Author: AUFTAU

Bats navigate just like humans – using their excellent eyesight and a cognitive map

Written by AUFTAU on 13 July 2020. Posted in Newsroom.

For the first time in history, researchers at Tel Aviv University tracked fruit bats from birth to maturity, in an attempt to understand how they navigate when flying long distances. The surprising results: Fruit bats, just like humans, build a visual cognitive map of the space around them, making use of conspicuous landmarks. In this case, bat pups from Tel Aviv University came to know the city by looking for large unique structures such as the Azrieli Towers, the Dizengoff Center etc. The groundbreaking study was conducted by Prof. Yossi Yovel, together with students Amitai Katz, Lee Harten, Aya Goldstein and Michal Handel from the Sensory Perception and Cognition Laboratory at the Department of Zoology. The paper was published in July 2020 as the cover story of the prestigious Science Magazine. “How animals are able to navigate over long distances is an ancient riddle,” explains Prof. Yovel. “Bats are considered world champions of navigation: they fly dozens of kilometers in just a few hours, and then come back to the starting point. For this study we used tiny GPS devices – the smallest in the world, developed by our team, in an experiment never attempted before: tracking bat pups from the moment they spread their wings until they reach maturity, in order to understand how their navigation capabilities develop. No such study has ever been conducted on any living creature, and the findings are very interesting.” The researchers monitored 22 fruit bat pups born in a colony raised at TAU – from infancy to maturity, tracking them as they scoured the city for food. The results show that Tel Aviv bats navigate the space around them in much the same way as the city’s human inhabitants. “Bats use their sonar to navigate over short distances – near a tree, for example,” says Prof. Yovel. “The sonar doesn’t work for greater distances. For this, fruit-bats use their vision. Altogether we mapped about 2000 bat flight-nights in Tel Aviv. We found that bats construct a mental map: They learn to identify and use salient visual landmarks such as the Azrieli Towers, the Reading Power Station and other distinct features that serve as visual indicators. The most distinct proof of this map lies in their ability to perform shortcuts. Like humans, bats at some stage get from one point to another via direct new routes not previously taken. Since we knew the flight history of each bat since infancy, we could always tell when a specific bat took a certain shortcut for the first time. We discovered that when taking new, unknown routes the bats flew above the buildings. Sending up drones to the altitude and location where a bat had been observed, we found that the city’s towers were clearly visible from this high angle. Here is another amazing example of how animals make use of manmade features.”

TAU-led Team Destroys Cancer Cells with Ultrasound

Written by AUFTAU on 9 July 2020. Posted in Newsroom.

An international research team, headed by Dr. Tali Ilovitsh from the Biomedical Engineering Department at Tel Aviv University, developed a noninvasive technology platform for gene delivery into cancer cells (breast cancer). The technique combines ultrasound together with tumor-targeted microbubbles. Once the ultrasound is activated, the microbubbles explode like smart and targeted warheads, creating holes in cancer cells’ membranes, and enabling the gene delivery. The two-year research was recently published in the prestigious journal Proceedings of the National Academy of Sciences (PNAS).

Dr. Ilovitsh developed this breakthrough technology during her post doctorate research at the lab of Prof. Katherine Ferrara at Stanford University. The technique utilizes low frequency ultrasound (250 kHz) to detonate microscopic tumor-targeted bubbles. In vivo, cell destruction reached 80% of tumor cells.

Dr. Ilovitsh explains: “Microbubbles are microscopic bubbles filled with gas, with a diameter as small as one tenth of a blood vessel. At certain frequencies and pressures, sound waves cause the microbubbles to act like balloons: they expand and contract periodically. This process increases the transfer of substances from the blood vessels into the surrounding tissue. We discovered that using lower frequencies than those applied previously, microbubbles can significantly expand, until they explode violently. We realized that this discovery could be used as a platform for cancer treatment and started to inject microbubbles into tumors directly.”

Dr. Ilovitsh and the rest of the team used tumor-targeted microbubbles, that were attached to tumor cells’ membranes at the moment of the explosion, and injected them directly into tumors in a mouse model. “About 80% of tumor cells were destroyed in the explosion, which was positive on its own,” says Dr. Ilovitsh. “The targeted treatment, which is safe and cost effective, was able to destroy most of the tumor. However, it is not enough. In order to prevent the remaining cancer cells to spread, we needed to destroy all of the tumor cells. That is why we injected an immunotherapy gene alongside the microbubbles, which acts as a Trojan horse, and signaled the immune system to attack the cancer cell.”

