Newsroom – Page 47 – Australian Friends of Tel Aviv University

Fighting Pollution With Seaweed

Written by AUFTAU on 13 September 2021. Posted in Newsroom.

Nitrogen is a common fertilizer for agriculture, but it comes with an environmental and financial price tag. Once nitrogen reaches the ocean, it disperses randomly, damaging various ecosystems. As a result, the state local authorities spend a great deal of money on reducing nitrogen concentrations in water, including in the Mediterranean Sea.

A new study by Tel Aviv University and University of California, Berkeley suggests that establishing seaweed farms in areas where freshwater rivers or streams meet the oceans, or so-called “river estuaries”, significantly reduces nitrogen concentrations and prevents pollution in marine environments.

As part of the study, the researchers built a large seaweed farm model for growing the ulva sp. green macroalgae in the Alexander River estuary, hundreds of meters from the open sea. The Alexander River was chosen because the river discharges polluting nitrogen from nearby upstream fields and towns into the Mediterranean Sea. Data for the model were collected over two years from controlled cultivation studies.

The study was headed by doctoral student Meiron Zollmann, under the joint supervision of Prof. Alexander Golberg of the Porter School of Environmental and Earth Sciences and Prof. Alexander Liberzon of the School of Mechanical Engineering at The Iby and Aladar Fleischman Faculty of Engineering, Tel Aviv University, and was conducted in collaboration with Prof. Boris Rubinsky of the Faculty of Mechanical Engineering at UC Berkeley. It was published in the prestigious journal Communications Biology.

“My laboratory researches basic processes and develops technologies for aquaculture,” explains Prof. Golberg. “We are developing technologies for growing seaweed in the ocean in order to offset carbon and extract various substances, such as proteins and starches, to offer a marine alternative to terrestrial agricultural production. In this study, we showed that if seaweed is grown according to the model we developed, in rivers’ estuaries, they can absorb the nitrogen to conform to environmental standards and prevent its dispersal in water and thus neutralize environmental pollution. This way, we actually produce a kind of ‘natural decontamination facility’ with significant ecological and economic value, as seaweed can be sold as biomass for human use.”

Profitable and Environmentally Friendly

“Our model allows marine farmers, as well as government and environmental bodies, to know in advance what the impact will be and what the products of a large seaweed farm will be – before setting up the actual farm,” adds Meiron Zollmann. “Thanks to mathematics, we know how to make the adjustments also concerning large agricultural farms and maximize environmental benefits, including producing the agriculturally desired protein quantities.”

“The whole world is moving towards green energy, and seaweed can be a significant source,” adds Prof. Liberzon, “and yet today, there is no single farm with the proven technological and scientific capability. The barriers are also scientific: We do not really know what the impact of a huge farm will be on the marine environment. It is like transitioning from a vegetable garden outside the house to endless fields of industrial farming. Our model provides some of the answers, hoping to convince decision-makers that such farms will be profitable and environmentally friendly. Furthermore, one can imagine even more far-reaching scenarios. For example, green energy: If we knew how to utilize the growth rates for energy in better percentages, it would be possible to embark on a one-year cruise with a kilogram of seaweed, with no additional fuel beyond the production of biomass in a marine environment.”

“The interesting connection we offer here is growing seaweed at the expense of nitrogen treatment,” concludes Prof. Golberg. “In fact, we have developed a planning tool for setting up seaweed farms in estuaries to address the environmental issue while producing economic benefit. We offer the design of seaweed farms in river estuaries containing large quantities of agriculturally related nitrogen residues to rehabilitate the estuary and prevent nitrogen from reaching the ocean while growing the seaweed itself for food. In this way, aquaculture complements terrestrial agriculture.”

Featured image: The cultivation reactor that was used as the base of the model

TAU Team Reverses Early Signs of Alzheimer’s

Written by AUFTAU on 10 September 2021. Posted in Newsroom.

Approximately 50 million people worldwide live with Alzheimer’s or other related forms of dementia. Alzheimer’s disease leads to memory loss and impairment in cognitive function, and is the most common cause of dementia among older adults. While certain treatments can help reduce symptoms and sometimes reduce disease progression, there is currently no way to prevent or cure Alzheimer’s.

Amid that backdrop, researchers from Tel Aviv University have developed a process for reversing the precursors of the disease, providing a promising foundation for new preventative therapies. This marks the first time that a non-drug therapy has proven effective in preventing the core biological processes that lead to the development of Alzheimer’s, providing hope that we will now be able to fight one of the greatest challenges to the Western world.

Targeting the Root of Alzheimer’s

Using hyperbaric oxygen therapy (HBOT), in which subjects breathe 100% oxygen in a special chamber of high atmospheric pressure, the researchers were able to reverse brain damages associated with the biological hallmarks of Alzheimer’s.

“By treating the root problem that causes cognitive deterioration with age, we are in fact mapping out the way to prevention,” says co-lead researcher Prof. Shai Efrati.

