Author: Star

Can Higher Temperatures Accelerate the Rate of Evolution?

Written by Star on February 16, 2022. Posted in Newsroom.

Can environment impact genetic diversity in face of changing conditions, such as higher temperatures (think global warming)? Researchers at Tel Aviv University have discovered that epigenetic inheritance – inheritance which does not involving changes in the DNA sequence – can affect the genetic composition of the population for many generations. The environment can actually impact genetic diversity under certain conditions and the researchers believe that it’s a way for the environment to adjust genetic diversity.

Worms Get It from their Mama’s Mama’s Mama’s…

Females of the worm species C. elegans produce both egg cells (or “oocytes”) and sperm, and can self-reproduce (hence are considered hermaphrodites). They produce their sperm in a limited amount, only when they are young. At the same time, there are also rare C. elegans males in the population that can provide more sperm to the female worms through mating.

In normal conditions, the female hermaphrodites secrete pheromones to attract males for mating only when they grow old and run out of their own sperm (at this point mating becomes the only way for them to continue and reproduce). Therefore, when the hermaphrodite is young, and still has sperm, she can choose whether to mix her genes by sexually reproducing with a male, or not.

In the new study, exposure to elevated temperatures was found to encourage more hermaphrodites to mate, and this trait was also preserved in the offspring for multiple generations, even though they were raised in comfortable temperatures and did not experience the stress from the increased heat.

The study, which was published today in the journal Development Cell, was led by Prof. Oded Rechavi and Dr. Itai Toker, as well as Dr. Itamar Lev and MD-PhD student Dr. Yael Mor, who did their doctorates under Prof. Rechavi’s supervision at the School of Neurobiology, Biochemistry & Biophysics, George S. Wise Faculty of Life Sciences, and the Sagol School of Neuroscience. The study was conducted in collaboration with the Rockefeller University in New York.

Securing Genetic Diversity

Why did the higher temperatures result in the C. elegans worms becoming more attractive, mating more with males? Dr. Itai Toker explains that “The heat conditions we created disrupted the inheritance of small RNA molecules that control the expression of genes in the sperm, so the worm’s sperm was not able to fertilize the egg with the efficiency that it normally would. The worm sensed that the sperm it produced was partially damaged, and therefore began to secrete the pheromone and attract males at an earlier stage, while it was still young.”

If that wasn’t enough, Dr. Rechavi points out that the really fascinating finding was that the trait of enhanced attractiveness was then passed on for many generations to offspring who did not experience the conditions of higher temperatures. The researchers found that heritable small RNA molecules, not changes in the DNA, transmitted the enhanced attractiveness between generations. Small RNAs control gene expression through a mechanism known as RNA interference or gene silencing – they can destroy mRNA molecules and thus prevent specific genes from functioning in a given time at a given tissue or cell.

Dr. Itai Toker adds that, “In the past, we discovered a mechanism that passes on small RNA molecules to future generations, in parallel and in a different way from the usual DNA-based inheritance mechanism. This enables the transmission of certain traits transgenerationally. By specifically inhibiting the mechanism of small RNA inheritance, we demonstrated that the inheritance of increased attractiveness depends on the transmission of small RNAs that control sperm activity.”

Mating, as opposed to fertilizing themselves, comes at a price for the female, hermaphroditic worms, as it allows them to pass on only half of their genome to the next generation. This “dilution” of the parents’ genetic contribution is a heavy price to pay. The benefit, however, is that it increases genetic diversity. By conducting lab evolution experiments we indeed discovered that it may be a useful adaptive strategy.

The researchers later experimented with evolution: They tracked the offspring of mothers who passed on the trait of attractiveness to males with the help of small RNAs, and allowed them to compete for males, for many generations, against normal offspring from a control group. The researhers observed how the inheritance of sexual attractiveness led to more mating in these competitive conditions, and that as a result the attractive offspring were able to spread their genes in the population more successfully.

Prof. Oded Rechavi (photo: Yehonatan Zur Duvdevani)

Environment’s Response to Global Warming?

In general, living things respond to their environment by changing their gene expression, without changing the genes themselves. The understanding that some of the epigenetic information, including information about the parents’ responses to environmental challenges, is encoded in small RNA molecules and can be passed down from generation to generation has revolutionized our understanding of heredity, challenging the dogma that has dominated evolution for a century or more. However, to date researchers have not been able to find a way in which epigenetic inheritance can affect the genetic sequence (DNA) itself.

“Epigenetics in general, and the inheritance of parental responses facilitated by small RNAs in particular, is a new field that is garnering a lot of attention,” says Dr. Lev. “We have now proven that the environment can change not only the expression of genes, but, indirectly, also genetic heredity, and for many generations.”

“Generally, epigenetic inheritance of small RNA molecules is a transient matter: the organism is exposed to a particular environment, and preserves the epigenetic information for 3-5 generations. In contrast, evolutionary change occurs over hundreds and thousands of generations. We looked for a link between epigenetics and genetics and found that a change in the environment, that is relevant to global warming, induces transgenerational secretion of a pheromone to attract males, and thus affects the evolution of the worms’ genome.”

Dr. Mor adds, “We think that it’s a way for the environment to adjust genetic diversity. After all, evolution requires variability and selection. The classical theory is that the environment can influence selection, but cannot affect variability, which is created randomly as a result of mutations. We found that the environment can actually impact genetic diversity under certain conditions.”

Finding the Optimal Location for the Tribal Bonfire

Written by Star on February 9, 2022. Posted in Newsroom.