On its own, the gene cannot enter into the cancer cells. However, this gene aimed to enhance the immune system was co-injected together with the microbubbles. Membrane pores were formed in the remaining 20% of the cancer cells that survived the initial explosion, allowing the entry of the gene into the cells. This triggered an immune response that destroyed the cancer cell.

“The majority of cancer cells were destroyed by the explosion, and the remaining cells consumed the immunotherapy gene through the holes that were created in their membranes. The gene caused the cells to produce a substance that triggered the immune system to attack the cancer cell. In fact, our mice had tumors on both sides of their bodies. Despite the fact that we conducted the treatment only on one side, the immune system attacked the distant side as well.”

Potential treatment for brain diseases such as Parkinson’s and Alzheimer’s

Dr. Ilovitsh says that in the future she intends to attempt using this technology as a noninvasive treatment for brain related diseases such as brain tumors and other neurodegenerative conditions such as Alzheimer’s and Parkinson’s disease. “The Blood-Brain barrier does not allow for medications to penetrate through, but microbubbles can temporarily open the barrier, enabling the arrival of the treatment to the target area without the need for an invasive surgical intervention.”

Photo: Dr. Tali Ilovitsh

New nanomedicines for mRNA therapeutics in breast cancer and heart failure

Written by AUFTAU on 7 July 2020. Posted in Newsroom.

TAU researcher Prof. Dan Peer, from the school of Molecular Cell Biology and Biotechnology, is one of 11 partners in the international project EXPERT that has been awarded a total of 14.9 million EUR from the EU Horizon 2020. The project is working to find efficient ways to deliver protein coding mRNA by using various nanoparticles for the treatment of breast cancer and myocardial infarction, which are two of the most pressing health challenges in European society today. Prof. Dan Peer, Director, Laboratory of Precision NanoMedicine, School of Molecular Cell Biology and Biotechnology, George S. Wise Faculty of Life Sciences and Department of Materials Sciences and Engineering, Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University Center for Nanoscience and Nanotechnology and Tel Aviv University Cancer Biology Research Center.

Dan, What is the research about in the EXPERT project?

“It is about developing mRNA therapy for the treatment of breast cancer. Much of it involves testing different methods to improve the delivery of mRNA to cells in vivo. These methods are fundamentally based either on lipid nanoparticles (LNPs), biological nanoparticles called exosomes, or cell penetrating peptides (CPPs). In addition to this, we intend to analyze what these nanoparticles bind to in biological fluids in order to better understand what drives uptake in specific cells types”.

What is your and TAU’s part in the project?

“Our lab was the first to show systemic, cell specific delivery of mRNA molecules that express therapeutic proteins in designated cells. We will further develop our ASSET platform for cell specific targeting of lipid nanoparticles to achieve improved delivery of therapeutic mRNAs and optimize formulations that enable systemic administration in different preclinical models. Part of the work will also consist of understanding how nanoparticle surfaces bind to host factors in blood and how this can affect the uptake of nanoparticles”.

What happens now, what is the next step?

“We will now see how these delivery methods work side by side in cell culture and animal models. The hope is then to be able to deliver an mRNA cocktail with one of the aforementioned vectors for the treatment of triple-negative breast cancer. In parallel, these vectors will also be evaluated for delivery of VEGF mRNA in the treatment of myocardial infarction”.

Tel Aviv University presents an analysis of the reaction of human antibodies to the coronavirus

Written by AUFTAU on 5 July 2020. Posted in Newsroom.

A team of researchers from Tel Aviv University and the Sharon Hospital at the Rabin Medical Center, led by Prof. Motti Gerlic and Prof. Ariel Munitz of the Department of Microbiology and Clinical Immunology at TAU’s Sackler School of Medicine, applied an innovative antibody test to about 70 COVID-19 patients at the Sharon Hospital. The researchers examined the development of antibodies targeting two different viral proteins in the patients’ bodies, and found that severely ill patients developed the antibodies at a faster rate than those with a mild case of the disease. In addition, antibodies of the type IgG were maintained in the blood of most patients throughout the study. This project has important implications for our understanding of the immune response to SARS-CoV-2, as well as future tracking of the effectiveness of vaccines and population surveys (serological tests).

