a doctoral student at the laboratory of Prof. Yoni Belmaker, School of Zoology, The George S. Wise Faculty of Life Sciences, and The Steinhardt Museum of Natural History at Tel Aviv University. The study was recently published in the Nature Ecology & Evolution Journal.

The “Edge Effect”

When a protected area functions properly, the expectation is that the recovery of the marine populations within it will result in a spillover, a process where fish and marine invertebrates migrate outside its borders. In this way, the protected area can contribute not only to the conservation of marine nature, but also to the renewal of fish populations surrounding it that have dwindled due to overfishing.

To identify the dominant spatial pattern of marine populations from within the protected areas to the surrounding areas (that are open for fishing), the researchers analyzed marine populations from dozens of protected areas located in different parts of the oceans.

“When I saw the results, I immediately understood that we are looking at a pattern of edge effect”, says Ohayon. “The edge effect is a well-studied phenomenon in terrestrial protected areas, but surprisingly it has not yet been studied empirically in MPAs. “This phenomenon occurs when there are human disturbances and pressures around the protected area, such as hunting/fishing, noise or light pollution that reduce the size of natural populations within the protected areas, close to their borders”.

No-Take Marine Protected Areas Are Too Small

The researchers found that 40% of the no-take MPAs (areas where fishing activity is completed prohibited) around the world are less than 1 km², which means that entire area is likely to experience an edge effect. In total, 64% of all no-take MPAs in the world are smaller than 10 km² and may hold only about half (45-56%) of the expected population size in their area compared to a situation without an edge effect. These findings indicate that the global effectiveness of existing no-take areas is far less than previously thought.

It should be emphasized that the edge effect pattern does not eliminate the possibility of fish spillover, and it is quite plausible that fishers still enjoy large fish coming from within the protected areas. This is evidenced by the concentration of fishing activity at their borders. At the same time, the edge effect makes it clear to us that marine populations near the borders of the protected areas are declining at a faster rate than the recovery of the populations surrounding them.

Buffer, Enlarge and Enforce

The study findings also show that in protected areas with buffer zones around them, no edge effect patterns were recorded, but rather a pattern consistent with fish spillover outside their borders. Additionally, a smaller edge effect was observed in well-enforced protected areas than in those where illegal fishing was reported.

“These findings are encouraging, as they signify that by putting buffer zones in place, managing fishing activity around marine protected areas and improving enforcement, we can increase the effectiveness of the existing protected areas and most probably also increase the benefits they can provide through fish spillover”, adds Ohayon.

“When planning new marine protected areas, apart from the implementation of regulated buffer zones, we recommend that the no-take MPAs targeted for protection be at least 10 km² and that their shape be as round as possible. These measures will reduce the edge effect. Our research findings provide practical guidelines for improving the planning and management of marine protected areas, so that we can do a better job of protecting our oceans.”

Featured image: Photo credit Dr. Shevy Rothman

This Exhibition Will Make You Sweat

Written by AUFTAU on 3 August 2021. Posted in Magazine, Newsroom.

New exhibition on climate crisis gives us tools to save the planet.

Recent news has covered extreme events all over the world: floods in Germany, Belgium and central China, huge wildfires raging in California, consuming thousands of acres of land and extreme temperatures in Canada, Iraq and the United States. Scientists no longer doubt that all this and more is taking place due to global warming, and what is commonly referred to as the “climate crisis”

Seeking to educate the Israeli public on the science behind the concepts that we keep hearing, such as the greenhouse effect, global warming and carbon footprint, the Steinhardt Museum of Natural History has set up the exhibition “Global Warning: The Climate, the Crisis and Us”, which encourages the public to learn more about the subject and become ambassadors who will lead the long-awaited change. We checked, and can share with you that it is impossible to remain indifferent after visiting the exhibition.

How Many Trees Are Working Just for You?

The exhibition, which the museum has been working on for over a year, guides the visitors to the sea, land, glaciers and forests, in the past, present and future. It presents current scientific findings and basic concepts in the field in simple terms and through interactive means, such as videos, thermal cameras that expose thermal gases that surround us, and more.