In a first-of-its kind study, the researchers developed a software-based smoke dispersal simulation model and applied it to a known prehistoric site. They discovered that the early humans who occupied the cave had placed their hearth at the optimal location – enabling maximum utilization of the fire for their activities and needs while exposing them to a minimal amount of smoke. The groundbreaking study provides evidence for high cognitive abilities in early humans who lived 170,000 years ago.

The study was led by PhD student Yafit Kedar, and Prof. Ran Barkai from the Jacob M. Alkow Department of Archaeology and Ancient Near Eastern Cultures at The Lester and Sally Entin Faculty of Humanities, together with Dr. Gil Kedar. The paper was published in Scientific Reports.

In the Back of the Cave? Or towards the front?

The use of fire by early humans has been widely debated by researchers for many years, regarding questions such as: At what point in their evolution did humans learn how to control fire and ignite it at will? When did they begin to use it on a daily basis? Did they use the inner space of the cave efficiently in relation to the fire? While all researchers agree that modern humans were capable of all these things, the dispute continues about the skills and abilities of earlier types of humans. One focal issue in the debate is the location of hearths in caves occupied by early humans for long periods of time.

“Multilayered hearths have been found in many caves, indicating that fires had been lit at the same spot over many years,” says Yafit Kedar. “In previous studies, using a software-based model of air circulation in caves, along with a simulator of smoke dispersal in a closed space, we found that the optimal location for minimal smoke exposure in the winter was at the back of the cave. The least favorable location was the cave’s entrance.”

Humans Need Balance

In the current study, the researchers applied their smoke dispersal model to an extensively studied prehistoric site – the Lazaret Cave in southeastern France, inhabited by early humans around 170-150 thousand years ago. “According to our model, based on previous studies, placing the hearth at the back of the cave would have reduced smoke density to a minimum, allowing the smoke to circulate out of the cave right next to the ceiling,” explains Kedar. “However, in the archaeological layers we examined, the hearth was located at the center of the cave.”

The team tried to understand why the occupants had chosen this spot, and whether smoke dispersal had been a significant consideration in the cave’s spatial division into activity areas. The researchers performed a range of smoke dispersal simulations for 16 hypothetical hearth locations inside the 290sqm cave. To understand the health implications of smoke exposure, measurements were compared with the average smoke exposure recommendations of the World Health Organization.

Excavations at the Lazaret Cave, France (photo: De Lumley, M. A. néandertalisation (pp. 664-p). CNRS éditions. (2018Les restes humains fossiles de la grotte du Lazaret. Nice, Alpes-Maritimes, France. Des Homo erectus européens évolués en voie de)

The researchers found that the average smoke density, based on measuring the number of particles per spatial unit, is in fact minimal when the hearth is located at the back of the cave – just as their model had predicted. However, Yafit Kedar and Dr. Gil Kedar explain that they also discovered that “In this situation, the area with low smoke density, most suitable for prolonged activity, is relatively distant from the hearth itself. Early humans needed a balance – a hearth close to which they could work, cook, eat, sleep, get together, warm themselves, etc. while exposed to a minimum amount of smoke. Ultimately, when all needs are taken into consideration – daily activities vs. the damages of smoke exposure – the occupants placed their hearth at the optimal spot in the cave.”

Our Ancestors Nailed It

The study identified a 25sqm area in the cave which would be optimal for locating the hearth in order to enjoy its benefits while avoiding too much exposure to smoke. Astonishingly, in the several strata examined in this study, the early humans actually did place their hearth within this area.

“Our study shows that early humans were able, with no sensors or simulators, to choose the perfect location for their hearth and manage the cave’s space as early as 170,000 years ago – long before the advent of modern humans in Europe. This ability reflects ingenuity, experience, and planned action, as well as awareness of the health damage caused by smoke exposure. In addition, the simulation model we developed can assist archaeologists excavating new sites, enabling them to look for hearths and activity areas at their optimal locations,” concludes Prof. Barkai.

In upcoming studies, the researchers intend to use their model to investigate the influence of different fuels on smoke dispersal, use of the cave with an active hearth at different times of year, use of several hearths simultaneously, and more.

And Let There Be Light

Written by Star on February 6, 2022. Posted in Magazine, Newsroom.

Efforts by TAU’s Clinical Law Program will help keep electricity running for those who are struggling to pay utility bills.

The recent drop in temperature in Israel has led to a significant increase in electricity consumption. But what about those who simply cannot afford basic necessities?

A petition jointly filed by Tel Aviv University’s Human Rights Clinic at The Buchmann Faculty of Law will help keep the electricity on for some of Israel’s most underprivileged populations. In response to the appeal, Israel’s High Court ruled that electricity must not be cut off for citizens who prove a difficult economic or medical condition, effective immediately. We spoke with attorney Adi Nir Binyamini from TAU’s Human Rights Clinic, one of the lawyers who handled the case.

Electricity – A Fundamental Right?

In a precedent-setting decision, the High Court ruled on January 20 that access to electricity should be considered a fundamental right and that the Electricity Authority must, within six months, amend the criteria for power outages as a means of collecting debt. Meanwhile, the new ruling assists electricity consumers who find themselves in serious economic or medical distress, and ensure that they will not be left in the dark or the cold and without other basic needs.

The ruling came in response to a petition filed by the Association for Civil Rights in Israel (ACRI) in collaboration with the Human Rights Clinic at Tel Aviv University, Physicians for Human Rights and the Israel Union of Social Workers against the Electricity Authority, the Israel Electric Corp. and Energy Minister. It was filed on behalf of several poor families whose electricity had been cut off for non-payment.

