News Category

Israel’s Hebrew University & Volcani Institute Team Up to Prevent Looming Global Food Crisis:

Israel’s Hebrew University & Volcani Institute Team Up to Prevent Looming Global Food Crisis:

23 August, 2022

New Biological Sensor Detects Hidden Disease in Potatoes.

Despite advances in increased food production, half of all world’s harvested food is lost due to שבrots caused by microorganisms.  Plants emit various volatile organic compounds into their surrounding environment, which can be monitored for early detection of plant disease and prevent food loss.

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New research study led by the Hebrew University of Jerusalem (HU) and the Israel’s Agricultural Research Organization (Volcani Institute) details the success of a biological sensor for early detection of hidden disease in potato tubers, one of Israel’s chief export industries at 700,000 tons a year. 

Israeli farmers import European potatoes for planting in Israel.  However, a certain percentage of them carry disease within—either visibly or invisibly—that cause rot and significantly reduce the potato’s quality.  The Hebrew University-Volcani alliance is about to change that. They’ve developed a sensor that detects disease and can be used to inhibit the rot from growing and spreading. Their study, published in the upcoming edition of Talanta, was conducted by Dr. Dorin Harpaz and her PhD student Boris Veltman at HU’s Faculty of Agriculture, Food and Environment, under the supervision of Dr. Evgeni Eltzov of the Volcani Institute.  The team collaborated with the Volcani Institute’s Dr. Sarit Melamed and Dr. Zipora Tietel, as well as Dr. Leah Tsror from the Gilat Research Center.

The sensor relies on smart bioengineering and optics.  When the sensor is exposed to an infected potato, a bacterial compound within lights up—with the strength of the luminescence indicating the concentration and composition of the rot.  “The intensity of the light given off by the bacteria panel makes it possible to quickly and quantifiably analyze the characteristics of the disease, which the sensor can ‘smell,’ before the appearance of visible symptoms,” explained Eltzov. “The biosensor we developed will help identify diseased potatoes that do not yet have any external indications, and keep them away from healthy tubers, thus preventing the rot from developing or spreading to other healthy plants,” Harpaz added.

To form the bacteria panel, the team created a compound of four genetically-engineered bacteria that measure biological toxicity.  In this study, the biological sensor detected disease before there was any visible trace, and caused the optical sensor to shine twice as brightly as did the sensors in non-infected potatoes. Their capabilities were also demonstrated in a previous study that used the sensors to detect toxicity among artificial sweeteners in sport supplements. 

According to the researchers, early discovery of disease--before the potatoes are exported to foreign markets or replanted, offers a significant advantage to food growers. “The biological sensor can be used to quickly and economically identify hidden rot in potatoes, facilitate better post-harvest management, and reduce food wastage—particularly important given the current global food crisis,” concluded Harpaz.

 

 

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Creating a Perfect Trap for Light - TU Vienna and Hebrew University Develop "Light Trap"— Beam of Light Prevents Itself from Escaping, Allowing Light to be Absorbed Perfectly

Creating a Perfect Trap for Light - TU Vienna and Hebrew University Develop "Light Trap"— Beam of Light Prevents Itself from Escaping, Allowing Light to be Absorbed Perfectly

29 August, 2022

Whether in photosynthesis or in a photovoltaic system: If you want to use light efficiently, you have to absorb it as completely as possible. However, this is difficult if the absorption is to take place in a thin layer of material that normally lets a large part of the light pass through. 

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Now, research teams from TU Wien and from The Hebrew University of Jerusalem (HU) have found a surprising trick that allows a beam of light to be completely absorbed even in the thinnest of layers: They built a "light trap" around the thin layer using mirrors and lenses, in which the light beam is steered in a circle and then superimposed on itself – exactly in such a way that the beam of light blocks itself and can no longer leave the system. Thus, the light has no choice but to be absorbed by the thin layer – there is no other way out. This absorption-amplification method, which has now been presented in the scientific journal Science, is the result of a fruitful collaboration between the two teams: the approach was suggested by Prof. Ori Katz from The Hebrew University of Jerusalem and conceptualized with Prof. Stefan Rotter from TU Wien; the experiment was carried out in by the lab team in Jerusalem and the theoretical calculations came from the team in Vienna.

"Absorbing light is easy when it hits a solid object," shared Prof. Stefan Rotter from the Institute of Theoretical Physics at TU Wien. "A thick black wool jumper can easily absorb light. But in many technical applications, you only have a thin layer of material available and you want the light to be absorbed exactly in this layer."

There have already been attempts to improve the absorption of materials: For example, the material can be placed between two mirrors. The light is reflected back and forth between the two mirrors, passing through the material each time and thus having a greater chance of being absorbed. However, for this purpose, the mirrors must not be perfect – one of them must be partially transparent, otherwise the light cannot penetrate the area between the two mirrors at all. But this also means that whenever the light hits this partially transparent mirror, some of the light is lost.

To prevent this, it is possible to use the wave properties of light in a sophisticated way. “In our approach, we are able to cancel all back-reflections by wave interference”, noted HU’s Prof. Ori Katz. Helmut Hörner, from TU Wien, who dedicated his thesis to this topic explained, "in our method, too, the light first falls on a partially transparent mirror. If you simply send a laser beam onto this mirror, it is split into two parts: The larger part is reflected, a smaller part penetrates the mirror."

