Culture

IIASA researchers have used Sentinel 1 satellite imagery from the European Space Agency to produce a map of the extent and year of detection of oil palm plantations in Indonesia, Malaysia, and Thailand that will help policymakers and other stakeholders understand trends in oil palm expansion while also providing an accurate map for landscape-level planning.

The world's appetite for palm oil seems to know no bounds. We use it in everything from beauty products and food, to industrial processes and biofuels to fulfill our energy needs. This ever growing demand has caused oil palm production to more than double in the last two decades, a development which has in turn deeply impacted natural forest ecosystems and biodiversity, while also significantly contributing to climate change by releasing carbon from converted forests and peatlands into the atmosphere. Today, almost 90% of the world's oil palm production takes place in Southeast Asia. While oil palm is known to be the most efficient oil producing plant globally, yields vary dynamically with plantation stand age, management practices, and location. To understand trends in oil palm plantation expansion and for landscape-level planning, accurate maps are needed. To this end, IIASA researchers have provided a detailed map of oil palm extent in 2017 using *Sentinel 1 satellite imagery from the European Space Agency in a new paper published in Nature Scientific Data.

"We specifically wanted to determine the extent and age of oil palm plantations across Southeast Asia and see if we could use technologies such as Google Earth Engine and data mining algorithms to produce an accurate map of oil palm extent from Sentinel 1 radar data, which could potentially be operationalized into a near-real time oil palm detection system. In addition, we wanted to explore the possibility of using time series analysis to go backwards in time and determine the age at which the plantation can first be detected (i.e., when trees are around 2 to 3 years in age)," explains lead author Olga Danylo, a researcher with the IIASA Novel Data Ecosystems for Sustainability Research Group.

While oil palm extent has been mapped before, this paper uses Sentinel 1 satellite data in combination with other data sets to map extent, along with time series from the Landsat archive to derive the year of plantation detection (which is a proxy for productive age of the plantations). This additional information is valuable for examining questions related to oil palm expansion over the last two decades, as well as the ability to calculate yields from the age information. (Yields increase during the plant's youth phase in the first seven years, reach a plateau during the prime age of 7-15 years, and then slowly start to decline before palms are replaced at the age of 25-30 years.) Therefore, knowing the exact extent and age of plantations across a landscape is crucial for landscape-level planning to allow for both sustainable oil palm production and forest conservation.

The paper's key output is a 30 m resolution map of Southeast Asia that indicates if oil palm is present and the year of detection of the plantation - a brand new feature that allows for a better understanding of oil palm expansion in Southeast Asia. The oil palm extent map has an overall accuracy of 83%, which is comparable to other products. The largest area of oil palm can be found in Sumatra and Kalimantan, with expansions in all major regions since the year 2000. The maps shows that the largest relative expansions over the last decade have taken place in Kalimantan, insular Malaysia, and Thailand, but interestingly, the net oil palm plantation area, excluding milling facilities, roads, and other related infrastructure, might be significantly smaller than previously thought.

According to the researchers, the new map could furthermore support the calculation of estimates of greenhouse gas emissions and removals for specific regions, provide a means whereby official statistics can be independently verified, and could also be used in analyses related to determining the economic trade-offs in different types of land use. In addition, the oil palm map in combination with spatial information about estate boundaries could help to identify specific actors and their adherence to environmental legislation and compliance with sustainability standards.

"Buying certified palm oil (RSPO) is a means of avoiding tropical deforestation. Our map can inform which sites are eligible for RSPO certification and it can help policymakers such as the EU commission to make more accurate and directed policies in relation to palm oil by for instance excluding palm oil from certain (recently deforested) areas from biofuels in the EU," concludes coauthor Johannes Pirker, a guest researcher with the Agriculture, Forestry, and Ecosystem Services Research Group at IIASA

The data set used in this paper is publicly accessible for download from the IIASA DARE repository.

* The Sentinel-1 mission comprises a constellation of two polar-orbiting satellites, operating day and night performing C-band synthetic aperture radar imaging, enabling them to acquire imagery regardless of the weather. Sentinel 1 satellite imagery is particularly valuable in tropical countries which are covered by clouds nearly all year.

RESTON, Va. - Greater sage-grouse populations have declined significantly over the last six decades, with an 80% rangewide decline since 1965 and a nearly 40% decline since 2002, according to a new report by the U.S. Geological Survey. Although the overall trend clearly shows continued population declines over the entire range of the species, rates of change do vary regionally.