The High Court of Justice ruled that, until the Electricity Authority establishes appropriate criteria and procedures (within six months from the time of the ruling), it must enable consumers facing power cuts from lack of payment to demonstrate whether they are suffering financial or health problems that justify their continued access to electric power. The court said the Electricity Authority must conduct a hearing prior to cutting a customer’s power. It gave the national electricity provider six months to revise its procedures and ordered it to pay the petitioners 40,000 NIS ($12,800) in expenses, to be divided among them. “This is a dramatic change from the previous situation, when it was possible to cut off people’s electricity access due to the accumulation of debt, except for very few exceptions,” explains Att. Nir Binyamini.

From the second hearing in Higher Court, on October 28, 2021 (from left to right): Gil Gan Mor (ACRI), Hicham Chabaita and Att. Adi Nir Binyamini from TAU’s Human Rights Clinic and Att. Mascit Bendel (ACRI)

The Beginning of a New Era

Binyamini, who has dealt with electricity litigation for several years now, says, “I feel personal and professional satisfaction that on the coldest day of the year, when people were left without heating, the High Court accepted our position and ruled not to cut off people’s electricity due to poverty and that debt must instead be collected by more moderate means.”

When asked how the Clinic got involved with the project, Binyamini explains that TAU’s Humans Rights Clinic was previously part of a legal battle over water disconnections for consumers unable to pay their water bill. “After that was successfully completed, we took on the subject of electricity and have been working on it continuously for the past eight years. The Clinic represented and handled the two petitions that were submitted to the Israeli High Court, and over the years we have dealt with hundreds of individual cases of people being cut off from electricity. We have also been guiding and assisting social workers with individual cases.”

She adds that a large number of students from the Clinic have worked on the case over the years, and stresses that such practical experience is an extremely valuable component of legal education.

Upon the court’s ruling, Binyamini along with Att. Maskit Bendel of the ACRI issued a statement, saying: “We hope that the ruling, which opened with the words ‘and let there be light,’ heralds the beginning of new era when it comes to protecting weak populations from having their electricity cut off.”

Attorney-at-law Adi Nir Binyamini from Tel Aviv University’s Human Rights Clinic (photo: Tomer Jacobson)

Reading Tea Leaves

Written by Star on January 25, 2022. Posted in news.

What is the origin of tea, and does the climate crisis threaten its production?

Tea – the ancient beverage comes in different flavors and colors. The Queen of England will never go without her afternoon tea, in India it’s enjoyed with milk and spices and we all like to pour ourselves an occasional cup of Earl Grey, especially when winter comes knocking. But have you ever wondered whether the saying “all the tea in China” really does indicate where tea drinking started? Or if the soothing drink may be affected by the climate crisis? Should we, in fact, be drinking it? We have, and our researchers explained, surprised us and busted some myths in the process.

When the Chinese Mystics Met the Tea Plant

We’re not going to keep you in suspense: It turns out that the coveted drink was sipped by the Indian Buddhist monks two thousand years ago – long before it became an integral part of Chinese culture and a long, long time before it became popular in Western cultures.

“The tea plant was known in China as early as the first centuries BCE, but recent studies show that the custom of drinking tea was brought to China from India,” explains Prof. Meir Shahar from The Department of East Asian Studies of The Lester and Sally Entin Faculty of Humanities at Tel Aviv University, who researches, among other things, the influence of Indian culture on Chinese religion and literature.

“In the first centuries CE Buddhism came to China from India and the Buddhist monks, who wanted to stay awake during the meditation, used to drink tea. The Chinese monks would observe this, and went on to adopt the custom as well, which then continued to spread to the rest of the Chinese population.”

While tea originates from India, the origin of the word ‘tea’ in most of the world’s languages, however, is Chinese. “In northern China it is called cha, hence the Russian chai, and in southern China it is pronounced as tcha, which is the origin of the English word tea,” reveals Prof. Shahar.

Buddhist monks on their tea break

What’s in Your Cuppa?

Buddhist monks realized long ago that tea keeps them awake and today, thanks to science, we are able to explain how the active ingredients of the plant affect us.

“Contrary to many people’s beliefs, all types of tea are produced from the same plant, namely the leaves and buds of the Camellia Sinensis plant. While there are several varieties of the plant, the types of tea that we are familiar with – white, green, oolong and black – differ according to the part of the plant from which they are produced and the way they’re processed. Green tea, for example, contains less caffeine than black tea. The leaves used to produce green tea undergo a minimal drying process while the leaves intended for black tea undergo drying and fermentation,” explains Guy Shalmon, a sports nutritionist and exercise physiologist at the Sylvan Adams Sports Institute.

“Tea leaves contain substances known as flavonoids. Their composition, however, varies from one tea to another. For example, green tea has a higher concentration of a substance called epigallocatechin 3-gallate, known for short as ‘EGCG’, than black tea which undergoes a prolonged processing process. It has antioxidant activity and is attributed various health effects,” says Guy.

“Having said that, tea may reduce the absorption of iron-derived iron minerals. The polyphenols (compounds with antioxidant properties), which exist in tea leaves, may bind inorganic iron mineral before it is excreted in the feces. In order to prevent this, one does not need to give up drinking tea, but instead make sure not to drink it while consuming iron-rich plant foods,” he advises.

Will Tea Survive the Climate Crisis?

The climate crisis brings with it many changes and different regions of the world are experiencing major climate fluctuations, ranging from heat and droughts to floods, storms and extreme cold. This could threaten the continued survival of agricultural crops. Some plants have crossed oceans and been absorbed by other continents, but what about those that require special conditions to thrive? Will the tea plant survive the changing conditions?

“A plant can adapt to new conditions up to a certain limit,” says Prof. Shaul Yalovsky of the School of Plant Sciences and Food Security at The George S. Wise Faculty of Life Sciences, who studies plant development mechanisms and their response to environmental stresses. His lab has succeeded in developing tomato varieties that consume less water and still deliver the same amounts of fruit while maintaining its quality.