This part of the light beam that penetrates the mirror is now sent through the absorbing material layer and then returned to the partially transparent mirror with lenses and another mirror. “The crucial thing is that the length of this path and the position of the optical elements are adjusted in such a way that the returning light beam (and its multiple reflections between the mirrors) exactly cancels out the light beam reflected directly at the first mirror”, said Yevgeny Slobodkin and Gil Weinberg, HU graduate students who built the system in Jerusalem.

The two partial beams overlap in such a way that the light blocks itself, so to speak: although the partially transparent mirror alone would actually reflect a large part of the light, this reflection is rendered impossible by the other part of the beam travelling through the system before returning to the partially transparent mirror.

Therefore, the mirror, which used to be partially transparent, now becomes completely transparent for the incident laser beam. This creates a one-way street for the light: the light beam can enter the system, but then it can no longer escape because of the superposition of the reflected portion and the portion guided through the system in a circle. So the light has no choice but to be absorbed – the entire laser beam is swallowed up by a thin layer that would otherwise allow most of the beam to pass through.

"The system has to be tuned exactly to the wavelength you want to absorb," explained Rotter. "But apart from that, there are no limiting requirements. The laser beam doesn't have to have a specific shape, it can be more intense in some places than in others – almost perfect absorption is always achieved."

Not even air turbulence and temperature fluctuations can harm the mechanism, as was shown in experiments conducted at The Hebrew University in Jerusalem. This proves that it is a robust effect that promises a wide range of applications – for example, the presented mechanism could even be well suited to perfectly capture light signals that are distorted during transmission through the Earth's atmosphere. The new approach could also be of great practical use for optimally feeding light waves from weak light sources (such as distant stars) into a detector.

 

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Improving the Success of IVF

Improving the Success of IVF

8 September, 2022

Hebrew University Review Reveals Simple Method to Increase Number of IVF Births.

Worldwide, around 10 -15% of couples have infertility problems. Many turn to artificial reproductive technologies (ARTs), most notably IVF (in vitro fertilization), in the hope of having a baby. But the process is fraught with anxiety, as only about one-third of IVF cycles, on average, are successful. However, a method of improving the success of IVF has been clearly identified in a systematic review of high-quality clinical trials – carried out by a team of researchers at Kaplan Hospital and the Hebrew University of Jerusalem (HU), led by Dr. Devorah Heymann.  Their findings were published in Human Reproduction.

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The trend throughout the world is for couples to delay starting a family until they have achieved greater financial stability. This takes women beyond their years of peak fertility – causing many to rely on processes such as IVF to have a baby.  In IVF, an egg is removed from the woman, fertilized in a dish and then, a few days later, the embryo is implanted in her womb.  While in the dish, the embryo is kept in a liquid, or culture medium, that supports its development.  The Hebrew U. review established that the addition of hyaluronic acid (HA) to this medium enhances the ultimate success of IVF. 

This significant finding was the result of a detailed systematic review and meta-analysis of the outcome of all high-quality clinical trials where HA was either added or not added to the culture medium. "We found that exposing an embryo to HA for more than 10 minutes prior to its transfer to the womb, increased the likelihood of a birth from 32% to 39%," shared Heymann.  The most marked success was in cases for women who had a poor prognosis of success.

Furthermore, the increase in birth rate was only seen in cases where a woman was implanted with her own fertilized egg and not in cases where donor eggs were used. "This could be because donor eggs tend to be of higher quality," explained Heymann. The main benefit being seen in poorer quality eggs.

This study, by Heymann and her colleagues, including IVF experts Prof. Zeev Shoham and Dr. Yuval Or, and builds on their work for Cochrane which published a review in 2020 showing an overall increase in success rate in ARTs when embryos are exposed to HA prior to implantation.

Although HA naturally occurs in the female reproductive tract, its role in improving IVF outcomes is unclear and "more research is needed," suggests Heymann. Meanwhile her prime concern is that IVF clinics act on the findings of this review. "However," she noted, "hyaluronic acid is expensive, and this might mean it is not as widely used as it should be."

 

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HOW DO WOODLICE CHOOSE FEMALE MATES WHEN PREDATORS LURK NEARBY?

HOW DO WOODLICE CHOOSE FEMALE MATES WHEN PREDATORS LURK NEARBY?

19 September, 2022

Hebrew University Study Reveals Impact of Predators on Male-Female Pairing.

Desert isopods might not make top of the list of most-endearing animals, but these small (up to two centimeters-long) creatures, with their segmented bodies and seven pairs of legs, are actually fascinating animals and ideal to study when looking at mating preferences.

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They mate only once in their lifetime and spend the rest of their yearlong life with their chosen mate and their family (of 60-70 offspring) in a single permanent burrow.  The isopod females initially dig the burrow and the males fight to win a particular female and a particular habitat.  Both parents take care of the brood, and all family members—young and old—continue to excavate and clean the burrow together.  Choosing where to establish a home is the responsibility of the female woodlouse (“desert isopod “) and under normal conditions, the largest males usually win the largest females.  However, what happens when there is a predator, such as an Israeli gold scorpion, living nearby? 