A diagnostic tool

The researchers found that antibodies of the type IgM, that usually develop at the early stages of viral contagions, developed early in this case only against the protein RBD – the site at which the virus SARS-CoV-2 binds to human cells, and not against the virus’s nuclear protein. “We sampled the antibodies of about 70 COVID-19 patients at the Sharon Hospital, throughout the outbreak of the disease in Israel,” says Prof. Munitz. “Our first finding was that not all viral proteins generate a rapid immune response, but that antibodies targeting the RBD protein did develop very quickly once the symptoms appeared. This finding is quite significant, because it suggests that the test we used may be utilized as a diagnostic tool at different stages of the illness.” “The second thing we noticed, which is even more interesting, is that patients defined as severely ill developed antibodies at a faster rate than mildly ill patients, but ultimately all patients exhibited a similar immune response,” recounts Prof. Munitz. “Patients with mild, moderate and severe COVID-19 all developed the same level of antibodies. This is important, because one might have thought that the severely ill became so sick because they did not develop a sufficient amount of antibodies, and were thus unable to combat the virus effectively. We assume that the fast development of antibodies in these patients indicates that their immune system is hyper-active, but this hypothesis requires further research.”

Immunological memory

“We measured the levels of antibodies in the patients’ blood when they arrived at the hospital, during the period of hospitalization and after their release,” explains Prof. Gerlic. “We tried to understand whether the level of antibodies in their blood corresponded in any way to the severity of the illness, whether the antibodies developed in a similar way in all patients, and whether they remained in the blood for long periods of time – a critical factor for the ‘herd immunity’ we all wish to attain. We found that at later stages of the disease, about 50 days after the initial appearance of symptoms, a significant decline occurred in the presence of antibodies types IgM and IgA, regardless of the severity of the illness. In IgG-type antibodies, however, we observed only a slight decrease, even in mildly ill patients. IgG-type antibodies play an extremely important role in the immune response because they can neutralize the protein that binds the virus to human cells to enable contagion – thereby preventing the virus from penetrating the cells. We have not yet examined how the antibody actually works, and we do not know whether or not it neutralizes the virus, but the facts that these antibodies are quickly produced in all patients, and stay in the blood for a long time, suggest that they provide some level of immunity. So far, we have found that IgG-type antibodies remain in the body for two months. We will continue to monitor the patients for another year, to find out how long the antibodies remain in their bodies – hoping for the formation of an immunological memory.” In the new study the researchers from TAU used a new serological test developed in their laboratory. The IDF’s Medical Corps has already used the serological test developed by Prof. Gerlic and Prof. Munitz to detect COVID-19 antibodies in the blood of IDF soldiers. Within the next few weeks the test will be sent to the Israel’s Ministry of Health for validation, so that it may be used in population surveys. “Alongside the interesting findings,” says Prof. Munitz, “we wanted to demonstrate that our method is valid and more effective than the prevalent test for antibodies targeting viral proteins. To this end we examined samples of antibodies from the blood of COVID-19 patients, alongside samples from 200 healthy participants, taken before November 2019. We proved that our test, based on the antibodies, was able to distinguish between those who were ill and those who were not – at very high levels of sensitivity and specificity. One reason for this success is that we screen for three different antibodies: IgM that appears early and declines early, IgA – found on mucous surfaces like the lungs, and IgG, which we intend to test in the long run, because it may possibly lead to immunity.

Straight to the Point

Written by AUFTAU on 5 July 2020. Posted in Newsroom.

Researches from Tel Aviv University proposed a novel model that ties arrowheads dated to the end of the First Temple and the beginning of the Second Temple period, with key historical events. They also managed to define different arrowhead types used by armies of ancient eastern empires. Many of the arrowheads, examined by the researchers, were found in destruction layers from Babylonian and Assyrian assaults on cities in the land of Israel, while others were found in camps in which those armies stayed. “Arrows were a key component in military tactics of the ancient world, and the importance of this weapon is mainly due to its ability to strike the enemy from afar.” Explains Dr. Guy Stiebel. “The use of arrows for hunting is already known from the prehistoric era, but developments in military forces during the Bronze era increased the use of bows and arrows.”