Often used to treat carbon monoxide poisoning and infections that starve tissues of oxygen, hyperbaric therapy, when applied in a specific way, has previously been found capable of repairing damaged brain tissue and renewing growth of blood vessels and nerve cells in the brain. Therefore, the researchers tested its potential for Alzheimer’s.

“After a series of hyperbaric treatments, elderly patients who were already suffering from memory loss showed an improvement of blood flow to the brain as well as a real improvement in cognitive performance,” said co-lead investigator Prof. Uri Ashery.

The new approach devised by the researchers unequivocally improved characteristics commonly associated with Alzheimer’s disease. Specifically, the hyperbaric treatment resulted in:

Improved memory in 16.5% of patients on average
Increased blood flow in 16%-23% of cases
Improved attention and concentration in 6% of patients
Improved information processing speed in 10.3% of all cases

A Future Without Alzheimer’s?

“Our findings provide hope that we will now be able to fight one of the greatest challenges to the Western world. According to our findings, hyperbaric therapy given at a young age is likely to prevent this severe disease entirely,” explains TAU team member Dr. Ronit Shapira.

The approach was first tested in laboratory settings followed by testing in patients over the age of 65 in stages of deteriorating mental function that often precede Alzheimer’s and dementia. The therapy included a series of 60 treatments in hyperbaric chambers over a period of 90 days.

The study is part of a comprehensive research program focused on reversing processes of aging and its accompanying ailments. The researchers note that the findings are an encouraging step toward new approaches to preventing Alzheimer’s by addressing not only the symptoms or targeting biomarkers, but the core pathology and biology responsible for the disease’s development.

The Tel Aviv University team that led the study included Prof. Shai Efrati of the Sackler Faculty of Medicine and the Sagol School of Neuroscience, Prof. Uri Ashery and Dr. Pablo Blinder of the The George S. Wise Faculty of Life Sciences and the Sagol School of Neuroscience, and Dr. Ronit Shapira and Dr. Amir Hadanny. They are all affiliated with the Shamir Medical Center. The findings were published in the journal Aging.

Featured image: Alzheimer’s Disease on MRI

Nicotine Testing of Children Curbs Parents’ Smoking

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

Warnings against the dangers of smoking can be read on every cigarette box and in every advertisement for smoking brands. Those who smoke endanger themselves and also those around them, who inevitably become passive smokers. This way, parents who smoke harm the health of their own children. A first-of-its-kind study in Israel by researchers from the Sackler Medical School of Tel Aviv University uncovers alarming data about secondhand smoking by children of smokers: According to the study, nicotine residues were found in the hair samples of 7 out of 10 children who participated. The research team found that parental behavior may be changed through regular monitoring of children’s exposure.

Nicotine Residue in Children’s Hair

The study was conducted under the leadership of a team of experts from the Tel Aviv University School of Medicine headed by Prof. Leah (Laura) Rosen of the School of Public Health together with researchers Dr. Vicki Myers, Prof. Nurit Guttman, Ms. Nili Brown, Prof. Mati Berkovitch, and Dr. Michal Bitan. Prof. David Zucker of the Hebrew University of Jerusalem and Dr. Anna Rule of Johns Hopkins University in the US also participated in the study. The study was published in the prestigious journal, Nicotine & Tobacco Research.

In the study, the researchers sought to examine whether raising awareness of children’s exposure by providing objective feedback might change the parents’ behavior and child exposure. 140 Israeli families participated in the study, parents of children up to age 8, at least one parent being a smoker. The smoking average per household was 15 cigarettes per day, where one third of the respondents reported that they smoke inside the home, and one third said that they smoke on the terrace but not inside the home.

First, researchers tested children’s level of exposure via a biomarker, nicotine in hair, which indicates cumulative exposure to tobacco smoke. The researchers took hair samples from the children and tested the nicotine levels in each sample (it is important to note that the test was for nicotine that became an integral part of the strand of hair and not just outside precipitate.) The findings were very concerning: Nicotine residue was found in the hair of 70% of the children tested. Only 29.7% of the children tested did not show nicotine residue in their hair samples.

The researchers divided the families into two groups: one group underwent comprehensive instruction about the effects and dangers of exposure to smoking, including feedback and information about the test results. The group was also given tools to protect their children from exposure to cigarette smoke and a recommendation to keep their home and car smoke-free. The second group received feedback about nicotine levels in the children’s hair after six months, at the end of the study.

Limiting Children’s Exposure

Six months after the start of the study, the researchers conducted additional nicotine tests on the children’s hair, and one could already see a significant improvement in the data: Among the group that received comprehensive training, the percentage of children whose hair samples contained nicotine decreased from 66% to 53%, whereas in the second group (which did not receive training at the start of the study), the percentage of children whose hair samples contained nicotine decreased from 74% to 49%. Thus, just testing the children, without even informing families of the results, was enough to seemingly change parents’ behaviors.