“Tea is a crop that grows in very rainy areas. Therefore, it is not cultivated in an area like Israel, for example. Tea plantations are usually located on hills, where the weather is humid and cool to the appropriate extent and the soil is deep enough.”

The tea fields stretching over hills and mountains. Tea harvest in action

Disguised as Tea

Did you know that red “tea” (also known as “red bush tea”) is actually an infusion from the Rooibos plant that grows in South Africa? Because it is processed in the same way as the tea plant, it is commonly referred to as “red tea”, while in reality it is not a tea, but an herbal infusion. It is naturally caffeine-free.

Just like many other plants, tea requires specific conditions to grow: deep and airy soil rich in minerals, and an optimal temperature range between 18 and 20 degrees Celsius. “Tea is sensitive to cold, dryness, humidity and lighting conditions. For example, high humidity impairs the quality of the tea while periods of dryness increase its quality, and growing at high altitudes increases the quality of the tea but lowers the amount of crop,” explains Prof. Yalovsky.

The tea is grown in Asia, Africa and South America. The six largest tea producers in the world are China, India, Kenya, Sri Lanka, Vietnam and Turkey. So what happens if growing conditions in East and Southeast Asia change? Prof. Yalovsky explains that it is necessary to adapt the types of tea plants according to their growing areas. “What works at one location does not necessarily work elsewhere: what grows well in East and Southeast Asia will not necessarily grow well in Kenya or Turkey, for example. Even if we should manage to copy a crop from one place to another, we may not succeed in maintaining its qualities and taste.”

When we drink Earl Grey tea we expect a very specific taste, and if the same tree were to be grown elsewhere – where the temperature may be the same as the original habitat but the soil is not – we would likely notice a change in the taste of the product. This is possibly one of the reasons why drinking Japanese green tea differs in taste from Chinese green tea.

With regard to the future of the in-demand beverage, Prof. Yalovsky says: “Even if the regions of the cultivated areas should experience floods – the tea plantations are positioned on the slopes of hills and mountains so it should not become an issue.” Another good news is that unlike many crops that depend on pollination to develop fruit – the tea plant is less reliant on this. “In the production of tea, we use its leaves and not its flowers or fruits and so it can be propagated by pruning (cutting a branch from a mature plant, a so-called ‘mother plant’, and creating a new plant through rooting). This method also ensures the genetic uniformity of the ‘daughter plants’, with everything that implies,” he concludes.

We made sure to ask Guy Shalmon which type of tea (if any) he recommends that our students drink during the exam period, to which he replied: “Actually, I wouldn’t say there’s any unique advantage or need to drink tea during an exam period. I’d say drink the kind of tea that you fancy and, ideally, try to rotate different types of tea. If the need for caffeine is the main consideration, black tea is the best choice, as it has the highest caffeine concentration. Black tea contains approx. 60-40 mg of caffeine per cup, while green tea contains only 20-15 mg.”

Well, who needs the exams as an excuse, anyway? If you’re like us, we suggest you pour yourself a cuppa on any day of the week – no special occasion required – and enjoy a peaceful break from everything and everyone.

How Can We Boost Our Fight Against Marine Plastic Pollution?

Written by Star on January 24, 2022. Posted in news.

Plastic wastes endanger marine life in many ways: animals get entangled in large plastic items or swallow small particles and chemicals, consequently dying of suffocation, starvation or poisoning. Awareness is growing, and research is expanding, but the effort to monitor and prevent plastic pollution encounters many obstacles, first of all due to the enormous complexity and diversity of plastic debris.

A new review from Tel Aviv University has determined that global standardization of methodologies for monitoring and measuring marine plastic pollution can significantly boost international efforts to mitigate this troubling phenomenon. In a comprehensive survey of all methods described in existing literature, the researchers charted the great complexity and diversity of marine plastic pollution, which makes unified measurement and accurate evaluation very difficult. According to the researchers, this is precisely why a standardized system is urgently needed, enabling comparisons, exchange of information, and effective tools for decisionmakers.

Grave and Immediate Threat

The study was led by Gal Vered and Prof. Noa Shenkar of the School of Zoology at The George S. Wise Faculty of Life Sciences and The Steinhardt Museum of Natural History at Tel Aviv University. Gal Vered is also a researcher at the Interuniversity Institute for Marine Sciences in Eilat. The review was published in Current Opinion in Toxicology.

According to Prof. Shenkar, plastic pollution, which is all human-made, poses a grave and immediate threat to the marine environment, with constantly rising amounts of plastic entering the oceans. Thus, for example, a 2013 survey conducted by Israel’s Ministry of Environmental Protection found that plastic accounts for about 41% of the volume of waste produced annually by Israelis. The Covid-19 pandemic, which has generated extreme demands for personal protective and single-use products, has further exacerbated the problem.

Comes in Different Shapes and Forms

The researchers explain that marine plastic pollution comprises many different types of plastic and plastic products of various shapes and sizes – from huge ghost nets to nanoparticles, as well as a vast range of chemical additives. Different methods for monitoring, sampling, and identifying plastic pollution relate to different properties of the sampled material: from size, source, and original use, through shape and color, to chemical composition and physical properties. Sampling is usually conducted with a towed net, with the size of collected pollutants dependent on the net’s mesh size, and tiny particles are identified in the lab using various spectroscopic and chemical methods. In addition to the diversity in sampling and identification methods, units used for reporting measured concentrations of pollutants also vary: from the number of plastic objects per area, to the weight of particles per organism, and more.