The following researchers took part in this study: Prof. Oded Lipschits and Dr. Guy Stiebel from the Department of Archaeology and Ancient Near East Studies, together with the research student Sean Dugaw, who wrote his M.A. thesis on the subject. The research was published in IEJ (Israel Exploration Journal).

In this study, the researchers show a model that accurately defines the development of arrowhead types starting from 7^th century BCE. Prof. Lipschits explains, “Creating a new typology and marking the evolutionary process of arrowhead types and their chronological point of reference, gives researchers a new dating tool, which allows connecting the layers and sites in which evidence of battle activities of the Empires’ Armies, inside and outside the region of Israel, were found.”

The researchers explain that the various arrowheads discussed in the paper were developed and employed starting from 7^th century BCE. Those arrowheads of the three bladed variety had an improved aerodynamic structure which steadied their flight and inflicted more serious wounds than the two bladed arrowheads which preceded them. The functional development of the arrowheads teaches us about combat tactics and the specialty of the archers in the East. Archers in these regions were known for their professionalism and the complex powerful bows that they used, as we see some arrowheads which were designed to penetrate armor (more common in the eastern Mediterranean) while others were made for accurate shooting from a distance.

The earliest known trilobate socketed copper-alloy arrowhead had two blades. Such arrowheads are often referred to by scholars as “Scytho-Iranian arrowheads”. They first appear in Israel during the mid-7th Century BCE at sites associated the Assyrian military occupation. In the study, the researchers suggest tying this appearance with mercenaries serving in the Assyrian army or exiles brought to the area from north of the Assyrian Empire. This arrowhead type does not appear in the Levant after the Assyrian Empire retreat.

The study identified a three bladed socket arrowhead variant associated with Babylonian activity in the region, especially during the military campaigns of Nebuchadnezzar II. This arrowhead type was initially used by the Scythians and Medes at the dawn of the Babylonian empire. It has been found at sites destroyed by Babylonians and Medes in Assyria and Syria. While it may have been used by Scythian mercenaries in Babylonian service, it was eventually adopted by the Babylonians themselves and was used prominently during the Babylonian military campaign against the Kingdom Judah which resulted in the destruction along with its main cities, most importantly – Jerusalem. It is possible that the development and intensive use of this arrowhead helped the Babylonians conquer their enemies. Such arrowheads are found in the administrative citadel in Ramat Rachel, and serve as a clear evidence of Babylonian presence in the area.

Additional arrowhead types were identified that dated to the Persian and Hellenistic eras, some of which were also found in capital cities of the Persian Empire and at the major battle sites of the Greco-Persian wars. They were used throughout the Hellenistic periodSome were even used by Jewish rebels during the second revolt. Although most of the arrowheads used by the Roman archers during the early Roman period were iron and were attached with a tang rather than a socket, they retained the three bladed design of the earlier periods.

This research fits well into the new program at the Departments of Archaeology and Jewish History. This program puts emphasis on the combined research and teaching M.A.: “Many Faces of War” – the History and Archeology of War in Israel, which is made for studying and examining the phenomenon of war, which is always both current and historic.

3D printed heart used to test life-saving drugs

Written by AUFTAU on 29 June 2020. Posted in Newsroom.

Last April, Prof. Tal Dvir of the George S. Wise Faculty of Life Sciences, the Iby and Aladar Fleischman Faculty of Engineering and his team successfully produced the first-ever 3D-printed heart, from tissue extracted from a patient. The researchers estimate that it will be possible to print personalized organs and tissues within 10-15 years, thus eliminating the need for organ donations and the risk of transplant rejection. Meanwhile, this innovative technology already has the potential to revolutionize a different medical field: drug screening.