The researchers theorize that the knowledge that the children were tested for tobacco smoke exposure, and that additional testing was planned at six months, resulted in the parents changing their behavior and reducing the children’s exposure. As a result of the study’s findings, the researchers recommend considering conducting such testing to measure exposure on a routine basis among young children in Israel.

The Right to Breathe Smoke-Free Air

Prof. Leah Rosen: “To our great dismay, according to the Ministry of Health’s data, approximately 60% of small children in Israel are exposed to secondhand smoke and its harmful effects. Based on the study’s findings, we believe that conducting nicotine testing – in the hair, urine, or using other testing methods – for every young child in Israel, may change parents’ perceptions about exposing their children to tobacco smoke. Changing this perception can also result in changing behavior, exposure levels, and even social norms regarding passive exposure to smoking – both exposure of children as well as exposure of adults.”

“We call upon smokers to avoid smoking anyplace where non-smokers and in particular, at-risk populations, including children, pregnant women, elderly, and those who are ill, could be exposed. Non-smokers must understand that there is genuine risk in exposure to tobacco smoke, and they must insist upon their right and the right of their children and family members to breathe air that is smoke-free everywhere. Of course, the government has a central role in enforcing laws pertaining to smoking in public places and continuing to enact laws to protect the individual everywhere from exposure to secondhand smoke.”

Raising the Bar in Film

Written by AUFTAU on 1 September 2021. Posted in Magazine, Newsroom.

TAU student Bar Cohen is bringing Israeli spirit and transgender representation to the big screen.

“I like to explore myself through film, as a woman and a transgender woman; filmmaking is always personal,” says Bar Cohen, a student at Tel Aviv University’s Steve Tisch School of Film and Television.

Cohen wrote and directed the semi-autobiographical film Her Dance, which in June won two awards at the Palm Springs International ShortFest—Best Student International Short and the Audience Award for Best Student Short.

Her Dance along with her upcoming release, Bug, are fictional short films inspired by her experiences as a transgender woman whose family has roots in the Orthodox Jewish community. The intimacy and pain expressed by Cohen’s work are hitting a nerve with audiences, and successfully bringing representation from the lesser-known transgender community in Israel to the local and world stage.

A Rising Auteur

Cohen, 26, realized at an early age that filmmaking was her calling.

“I’ve had a camera in my hand since I was eight years old,” she says. Cohen studied in a cinema track in high school and began her journey at TAU following her IDF service and after transitioning from the male gender assigned to her at birth to identifying as a woman.

Cohen, who recently completed her final year of undergraduate studies, is a scholarship recipient of both the Blavatnik Student Film Production Fund at TAU and Israeli transgender rights organization Ma’avarim (transitions).

Bar Cohen at Tel Aviv University

“The most amazing thing here at Tel Aviv University is the diversity of voices among the teachers,” she says. That range, she adds, provides a broad pool of mentors who can help students craft their own artistic expression. Cohen credits her academic mentor, Maya Dreifus, for providing invaluable guidance and inspiration.

“The best advice she gave me was to believe in myself and not worry about the opinions of others, because there will always be critics,” explains Cohen, who took that advice and ran with it.

Inspiration from the Heart

Cohen explains that lean budgets require Israeli filmmakers to rely on creativity and strong plotlines, rather than blockbuster action and overblown special effects.

“Israeli film brings heart,” she says. “Our main strength is telling meaningful stories.”

Cohen’s work is extremely close to her heart; she draws inspiration from the most vulnerable and authentic of sources—her own life.

A scene from Bar Cohen’s award-winning short film Her Dance

“It can be frightening to display elements of your real life on the big screen, but it’s the only way to create something of consequence,” she says.

A Journey of Self-Discovery

Originally from Bnei Barak, Cohen’s parents separated when she was three. Afterward, she lived with her mother in a secular home while her father remained Orthodox. At age five, Cohen told her mother that she didn’t feel like a boy, but rather a girl.

“My mom didn’t really understand it and thought it was just a phase,” explains Cohen.

“For a good part of my life, I was playing a role that wasn’t the real me. I was acting,” she says. That experience, she adds, contributed to her desire to study film.

Following a post-army trip to India, Cohen urgently felt the need to live her truth and told her parents that she had decided to transition to live as a woman.

“My parents lost a son, but gained a daughter,” she muses, noting that she made Her Dance to convey the complexities of that reality.

On the World Stage

Her Dance follows Aya, a secular transgender woman who arrives uninvited to her estranged, Orthodox family’s house during celebrations for her sister’s wedding. The heartrending 22-minute film debuted at the 2020 Tel Aviv Student Film Festival before premiering internationally.

WATCH: The trailer for TAU student Bar Cohen’s film Her Dance:

“It was the first time I saw my film in-person on the big screen since festivals went virtual due to COVID-19,” she explains shortly after returning from the Palm Springs ShortFest. “The audience was so receptive. After the screening, they had tears in their eyes and even gave me a standing ovation!”

In addition to Her Dance, the festival selected three other films by students of TAU’s Tisch School among the showcase of over 300 works from around the world: Borekas by Saleh Saadi, Neurim by Shaylee Atary, and Complicated by Isak Kohaly.