“These differences generate confusion and lack of communication among researchers in different parts of the world, hampering our efforts to work together toward our common goal: providing decision makers with reliable data in order to promote the efforts to reduce plastic pollution and its many hazards,” explains Prof. Shenkar. “We are in urgent need of standardized methods and comparable measures for monitoring, sampling, identifying, classifying, and quantifying marine plastic pollution and its impact.”

International Collaboration Needed

“This study is a response to problems encountered in my research, which deals with the impact of plastic and its chemical additives on marine life in the Eilat coral reef (presenting Israel’s largest marine biodiversity),” says Gal Vered and explains: “The differences in methodology make it difficult to use the findings of other researchers – as either a source of information or for comparing results. Thus, for example, most measurements worldwide relate to samples obtained with a towed net from the surface of the water, while I wish to discover which materials reach the seafloor and reef organisms.”

“Standardization will enable accurate evaluations and valid comparisons between plastic pollutions in different places on the globe. This will maximize the power of scientific research, enhance our understanding of the impact of plastic pollution on ecosystems and marine life, and help us develop effective tools for decisionmakers facing this crucial issue.”

Prof. Shenkar concludes: “Marine plastic pollution is a global problem, which requires extensive international collaboration. At the bottom line, we all wish to focus our efforts and obtain the best results. Like many others, we believe that efforts should begin close to the shoreline, in areas directly impacted by plastic pollution. However, a great deal of research is still required in order to establish this assumption and build effective strategies for managing plastic pollution. But first of all, we urgently need standardization that will enable all of us, all over the world, to work together.”

Featured image: Prof. Noa Shenkar

Start Up Nation in Ancient Canaan

Written by Star on January 24, 2022. Posted in Newsroom.

A new Tel Aviv University study has determined that thanks to advanced management methods and impressive technological creativity, about three thousand years ago, the Arava Valley’s [located deep in the Southern Negev desert in Israel, along the Jordanian border] copper industry managed to thrive and become the largest and most advanced smelting center in the ancient world. The study was conducted by graduate student David Luria of TAU’s Jacob M. Alkow Department of Archaeology and Ancient Near Eastern Cultures and The Sonia & Marco Nadler Institute of Archaeology, and is being published in the prestigious journal PLOS ONE.

Ancient Practice of “Trial and Error”

According to Luria, the copper industry in Canaan at that time was concentrated in two large mining areas – one in Timna (north of Eilat) and the other in Faynan (in the northern Arava, in Jordan). Previous research on the subject has claimed that the high level of technology employed there was made possible thanks to Egyptian technologies brought to the region during the voyage of the Egyptian Pharoah Shishak in 925 BC. This theory was strengthened in 2014 following the discovery of a scarab bearing the figure of Shishak in Faynan, and again later in 2019, following the development of a new scientific model that claimed that a sudden technological leap had taken place around the time of Shishak’s journey.

Luria, on the other hand, argues that the great economic and technological success of the copper industry in the Arava was not related to Egyptian capabilities, but rather to the talent of the Arava people, who learned to use the two advanced methods we know today as “trial and error” and “scaling up.” “Obviously these terms were not in use in ancient times, but the application of their practical principles was made possible due to a basic understanding of engineering and common sense, which were seen in other places in the ancient world as well,” says Luria.

Luria explains that the “trial and error” method allowed the Arava metalworkers to slowly improve technological processes, as well as to increase the volume and quality of production. In addition, “scaling up” made it possible to increase the dimensions of the existing means of production using materials and processes that were common at the time, thereby developing advanced production equipment within a short amount of time and with minimum cost and technological risk.

The Secret Behind the Technological Success

“Shishak’s expedition was not intended to physically take over the copper mines in the Arava, but rather to formulate a long-term agreement with the Arava people in order to bolster local production and thus increase copper exports to Egypt, which was suffering from local production difficulties at the time,” Luria says.

“It appears that the secret of the success of the ancient copper industry in the Arava lies in the skills and abilities of efficient managers, who were assisted at every stage of their decision-making by talented technological experts. Archeology today can’t identify who these executives were, but a careful analysis of the deposits left in the area can tell us an accurate story. These findings are the residues of copper production that have accumulated as heaps of waste that can be dated, and whose size allows us to assess the volume of production at any given time. Moreover, by conducting a chemical analysis of the copper content remaining in the waste, we can determine the quality of the production; when the amount of copper in the waste diminishes, we can conclude that the process had become more efficient.”

Luria also says that traces detected at these sites show that throughout the production period, the management team was able to close inefficient mines and open more efficient ones. Moreover, at certain points a decision was taken to reuse waste from earlier periods, which was produced in less efficient processes in which a lot of copper remained, rather than use the pure mineral. These decisions could not have been made without an excellent technical team that backed management decisions with regular technological testing. The management also engaged in extensive marketing of the copper throughout the ancient world.

“The important lesson to take away from this technological success is that the high-tech savvy of individuals – educated and energetic people who lived here in the first millennium BCE – succeeded, just like it does today, in bringing about a huge revolution in the local economy,” Luria concludes. “As they say, there is nothing new under the sun.”

Featured image: David Luria

Learning from The Fastest Growing Alga in The World

Written by Star on January 24, 2022. Posted in Newsroom.

Sustainable food are grown, produced, distributed and consumed whilst keeping the environment in mind, and thus believed to help combat climate change. In a recent study, researchers set out to reveal the secret behind the rapid growth of “the fastest growing plant cell in the world,” the green alga Chlorella ohadii. Why? A better understanding of Chlorella ohadii, they assessed, might possibly help improve the efficiency of photosynthesis in other plants as well, and in turn help develop new engineering tools that could provide a solution for sustainable food.