It uncovers the dire consequences of the climate crisis here in Israel and worldwide, and illustrates the impact of our daily choices as individuals. Everything is not lost; the exhibition illuminates how we can counteract the changes that are causing the crisis and reduce the harm caused to us and the environment.

The various stations of the exhibition show how popular tourist spots may look like in 20 years from now, what the atmospheric composition was thousands of years ago, and what it may be in a few decades from now. The connection between allergies and global warming is explained, as well as what it will be like when sea level reaches our shoulders. You can even check what your personal carbon footprint is, by the help of an online calculator which was developed especially for the exhibition and is the first of its kind in Israel.

What do greenhouse gases look like? Judi Lax explains big concepts in simple language.

Fostering Change Agents

The new exhibition does not, however, intend to scare us into passivity: “We wish to increase the awareness surrounding our daily choices, such as what to eat, how to travel, what to buy and what not to buy. These things have implications and a price beyond the cost of the purchase itself. Oftentimes, people hear about the climate crisis and say, “Ok, but how does this relate to me?” We wish to impart that, although a lot [of damage] has accumulated, it is not all lost. We also have a hand in the matter, and can undo some of the damage,” explains Hadas Zemer Ben-Ari, the exhibition’s curator and designer. “Along with the experience of visiting the exhibition, we strive to make our visitors agents of change, who will spread the message outside the walls of the museum and inspire many others to work for the change that we so desperately need,” says Prof. Tamar Dayan, Museum Chair at the Steinhardt Museum of Nature.

The Museum joins some of the worlds’ largest museums in the common mission to carry out their social role in educating the wider audience on the topic of the climate crisis and the discussion of the biodiversity crisis and its impacts. Museum Director Alon Sapan explains that museums are capable of illustrating and simulating a complex reality and the processes that led to it, along with predictions for the future, while ensuring the visitors’ experience and encouraging their curiosity. “I hope that the exhibition will inspire questions, and also enlighten individuals on how they contribute to positive change by adjusting their personal habits,” concludes Sapan.

An invitation to change a habit (or three!) at the “Global Warning” exhibition.

Featured image: The exhibition “Global Warning: The Climate, the Crisis and Us” (Photo: Dor Kimchi)

He’s Bringing Plastic Back

Written by AUFTAU on 2 August 2021. Posted in Magazine, Newsroom.

TAU alumnus Tal Cohen and his company “Plastic Back” converts plastic waste back to its original form.

We use plastic in almost every aspect of our lives. It is cheap in production, durable and can be reused multiple times. The problem is, though, that 350M tons of plastic waste is produced annually, out of which only 8% is recycled. To counter the environmental hazard, laws and regulations, are implemented towards reducing landfill and increasing recycling. The EU has pledged to reduce landfilling to 10% of its current capacity by 2030. We spoke with Tal Cohen, a TAU alumnus with an MBA from the Coller School of Management and founder of a startup company called “Plastic Back”, who may have found the perfect solution.

The Big Savior Becomes the Big Offender

When plastic was originally introduced, 70 years ago, it was commonly believed that it would contribute to save the environment. “When plastic was first introduced, it was actually thought to be the big savior of the future environment, replacing the use of ivory, tortoise shell and corals. While petroleum came to the relief of the whale, plastic has given the elephant, the tortoise and the coral a respite in their native haunts,” says Tal. With time, however, it went from being the big savior to instead becoming recognized as a major environmental hazard,” Tal muses. Over the past 70 years since its invention, 8.3 billion tons of plastic waste has been accumulated worldwide.

And how is plastic produced? “After developing over millions of years underground, crude oil is drilled out and extracted. It is then sent to be refined by the petrochemical industry, after which it can be used for various purposes, such as fuel for cars and… plastic production,” explains Tal. Plastic is, in other words, produced from oil, a non-renewable source of energy.

Tal is well acquainted with plastic. After earning his B.Sc. in Marine Sciences and Environment at the Ruppin Academic Center, Tal Cohen worked as a marine biologist. Three kilometers offshore, surrounded by fish and – you guessed it – plastic, he would research, work in the lab and dive. After a few years, he went on to study for an MBA at Tel Aviv University: “I wanted to learn how to develop technologies and businesses that are focused on ecological solutions. While studying ‘Entrepreneurship and Innovation Technology Management’ at TAU, I was also working at a venture capital fund, handling portfolios of ten renewable energy companies. It taught me a lot about the needs of startups in the renewables field.”