A study of this scenario was carried out in the Negev Desert, in southern Israel, by a Hebrew University of Jerusalem (HU) research team led by Professor Dror Hawlena and Dr. Viraj Torsekar.  They observed the mating behavior of male desert isopods in two locations – one close to the burrow of an Israeli gold scorpion (a risky area), and one further away (a safe area).  Their findings, recently published in Ecology, demonstrated the preference of large males for larger females in safe areas but less so for large females in risky areas.  “Using this manipulative field experiment, we found that desert isopods under risk of scorpion predation maintained ‘size assortative mating’, but that males that chose and fought over females were on average smaller for a given female size,” Torsekar explained.  Additionally, while bigger males stayed longer near safe burrows and won more male-male contests, fewer pairs were formed in risky sites.

The researchers also showed that the smaller males had often accepted second best and moved in with smaller females close to the lurking scorpion. Medium sized males chose between smaller females in safe places and larger female in risky places - demonstrating an equal fitness choice.

"This supported our novel hypothesis that the males anticipated the future risk of predation," noted Torsekar. The males seemed to incorporate information on the proximity of a predator when choosing a mate. They no longer made their selection based solely on the size of the female, although larger females do have larger broods.

It is hard work for the females to dig into the dry compacted soil of the desert, so they are always on the lookout for holes that can make life a little easier. The HU researchers dug holes in two groups, one near the burrow of an Israeli gold scorpion and one further away.  Female isopods readily adopted the holes and excavated full-size burrows. However, the study showed that fewer isopod pairs took up residence in burrows near predators, despite it being virtually free real estate.

It should be noted that the predatory behavior of scorpions is localized to the immediate vicinity around their burrows.  They don't go wandering off to look for prey but emerge only to attack prey that is detected by the vibrations isopods cause as they walk across the burrow roof.  However, it is known that the odor of the scorpion does alert isopods when they are near to its lair.

In courtship, once the females adopt a burrow, they are ready to admit a male. Peeping out from the top of the burrow, male and female encounter each other face-to-face - probably using the separation between the eyes of their prospective mate to assess size. Males compete furiously over the larger females, in hopes of producing a large brood.

"This information is crucial in predicting how the fear of a predator may affect prey population dynamics and evolutionary processes in the creation of new species," concluded Torsekar.

 

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Sweeter Isn’t Always Tastier, Finds Hebrew U. Study

Sweeter Isn’t Always Tastier, Finds Hebrew U. Study

3 October, 2022

Taste Experts Analyze Half a Million Amazon and iHerb Customer Reviews, Find Foods Considered “Too Sweet” Given Lower Scores.

Most of us struggle with a sweet tooth despite wanting to eat healthy.  However, is sweeter always tastier? A new study conducted by student Kim Asseo, under the supervision of Professor Masha Niv, a taste expert at the Hebrew University of Jerusalem (HU)’s Robert H. Smith Faculty of Agriculture, Food and Environment, analyzed thousands of customer reviews of food products sold online, and found that reviewers tend to give lower scores to products deemed “too sweet”. Their study was published in the scientific journal Foods.

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The team studied roughly 560,000 reviews of 31,000 food products sold on the leading online marketplaces Amazon and iHerb and found that 10% of the reviews refer to the products’ sweetness. The researchers then used machine learning and natural language processing to categorize the responses by level of sweetness. “7–16% of the reviews we examined indicated oversweetness. This is important because customers who complained about products being oversweet gave them significantly lower scores (one star less) than did customers who did not complain about oversweetness. In addition, the reviews mentioning oversweetness came from different customers and only for some of the products those customers tried, rather than from ‘serial complainers,’” shared Niv.

One of the ingredients that most frequently led to reviews citing oversweetness was the artificial sweetener Sucralose. “Food companies that make candies, snacks, and soft drinks must also pay attention to the demand for products that are less sweet,” added Asseo. “This is important not just for public health reasons (supplying members of the public who prefer it with food that is less sweet and is healthier), but also for the food companies themselves, so that they can boast a healthier product line and sell these healthier products to customers who actually find them tastier.”

Niv concluded that “despite popular opinion, it is not the case for everyone that sweeter means tastier. There is an opportunity here to diversify the levels of sweetness in products and to create healthier versions that are more closely tailored to the preferences of certain customer groups.”

 

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LOOKING TO MOVE TO A GALAXY FAR, FAR AWAY? Innovative System Developed at Hebrew U. Evaluates Habitability of Distant Planets

LOOKING TO MOVE TO A GALAXY FAR, FAR AWAY? Innovative System Developed at Hebrew U. Evaluates Habitability of Distant Planets

19 October, 2022

Computerized System Classifies Atmospheres of Planets and Identifies Those Suitable for Future Human Settlements

The climate crisis presents a huge challenge to all people on Earth. It has led many scientists to look for exo-planets, planets outside our solar system that humans could potentially settle. The James Webb Space Telescope was developed as part of this search to provide detailed observational data about earth-like exo-planets in the coming years. A new project, led by Dr. Assaf Hochman at the Fredy & Nadine Herrmann Institute of Earth Sciences at the Hebrew University of Jerusalem (HU), in collaboration with Dr. Paolo De Luca at the Barcelona Supercomputing Center and Dr. Thaddeus D. Komacek at the University of Maryland, has successfully developed a framework to study the atmospheres of distant planets and locate those planets fit for human habitation, without having to visit them physically. Their joint research study was published in the prestigious Astrophysical Journal.