The report represents the most comprehensive analysis of greater sage-grouse population trends ever produced and lays out a monitoring framework to assess those trends moving forward. The study can also be used to evaluate the effectiveness of greater sage-grouse conservation efforts and analyze factors that contribute to habitat loss and population change -- all critical information for resource managers.

"Every day, the USGS brings diverse stakeholders the compelling science they need to make strategic, on-the-ground policy and management decisions," said David Applegate, associate director exercising the delegated authority of the USGS director. "With this framework in place, resource managers can more nimbly respond to population declines with actions such as redistributing monitoring efforts or prioritizing where management intervention may be needed."

USGS scientists and colleagues developed the framework to estimate greater sage-grouse population trends in the 11 western states where the species lives - California, Colorado, Idaho, Montana, Nevada, North Dakota, Oregon, South Dakota, Utah, Washington and Wyoming. The greater sage-grouse is a vulnerable species and an indicator of the overall health of the iconic sagebrush ecosystem.

The research found that in recent decades the rate of greater sage-grouse decline increased in western portions of the species' range, particularly in the Great Basin, while the declines have been less severe in eastern areas. Western Wyoming was the only region to show relatively stable sage-grouse populations recently. Taken as a whole, the greater sage-grouse population now is less than a quarter of what it was more than 50 years ago.

To complete the framework, USGS and Colorado State University researchers collaborated with the Western Association of Fish and Wildlife Agencies, individual state wildlife agencies and the Bureau of Land Management. Together, they compiled information and created a rangewide database of greater sage-grouse breeding grounds. Researchers used that information to assess past and current sage-grouse population trends in different parts of the species' range.

In addition to the database and population-trend assessment, researchers also developed a "Targeted Annual Warning System" to alert biologists and managers when local greater sage-grouse populations begin to decline or have diverged from regional trends. The research identified the most at-risk breeding grounds, with the greatest risk seen at the periphery of the species' range. The report shows that there is only a 50% chance that most breeding grounds, called leks, will be productive in about 60 years from now if current conditions persist. USGS scientists will continue to analyze information to determine the factors driving changes in breeding areas and populations, including the influence of habitat loss and degradation.

"The framework we developed will help biologists and managers make timely decisions based on annual monitoring information," said Peter Coates, USGS scientist and lead author of the report. "This will allow them to address local issues before they have significant impacts on the population."

What The Study Did: Researchers investigated COVID-19 vaccine intentions among racially and ethnically diverse samples of health workers and the general population in the San Francisco Bay area.

Authors: Kevin Grumbach, M.D., of the San Francisco General Hospital and University of California, San Francisco, is the corresponding author.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamainternmed.2021.1445)

Editor's Note: The article includes conflict of interest and funding/support disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.

Working with fruit flies, scientists at Johns Hopkins Medicine say they have identified a new molecular pathway that helps steer moving cells in specific directions. The set of interconnected proteins and enzymes in the pathway act as steering and rudder components that drive cells toward an "intended" rather than random destination, they say.

In a report on the work, published March 2 in Cell Reports, these same molecular pathways, say the scientists, may drive cancer cells to metastasize or travel to distant areas of the body and may also be important for understanding how cells assemble and migrate in an embryo to form organs and other structures.

The team of scientists was led by Deborah Andrew, Ph.D., professor of cell biology and associate director for faculty development for the Institute for Basic Biomedical Sciences at the Johns Hopkins University School of Medicine.

Andrew and her colleagues began this research while studying a gene called Tre1 and its role in the development of salivary glands in fruit flies. The tools to study the effects of turning the gene on and off weren't ideal, she says. So, two of the team members, Caitlin Hanlon, Ph.D., of Quinnipiac University and JiHoon Kim, Ph.D., of Johns Hopkins, generated fruit flies that lack the protein-coding portion of the Tre1 gene. The pair also put a fluorescent tag on the Tre1 protein to learn where it localized during key steps in development.

In experiments with fruit fly embryos carrying an intact Tre1 gene, cells that produce future generations of the organism, called germ cells, migrate correctly to the sex organ, known as the gonad.

"Without the Tre1 gene, however, most of the germ cells failed to meet up with other nongerm cells, or somatic cells, of the gonad," says Andrew. "Correct navigation of germ cells is important to ensure that future generations of the organism will happen."