Plastic Back’s technology offers waste handlers to help treat their waste streams and create profit, as an alternative to landfill

Bring it Back: A Chemical Solution

Tal Cohen and his Israeli based startup company “Plastic Back” offers an interesting solution: “By way of ‘reverse engineering’, we are able to convert plastic waste back to its original, valuable form of oils, waxes and other valuable chemicals. With unique chemicals, ratios and timing, our technology breaks down the carbon-to-carbon bonds of the plastic polymer to liquid fractions that can be (re)used by the petrochemical industry.” Brilliant, isn’t it?

“While transforming plastic back to oil through burning is already done, that requires very high temperatures, between 600-1000 degrees Celsius, which constitutes an environmental and financial burden. The real innovation here, is that we manage to convert the plastic to oil by chemical means only, and at room temperature. So there’s an environmental advantage which is expressed financially, and it is also advantageous energy-wise. The goal is to offer an alternative to the traditional drilling for additional non-renewable oil.”

The idea, Tal got while he was working with one of the aforementioned portfolio companies: “Once I felt like I had learnt enough about the startup world and what setting up a startup entailed, I went on a mission to find technologies. At The Hebrew University, they had a technology in place from 2016-17. It spoke to me, as it was related to plastic, which I was intimately familiar with from my time working underwater as a marine biologist, and I also knew that the renewables field is evolving.”

“The technology was in place, and so I decided to find out if there was any business interest for it. In 2019, I attended Shell’s competition in Holland, which is the largest energy competition in the EU, where more than 250 companies competed during 10 days of business and technological validation. We ended up in 2^nd place. We knew then that there was demand for the crude oil which we were able to convert the plastic back to. Shell was willing to invest and to pay some money up front, so we had some starting capital. I went ahead and founded the company. We have since found an angel investor who invested a certain amount, have received recognition from the European Commission and are taking part in the EU accelerator program.”

Making Waste Vanish and Renewing Non-renewables

Who are the winners with this initiative? “Plastic Back enables a shift from a linear to a circular economy, by closing the loop between the petrochemical industry (including companies such as Shell), which is currently dependent of crude oil drilling and operating under increasingly heavy regulation and pressure, and the waste handlers who receive millions of tons of plastic waste from waste manufacturers, such as agriculture, factories and hospitals and medical devices, most of which goes to landfill. The waste handlers are seeking alternatives, especially as there’s been a fivefold increase in landfill price since 2019. The waste manufacturers, on their side, would gain the ability to treat their waste on site/close by, save expenses on removal and treatment fee and even create profits from their plastic waste.”

Tal is not planning to rest in the coming years, “The research and development phase of our project is completed for the most part. Last year, we successfully proved that there is demand for what we are offering. We have received a grant from the Ministry of Energy to set up our first pilot facility together with an industrial partner in the South of Israel in 2022. A year and a half after that, we would like to set up our first facilities. In five years from now, we should have two or three active facilities, hopefully one of them here in Israel and the rest in Europe.”

Tal Cohen presenting his startup at TAU’s Coller $100,000 Startup Competition in July 2021

Featured image: By way of ‘reverse engineering’, Tal’s team is able to convert plastic waste back to its original form.

COVID-19 Immunity Varies Among Genders and Age Groups

Written by AUFTAU on 25 July 2021. Posted in Newsroom.

As experts continue to learn more about immune responses to COVID-19 and the effectiveness of vaccines, researchers from Tel Aviv University have contributed a new piece to the puzzle. A joint study conducted by researchers from TAU and the Shamir Medical Center (Assaf Harofe) indicates that the level of antibodies changes according to age groups, gender, symptoms, and time elapsed since vaccination. The findings are the latest from the researchers in a series of studies aimed at providing reliable measures on the effectiveness of COVID-19 vaccination.

The new study examined the level of antibodies in over 26,000 blood samples taken from COVID-19 convalescents, as well as vaccinated and unvaccinated individuals.