Saving precious time

“In a Petri dish, all the cells line up in 2D, and it’s only one type of cell” says Prof. Dvir. “In contrast, our engineered tissues are 3D-printed, and therefore better resembles real heart tissues. Our printed tissues contain cardiac muscle, blood vessels and the extracellular matrix which connects the different cells biochemically, mechanically and electrically. Moving away from Petri dishes to 3D printed tissues could significantly improve drug tests, saving precious time and money with the hope of producing safer and more effective medication”. Ramot at Tel Aviv University has signed a collaboration agreement with Bayer to develop and validate a platform for in vitro cardiotoxicity screening, using human heart tissues 3D-printed in Prof. Tal Dvir’s Laboratory for Tissue Engineering and Regenerative Medicine. In upcoming years, Prof. Dvir’s team and Bayer plan to test new medication for toxicity and efficacy using printed whole human hearts. Drug candidates go through several phases of screening before reaching pharmacies. First, the new chemical compound is tested on human tissue cultures. Then, it is administered to lab animals. Finally, the drug is approved for human clinical trials. Prof. Dvir’s 3D-printed tissues could enable faster, cheaper and more efficient screening than Petri dishes. Prof. Dvir hopes to offer Bayer, in the near future, pre-clinical trials on complete printed organs. “Our agreement is just the beginning,” says Prof. Dvir. “Our end goal is to engineer whole human hearts, including all the different chambers, valves, arteries and veins – the best analogue of this complex organ – for an even better toxicological screening process.” To make further use of the application, Ramot at Tel Aviv University licensed the technology to a spin-off company called Matricelf, which first focuses on engineering personalized spinal cord implants to treat paralyzed patients. Matricelf has recently secured a large investment, allowing it to reach clinical settings in the near future.

New, innovative drugs

Keren Primor Cohen, Ramot CEO said: “Prof. Dvir’s platform groundbreaking innovation is very promising. We believe that this collaboration with Bayer will support the evaluation and development of new drugs and is a step in building long-term relations with Bayer that we hope will benefit both partners and ultimately patients.” “We are excited to start this new collaboration with Tel Aviv University, which will address a new area of early assessment of safety and tolerability of drug candidates,” said Eckhard von Keutz, Head of Translational Sciences at Bayer. “We already have a global network of partners and this new project will enable Bayer to expand its open innovation activities to Israel, which provides a dynamic ecosystem for innovation in biotech and medical research

A worldwide wave of antisemitism unleashed by COVID-19 pandemic

Written by AUFTAU on 25 June 2020. Posted in Newsroom.

The Kantor Center for the Study of Contemporary European Jewry at Tel Aviv University, published a special report: a summary of worldwide antisemitic phenomena associated with the COVID-19 pandemic. The report relies on hundreds of accounts from different locations around the world, and come from an international network of colleagues, living in 35 countries, who identify and classify acts of anti-Semitism, which are added the material to The Moshe Kantor Database on Antisemitism. The network was established by Tel Aviv University over 30 years ago and today numbers about 60 participants. The database is an up-to-date collection of materials and resources on trends and events related to contemporary antisemitism, which includes English summaries based on source materials in all languages and formats including texts, visuals and audiovisuals. Professor Dina Porat, Head of the Kantor Center said: “These common motifs perpetuate antisemitic accusations from previous generations and other global catastrophes, once again presenting the well-known image of the Jew. However, the antisemitism generated by the coronavirus is fiercer and more intensive, has continued unremittingly for several months, and reflects a high level of anxiety and fear in many populations. This having been said, the situation should be seen in its overall context — in which others are also blamed for spreading the virus: first of all, the Chinese, 5G antennas and the authorities who allegedly are not doing enough to stop the epidemic. Countries close down their borders, every foreigner is a suspect, and no new immigrants are allowed”.

Antisemitism in the age of coronavirus

Coronavirus-related antisemitism is manifested in many parts of the world: A significant portion comes from the US and from Middle Eastern countries such as Iran and Turkey as well as the Palestinian Authority, but also from Europe and South America. While in the US, accusations come mainly from white supremacists and ultraconservative Christians, pointing the finger at Jews in general and Haredi Jews in particular, accusers in the Middle East mostly blame Israel, Zionism and the Mossad for creating and spreading the virus and intending to make a vast fortune from medications and the vaccine they are already developing. In the western world, the main elements promoting antisemitic discourse are civil society groups with various ideologies, while in the Middle East some of this discourse is put forth by the regimes themselves. Dr. Giovanni Quer adds: “Universal disasters have been attributed to the Jews and to Israel before, giving rise to antisemitic discourse — such as conspiracy theories blaming Israel for 9/11, or false reports accusing Israeli soldiers of harvesting organs from the bodies of dead Palestinians. The current wave of antisemitism is unprecedented, however, because, spreading very swiftly through the social media, it focused at first on the COVID-19 crisis and then quickly moved on because of social and political changes: Just a few days passed between the coronavirus crisis and the racism-related social crisis in the US, but antisemitic discourse remained just as fierce, with its proponents simply adapting their antisemitic narratives to the changing social contexts.”