Can We Boost the Photosynthesis in Plants?

The study’s findings indicate that the main factors behind the plant’s rapid photosynthesis rate lie in its efficient metabolic processes. The researchers found that this alga has a unique ability to elicit a chemical reaction in which it is able to efficiently and quickly recycle one of the components used by an enzyme called RuBisCO, in a manner that significantly speeds up the photosynthetic processes.

The study was led by researchers from the Max-Planck Institute for Molecular Plant Physiology in Germany, Participating in the study was Dr. Haim Treves, a member of the School of Plant Sciences and Food Security at Tel Aviv University, together with colleagues at the Max-Planck Institute for Molecular Plant Physiology in Germany. The study was published in the prestigious journal Nature Plants.

In the framework of the study, the researchers sought to examine whether it is possible to improve the efficiency of photosynthesis in plants, an energetic process that has been occurring in nature for about 3.5 billion years. To try to answer this question, the researchers decided to focus on green algae, particularly the Chlorella ohadii variety. This alga is known for its ability to survive in extreme conditions of heat and cold, which forces it to exhibit resilience and grow very quickly.

The researchers assessed that a better understanding of Chlorella ohadii (named after the late botanist Prof. Itzhak Ohad) would make it possible to improve the efficiency of photosynthesis in other plants as well, and in turn to develop new engineering tools that could provide a solution for sustainable food.

Online Monitoring of Photosynthesis

In the process of photosynthesis, plants and algae convert water, light and carbon dioxide into the sugar and oxygen essential for their functioning. The researchers used innovative microfluidic methods based on complex physical, chemical and biotechnological principles in order to provide the algae with carbon dioxide in a measured and controlled manner and monitor the photosynthesis “online.”

By using a comparative analysis, the researchers identified that there was a fundamental difference in the photosynthetic processes carried out in in green algae compared to the model plants. They assess that the difference lies in variations in the metabolic networks, a deeper understanding of which will help in developing innovative engineering solutions in the field of plant metabolism, as well as the optimal engineering of future agricultural products.

“Past empirical studies have shown that photosynthetic efficiency is higher in microalgae than in C3 or C4 crops, both types of plants that have transport systems but which are completely different in terms of their anatomy and the way they carry out photosynthesis,” Dr. Treves explains. “The problem is that the scientific community does not yet know how to explain these differences accurately enough.”

Dr. Treves adds, “In our current study we mapped the patterns of energy production and photosynthetic metabolism in green algae and compared them to existing and new data collected from model plants. We were able to clearly identify the factors that influence the difference in these patterns. Our research reinforces previous assessments that the metabolic pathway responsible for recycling is one of the major bottlenecks in photosynthesis in plants. The next step, is to export the genes involved in this pathway and in other pathways in which we have detected differences from algae, and to test whether their insertion into other plants via metabolic engineering will increase their rate of growth or photosynthetic efficiency.

“The toolbox we have assembled will enable us to harness the conclusions from the study to accelerate future developments in engineering in the field of algae-based sustainable food as a genetic reservoir for plant improvement; monitoring the photosynthesis is a quantitative and high-resolution process, and algae offer an infinite source of possibilities for improving photosynthetic efficiency.”

Featured image: Dr. Haim Treves

The Magnificent TAU Trees

Written by Star on January 16, 2022. Posted in Magazine, Newsroom.

Tel Aviv University campus lawns are legendary, but on the occasion of Tu B’Shvat, we thought we’d take a moment to celebrate our many trees.

They paint our campus in a variety of colors throughout the seasons, provide us with shade on hot sunny days and fill our souls with gladness. Our campus wouldn’t have been the same without them, and what better time than Tu B’Shvat to celebrate them? Below are some of the most interesting trees of Tel Aviv University. How many do you recognize?

The Root of the Matter

While most of the trees on campus boast broad, branched out branches, there is one tree that attracts attention for the opposite reason, namely its impressing branched-out roots. This fascinating fig tree (Ficus) ain’t planning on going anywhere – you can find it between the Dan David building and the Library of Exact Sciences, its roots extended with a radius of about five meters across the courtyard.

Summer-Time Snow

If you’ve ever visited the secret courtyard behind the building of the Faculty of Engineering during the hot summer months, you may have noticed that the green grass appears to be coverd in soft and airy snow. While it may not be real snow, it is fun to pretend that’s what the seeds from the white silk floss tree (Ceiba insignis) are. When the fruits of the tree ripen, they open up and a swollen crest bursts out – it looks just like a cotton ball – containing small brown seeds that are quickly spread everywhere.

Red Flame

At the beginning of summer, our campus is painted in a fiery red, thanks to the beautiful Royal Poinciana (Delonix regia), also known as ‘flamboyant tree’ or ‘peacock tree’. The trees are a delight to the eye for every passerby, and during this time of the year the lawn in front of the Gilman building becomes a favored destination for avid campus photographers, eager to document the breathtaking blossom from every possible angle.

Pretty in Pink

During spring, the courtyard between the Faculty of Exact Sciences and Dan David is painted pink and feels like a beautiful paradise, thanks to the spectacular flowers of the Bauhinia variegata. As the grass gets sprinkled with pink petals that slowly fall from the trees, the world looks really perfect for a moment, so we highly recommend you to bring your camera and come for a visit in April.

The Tree of Knowledge?

Strange-looking trees are growing in front of the George S. Wise Senate building, with large and impressive flowers and reddish fruits with an intriguing and tropical appearance. What’s the name of this strange tree, you ask? This is none other than a large-flowered magnolia tree, named after the French botanist Pierre Magnol. When its red seeds are exposed from its fruits, a small feathery tail is also revealed, allowing for flight and levitation, reminding us how ingenious and sophisticated nature is.