In vaccinated individuals, the researchers found differences between women and men in the concentration of antibodies in the blood relative to both age and gender. In women, the level of antibodies begins to rise from the age of 51, and is higher than the levels found in men of similar age. This phenomenon may be related change in levels of the estrogen hormone, observed around this age, which affects the immune system. In men, a rise in antibody levels is seen at an earlier age, starting around 35, and may be related to changes in levels of testosterone and the effect on the immune system.

In young adults, a high concentration of antibodies generally signals a strong healthy functioning immune response, while in older demographics it typically indicates overreaction of the immune system associated with severe illness. In general, young adults were found to have a higher level of antibodies sustained for a longer period of time compared to older vaccinated persons. The findings further validate existing evidence that, depending on age, higher antibody count isn’t necessarily equivalent to higher rates of recovery.

Furthermore, the study found that the immune response of vaccinated individuals (after two doses) is much stronger than that of people who have recovered from COVID-19. The findings show that vaccinated individuals have four times the level of antibodies compared to convalescents.

The study was conducted by Tel Aviv University’s Prof. Noam Shomron, Head of the Computational Genomics Laboratory at the Sackler Faculty of Medicine and a member of the Edmond J. Safra Center for Bioinformatics and Dr. Adina Bar Chaim from the Shamir Medical Center. The data were collected by Dr. Ramzia Abu Hamad from the Shamir Medical Center, and analysis was conducted by Guy Shapira, a PhD student at Prof. Shomron’s laboratory. The study was published in Medrxiv.

What to Do When Everything is Vulnerable and Under Attack

Written by AUFTAU on 25 July 2021. Posted in Newsroom.

Israel’s 11^th Annual Cyber Week Conference, this year hosted in a hybrid in-person and online format, was attended last week by 2,500 in-person and 3,700 online, among them top Israeli politicians, global cyber policymakers and executives from multinational companies and cutting-edge startups from more than 80 countries.

TAU Professor behind Israel’s ‘Magic Circle’ and Cyber Week

Prof. Isaac Ben-Israel, Conference Chairman of Cyber Week, submitted a plan to the government in 2011 after his appointment by the Prime Minister to head a multidisciplinary task force in order to prepare Israel for future cyber threats. The plan outlined a solution whereby an entire ecosystem, or ‘magic circle’ was built (combining the forces of defense and government, industry and academia) to handle new and unpredicted cyber threats on a continuous basis. Ever since, the annual Cyber Week Conference at Tel Aviv University has been an important meeting point for experts from industry, government and academia across the globe.

Participants at Cyber Week 2021

Will The Iron Dome be Joined by A “Cyber Dome”?

In his speech at this year’s event, Israel’s Prime Minister Naftali Bennett stressed the need for further cooperation and invited other nations to join a global “Cybernet Shield” initiative to jointly coordinate the fight against cyber threats globally, stressing that “(…) if you fight alone you will lose, but if we fight together we will win.”

2020 was a rough year, with more than 300M ransomware attacks worldwide. Cyber warfare continues its rapidly growing military importance and global cyber security investment is skyrocketing, 80% of which went to US and Israeli companies. “Everything is vulnerable and everything is under attack” Bennett warned.

Israel’s Defense Minister, Benny Gantz, expressed similar sentiments and called for a cyber-version of Israel’s famous anti-missile defense system, the Iron Dome, “Cyber is now a vulnerable space that must be protected like the sea, space, air, and ground”. He called for a no-tolerance policy by the Israeli government when it comes to cyberattacks, “Our message is very clear – be it a rocket, or a keyboard, we will not tolerate anyone to threaten our people.”

And the Winner of This Year’s Cyber Shield Award…

True to tradition, also this year the Cyber Week Committee nominated a winner of the Cyber Shield Award, based on contributions to Israel’s cyber ecosystem. This year’s prize was awarded the Israeli Defense Forces (IDF) for their longstanding, inspiring and groundbreaking achievements in promoting the Israeli cyber scene and bringing Israel to the status of a global cyber power.

The IDF is awarded the Cyber Shield Award. From left to right: Major General Lior Carmeli, Major General Tamir Hayman, Gili Drob-Hiesten Managing Director ICRC, TAU President Prof. Ariel Porat and Prof. Isaac Ben Israel

The conference is a joint effort by Tel Aviv University’s Blavatnik Interdisciplinary Cyber Research Center (ICRC) and Yuval Ne’eman Workshop for Science, Technology and Security, and the Israeli National Cyber Directorate under the Prime Minister’s Office and the Ministry of Foreign Affairs.