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Classifying climate conditions and measuring climate sensitivity are central elements when assessing the viability of exoplanets as potential candidates for human habitation. In the current study, the research team examined TRAPPIST-1e, a planet located some 40 light years from the Earth and scheduled to be documented by the James Webb Space Telescope in the coming year. The researchers looked at the sensitivity of the planet’s climate to increases in greenhouse gases and compared it with conditions on Earth. Using a computerized simulation of the climate on TRAPPIST-1e, they could assess the impact of changes in greenhouse gas concentration.

The study focused on the effect of an increase in carbon dioxide on extreme weather conditions, and on the rate of changes in weather on the planet. “These two variables are crucial for the existence of life on other planets, and they are now being studied in depth for the first time in history,” explained Hochman.

According to the research team, studying the climate variability of earth-like exo-planets provides a better understanding of the climate changes we are currently experiencing on Earth. Additionally, this kind of research offers a new understanding of how planet Earth’s atmosphere might change in the future.

Hochman and his research partners found that planet TRAPPIST-1e has a significantly more sensitive atmosphere than planet Earth. They estimate that an increase in greenhouse gases there could lead to more extreme climate changes than we would experience here on Earth because one side of TRAPPIST-1e constantly faces its own sun, in the same way, that our moon always has one side facing the Earth.

As Hochman concluded, “the research framework we developed, along with observational data from the Webb Space Telescope, will enable scientists to efficiently assess the atmospheres of many other planets without having to send a space crew to visit them physically. This will help us make informed decisions in the future about which planets are good candidates for human settlement and perhaps even to find life on those planets.”

 

 

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Israeli Government Approves $18 Million USD for New Albert Einstein Museum at Hebrew University

Israeli Government Approves $18 Million USD for New Albert Einstein Museum at Hebrew University

23 October, 2022

 

Today, Israel’s government approved the establishment of the Albert Einstein Museum at Safra Campus of the Hebrew University of Jerusalem, at the cost of $18 million USD / NIS 64 million.

 

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This project, led by the Ministry of Jerusalem Affairs and Heritage and the Hebrew University of Jerusalem, includes the construction of a unique building on the university’s Safra Campus at Givat Ram that will house the full Einstein archives. The archives will be accessible to the general public in digital format and the museum will also serve as an innovative space for scientific and technological education.

The Albert Einstein Museum will showcase the research, activities, and legacy of Albert Einstein, a Nobel prizewinner and one of the world’s most renown scientists. With cutting-edge exhibition techniques, scientific demonstrations, and original documents, the Museum will present Einstein’s contributions to science, the impact of his discoveries on our lives today, his public activity and involvement in key historical moments during his lifetime.  Further, the Museum will highlight Einstein’s deep connection with the destiny of the Jewish people, the State of Israel, and the Hebrew University of Jerusalem, of which he was a founder.

Visitors will be able to tour a reconstruction of Einstein’s library and office, and to view several original papers of his.  The project directors expect the Albert Einstein Museum to become a major tourist attraction in Israel.

This initiative was made possible through funding by Israel’s Ministry of Jerusalem Affairs and Heritage, headed by MK Ze’ev Elkin, as well as the Ministry of Education, Culture and Sport, the Ministry of Finance, and the Prime Minister’s Office. The government will provide NIS 22.5 million and the University NIS 41.5 million.

MK Ze’ev Elkin, Minister of Construction and Housing, and of Jerusalem Affairs and Heritage: “Today, as the new academic year opens, we are passing an important resolution for strengthening academia in Israel, the capital of Israel, and the Hebrew University. The establishment of the Albert Einstein Museum and the provision of a permanent home for the full Einstein archives will bolster the standing of Israeli academia in general, and of the Hebrew University in particular, in the international arena; will reinforce the international status of Jerusalem as Israel’s capital; and will bring tens of thousands of tourists to this unique site. I would like to thank our partners in this unique project in the government and at the university, and as a Hebrew University graduate and former lecturer, I would like to wish every success to the hundreds of thousands of students who are beginning their academic studies today.”

Professor Asher Cohen, president of the Hebrew University of Jerusalem: “Albert Einstein was one of the most prominent supporters of the State of Israel and one of the founding fathers of Hebrew University. His legacy of excellence in academic research forms the very foundation of our university, whereas his scientific achievements, which changed the world of physics, continue to impact all of our lives, from lasers and nuclear energy to GPS and space travel. These developments, and many more, can be traced to Einstein’s Theory of Relativity. On behalf of the entire Hebrew University community, I would like to thank Minister Ze’ev Elkin and the government of Israel for helping to establish of this museum, which will preserve and cherish the legacy of the greatest scientist of our time.”

 

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meta

Hebrew University and Meta AI Launch Joint AI PhD Program to Drive Cutting-Edge Research

26 October, 2022

This first of its kind partnership between Meta and an Israeli university marks a significant step to bring industry-leading Artificial Intelligence research from Hebrew University’s Rachel and Selim Benin School of Computer Science and Engineering to the AI marketplace. 

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Today, the Hebrew University of Jerusalem (HU)’s School of Engineering and Computer Science and Yissum, HU’s technology transfer company announced a new research partnership with Meta AI.