European Fall

How many songs do you think have been written about the season of fall? While that was meant as a rhetorical question, if you google “songs about fall”, you’ll get an idea. How is it that, even as the leaves dry out at the end of their life cycle, they are nevertheless so beautiful and inspiring? Get a small taste of European fall on Tel Aviv University campus, as the chestnut trees put on a display in shades of orange and brown next to our law school and the memorial monument of the Dan David building.

The above mentioned trees are only a small selection of the trees of our campus. According to Ilan Sharon, Head of TAU’s Yard Gardening and Maintenance Department, several thousand trees grow here, including pines, almonds, groves, palms and more. And let there be no doubt: We love and appreciate them all.

What is your favorite tree on campus? Give it a big hug, document the moment and tag us on Instagram with hashtag #tau-campus.

Wishing those of you who celebrate a Tu B’Shvat Sameach!

Out of This World

Written by Star on January 5, 2022. Posted in news.

A new star and satellite observatory is currently being set up on the roof of TAU’s Shenkar building, and is set to become one of the most sophisticated labs in the world.

If you’d like to take a look at the positioning of the receivers at the International Space Station or see how TAU’s own Nano-satellite, TAU SAT-1 (which has been orbiting the Earth for almost a year now) is doing, we’re here to tell you that you will soon be able to do so. A new state-of-the-art optical ground station is currently being built on the roof of Raymond & Beverly Sackler School of Physics & Astronomy. The new optical ground station will allow us to observe tiny details far above us.

The optical ground station will be used for advanced communication with satellites and other spacecraft and tracking of relatively close-up celestial bodies, but also stars that are millions of light-years away. At a later stage, the station will serve as a tool for quantum encryption in space, one that will allow us to best encrypt any type of information.

Moments before the most sophisticated telescope in Israel will be installed here at Tel Aviv University, we met with Prof. Yaron Oz, Head of the Quantum Center; Prof. Haim Suchowski from the School of Physics and Astronomy, and Michael Tzukran, a professional astronomy photographer who will be operating the new station, for a light conversation about, you know, the usual: quantum optical communication, space photography and surprise meetings that would lead to groundbreaking projects.

Replacing Light Pollution

Prof. Suchowski’s department, together with the University’s Engineering and Maintenance Division and partial funding from the Quantum Center, are currently working on making the Tel Aviv University campus free of celestial light pollution. This is a side-project that was born in conjunction with the construction of the new observation station. In the coming months, all polluting lighting on campus will be replaced with ecological lighting fixtures, making Tel Aviv University the first University in Israel to be free of light pollution.

Where it all started: Michael Tzukran in the old observatory on the roof of the Shenkar building the non-linear interaction of light with various materials in nature. In recent years, I’ve also been involved in the intensive activities at the Nano-Satellite Center and the new Quantum Center that have started operating on campus. What we’re dealing with on the roof these days is a combination of all these things,” he explains.

“The field of space once ‘belonged’ exclusively to NASA and very specific bodies, such as the aerospace industry in the case of Israel. Today, even high school students can send satellites into space,” explains Suchowski. “The New Space Revolution allows private companies to send and operate relatively affordable Nano-satellites into space and has changed our lives. Over the past 15 years, universities have been sending their own Nano-satellites as well.”

The University’s own Nano-satellite, TAU SAT-1, was devised, developed, assembled and tested under the leadership of Dr. Meir Ariel, Dr. Ofer Amrani of The Iby and Aladar Fleischman Faculty of Engineering and Prof. Colin Price of the Porter School of the Environment and Earth Sciences. The satellite, which carries scientific experiments, was launched about a year ago.

Up until now, the project has consisted in building a standard radio communication ground station to communicate with the launched satellite. According to Suchowski, one of the next projects will be to create optical communication through space, and thereafter quantum optical communication through space, which is a new and evolving field.

Quantum-Encrypted Communication Satellites

Information encryption is an essential subject with many applied meanings, and quantum mechanics is changing the rules of the game in this regard.

“Today, we encrypt our information based on complex mathematical algorithms, and assume that computers will take a long time to solve these problems and therefore the information is secure,” explains Prof. Yaron Oz, Chairman of the Tel Aviv University Quantum Science and Technology Center. “Quantum computers, however, are based on a different computational paradigm and can change the picture. Decomposing an integer into its primary factors – the complexity of which protects encryption algorithms that are widely used today – will be quickly solved by a quantum computer. Therefore, it is important to depict what the encrypted methods will be in the age of quantum computers.”

“Quantum systems have exceptional encrypted information transfer capabilities due to the fact that quantum mechanics do not allow information to be copied. Any attempt to copy or modify it destroys the original information. As a result, a quantum communication line is completely safe from eavesdropping. Transmitting a cipher key in a quantum communication network is completely secure, and indeed quantum optical encryption already exists via fiber optics,” he says.

Today, this type of encryption is possible, but limited to a distance of 150-200 km. Prof. Oz tells us that such communication networks already aid financial sectors in Switzerland. However, the transfer of information between continents (for example from New York to London) in this way is not yet possible.

Prof. Yaron Oz

Prof. Oz explains that in Israel there’s an understanding of the need to move in the direction of encrypting information on a satellite quantum communications network, and here at Tel Aviv University we have decided to take steps at the operational and research level. The new lab with the telescope on the roof is thereby about to take part in the future satellite project of the Nano-Satellite center.