Turning vapor into electricity?

Written by AUFTAU on 9 June 2020. Posted in Newsroom.

The search for renewal energy sources, which include wind, solar, hydroelectric dams, geothermal, and biomass, has preoccupied scientists and policymakers alike, due to their enormous potential in the fight against climate change. A new Tel Aviv University study finds that water vapor in the atmosphere may serve as a potential renewable energy source in the future. The research, led by Prof. Colin Price in collaboration with Prof. Hadas Saaroni and doctoral student Judi Lax, all of TAU’s Porter School of the Environment and Earth Sciences, is based on the discovery that electricity materializes in the interaction between water molecules and metal surfaces. “We sought to capitalize on a naturally occurring phenomenon: electricity from water,” explains Prof. Price. “Electricity in thunderstorms is generated only by water in its different phases – water vapor, water droplets, and ice. Twenty minutes of cloud development is how we get from water droplets to huge electric discharges – lightning – some half a mile in length.” The researchers set out to try to produce a tiny low-voltage battery that only works on humidity in the air, building on the findings of earlier discoveries. In the nineteenth century, for example, English physicist Michael Faraday discovered that water droplets could charge metal surfaces due to friction between the two. A much more recent study showed that certain metals spontaneously build up an electrical charge when exposed to humidity,

Voltage in the air

The scientists conducted a laboratory experiment to determine the voltage between two different metals exposed to high relative humidity, while one is grounded. “We found that there was no voltage between them when the air was dry,” Prof. Price explains. “But once the relative humidity rose above 60%, a voltage began to develop between the two isolated metal surfaces. When we lowered the humidity level to below 60%, the voltage disappeared. When we carried out the experiment outside in natural conditions, we saw the same results.” “Water is a very special molecule that during molecular collisions can transfer an electrical charge from one to the other. Through friction, it can build up a kind of static electricity,” says Prof. Price. “We tried to reproduce electricity in the lab and found that different isolated metal surfaces will build up different amounts of charge from water vapor in the atmosphere, but only if the air relative humidity is above 60%. This occurs nearly every day in the summer in Israel and every day in most tropical countries.” According to Prof. Price, this study challenges established ideas about humidity and its potential as an energy source. “While people know that dry air results in static electricity and you sometimes get ‘shocks’ you when you touch a metal door handle, water is normally thought of as a good conductor of electricity, not something that can build up charge on a surface, however, it seems that things are different once the relative humidity exceeds a certain threshold” he says. The researchers, however, showed that humid air may be a source of charging surfaces to voltages of around 1 Volt. “If a AA battery is 1.5V, there may be a practical application in the future: to develop batteries that can be charged from water vapor in the air,” adds Prof. Price. “The results may be particularly important as a renewable source of energy in developing countries, where many communities still do not have access to electricity, but the humidity is constantly about 60%,” concludes Prof. Price.

Zooming in and out of class

Written by AUFTAU on 4 June 2020. Posted in Newsroom.

Due to the coronavirus, Tel Aviv University, like many universities across the globe, has moved its classes to an online format. But can you really copy-paste a class into Zoom and expert the same experience for students? How are professors coping with the challenges of students who are sitting at home, amid a million distractions? We talked to different professors from across campus to find out.

The unexpected benefits of a crisis

Dr. Jonathan Ostrometzky teaches at the “Sciences for High Tech” program. He’s currently teaching two courses over Zoom, both for advanced B.Sc students.

According to him, remote teaching has brought unexpected advantages. “In “Introduction to Hardware”, the larger class I teach, I’ve been recording myself giving the lecture, with the presentation and all the details, and then sending students the video, even as far as a week in advance,” says Dr. Ostrometzky.

Doesn’t that make the class over Zoom unnecessary? “Not at all,” he says. “Some of the students watch the lecture in advance, though not all of them. The material is packed with details and it really helps students to be able to review things before the live lecture. It also means the questions I get, the discussion we can have, goes much deeper.”

Saving the environment through Zoom

Prof. Hadas Mamane, who teaches the class “Water Purifying Technologies” to Master’s students, finds remote learning has its upsides. “I can see questions students have over chat,” Prof. Manage says. “Share different screens with them, do a poll in the middle of the class to check whether they’ve understood the material. It’s also easier to bring on guest lecturers and expose the students to broader perspectives, and it allows flexibility for students who study and work at the same time.”