This partnership stems from Hebrew University's efforts to strengthen the ties between academia and the tech industry. Meta AI’s research advances the state-of-the-art in artificial intelligence through fundamental and applied research in open collaboration with the community. PhD students who are accepted into the program will have the opportunity to merge theory with real work experience, to gain a better understanding of emerging technologies and to develop new ones. 

The results of the research conducted as part of this strategic partnership will be published for the benefit of the scientific community and industry. Meta will assign the HU students mentors and scholarships to deepen their understanding in AI and machine learning. Further, these students will have access to Meta’s computational infrastructure and facilities.

Professor Sara Cohen, Dean of the Rachel and Selim Benin School of Computer Science and Engineering at the Hebrew University: “This partnership offers our students a unique opportunity to experience the world of research and development from two perspectives: a research perspective that enables experimentation, innovation, and breakthroughs, and an implementation perspective, which will give them an understanding of the real-world impact of their research. This one-of-a-kind collaboration will empower Hebrew U.’s PhD students to both study at one of Israel’s leading universities and to test their ideas in Meta’s industry-leading AI laboratory.”

Dr. Itzik Goldwaser, CEO of Yissum: “Meta’s choice to collaborate with the Hebrew University is proof of our institution’s scientific excellence and the commercial success that Yissum has achieved for its leading professors. The university’s curious and innovative researchers play a critical role in the marketplace, and we are proud to facilitate this collaboration with Meta to impact the scientific community.”

Professor Joelle Pineau, Managing Director of FAIR: “Exploratory research, open science, and cross-collaboration are foundational to our AI efforts. Many of our projects are done with researchers both in industry and academia as we believe this is the fastest way to make progress in research. Bringing our PhD program to Israel, in partnership with the Hebrew University, will further our collective impact as we together accelerate the world's progress toward more capable AI."

 

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hu

Hebrew University Ranks 77th Worldwide and #1 in Israel, According to the 2022 Academic Ranking of World Universities

15 August, 2022

The Hebrew University of Jerusalem (HU) climbed 13 places to rank 77th among the world’s top universities and number one in Israel, according to the 2022 Academic Ranking of World Universities (ARWU).

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Topping the list were Harvard, followed by Stanford, MIT, Cambridge, and UCLA Berkeley.  Two other Israeli universities placed in the top 100, as well—the Technion and Weizmann Institute both shared the 83rd spot.  This is a major achievement for Israel’s higher education at large and for Hebrew U., specifically.

 

This past July, ARWU released its Global Ranking of Academic Subjects, where HU University topped the list among Israeli institutions for higher education in: mathematics, earth sciences, atmospheric sciences, nanoscience and nanotechnology, environmental sciences, water resources, food sciences, agriculture, dentistry, medical technology, economics, law, political science, communications, and public policy. Globally, Hebrew U. strengthened its academic standing, placing 17th in mathematics and communications (up 7-8 places, respectively, relative to 2021), 30th in law, and 48th in public policy.

 

Upon hearing the news, Professor Asher Cohen, president of the Hebrew University, shared, “Hebrew University’s success in this year’s rankings is a testament to our ongoing academic and research excellence.  To date, we’ve made notable achievements in a variety of disciplines, have developed lifesaving medicines and established influential companies in cutting-edge industries, placing Israel at the forefront of science worldwide.”

 

Rector Prof. Barak Medina noted, “Hebrew University is a symbol, an exemplar of uncompromising excellence in research and equal access to higher education.  Our researchers are involved in theoretical and applied sciences and stand at the forefront of science that will change our lives for the better.  Thanks to our wonderful student body, faculty, staff and academic partnerships with leading universities worldwide, Hebrew University’s reputation has been forged as a local and global leader, and a key driving force behind Israel’s thriving economy and society.

 

ShanghaiRanking’s ARWU, published annually, is considered one of the most reliable ratings in academia. It assesses the quality of research at academic institutions and is based on various indicators including the number of faculty members and alumni who have won Nobel prizes and Fields medals, the number of articles published by researchers in leading scientific journals, and the extent to which researchers’ articles are cited by their peers.  The full rankings are available at http://www.shanghairanking.com/

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rainy

Rainy days make us meaner online reviewers

11 August, 2022

 

Hebrew U. Research Shows How a Rainy Day Affects Our Reviews of a Past Stay in a Hotel

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Gone are the days when people relied on recommendations from friends and family before making consumer purchases, choosing a vacation destination or perhaps even when casting a vote.  Today, there is a whole online community influencing us.  Understanding how opinions are formed and decisions are made in our online world is the focus of the research by Dr. Yaniv Dover of the Jerusalem Business School and the Federmann Center for the study of Rationality at the Hebrew University of Jerusalem, Israel (HU). His latest publication, in one of the top leading journals in management, the Journal of Consumer Research, shows that even the weather of the day can color our perception of past experiences.

 

Dover's research, done in collaboration with Prof. Leif Brandes at the University of Lucerne, Switzerland, used 12 years of data and 3 million hotel bookings to examine how 340 000 anonymous online reviews of hotels were influenced by the weather on the day they were written.  This was a far from simple evaluation that included matching between the booking made by the consumer and the written review, identifying the weather at the location of the reviewer, the star rating given, classification of vocabulary used to describe the stay, and the weather experienced during the stay at the hotel.  The researchers also used a special statistical model that takes into account both the decision to provide a review and the content of the review.