This is not the first time that scientists noted Tre1's importance in germ cell navigation. Two research teams from Indiana University and the Massachusetts Institute of Technology had previously made the link. However, says Andrew, questions remained about what happens inside germ cells to get cells to the right place once Tre1 activates.

It was already known that the Tre1 gene encodes a protein that spans the cell membrane multiple times and pokes out onto the cell's surface. It's a member of a large family of proteins called G protein-coupled receptors, which enable cells to communicate and respond to signals from other cells and light and odor cues. Nearly 35% of FDA approved medicines target G protein-coupled receptors, says Andrew.

To more precisely track the molecular events downstream of Tre1, Kim, a research associate and postdoctoral fellow at the Johns Hopkins University School of Medicine, used tissue cultures of fruit fly cells to find the location of fluorescently tagged molecules that are potentially triggered by the activated Tre1 protein. In the tissue cultures and germ cells of living flies, Kim uncovered the downstream genetic pathway.

He found that Tre1 functions as the cell's helmsman, controlling steering of the cell. Tre1 activates the cell's steering and rudder components by spurring on a cascade of proteins and enzymes, including a phospho-inositol kinase, PI(4,5)P2, dPIP5K, dWIP and WASp.

At the end of the molecular cascade, a chain of actin proteins forms in a protrusion at the cell's leading edge to exert mechanical forces for movement.

The scientists also searched for the upstream signal that activates Tre1. They used a genetically engineered protein made by researchers at the University of California, San Francisco to track the location of a signaling protein called Hedgehog, which has previously been linked to germ cell migration, although its role in this process has been disputed.

In germ cells, Hedgehog signaling increases the membrane levels of a protein called Smoothened, which is found in the cells' leading edge protrusion where Tre1 is also found.

The scientists plan to continue studying the pathways surrounding Tre1 and connections between the proteins and enzymes involved in the pathway.

"A deeper understanding of how moving cells navigate and spread has the potential to provide more targets for interrupting the spread of cancer cells," says Andrew.

Researchers at KU Leuven (Belgium) have succeeded for the first time in measuring brain waves directly via a cochlear implant. These brainwaves indicate in an objective way how good or bad a person's hearing is. The research results are important for the further development of smart hearing aids.

A cochlear implant enables people with severe hearing loss to hear again. An audiologist adjusts the device based on the user's input, but this is not always easy. Think of children who are born deaf or elderly people with dementia. They have more difficulty assessing and communicating how well they hear the sounds, resulting in an implant that is not optimally tuned to their situation.

A possible solution is to adjust the implant based on brain waves, which contain information about how the person processes the sounds that they hear. This kind of objective measurement can be made with an electroencephalogram (EEG), whereby electrodes are placed on the head. However, it would be more efficient if the implant itself could record the brain waves to measure hearing quality.

Experimental implant

Research by KU Leuven and manufacturer Cochlear on a few human test subjects has shown for the first time that this is possible. "We used an experimental implant that works exactly the same way as a normal implant, but with easier access to the electronics," says postdoctoral researcher Ben Somers from the Experimental Oto-rhino-laryngology unit.

"A cochlear implant contains electrodes that stimulate the auditory nerve. This is how sound signals are transmitted to the brain. In our research, we have succeeded in using these implanted electrodes to record the brain waves that arise in response to sound. That is a first. An additional advantage is that by carefully choosing the right measuring electrodes, we can measure larger brain responses than the classical EEG with electrodes on the head."

Self-tuning device

An implant that can register brain waves and measure hearing quality on its own has various advantages, adds co-author Professor Tom Francart. "Firstly, we get an objective measurement that does not depend on the user's input. In addition, you could measure a person's hearing in everyday life and monitor it better. So, in the long run, the user would no longer have to undergo testing at the hospital. An audiologist could consult the data remotely and adjust the implant where necessary."

"In the future, it should even be possible for the hearing implant to adjust itself autonomously based on the recorded brain waves. We have a long way to go before that, but this study is a necessary first step. Based on our findings, manufacturers can now move forward with developing smart hearing devices that improve the quality of life of the people that use them. Besides audiological applications, there are numerous other possibilities that come with measuring brain waves. Think of monitoring sleep, attention span or epilepsy, but also, for example, so-called brain computer interfaces that allow you to control other devices with brainwaves."