^{Is Zoom better for the environment?}

There’s also one major advantage to remote learning that Prof. Mamane sees as especially relevant for her work. “As someone who cares deeply about the environment, I see a huge benefit in the fact that my students and I don’t have to waste fuel or resources to attend a class. We, as a society and a university, have to keep our eyes on the environmental crisis, and remote learning allows us to cut back on harmful emissions.”

The challenge of engagement

But of course, there are some challenges that come with remote teaching as well. “It’s harder to tell whether students are really engaged,” says Dr. Ostrometzky. “I sometimes pause the class and ask them a question, just to see who’s listening and get some kind of feedback.”

^{Is anyone out there? Telling whether students are engaged can be tough.}

Dr. Gal Raz, who teaches two advanced film classes at the David and Yolanda Katz Faculty of the Arts, agrees. “I teach two 4-hour classes in one day, and it’s not easy sitting in front of a screen for eight hours and feeling a bit like I’m talking to myself. The lack of eye contact isn’t very pleasant. It’s also not easy for my three children to stay quiet for that long.”

Maya Dreifuss, a director who teaches film directing and screenwriting, finds the classroom atmosphere is also difficult to replicate. “Things happen when people are in the same space together, students barge into each other’s words, talk at the same time, even when these interactions are a little disruptive they still contribute to a vibrant energy and class atmosphere.”

What happens after the pandemic?

The professors we spoke to were divided in how much of the online learning experience can be taken back into the classroom, once we eventually return to normal life.

“Everyone should be able to study in the way that works best for them,” says Dr. Ostrometzky. “I plan to keep the videos for every future iteration of the class, so students can review them whenever they want. It only enhances the classroom experience.”

^{What happens when we all go back to our regular classrooms?}

Dr. Mamane agrees. “I feel like I’ve gone through a huge change and I don’t want to go back to how things were. I want to meet students face-to-face but also use Zoom for flexibility and things like guest lectures.”

Dr. Raz and Maya Dreifuss see things differently, both agreeing that not much of remote learning can be taken back into post-pandemic life. “Zoom can be good for one-on-one meetings with students,” Dr. Raz says. “But nothing can replace the classroom atmosphere.”

Maybe the difference of opinion can be attributed to the fact that in the arts, the classroom discussion generally carries a greater weight than in the exact sciences? Regardless, all the professors we spoke to felt remote learning has changed their perspective in some way, and has given them a new experience of teaching. Hopefully, when we all return to our classes, this new perspective will lead to even better teaching and greater academic insights.

Dead Sea Scrolls “puzzle” solved with DNA from ancient animal skins

Written by AUFTAU on 4 June 2020. Posted in Newsroom.

An interdisciplinary team from Tel Aviv University, led by Prof. Oded Rechavi of TAU’s George S. Wise Faculty of Life Sciences, Prof. Noam Mizrahi of TAU’s Department of Biblical Studies, in collaboration with Prof. Mattias Jakobsson of Uppsala University in Sweden, the Israel Antiquities Authority and Prof. Christopher E. Mason of Weill Cornell Medicine, has successfully decoded ancient DNA extracted from the animal skins on which the Dead Sea Scrolls were written. By characterizing the genetic relationships between different scroll fragments, the researchers were able to discern important historical connections. The research, conducted over seven years, sheds new light on the Dead Sea Scrolls. “There are many scroll fragments that we don’t know how to connect, and if we connect wrong pieces together it can change dramatically the interpretation of any scroll. Assuming that fragments that are made from the same sheep belong to the same scroll,” explains Prof. Rechavi, “it is like piecing together parts of a puzzle.” The Dead Sea Scrolls refers to some 25,000 fragments of leather and papyrus discovered beginning in 1947, mostly in the Qumran caves but also in other sites located in the Judean Desert. Among other things, the scrolls contain the oldest copies of biblical texts. Since their discovery, scholars have faced the breathtaking challenge of classifying the fragments and piecing them together into the remains of some 1,000 manuscripts, which were hidden in the caves before the destruction of the Second Temple in 70 CE.