Her Dance was also among the competitions at the Aspen ShortFest, the BAFTA Student Film Awards, and the Indy Shorts International Film Festival.

Boosting Transgender Representation

For her next production, Cohen will soon shoot her graduation film about two friends navigating life and love after transitioning. It will feature a reprisal of the character Aya from Her Dance.

Following graduation, Cohen aims to create a TV series expanding upon the universe of her existing works.

While Cohen plans to initially establish her career in Israel, she notes that it is difficult to find local transgender actors and actresses.

“It’s important for me to bring real representation from the community,” she says. “It’s important for trans directors, actors and writers to take a part in our own stories.”

While transgender representation has made some significant steps in recent years with shows like Netflix’s Pose and the HBO adaption of Israeli drama Euphoria, Cohen acknowledges that there is still a long way to go.

And she believes she is well-position to help bring about that change.

Featured image: Bar Cohen accepts two awards at the Palm Springs International ShortFest (Photo: Nathan Cox, Palm Springs International ShortFest)

The Silent Prophets

Written by AUFTAU on 31 August 2021. Posted in Newsroom, Press release.

Our genome, our complete set of genetic instructions, contains mutations that can change the sequence of amino acids in the coded proteins. Since these proteins are responsible for the various cell mechanisms, such mutations are involved in turning healthy cells into cancer cells. In contrast, there are so-called ‘silent mutations’ that don’t change the sequence of amino acids in proteins. In recent years, it has been shown that silent mutations, both in and out of the cell’s genetic coding region, can affect gene expression, and may be associated with the development and spread of cancer cells. However, the question of whether silent mutations can help identify cancer types or predict patients’ chances of survival has never before been investigated with quantitative tools. Researchers from TAU’s Department of Biomedical Engineering and the Zimin Institute for Engineering Solutions Advancing Better Lives have been able to predict both the type of cancer and patients’ survival probability based on silent mutations in cancer genomes – a proof of concept that may well save lives in the future.

Predictive Power Similar to That of ‘Ordinary’ Mutations.

The groundbreaking study, led by Prof. Tamir Tuller and research student Tal Gutman, is based on about three million mutations from cancer genomes of 9,915 patients. The researchers attempted to identify the type of cancer and predict survival probability 10 years after the initial diagnosis – on the basis of silent mutations alone. They found that the predictive power of silent mutations is often similar to that of ‘ordinary’, non-silent mutations.

In addition, they discovered that by combining information from silent and non-silent mutations classification could be improved for 68% of the cancer types, and the best survival estimations could be obtained up to nine years after diagnosis. In some types of cancer classification was improved by up to 17%, while prognosis was improved by up to 5%. The findings of the study were recently published in NPJ Genomic Medicine.

Silent, Yet Making Noise

“‘Silent mutations’ have been ignored by researchers for many years,” explains Prof. Tuller. “In our study, about 10,000 cancer genomes of every type were analyzed, demonstrating for the first time that silent mutations do have diagnostic value – for identifying the type of cancer, as well as prognostic value – for predicting how long the patient is likely to survive.”

According to the professor, the cell’s genetic material holds two types of information: first, the sequence of amino acids to be produced, and second, when and how much to produce of each protein – namely regulation of the production process. “Even if they don’t change the structure of the protein, silent mutations can influence the process of protein production (gene expression), which is just as important. If a cell prodces much smaller quantities of a certain protein – it’s almost as though the protein has been eliminated altogether.”

“Another important aspect, which can also be affected by silent mutations, is the protein’s 3D folding, which impacts its functions: Proteins are long molecules usually consisting of many hundreds of amino acids, and their folding process begins when they are produced in the ribosome. Folding can be affected by the rate at which the protein is produced, which may in turn be affected by silent mutations.”

“Also, in some cases, silent mutations can impact a process called splicing, in which pieces of the genetic material are cut and rearranged to create the final sequence in the protein.”

Apparently, silent mutations can actually make a lot of noise, and Prof. Tuller and his colleagues were able to quantify their impact for the first time.

Saving as Many Lives as Possible

To test their hypothesis and quantify the effect of the silent mutations, the researchers used public genetic information about cancer genomes from the NIH in the USA. Applying machine learning techniques to this data, the team obtained predictions of the type of cancer and prognoses for patients’ survival – based on silent mutations alone. They then compared their results with real data from the database.

“The results of our study have several important implications,” says Prof. Tuller. “First of all, there is no doubt that by using silent mutations we can improve existing diagnostic and prognostic models. It should be noted that even a 17% improvement is very significant, because there are real people behind these numbers – sometimes even ourselves or our loved ones.”