Tel Aviv Bats Have More Fun

Written by AUFTAU on 22 July 2021. Posted in Newsroom.

Urbanization processes tend to lead animals to leave the city, but some animals are able to thrive in an urban domain. A new Tel Aviv University study found that fruit bats, just like humans, are able to adapt to a variety of environments, including the city and the countryside.

Prof. Yossi Yovel: “How animals cope with urbanization is one of the most central and important questions in ecological research today. Understanding the ways in which animals adapt to urban areas can help us in our conservation efforts. The urban environment is characterized by much fragmentation, and we currently have little understanding of how animals, especially small animals, like the bats, move and fly in such areas.”

The City Bat and the Country Bat

The urban environment is fundamentally different from the rural environment in terms of the diversity and accessibility of food. Although the city has a larger variety of trees per area, there are many challenges that bats have to face, such as buildings and humans. In rural areas, on the other hand, most of the trees are concentrated in orchards without barriers, but have less diversity – the trees are mostly of one type.

Because of the environmental differences between the city and the country with regards to the distribution and variety of fruit trees, the nature of the bats’ movement when foraging in these areas differs as well. In this new study, the researchers compared the nature of the movement of rural bats and city bats as they foraged for food, using tiny GPS devices to track the bats to see if the way they moved while searching for food was affected by their living environment, or the environment in which they were foraging.

The study was led by research student Katya Egert-Berg, under the guidance of aforementioned Prof. Yossi Yovel, head of Tel Aviv University’s Sagol School of Neuroscience and a faculty member of the School of Zoology in The George S. Wise Faculty of Life Sciences and The Steinhardt Museum of Natural History, as well as a recipient of the 2021 Kadar Family Award for Outstanding Research. The study was published in the journal BMC Biology.

Enjoying their Meals in the Big City

The researchers found that the fruit bats hunting for food in the city are much more exploratory, enjoy the abundance of the urban environment, visit a variety of fruit trees every night, and feed from a wide a variety of trees. In contrast, the rural bats focus on only one or two fruit trees each night. Moreover, the researchers found that among the rural bats who rest in the countryside, there were many who left their rural homes every night in search of food in the city, and then flew back to the country after their meal. During their stay in the city, such bats share the same flight patterns as those of the bats that live in the city around the clock.

The study’s findings led the researchers to assess that even bats that live in rural environments their entire lives will be able to orient themselves in an urban, industrialized environment. They explain that there are animal species that are flexible – for them, the ability to adapt to a new and unfamiliar environment such as an urban settlement is an acquired skill. Such species, of which the fruit bats are an example, will in many cases be able to adapt to life in urban areas.

Featured image: A Tel Aviv bat in action. Photo: S. Greif

See You at Naftali

Written by AUFTAU on 22 July 2021. Posted in Magazine, Newsroom.

Prof. Itai Sened explains how TAU students will tackle global warming from what will become the greenest building on campus.

The Naftali building, which houses the Gershon H. Gordon Faculty of Social Sciences and was built in the 1960s, is one of the most iconic buildings on campus. And now, Prof. Itai Sened the Dean of the Faculty is planning to turn the building into a green island, attracting students from all faculties.

Imagine walls covered with photovoltaic cells (solar cells that convert solar energy to produce electricity), an open research lab on a roof top, and a green wall in the garden… The physical makeover of the building is only the tip of the iceberg: “This is the infrastructure of the program, and will serve as a focal point for research and development on the topic of climate change for the entire university, quietly contributing ideas and environmental solutions touching on all faculties,” says Prof. Sened.

A Lab that is not a Lab

What will it look like? The walls of the Matanel Garden on the ground floor are already covered with tropical vegetation that gives a sense of freedom and nature. In the garden, it will be possible to hold academic meetings on any subject, and there will be indoors work spaces with screens on the walls, displaying data on how much alternative energy the university produces on all roofs at any given moment. There will be a facility for landless agriculture, where the products will be monitored and tested by research teams. It will also provide raw materials for the cafeteria, which will make a comeback. The cafeteria will be operated by youth at risk, closely accompanied by students of social work and psychology.