Replacing regular common salt consumed by hypertensive patients in rural areas with a salt substitute can have a significant impact in terms of lowering their blood pressure, a new study by The George Institute for Global Health has revealed.

Researchers found that substituting a small part of the sodium in salt with potassium without altering the taste led to a substantial reduction in systolic blood pressure in these patients, supporting salt substitution as an effective, low-cost intervention for lowering blood pressure in rural India.

The study entitled "Effects of reduced-sodium added-potassium salt substitute on blood pressure in rural Indian hypertensive patients: a randomized, double-blind, controlled trial" provides the first-of-its-kind evidence from rural India on the effectiveness of a salt substitute and has been published in the American Journal of Clinical Nutrition.

Excess salt intake causes high blood pressure, a leading risk for cardiovascular disease. Almost all adult populations worldwide consume more than the recommended level of salt including those living in rural India, where average salt intake is nearly double the World Health Organization (WHO) recommendations of less than 5 g/day (2 g/day sodium).

"A large proportion of dietary salt in India comes from salt added to food cooked at home, but whether reduced-sodium salt substitutes can help to lower blood pressure had not been tested thus far," said Dr Jie Yu, Research Fellow, Cardiovascular Program, The George Institute and lead author of the study. "Our study is the first to show that salt substitutes could make a real difference in these communities."

"The study was conducted in the Siddipet region of Telangana State, and 502 participants with hypertension from 7 villages were enrolled," She added, "Participants were randomized to receive either regular salt (100% sodium chloride) or the salt substitute (70% sodium chloride/30% potassium chloride blend) and advised to replace all home salt use with the substitute."

The primary outcome was the change in systolic blood pressure from baseline to 3 months in the salt substitute group compared to the regular salt groups. Secondary outcomes included the change in diastolic blood pressure, 24-hour urinary biomarkers, and self-reported use and satisfaction with the study salts provided.

"At 3 months, the salt substitute intervention significantly decreased average systolic blood pressure by about 4.6 units, an effect comparable to some commonly prescribed anti-hypertensive medications," said Sudhir Raj Thout, Research Fellow, The George Institute India, the study co-author who led the study's field operations.

"There was also a significant increase in the amount of potassium consumed in the salt substitute group. Participants reported that they used the study salt nearly every day of the week and rated the taste of the study salts similarly, indicating that the reduced-sodium salt substitutes are acceptable for home cooking for our study participants." he added.

The findings have policy implications. "Our data suggest that using reduced-sodium, added-potassium salt substitute to replace regular salt for home cooking will likely be an effective and scalable intervention for blood pressure control in rural India," said Jason Wu, Associate Professor and Scientia Fellow at The George Institute, and supervisor of the study.

"As none of the participants were aware of the existence of reduced-sodium salt at the beginning of the study, this suggests policymakers should consider supporting increased access to, and education about the use of such salt substitutes for hypertensive patients in India."

Tsukuba, Japan - Although the heart beats autonomously, its function can be regulated by the brain in response to, for instance, stressful events. In a new study, researchers from the University of Tsukuba discovered a novel mechanism by which a specific part of the brain, the lateral habenula (LHb), regulates the cardiovascular system.

The cardiovascular system, specifically the heart and blood vessels, have a certain autonomy that allows them to function independently from the brain. In order for the individual to adapt to new, potentially threatening situations, the brain does have some regulatory power over the cardiovascular system. This is achieved by controlling the autonomic nervous system, which consists of the sympathetic and parasympathetic system. While the former has a stimulating effect on the cardiovascular system, including increasing the heart rate and blood pressure, the latter causes the opposite.

"From an evolutionary standpoint, the brain has had in incredibly important function in protecting the individual from predators," says lead author of the study Professor Tadachika Koganezawa. "But even in the absence of predators, our bodies react to stressful situations. In this study, we wanted to determine how the brain regulated the cardiovascular system via the autonomic nervous system."

To achieve their goal, the researchers focused on the LHb. Located deep within the brain, the LHb has been known to control behavioral responses to stressful events, and as such to elicit strong cardiovascular responses. However, the way in which it does so has remained unclear. To address this question, the researchers electrically stimulated the LHb in rats by inserting an electrode through the skull. Stimulation of the LHb resulted in bradycardia (low heart rate) and increased mean arterial pressure (MAP), which is a clinically useful parameter for assessing overall blood pressure.