“Doctors discovering metastases would like to know where they came from and how the disease has developed, in order to prescribe the best treatment. If, hypothetically, instead of giving wrong diagnoses and prognostics to five out of ten cancer patients, they only make mistakes in four out of ten cases, millions of lives may ultimately be saved. In addition, our results indicate that in many cases silent mutations can by themselves provide predictive power that is similar to that of non-silent mutations. These results are especially significant for a range of technologies currently under development, striving to diagnose cancer types based on DNA from malignant sources identified in simple blood tests. Since most of our DNA does not code for proteins, we may assume that most cancer DNA obtained from blood samples will contain silent mutations.”

The new study has implications for all areas of oncological research and treatment. Following this proof of concept, the researchers intend to establish a startup with Sanara Ventures, focusing on silent mutations as a diagnostic and prognostic tool.

Featured image: Prof. Tamir Tuller (Photo: Rafael Ben Menashe)

Want to Fall in Love? Step Outside in The Sun

Written by AUFTAU on 30 August 2021. Posted in Newsroom.

Any Tel Avivian will tell you that the perfect place for a first date is at the beach. Now, we have the science to support that claim. Researchers at Tel Aviv University have found that exposure to ultraviolet radiation from sunlight enhances romantic passion in humans. In the study, men and women were exposed to UVB (ultraviolet radiation type B) under controlled conditions, and the findings were unequivocal: increased levels of romantic passion in both genders.

Sun + Skin = Love

The study revealed that exposure to sunlight affects the regulation of the endocrine system responsible for the release of sexual hormones in humans. The discovery may lead to practical applications down the line, such as UVB treatments for sexual hormone disorders.

In animal models, the effect was dramatic: the females’ hormone levels rose significantly, enlarging their ovaries and prolonging their mating season; the attraction between males and females increased; and both were more willing to engage in sexual intercourse.

The researchers repeated the experiment on the animal model, this time removing from the skin a protein called p53, which identifies DNA damage and activates pigmentation during exposure to sunlight as protection against its adverse effects. The removal of the protein eliminated the effect of UVB exposure on the animals’ sexual behavior, convincing the researchers that exposure to radiation through the skin was the cause of the observed hormonal, physiological and behavioral changes, and that the protective system is also responsible for the regulation of sexuality.

Furless Humans and Sun Exposure

In the 32 human subjects of the study, all treated with UVB phototherapy at the Tel Aviv Sourasky (Ichilov) and Assuta Medical Centers, both genders exhibited a rise in romantic passion, and males also noted an increase in levels of aggression.

Similar results were found when the subjects were asked to avoid sunlight for two days, and then tan themselves for approximately 25 minutes. Blood tests revealed that exposure to sunlight resulted in a higher release of hormones like testosterone compared to one day before exposure. A rise in testosterone in males during the summer was also found in analyses of data from the Israeli health maintenance organizations Clalit and Maccabi Health Services.

Prof. Carmit Levy (on the left) & PhD student Roma Parikh.

The new discovery from TAU may lead to future practical applications, such as UVB treatments for sexual hormone disorders. The breakthrough opens up for further discoveries in basic science, “As humans, we have no fur, and our skin is thus directly exposed to sunlight. We are only beginning to understand what this exposure does to us, and the key roles it might play in various physiological and behavioral processes. It’s only the tip of the iceberg,” says Prof. Carmit Levy from the Department of Human Molecular Genetics and Biochemistry at the Sackler Faculty of Medicine.

The study was led by PhD student Roma Parikh and Ashchar Sorek from the laboratory of Prof. Levy. UVB phototherapy was administered to the subjects at the Tel Aviv Sourasky (Ichilov) and Assuta Medical Centers. The groundbreaking discovery was published as a cover story in the prestigious scientific journal Cell Reports.

Recordings of the magnetic field from 9,000 years ago teach us about the magnetic field today

Written by AUFTAU on 19 August 2021. Posted in Newsroom, Press release.

View west of the 1999 excavations, Stratum IIB, Tel Tifdan/ Wadi Fidan. Photo courtesy of Thomas E. Levy

Tel Aviv University Research Links Archaeology, Physics, and Geophysics

Burnt archaeological flints enable us to determine the strength of the Earth’s magnetic field during prehistoric periods.
Information about the magnetic field in antiquity helps us understand the magnetic field today. Researchers: “the current weakening of the field is a reversible trend; Seven thousand six hundred years ago, the strength of the magnetic field was even lower than today, but within approximately 600 years, it gained strength and again rose to high levels.”

International research by Tel Aviv University, the Istituto Nazionale di Geofisica e Vulcanologia, Rome, and the University of California San Diego uncovered findings regarding the magnetic field that prevailed in the Middle East between approximately 10,000 and 8,000 years ago. Researchers examined pottery and burnt flints from archaeological sites in Jordan, on which the magnetic field during that time period was recorded. Information about the magnetic field during prehistoric times can affect our understanding of the magnetic field today, which has been showing a weakening trend that has been cause for concern among climate and environmental researchers.

The research was conducted under the leadership of Prof. Erez Ben-Yosef of the Jacob M. Alkow Department of Archaeology and Ancient Near Eastern Cultures at Tel Aviv University and Prof. Lisa Tauxe, head of the Paleomagnetic Laboratory at the Scripps Institution of Oceanography, in collaboration with other researchers from the University of California at San Diego, Rome and Jordan. The article was published in the journal PNAS.