With the help of various bodies here at TAU, the Quantum Center in particular, and with the support of Prof Erez Etzion, Head of the School of Physics and Astronomy, budget and space was ensured to build the advanced observatory and buy the massive equipment. With a telescope with a 24-inch mirror, the precise and huge robot will be able to track stars, galaxies, nebulae and other bodies. The robot, which weighs 300 kg, can move at an angular speed of up to 50 degrees per second and accurately track moving satellites at low altitudes, as well as lower flying aircraft. “We are already doing preliminary experiments in optical communication. With the level of accuracy of the new telescope we’ll be the only ones in Israel with such equipment,” promises Prof. Suchowski.

The construction of the new ground station, as documented in Michael Tzukran’s Instagram account

The Stargazer

Quite by chance, another actor entered the picture and helped Prof. Suchowski leverage the idea into practice: Michael Tzukran, a world expert in astronomical and satellite photography and research observatory construction consultant.

“As a seasoned astronomy photographer, I wanted to challenge myself and photograph the International Space Station. I needed an open roof close to the space station’s orbit as it passes over the skies of Israel. And so I simply asked whether it could be done here.” Tzukran brought his own equipment and took one of the most detailed photos ever taken of the space station from Earth. During the photography, the space station was flying at a speed of close to 28,000 km per hour. No big deal.

Passing at a speed of close to 28,000 km/h. The space station, photographed by Michael Tzukran

Michael’s specialty is to adjust and control the sophisticated robot, monitor the satellites and photograph them according to requests from researchers. With the new equipment, he plans to document satellites like they’ve never been observed before from Earth.

Prof. Ady Arie from the Faculty of Engineering and doctoral students Dolev Bashi, Georgi Gary Rosenman, Yonatan Piasetski, Sahar Shahaf, Tomer Nahum and Yuval Reches are also working on the establishment of the technological system for laboratory quantum optical communication.

Prof. Suchowski estimates that various industries, such as security and other universities, will be interested in using the new platform in the future: “This is a national resource. I believe it will become instrumental in promoting applied and basic research in Israel and the world,” he concludes.

Health Revelations from Ancient Jerusalem

Written by Star on January 4, 2022. Posted in Newsroom.

‘Who is wealthy?… Rabbi Yosef says: Anyone who has a bathroom close to his table.’ (The Talmud, Bavli Shabbat 25: 2).

Having a toilet was indeed an indicator of wealth in Jerusalem 2,700 years ago. The wealth was, however, no guarantee for good health, as a joint study by Tel Aviv University and the Israel Antiquities Authority (IAA) shows that even the wealthy residents of Jerusalem at that time suffered from diseases and epidemics. This became evident as an ancient toilet was uncovered in the garden of a luxury estate uncovered at the Armon Hanatziv Promenade in Jerusalem, and the researchers concluded that while the owners were undoubtable wealthy they also suffered from a range of intestinal parasites.

Rich, Yet in Poor Health

The study was led by Dr. Dafna Langgut of Tel Aviv University’s Jacob M. Alkow Department of Archaeology and Ancient Near Eastern Cultures, director of The Laboratory of Archaeobotany and Ancient Environments at The Sonia & Marco Nadler Institute of Archaeology and The Steinhardt Museum of Natural History. The research was published in the recent edition of the International Journal of Paleopathology.

Ya’akov Billig, who directed the excavation of the villa on behalf of the Israel Antiques Authority, dated the villa to the Late Iron Age of the 7th century BC. Aside from the toilet, magnificent stone artifacts of extraordinary workmanship were found at the site, such as decorated stone capitals of a quantity and quality never before observed in ancient Israel.

Langgut and Billig were not surprised by the recovery of a toilet in the garden of the estate, explaining that toilet facilities were extremely rare at that time and were a status symbol – a luxury facility that only the rich and high-ranking could afford.

Dr. Langgut collected sediment samples from underneath the stone toilet, chemically extracted the parasite eggs, scrutinized them under a light microscope, and identified them. The egg remains were discovered as part of a salvage excavation by the Israel Antiquities Authority, recently carried out at the Armon Hanatziv and funded by the Ir David Foundation. “The findings of this study are among the earliest observed in Israel to date,” she says. “These are durable eggs, and under the special conditions provided by the cesspit, they survived for nearly 2,700 years.”

She says the parasites that were found cause symptoms like abdominal pain, nausea, diarrhea, and itching. Some of them are especially dangerous for children and can lead to malnutrition, developmental delays, nervous system damage, and, in extreme cases, even death.

Dr. Dafna Langgut at the Laboratory of Archaeobotany and Ancient Environments

Intestinal disease at the time, she explains may have been the result of either poor sanitary conditions, the use of human feces to fertilize field crops or the consumption of improperly cooked beef or pork. In the absence of medicine, its recovery was difficult to impossible, and those infected could suffer from the parasites for the rest of their lives. Therefore, it is quite possible that the findings of the study indicate a bothersome and long-lasting infectious that affected the entire population. Langgut points out that these parasites still exist today, but the modern Western world has developed effective diagnostic means and medications, so they don’t turn into an epidemic.

The examination of the toilet samples came as Dr. Langgut was developing a new field of research called ‘archeoparasitology’, whereby researchers identify microscopic remains of intestinal worm eggs to learn about the history of diseases and epidemics. This area provides new information regarding human hygiene, lifestyle, and sanitary conditions.

“Studies like this one help us document the history of infectious diseases in our area and provide us with a window into the lives of people in ancient times,” Dr. Langgut concludes.

The excavation site at the Armon Hanatziv Promenade in the Jerusalem where the toilet was found (Photo: Yuli Schwartz, Israel Antiquities Authority)

Featured image: The stone toilet seat found during the 2019 excavation at Armon Hanatziv.