To determine how the LHb interplays with the autonomic nervous system to regulate the cardiovascular system, the researchers then turned off the parasympathetic system by means of cutting the main parasympathetic nerve, the vagal nerve, or using a drug to antagonize it. While this suppressed the LHb's effect on the heart rate, it did not change the MAP. Antagonizing the sympathetic system did the opposite--it decreased the MAP but did not change the heart rate.

To understand the mechanism by which the LHb elicits these cardiovascular responses, the researchers focused on the neurotransmitter serotonin, which plays an important role in the brain in modulating mood, cognition, and memory, among other functions. While blocking all serotonin receptors significantly reduced the LHb's effect on both the MAP and heart rate, the researchers found that specific subtypes of serotonin receptors were particularly involved in the process.

"These are striking results that show how the lateral habenula controls the cardiovascular system. Our results demonstrate the mechanism of a neural circuit that plays an important role in stress-induced behavioral responses," says author of the study Professor Masayuki Matsumoto.

Primary sclerosing cholangitis (PSC) is a rare, chronic, inflammatory disease of the bile ducts and is difficult to treat, since its causes have not yet been adequately researched. Using RNA sequencing, an international research consortium led by Michael Trauner, Head of MedUni Vienna's Division of Gastroenterology and Hepatology (Department of Medicine III), has now succeeded in identifying a new prognostic factor for PSC from liver biopsies. This is so-called cellular ER stress. ER stress is the name given to a complex cellular response to stress caused by the build-up of misfolded proteins in the endoplasmic reticulum (ER).

PSC is a rare disease with a poor prognosis and can lead to cirrhosis of the liver or bile duct cancer. It affects 0.01% of the population but, even though it is rare, PSC is responsible for more than 10% of all liver transplants, making it the third most common indication on liver transplant waiting lists in Europe.

In the recent study, which has now been published in the leading journal Hepatology, the researchers were able to identify a molecular signature for ER stress both in the liver cells (hepatocytes) and also in the bile duct epithelium - and notably as a stand-alone factor that is independent of the disease stage or degree of liver fibrosis (laying down of scar tissue) as a precursor to possible liver cirrhosis. "Using transcriptional analysis, we were able to identify a personalised molecular signature of primary sclerosing cholangitis, which shows that patients with an impaired response to ER stress have a poorer prognosis with a higher incidence of complications," explains Trauner. "This discovery also opens up new treatment options, since ER stress can be counteracted with drugs."

Since the build-up of potentially toxic bile acids in cholestasis results in ER stress, it is now being attempted to restore this balance pharmacologically using the new bile acid therapeutics that are available. Beneficial effects can reportedly be expected from drugs already in clinically testing - however, more research has already been initiated to explore this further.

Researchers have mapped the distribution of SARS-CoV-2, the virus that causes COVID-19, in deceased patients with the disease, and shed new light on how viral load relates to tissue damage.

Their study of 11 autopsy cases, published today in eLife, may contribute to our understanding of how COVID-19 develops in the body following infection.

More than 24 million SARS-CoV-2 infections have been reported to date, and the number of deaths attributed to COVID-19 has exceeded 828,000 worldwide. COVID-19 occurs with varying degrees of severity. While most patients have mild symptoms, some experience more severe symptoms and may need to be hospitalised. A minority of those in hospital may enter a critical condition, with respiratory failure, blood vessel complications, or multiple organ dysfunction.

"Clinical observations suggest that COVID-19 is a systemic disease, meaning that it affects the entire body rather than just a single organ such as the lungs," explains co-first author Stefanie Deinhardt-Emmer, Resident in Medical Microbiology, Jena University Hospital, Jena, Germany. "But we don't currently have a clear understanding of disease development in humans and other organisms, due to the lack of appropriate experimental models. Investigating the viral distribution of SARS-CoV-2 within the human body and how this relates to tissue damage would help us address this gap."

To do this, Deinhardt-Emmer and colleagues studied 11 autopsy cases of patients with COVID-19. They performed the autopsies at the early postmortem stage to minimise bias due to the degradation of tissues and viral ribonucleic acid (RNA - a molecule similar to DNA).

Their analysis revealed high viral loads in most of the patients' lungs, which had caused significant damage to those organs. Using an imaging technique called transmission electron microscopy, the team also visualised intact viral particles in the lung tissue.