The green wall and the agricultural garden will be irrigated with water extracted from the Tel Aviv air, which has been proven suitable for drinking, operated from the roof. An extension of the project, on the roof of the nearby Social Sciences Library, will include gray water purification laboratories, wind energy facilities and more. Solar panels will also cover the southern wall of the building.

The real focal point, however, is the lab. The ‘Laboratory without a laboratory’, as Prof. Sened calls it, will be run by Prof. Hadas Mamane, head of the Environmental Engineering Program at The Iby and Aladar Fleischman Faculty of Engineering, and Dr. Vered Blass from The Department of Environmental Studies, who specializes in circular economy. And where will it be? “The laboratory is located in the minds of students and researchers,” explains Prof. Sened. “The spaces must be open; we cannot continue working with closed laboratories. We are building a unique program here that will take on anything that can be changed. Our goal is to train future leaders to deal with climate and water crises, to create a sustainable future.”

The future Naftali building, complete with vertical gardens, biodomes, solar panels, a shaded lab area, grey water tank and algae ponds.

Flow of Thought

The students in the novel program entailing a “lab-less lab” are master students, Israeli and international. “With us, they learn how to do special things in the most remote places in the world, but they need freedom. It’s a new era. These are young people who grew up in a world without limits. There is no Faculty of Engineering, no Faculty of Law. There are young people who hang out, they are here and there and they keep returning, ” Prof. Sened shares his reasons for setting up the special venture.

“Here you will see graduates of selected academic units who travel to the most remote villages in the world, together with someone from the Faculty of Life Sciences, someone from the School of Computer Science, students from the Faculty of Social Sciences – from Economics, Public Policy, Psychology and Anthropology. They go to those villages because that is what they enjoy doing and exploring. They will not sit here and write a doctorate for five years – that would be torture for them, as it does not suit them anymore. However, if we put them in this new type of lab, they will get a doctorate after they do much more. That is the guiding principle. “

An Entire Generation Looking for Purpose

Prof. Sened explains that while the whole thing may give off an “engineering and life sciences” vibe, most of the projects that are undertaken there are actually related to the social sciences. “One of our most talented doctoral students is about to start working at the State Comptroller’s Office as a real estate expert. Individuals like her wish to succeed and to change the legislation on all aspects of renewable energy. “

He explains that it is important for their students to know, right from the start, where they will be able to integrate when they complete their degree. “In these projects, they often integrate in the process. A student who goes to Kenya to purify water, install solar panels, or to study a worm that is making its name known in corn crops – may be noticed and ‘snatched” – and will already be on his way to another project. That’s how it works.”

“The infrastructure of what we are building here is 20% of the matter, and it is what is visible to the eye. However, the most interesting part is the remaining 80%, the minds involved. And they are not limited by space (…) We needed something visible, and so we built the green Naftali. Now they will finally be visible, ” concludes Prof. Sened.

Students hanging out in the Naftali garden surrounded by its green walls

When the stars aligned: A star in a distant galaxy blew up in a powerful explosion, solving an astronomical mystery from the 11th century

Written by AUFTAU on 16 July 2021. Posted in Newsroom, Press release.

Las Cumbres Observatory and Hubble Space Telescope color composite of the electron-capture supernova 2018zd (the large white dot on the right) and the host starburst galaxy NGC 2146 (toward the left).

Giant Explosion in Space Illuminates Thousand-Year Mystery.

Dr. Iair Arcavi.
Credit: Israel Hadari

Dr. Iair Arcavi, a Tel Aviv University researcher at the Raymond and Beverly Sackler Faculty of Exact Sciences, participated in a study that discovered a new type of stellar explosion – an electron-capture supernova. While they have been theorized for 40 years, real-world examples have been elusive. Such supernovas arise from the explosions of stars 8-9 times the mass of the sun. The discovery also sheds new light on the thousand-year mystery of the supernova from A.D. 1054 that was seen by ancient astronomers, before eventually becoming the Crab Nebula, that we know today.