Prof. Erez Ben-Yosef
Photo courtesy of Yoram Reshef

“Albert Einstein characterized the planet’s magnetic field as one of the five greatest mysteries of modern physics…”

Prof. Ben-Yosef explains, “Albert Einstein characterized the planet’s magnetic field as one of the five greatest mysteries of modern physics. As of now, we know a number of basic facts about it: The magnetic field is generated by processes that take place below a depth of approximately 3,000 km beneath the surface of the planet (for the sake of comparison, the deepest human drilling has reached a depth of only 20 km); it protects the planet from the continued bombardment by cosmic radiation and thus allows life as we know it to exist; it is volatile and its strength and direction are constantly shifting, and it is connected to various phenomena in the atmosphere and the planet’s ecological system, including – possibly – having a certain impact on climate. Nevertheless, the magnetic field’s essence and origins have remained largely unresolved. In our research, we sought to open a peephole into this great riddle.”

The researchers explain that instruments for measuring the strength of the Earth’s magnetic field were first invented only approximately 200 years ago. In order to examine the history of the field during earlier periods, science is helped by archaeological and geological materials that recorded the properties of the field when they were heated to high temperatures. The magnetic information remains “frozen” (forever or until another heating event) within tiny crystals of ferromagnetic minerals, from which it can be extracted using a series of experiments in the magnetics laboratory. Basalt from volcanic eruptions or ceramics fired in a kiln are frequent materials used for these types of experiments. The great advantage in using archaeological materials as opposed to geological is the time resolution: While in geology dating is on the scale of thousands years at best, in archaeology the artifacts and the magnetic field that they have recorded can be dated at a resolution of hundreds and sometimes even tens of years (and in specific cases, such as a known destruction event, even give an exact date). The obvious disadvantage of archaeology is the young age of the relevant artifacts: Ceramics, which have been used for this purpose up until now, were only invented 8,500 years ago.

Burnt flints and ceramics used to reconstruct the strength of the ancient geomagnetic field
(https://doi.org/10.1073/pnas.2100995118)

The current study is based on materials from four archaeological sites in Wadi Feinan (Jordan), which have been dated (using carbon-14) to the Neolithic period – approximately 10,000 to 8,000 years ago – some of which predate the invention of ceramics. Researchers examined the magnetic field that was recorded in 129 items found in these excavations, and this time, burnt flint tools were added to the ceramic shards. Prof. Ben-Yosef: “This is the first time that burnt flints from prehistoric sites are being used to reconstruct the magnetic field from their time period. About a year ago, groundbreaking research at the Hebrew University was published, showing the feasibility of working with such materials, and we took that one step forward, extracting geomagnetic information from tightly dated burned flint. Working with this material extends the research possibilities tens of thousands of years back, as humans used flint tools for a very long period of time prior to the invention of ceramics. Additionally, after enough information is collected about the changes in the geomagnetic field over the course of time, we will be able to use it in order to date archaeological remains”.

Wadi Fidan 61 Pottery Neolithic.
Photo courtesy of Thomas E. Levy

An additional and important finding of this study is the strength of the magnetic field during the time period that was examined. The archaeological artifacts demonstrated that at a certain stage during the Neolithic period, the field became very weak (among the weakest values ever recorded for the last 10,000 years), but recovered and strengthened within a relatively short amount of time. According to Prof. Tauxe, this finding is significant for us today: “In our time, since measurements began less than 200 years ago, we have seen a continuous decrease in the field’s strength. This fact gives rise to a concern that we could completely lose the magnetic field that protects us against cosmic radiation and therefore, is essential to the existence of life on Earth. The findings of our study can be reassuring: This has already happened in the past. Approximately 7,600 years ago, the strength of the magnetic field was even lower than today, but within approximately 600 years, it gained strength and again rose to high levels.”

The research was carried out with the support of the US-Israel Binational Science Foundation, which encourages academic collaborations between universities in Israel and in the US. The researchers note that in this case, the collaboration was particularly essential to the success of the study because it is based on a tight integration of methods from the fields of archaeology and geophysics, and the insights that were obtained are notably relevant to both of these disciplines.

Link to the article:

https://doi.org/10.1073/pnas.2100995118

First 3D-bioprinting of entire active tumor

Written by AUFTAU on 19 August 2021. Posted in Newsroom, Press release.

Research team(Left to right): Eilam Yeini, Prof. Satchi-Fainaro and Lena Neufeld

Scientific breakthrough in the battle against cancer

The 3D print of glioblastoma – the deadliest type of brain cancer – is printed from human glioblastoma tissues containing all components of the malignant tumor

Researchers: the breakthrough will enable much faster prediction of best treatments for patients, accelerate the development of new drugs and discovery of new druggable targets

A scientific achievement for researchers at Tel Aviv University: printing an entire active and viable glioblastoma tumor using a 3D printer. The 3D-bioprinted tumor includes a complex system of blood vessel-like tubes through which blood cells and drugs can flow, simulating a real tumor.