 

The results showed conclusively that, on average, bad weather (rain or snow) reduced the reviewers’ evaluation of their past hotel experience sufficiently to nearly demote the hotel from a 5- to a 4-star rating. Bad weather also made reviewers write longer and more critical and detailed reviews. They also showed that on rainy days there was a higher chance of choosing to write a review and that the effect of weather on the review was independent of the weather they experienced during the hotel stay. The authors suggest that this effect may be because bad weather days trigger more negative memories, or induce a negative mood which colors the review.

 

This research is interesting in itself but has much wider implications because it shows, for the first time, how our external physical environment—in this case the weather—can be a factor in our online judgments. Dover explains that this type of research "exposes an aspect of the dynamics of our new digital world… and can help policy makers frame policies to better engineer a more productive and healthy effect of online activities on our daily lives."

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CITATION: Offline Context Affects Online Reviews: The Effect of Post-Consumption Weather. Leif BrandesYaniv Dover Journal of Consumer Research, Jan 28 2022, DOI: 10.1093/jcr/ucac003

 

FUNDING: Israel Science Foundation

 

LINK TO ARTICLE:  

https://academic.oup.com/jcr/advance-article-abstract/doi/10.1093/jcr/ucac003/6516531

 

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Lights

Heberew U. Researchers Discover Why There’s Less Lightning in Storms Over Oceans than on Lan

8 August, 2022

 

As the world grapples with the cataclysmic events associated with climate change, it is increasingly important to have accurate climate models that can help predict what might lie ahead. 

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Research at the Hebrew University of Jerusalem (HU)’s Institute of Earth Sciences, led by Professor Daniel Rosenfeld and his doctoral student Zengxin Pan, focused on the role of small particles (aerosols) in controlling the amount of rain and lightning produced by clouds. Their research has been able to explain why heavy ocean storms are accompanied by much less lightning than when a similar event occurs on land.  They identified that it is the larger, coarse sea spray that reduces the amount of lightning by as much as 90%, whereas smaller aerosols increase lightning. The size of particle also affects rainfall.  Their work clearly shows that the role of aerosols in clouds needs to be incorporated in climate models. 

 

Rosenfeld’s findings, published in Nature Communications, fill in the gaps in previous theories about what was responsible for the difference in lightning between land and ocean storms. It had always been assumed that the dearth of lightning in ocean storms was due to cleaner air over the ocean.  However, keen observations had already shown that even highly polluted air is associated with reduced lightning at sea when sea spray aerosols are abundant. 

 

The HU researchers in collaboration with scientists at Wuhan and Nanjing Universities in China, and the University of Washington, were able to use satellite imagery to track clouds over land and sea.  This was combined with lightening measurements from the Worldwide Lightning Location Network (WLLN) and with data that provided information on the amount of aerosols in the clouds.   "We found a major cause for such a difference between ocean storms and those on land," shared Rosenfeld. "The effect of aerosols on clouds has been underappreciated.  It needs to be incorporated into the models for better weather and climate prediction."

 

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CITATION:   Zengxin Pan, Feiyue Mao, Daniel Rosenfeld, Yannian Zhu, Lin Zang, Xin Lu, Joel A. Thornton, Robert H. Holzworth, Jianhua Yin, Avichay Efraim & Wei Gong, Coarse sea spray inhibits lightning, Nature Communications

ARTICLE: https://www.nature.com/articles/s41467-022-31714-5

 

FUNDING:  BSF, NSF.

 

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molecole

Promising New Molecule Developed at Hebrew University May Prevent Age-Related Diseases and Increase Life Expectancy and Wellness

1 August, 2022

With a constant renewal of cell vitality in diseased tissues, this new drug will hopefully lead to the treatment or prevention of diseases, such as Alzheimer’s and Parkinson’s

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While breakthroughs in the world of medicine and technology account for the global increase in life expectancy, improvements in quality of life for the elderly population lag far behind.  Longevity without a decline in health is one of the major challenges that faces the world of medicine. A new study led by Professors Einav Gross and Shmuel Ben-Sasson of the Faculty of Medicine at the Hebrew University of Jerusalem (HU) has identified a group of molecules that enable cells to repair damaged components, making it possible for those tissues to retain proper function. The efficacy of the molecules was demonstrated on a model-organism.  The research team examined the effect of various therapies on longevity and quality of life, and successfully proved they can protect the organism’s and human cells from damage. Their findings were published in Autophagy.

 

Currently, a major factor in aging tissues is the reduced effectiveness of the cell’s quality-control mechanism, which leads to the accumulation of defective mitochondria. As Gross explained, “mitochondria, the cell’s ‘power plants,’ are responsible for energy production. They can be compared to tiny electric batteries that help cells function properly.  Although these ‘batteries’ wear out constantly, our cells have a sophisticated mechanism that removes defective mitochondria and replaces them with new ones.” However, this mechanism declines with age, leading to cell dysfunction and deterioration in tissue activity.