A supernova is the explosion of a star following a sudden imbalance between two opposing forces that shaped the star throughout its life. Gravity tries to contract every star. Our sun, for example, counter balances this force through nuclear fusion in its core, which produces pressure that opposes the gravitational pull. As long as there is enough nuclear fusion, gravity will not be able to collapse the star. However, eventually, nuclear fusion will stop, just like gas runs out in a car, and the star will collapse. For stars like the sun, the collapsed core is called a white dwarf. This material in white dwarfs is so dense that quantum forces between electrons prevent further collapse.

For stars 10 times more massive than our sun, however, electron quantum forces are not enough to stop the gravitational pull, and the core continues to collapse until it becomes a neutron star or a black hole, accompanied by a giant explosion. In the intermediate mass range, the electrons are squeezed (or more accurately, captured) onto atomic nuclei. This removes the electron quantum forces, and causes the star to collapse and then explode.

Historically, there have been two main supernova types. One is a thermonuclear supernova — the explosion of a white dwarf star after it gains matter in a binary star system. These white dwarfs are the dense cores of ash that remain after a low-mass star (one up to about 8 times the mass of the sun) reaches the end of its life. Another main supernova type is a core-collapse supernova where a massive star — one more than about 10 times the mass of the sun — runs out of nuclear fuel and has its core collapsed, creating a black hole or a neutron star. Theoretical work suggested that electron-capture supernovae would occur on the borderline between these two types of supernovae.

That’s the theory that was developed in the 1980’s by Ken’ichi Nomoto of the University of Tokyo, and others. Over the decades, theorists have formulated predictions of what to look for in an electron-capture supernova. The stars should lose a lot of mass of particular composition before exploding, and the supernova itself should be relatively weak, have little radioactive fallout, and produce neutron-rich elements.

The new study, published in Nature Astronomy, focuses on the supernova SN2018zd, discovered in 2018 by Japanese amateur astronomer Koihchi Itagaki. Dr. Iair Arcavi, of the astrophysics department at Tel Aviv University, also took part in the study. This supernova, located in the galaxy NGC 2146, has all of the properties expected from an electron-capture supernova, which were not seen in any other supernova. In addition, because the supernova is relatively nearby – only 31 million light years away – the researchers were able to identify the star in pre-explosion archival images taken by the Hubble Space Telescope. Indeed, the star itself also fits the predictions of the type of star that should explode as an electron-capture supernovae, and is unlike stars that were seen to explode as the other types of supernovae.

From left: Japanese amateur astronomer Koichi Itagaki (who discovered the supernova), Tel Aviv University researcher Dr. Iair Arcavi (who participated in the study), and University of California graduate student Daichi Hiramatsu (lead author of the study), at one of Itagaki’s telescopes in Japan.

While some supernovae discovered in the past had a few of the indicators predicted for electron-capture supernovae, only SN2018zd had all six – a progenitor star that fits within the expected mass range, strong pre-supernova mass loss, an unusual chemical composition, a weak explosion, little radioactivity, and neutron-rich material. “We started by asking ‘what’s this weirdo?’” said Daichi Hiramatsu of the University of California Santa Barbara and Las Cumbres Observatory, who led the study. “Then we examined every aspect of SN 2018zd and realized that all of them can be explained in the electron-capture scenario.”

The new discoveries also illuminate some mysteries of one of the most famous supernovae of the past. In A.D. 1054 a supernova happened in our own Milky Way Galaxy, and according to Chinese and Japanese records, it was so bright that it could be seen in the daytime and cast shadows at night. The resulting remnant, the Crab Nebula, has been studied in great detail, and was found to have an unusual composition. It was previously the best candidate for an electron-capture supernova, but this was uncertain partly because the explosion happened nearly a thousand years ago. The new result increases the confidence that the historic 1054 supernova was an electron-capture supernova.

“It’s amazing that we can shed light on historical events in the Universe with modern instruments,” says Dr. Arcavi. “Today, with robotic telescopes that scan the sky in unprecedented efficiency, we can discover more and more rare events which are critical for understanding the laws of nature, without having to wait 1000 years between one event and the next.”

Dr. Arcavi is a member of the Global Supernova Project, and makes use of the Las Cumbres telescope network to study rare transient phenomena like supernovae, neutron star mergers, and stars torn apart by black holes.