A puzzle with thousands of pieces

Researchers have long been puzzled as to the degree this collection of manuscripts, a veritable library from the Qumran caves, reflects the broad cultural milieu of Second Temple Judaism, or whether it should be regarded as the work of a radical sect (identified by most as the Essenes) discovered by chance. “Imagine that Israel is destroyed to the ground, and only one library survives — the library of an isolated, ‘extremist’ sect: What could we deduce, if anything, from this library about greater Israel?” Prof. Rechavi says. “To distinguish between scrolls particular to this sect and other scrolls reflecting a more widespread distribution, we sequenced ancient DNA extracted from the animal skins on which some of the manuscripts were inscribed. But sequencing, decoding and comparing 2,000-year old genomes is very challenging, especially since the manuscripts are extremely fragmented and only minimal samples could be obtained.” Pnina Shor, founder of the Dead Sea Scrolls Unit at the Israel Antiquities Authority, adds, “The Israel Antiquities Authority is in charge of both preserving the scrolls for posterity and making them accessible to the public and to scholars. Recent scientific and technological advances enable us to minimize physical intervention on the scrolls, thus facilitating multidisciplinary collaborations.” New methods for solving ancient mysteries To tackle their daunting task, the researchers developed sophisticated methods to deduce information from tiny amounts of ancient DNA, carefully filtering out potential contaminations and statistically validating the findings. The team employed these mechanisms to deal with the challenge posed by the fact that genomes of individual animals of the same species (for instance, two sheep of the same herd) are almost identical to one another, and even genomes of different species (such as sheep and goats) are very similar. For the purpose of the research, the Dead Sea Scrolls Unit of the Israel Antiquities Authority supplied samples — sometimes only scroll “dust” carefully removed from the uninscribed back of the fragments — and sent them for analysis by Prof. Rechavi’s team: Dr. Sarit Anava, Moran Neuhof, Dr. Hila Gingold and Or Sagi. To prevent DNA contamination, Dr. Anava traveled to Sweden to extract the DNA under the meticulous conditions required for ancient DNA analysis (e.g. wearing special full-body suits) in Prof. Jakobsson’s paleogenomics lab in Uppsala, which is equipped with cutting-edge equipment. In parallel to the teams that were studying the animals’ ancient DNA, Prof. Mason’s metagenomics lab in New York studied the scrolls’ microbial contaminants. Prof. Jakobsson says, “It is remarkable that we were able to retrieve enough authentic ancient DNA from some of these 2,000 year old fragments considering the tough history of the animal hides. They were processed into parchment, used in a rough environment, left for two millennia, and then finally handled by humans again when they were rediscovered.”

Textual pluralism opens window into culture of Second Temple Jewish society

According to Prof. Rechavi, one of the most significant findings was the identification of two very distinct Jeremiah fragments. “Almost all the scrolls we sampled were found to be made of sheepskin, so most of the effort was invested in the very challenging task of trying to piece together fragments made from the skin of particular sheep, and to separate these from fragments written on skins of different sheep that also share an almost identical genome,” says Prof. Rechavi. “However, two samples were discovered to be made of cowhide, and these happen to belong to two different fragments taken from the Book of Jeremiah. In the past, one of the cow skin-made fragments was thought to belong to the same scroll as another fragment that we found to be made of sheepskin. The mismatch now officially disproves this theory.

“What’s more, cow husbandry requires grass and water, so it is very likely that cow hide was not processed in the desert but was brought to the Qumran caves from another place. This finding bears crucial significance, because the cowhide fragments came from two different copies of the Book of Jeremiah, reflecting different versions of the book, which stray from the biblical text as we know it today.” Prof. Mizrahi further explains, “Since late antiquity, there has been almost complete uniformity of the biblical text. A Torah scroll in a synagogue in Kiev would be virtually identical to one in Sydney, down to the letter. By contrast, in Qumran we find in the very same cave different versions of the same book. But, in each case, one must ask: Is the textual ‘pluriformity,’ as we call it, yet another peculiar characteristic of the sectarian group whose writings were found in the Qumran caves? Or does it reflect a broader feature, shared by the rest of Jewish society of the period? The ancient DNA proves that two copies of Jeremiah, textually different from each other, were brought from outside the Judean Desert. This fact suggests that the concept of scriptural authority — emanating from the perception of biblical texts as a record of the Divine Word — was different in this period from that which dominated after the destruction of the Second Temple. In the formative age of classical Judaism and nascent Christianity, the polemic between Jewish sects and movements was focused on the ‘correct’ interpretation of the text, not its wording or exact linguistic form.”

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