 

This degenerative process lies at the heart of many age-related diseases, such as Alzheimer’s disease, Parkinson’s disease, heart failure and sarcopenia, which are on the rise.  Gross and Ben-Sasson’s study may have far-reaching practical applications since their new technology, developed at Hebrew U., helped create innovative compounds to treat diseases that are currently incurable.  The study also showed that these molecules can be used preventively. “In the future, we hope we will be able to significantly delay the development of many age-related diseases and improve people’ quality of life,” shared Ben-Sasson.  Further, these compounds are user-friendly and can be taken orally. 

 

To advance their important research and translate it into medical treatment for a variety of patients, the research team, together with Yissum, Hebrew University’s tech transfer company, established Vitalunga, a startup that is currently developing this drug.  “Ben-Sasson’s and Gross’s findings have significant value for the global aging population,” noted Itzik Goldwaser, CEO of Yissum. “As Vitalunga advances towards pre-clinical studies, they’re closer than ever to minimizing the unbearable burden that aging-related diseases, such as Alzheimer’s and Parkinson’s, has on individuals, their families and the our health care systems.“

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CITATION: Vijigisha Srivastava, Veronica Zelmanovich, Virendra Shukla, Rachel Abergel, Irit Cohen, Shmuel A. Ben-Sasson & Einav Gross (2022) Distinct designer diamines promote mitophagy, and thereby enhance healthspan in C. elegans and protect human cells against oxidative damage, Autophagy, DOI: 10.1080/15548627.2022.2078069  

 

LINK TO ARTICLEhttps://www.tandfonline.com/doi/full/10.1080/15548627.2022.2078069

 

 

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Food

FOOD AS POLITICAL POWER IN PUTIN'S RUSSIA

27 July, 2022

Hebrew University Researchers Provide Timely Understanding of Putin's Food PolicyRecent headlines of a deal between Russia and Ukraine on the export of Ukrainian grain have focused attention on the vital role of these key providers in global food markets. A timely paper by Hebrew University of Jerusalem (HU) researchers on the political role of food in Putin's Russia presents a detailed analysis of Kremlin policies on food security from a historico-political perspective. 

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It shows how Putin's determination to develop Russian agriculture has, at the moment, paid off – not only by protecting Russia from threats of food sanctions but also by providing political control over the countries dependent on Russian grain imports. The paper was published in the recent issue of the Journal of Democracy.

 

The authors, Professor Yitzhak Brudny and two former doctoral students Dr. Janetta Azarieva and Prof. Eugen Finkel, present in this paper, "Bread and Autocracy in Putin's Russia," an overview of Putin's policies of nutritional self-sufficiency that now enable Russia to use food as both a shield and a weapon.  A book of the same title will be published by Oxford University Press.

 

This paper provides an important perspective for understanding global politics. As Prof Brudny explained, "It highlights the importance of food independence for authoritarian regimes…We take food for granted but non-democratic countries can only survive if they keep prices down." And that is problematic in closed markets without competition.

 

The paper charts how every major development in Russian and Soviet history since the 1917 revolution has either been driven by or closely associated with the availability of food. Indeed, it explains, how food scarcity in the USSR during the 1980s doomed President Mikhail Gorbachev's plans to revitalize communism.  It also shows that in 1992, Putin, as the vice-mayor of St Petersburg was committed to a policy of food security for the city.  The plan was a disaster but as soon as Putin became president in 2000, he embarked on a path of securing Russia's food independence from imports. The success of his policies owing much to the skills and professional expertise of the Minister of Agriculture (1999-2009) Aleksei Gordeev.

 

But total self-sufficiency brings its own problems. The system is vulnerable, explained Azarieva, "A few agro-industrial companies, controlled by the state, in turn, monopolize food production in Russia … the lack of competition results in price rises." Putin has responded, she said, by increasing salaries and social welfare payments – all funded by Russia's considerable gas and oil revenues. 

 

However, the country's revenues from grain exports have diminished – even though the West has not imposed sanctions on food from entering or leaving Russia. There is no point in sanctioning food imports when a country is self-sufficient, noted Azarieva.  However, sanctions on banks do impact the international network required to keep Russian exports flowing.  Further, silos are not emptying fast enough to provide storage for the next bumper harvest.  Countries of the former Soviet Republics anxiously await supplies, as does Turkey, and countries in North Africa and further afield. It is a complex interdependent web. This paper helps clarify and contextualize many of these complexities.

 

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CITATION: Azarieva, J., Y. Brudny, and E. Finkel. “Bread and Autocracy in Putin’s Russia”. Journal of Democracy, vol. 33, no. 3, July 2022, pp. 100–14.

 

LINK TO ARTICLE: https://www.journalofdemocracy.org/articles/bread-and-autocracy-in-putins-russia/

 

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archeology

HEBREW UNIVERSITY UNCOVERS RITUAL BATH USED BY JERUSALEM’S ELITES ON EVE OF DESTRUCTION OF SECOND TEMPLE

20 July, 2022

Archaeological Excavations near Temple Mount Also Unearth Pool Built by Soldiers from Rome’s 10th Legion and Byzantine lamp inscribed, “The light of Christ shines for all”

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A salvage excavation near the Temple Mount by the Hebrew University of Jerusalem’s Institute of Archaeology has unearthed a unique ritual bath (“mikveh”) dating back to the Late Second Temple period (1st Century CE).   These excavations, begun in February 2021 to provide handicap access between Jerusalem’s Old City and the Western Wall, were overseen by HU’s Michal Haber and Dr. Oren Gutfeld, funded in part by Israel’s Ministry for Jerusalem Affairs and the William Davidson Foundation, and spearheaded by the Company for the Reconstruction and Development of the Jewish Quarter of the Old City of Jerusalem.