Illustration.
Credit: Veronica Hughes, PhD of STEAM visuals

The study was led by Prof. Ronit Satchi-Fainaro, Sackler Faculty of Medicine and Sagol School of Neuroscience, Director of the Cancer Biology Research Center, Head of the Cancer Research and Nanomedicine Laboratory and Director of the Morris Kahn 3D-BioPrinting for Cancer Research Initiative, at Tel Aviv University.

The new technology was developed by PhD student Lena Neufeld, together with other researchers at Prof. Satchi-Fainaro’s laboratory: Eilam Yeini, Noa Reisman, Yael Shtilerman, Dr. Dikla Ben-Shushan, Sabina Pozzi, Dr. Galia Tiram, Dr. Anat Eldar-Boock and Dr. Shiran Farber.

The 3D-bioprinted models are based on samples from patients, taken directly from operating rooms at the Tel Aviv Sourasky Medical Center. The new study’s results were published today in the prestigious journal Science Advances.

“Glioblastoma is the most lethal cancer of the central nervous system, accounting for most brain malignancies”

“Glioblastoma is the most lethal cancer of the central nervous system, accounting for most brain malignancies,” says Prof. Satchi-Fainaro. “In a previous study, we identified a protein called P-Selectin, produced when glioblastoma cancer cells encounter microglia – cells of the brain’s immune system. We found that this protein is responsible for a failure in the microglia, causing them to support rather than attack the deadly cancer cells, helping the cancer spread. However, we identified the protein in tumors removed during surgery, but not in glioblastoma cells grown on 2D plastic petri dishes in our lab. The reason is that cancer, like all tissues, behaves very differently on a plastic surface than it does in the human body. Approximately 90% of all experimental drugs fail at the clinical stage because the success achieved in the lab is not reproduced in patients.”

Prof. Ronit Satchi-Fainaro

To address this problem, the research team led by Prof. Satchi-Fainaro and PhD student Lena Neufeld, recipient of the prestigious Dan David Fellowship, created the first 3D-bioprinted model of a glioblastoma tumor, which includes 3D cancer tissue surrounded by extracellular matrix, which communicates with its microenvironment via functional blood vessels.

Microscopic image of the 3D-bioprinted glioblastoma model. The bioprinted blood vessels are covered with endothelial cells (red) and pericytes (cyan). The blood vessels are surrounded with a brain-mimicking tissue composed of gliblastoma cells (blue) and the brain microenvironment cells (green). Different drugs or cells can be perfused through the 3D-bioprinted blood vessels to test their effect on the tumor tissue

“It’s not only the cancer cells…”

“It’s not only the cancer cells,” explains Prof. Satchi-Fainaro. “It’s also the cells of the microenvironment in the brain; the astrocytes, microglia and blood vessels connected to a microfluidic system – namely a system enabling us to deliver substances like blood cells and drugs to the tumor replica. Each model is printed in a bioreactor we have designed in the lab, using a hydrogel sampled and reproduced from the extracellular matrix taken from the patient, thereby simulating the tissue itself. The physical and mechanical properties of the brain are different from those of other organs, like the skin, breast, or bone. Breast tissue consists mostly of fat, bone tissue is mostly calcium; each tissue has its own properties, which affect the behavior of cancer cells and how they respond to medications. Growing all types of cancer on identical plastic surfaces is not an optimal simulation of the clinical setting.”

After successfully printing the 3D tumor, Prof. Satchi-Fainaro and her colleagues demonstrated that unlike cancer cells growing on petri dishes, the 3D-bioprinted model has the potential to be effective for rapid, robust, and reproducible prediction of the most suitable treatment for a specific patient.

“We proved that our 3D model is better suited for prediction of treatment efficacy, target discovery and drug development in three different ways.

First, we tested a substance that inhibited the protein we had recently discovered, P-Selectin, in glioblastoma cell cultures grown on 2D petri dishes, and found no difference in cell division and migration between the treated cells and the control cells which received no treatment. In contrast, in both animal models and in the 3D-bioprinted models, we were able to delay the growth and invasion of glioblastoma by blocking the P-Selectin protein.

This experiment showed us why potentially effective drugs rarely reach the clinic simply because they fail tests in 2D models, and vice versa: why drugs considered a phenomenal success in the lab, ultimately fail in clinical trials. In addition, collaborating with the lab of Dr. Asaf Madi of the Department of Pathology at TAU’s Faculty of Medicine, we conducted genetic sequencing of the cancer cells grown in the 3D-bioprinted model, and compared them to both cancer cells grown on 2D plastic and cancer cells taken from patients.

Thus, we demonstrated a much greater resemblance between the 3D-bioprinted tumors and patient-derived glioblastoma cells grown together with brain stromal cells in their natural environment. Through time, the cancer cells grown on plastic changed considerably, finally losing any resemblance to the cancer cells in the patient’s brain tumor sample.

The third proof was obtained by measuring the tumor growth rate. Glioblastoma is an aggressive disease partially because it is unpredictable: when the heterogeneous cancer cells are injected separately into model animals, the cancer will remain dormant in some, while in others, an active tumor will develop rapidly. This makes sense because we, as humans, can die peacefully of old age without ever knowing we have harbored such dormant tumors. On the dish in the lab, however, all tumors grow at the same rate and spread in the same rate. In our 3D-bioprinted tumor, the heterogeneity is maintained and development is similar to the broad spectrum that we see in patients or animal models.”

“…perhaps the most exciting aspect is finding novel druggable target proteins and genes in cancer cells…”

According to Prof. Satchi-Fainaro, this innovative approach will also enable the development of new drugs, as well as discovery of new drug targets – at a much faster rate than today. Hopefully, in the future, this technology will facilitate personalized medicine for patients.

“If we take a sample from a patient’s tissue, together with its extracellular matrix, we can 3D-bioprint from this sample 100 tiny tumors and test many different drugs in various combinations to discover the optimal treatment for this specific tumor. Alternately, we can test numerous compounds on a 3D-bioprinted tumor and decide which is most promising for further development and investment as a potential drug.

But perhaps the most exciting aspect is finding novel druggable target proteins and genes in cancer cells – a very difficult task when the tumor is inside the brain of a human patient or model animal. Our innovation gives us unprecedented access, with no time limits, to 3D tumors mimicking better the clinical scenario, enabling optimal investigation.”

Illustration for demonstration of 3D printing of a tumor in a brain Microenvironment according to a computed 3D model

The study was funded by the Morris Kahn Foundation, European Research Council (ERC), Israel Cancer Research Fund (ICRF), the Israel Cancer Association and Israel Science Foundation (ISF), and Check Point Software Technologies LTD.

Prof. Isaac Ben-Israel Receives the IEEE Leadership Award

Written by AUFTAU on 14 August 2021. Posted in Newsroom.

Where Have All the Birds Gone?

Written by AUFTAU on 11 August 2021. Posted in Newsroom.

A new study from Tel Aviv University and the Weizmann Institute revealed that over the last 20,000-50,000 years, birds have undergone a major extinction event, inflicted chiefly by humans, which caused the disappearance of about 10%-20% of all avian species. The vast majority of the extinct species shared several features: they were large, they lived on islands, and many of them were flightless.

The main cause for extinction of species by humans today has evolved from being hunting to the destruction of the animals’ natural habitats, but the researchers hope their findings will serve as warning signals regarding bird species currently threatened with extinction.

The study was led by Prof. Shai Meiri 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, and Amir Fromm of the Weizmann Institute of Science. The paper was published in the Journal of Biogeography.

Human-Inflicted Extinction

Prof. Meiri: “We conducted a comprehensive review of scientific literature, and for the first time collected quantitative data on the numbers and traits of extinct species of birds worldwide. Those that became extinct in the last 300 years or so are relatively well known, while earlier species are known to science from remains found in archaeological and paleontological sites worldwide. Altogether we were able to list 469 avian species that became extinct over the last 50,000 years, but we believe that the real number is much higher.”

The researchers believe that the vast extinction was caused primarily by humans who hunted the birds for food, or by animals brought to islands by humans – that fed on the birds and/or their eggs. This assumption is based on the fact that the greater part of bird remains was found on human sites, apparently belonging to birds consumed by the inhabitants, and in most cases the extinctions occurred shortly after the arrival of humans.

Coveted Targets for Hunters

Most extinct species shared three major features:

About 90% of them lived on islands – When humans arrived on the island, the birds were hunted by them, or fell victim to other animals introduced by humans, such as pigs, rats, monkeys, and cats.
Most extinct bird species were large, some very large – The body mass of the extinct species was found to be up to 10 times as large as that of surviving species. The larger birds provided humans with a great quantity of food, thus they were a preferred target for hunters. Previous studies have found a similar phenomenon among mammals and reptiles, especially lizards and turtles that lived on islands: the larger ones were hunted by humans and became extinct.
A large portion of the extinct bird species were flightless, and often unable to escape their pursuers – The study found that the number of flightless bird species that became extinct is double the number of flightless species still existing today; all in all, 68% of the flightless bird species known to science became extinct. One of the better-known examples is the moa bird in New Zealand: 11 species of moa became extinct within 300 hundred years, due to hunting by humans

Prof. Meiri: “Our study indicates that before the major extinction event of the past millennia, many more large, even giant, as well as flightless avian lived on our globe, and the diversity of birds living on islands was much greater than today. We hope that our findings can serve as warning signals regarding bird species currently threatened with extinction, and it is therefore important to check whether they have similar features. It must be noted, however, that conditions have changed considerably, and today the main cause for extinction of species by humans is not hunting but rather the destruction of natural habitats.”

Featured image: Bird species at the Zoological Garden

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