 

The ritual bath was found within a private villa, hewn into the bedrock and featuring a vaulted ceiling with fine masonry typical of the Herodian period.  It is located on top of a cliff in the “Upper City”—a phrase coined by historian Josephus Flavius to describe the area of Herod’s City which housed Jerusalem’s elites.  A plastered water cistern was uncovered near the same villa.  It had been in use until the destruction of the Second Temple by Rome in 70 CE, and held the remains of nearly 40 cooking pots, some still intact.

 

In addition to the ritual bath, the excavations unearthed additional artifacts that span the Second Temple, Roman-Byzantine and Ottoman periods, including a network of plastered pools and channels.  Among the finds were a section of the Ottoman-period phase of the “Lower Aqueduct” which transported water from Solomon’s Pools near Bethlehem all the way to the Temple Mount in Jerusalem during the Second Temple period; and an industrial pool built by soldiers of Rome’s Tenth Legion who were stationed in Jerusalem after the establishment of the Roman colony of “Aelia Capitolina” in 130 CE. The pool lies on top of the remains of an earlier Roman oven, also installed by soldiers of the Legion.  The bottom contains a layer of tile bricks, one of which was stamped with the letters “LXF,” alluding to “Legio X Fretensis,” the full name of the Tenth Legion. 

 

Also discovered over the course of excavation was a fragment of Late Byzantine-period ceramic oil lamp, inscribed with the Greek formula "The Light of Christ shines for all." This phrase may have its source in the ceremony of the Holy Fire, part of the Orthodox Easter celebrations in the Church of the Holy Sepulchre. Such oil lamps, dated primarily to the 6th and 7th centuries CE, may have been purchased by Christian pilgrims thronging to the Byzantine city -- by now known as “Hierosolyma”. 

 

Zeev Elkin, Israel’s Minister of Construction and Housing and of Jerusalem Affairs, inaugurated the Western Wall Elevator Project, noting “these rare finds, made during the Western Wall Elevator Project excavations, are truly exciting.  They provide proof of a continuous Jewish presence in Jerusalem for millennia.  Under my leadership, Israel’s Ministry of Jerusalem Affairs and Heritage will continue to preserve and develop Jerusalem’s rich Jewish past and to transform the capital into a modern, innovative city.”

 

Surveying the unique finds, Gutfeld shared, “The excavation revealed remains dating from the Second Temple, Roman-Byzantine, and Ottoman periods. The amount of water channels, cisterns and pools discovered in the area reflect the central role played by Jerusalem’s water supply throughout the ages.”

 

As noted, the highlight of the archaeological dig was the ritual bath. Haber explained the significance of this find, “during the Herodian period, the area in question was home to the city’s wealthiest residents. While several other ritual baths have been unearthed in the area, the importance of this particular discovery stems from its striking proximity to the Temple Mount—raising the question of who lived in this grand villa on the eve of the city’s destruction. It may well have been a priestly family.”

 

With the help of Dr. Amit Reem, chief archaeologist of the Israel Antiquities Authority’s Jerusalem District, the ritual bath will be preserved and incorporated into the new Western Wall Elevator complex.

 

The Ministry of Jerusalem Affairs, headed by Minister Elkin, continues to develop Jerusalem’s Jewish Quarter.  Current projects include the Western Wall Elevator, the Tiferet Israel synagogue, upgrades to the Herodian Quarter and the Broad Wall archaeological site.

 

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HU Entrance

HEBREW UNIVERSITY RANKED ISRAEL’S LEADING UNIVERSITY IN 15 ACADEMIC SUBJECTS

19 July, 2022

The Hebrew University of Jerusalem (HU) has maintained its status as the leading academic institution in Israel and was ranked number one in half the academic subjects assessed, according to Shaghai Ranking’s Global Ranking of Academic Subjects published today.  Further, Hebrew University was ranked among the 50 best academic institutions in the world in Mathematics, Law, Communications, and Public Policy.

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According to the ranking, the Hebrew University placed 17th worldwide in Mathematics and Communications and 30th in Law.  In Israel, HU was ranked first for the following subjects: Mathematics, Earth Sciences, Atmospheric Sciences, Nanoscience and Nanotechnology, Environmental Sciences, Water Resources, Food Sciences, Agriculture, Dentistry, Medical Technology, Economics, Law, Political Science, Communications, and Public Policy.

Professor Asher Cohen, President of Hebrew University, noted, “Academic and research excellence is part of Hebrew University’s DNA. The amazing breakthroughs happening here will enable all of us to live better, healthier and, most likely, longer lives, as well.  Hebrew U.’s strong position helps our alumni pave the way to lead Israel to achievements on an international scale.”

Shanghai Ranking Consultancy, the independent body which publishes the yearly ARWU, uses six objective indicators to rank world universities, including the number of alumni and staff winning Nobel Prizes and Fields Medals, the number of highly cited researchers, the number of articles published in journals of Nature and Science, the number of articles indexed in the Science Citation Index, and universities’ per capita performance. 

For the full list of rankings, see http://www.shanghairanking.com    

 

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