"Interestingly, we also detected SARS-CoV-2 RNA throughout various other tissues and organs unrelated to the lungs that did not cause visible tissue damage," says co-first author Daniel Wittschieber, Senior Forensic Pathologist at Jena University Hospital. The researchers say that this distribution of viral RNA throughout the body supports the idea that our immune system is unable to respond adequately to the virus' presence in the blood.

"We show that COVID-19 is a systemic disease as determined by the presence of virus RNA, and yet unrelated to tissue damage outside the lungs," says co-senior author Bettina Löffler, Director of the Institute for Medical Microbiology, Jena University Hospital. "To our knowledge, this study is the only one to date that has measured viral loads in a wide variety of organs and tissues, with more than 60 samples studied per patient."

"The insights gathered from our work may add to our understanding of how COVID-19 develops in the body following infection," concludes co-senior author Gita Mall, Head of the Institute of Forensic Medicine, Jena University Hospital.

Math's top prize, the Fields Medal, has succeeded in making mathematics more inclusive but still rewards elitism, according to a Dartmouth study.

Published in Nature’s Humanities and Social Sciences Communications, the study analyzed the effectiveness of the Fields Medal to make math at its highest level more representative across nations and identities. The result provides a visual, data-driven history of international migration and social networks among math elites, particularly since World War II.

"With so much recent discussion on equality in academia, we came to this study recognizing that math has a reputation of being egalitarian," says Herbert Chang, a research affiliate in Dartmouth's Fu Lab and lead author of the paper. "Our results provide a complex and rich story about the world of math especially since the establishment of the Fields Medal."

The Fields Medal, widely considered the Nobel Prize of mathematics, is awarded every four years to mathematicians under the age of 40. It was first presented in 1936 to honor young mathematicians from groups that were typically underrepresented in top math circles.

According to the Dartmouth mathematicians, the prize has received criticism over its history for rewarding existing power structures rather than making math more inclusive and equitable at the elite level. Against this criticism, the study set out to explore how well the award has lived up to its original promise.

The analysis shows that the Fields Medal has elevated mathematicians of marginalized nationalities, but that the there is also "self-reinforcing behavior," mostly through mentoring relationships among math elites.

As example, the study found that the award succeeded in integrating mathematicians from Japan and Germany after WWII. But it also found that two-thirds of 60 medalists emerged from the same math "ancestral tree."

Although the study found diversity among award winners from top math countries, it also found that groups with Arabic, African, and East Asian language identities remain under-represented at the elite level.

The research team defines "elite" as a connection between Fields medalists, rather than other indicators that measure academic productivity and impact.

"It's a privilege for a young mathematician to inherit a powerful network of relationships from an influential academic advisor," says Feng Fu, an assistant professor of mathematics and the senior researcher for the study. "The growing number of doctoral degrees awarded to international mathematicians in the U.S. indicates that mathematics can be a powerful integrative force in our common humanity."

According to the paper, only France exports more elite mathematicians to the United States than it receives from the U.S. "This seems to affirm France as the intellectual capital of mathematics," say the authors.

"A mathematician that is French and attends a top 50 institution means they are 6.4 times more likely to gain membership into the elite circle," the research team says in the study. "On the other hand, being East Asian and attending a top 50 institution only affords you 1.5 times the likelihood of gaining membership into this elite circle."

Among other findings of the study:

- All Fields medalists can be traced to nine "academic family trees"; the largest holds 44 out of 60 medalists.

- Germany has consistently high levels of pluralism in mathematics except for the period of WWII.

- Japan has recently opened to higher levels of non-Japanese elites within the country.

- The number of Russian elite mathematicians decreased significantly after the dissolution of the Soviet Union.

The research team used artificial intelligence techniques to study data on more than 240,000 mathematicians dating as far back as the 16th century. The information was taken from the Mathematics Genealogy database maintained by North Dakota State University.

Researchers organized elite mathematicians by countries and lingo-ethnic categories and then mapped their flow between nations and across ethnic lines. Connections were drawn to show the physical movement, identity and academic relationship of mathematicians.

"There are many sources of inequality in elite-level math and academia. Our goal was to characterize how a single factor--mentorship--plays a role, while telling a comprehensive story about mathematics," says Chang, who was in Dartmouth’s Jack Byrne Scholars Program in Math and Society as an undergraduate.

Prior studies of the Fields Medal and elitism in math have focused on how mathematicians cite research. According to the research team, such an approach might miss the structural forces that prevent access to individuals from outside elite math circles.

The research advances past studies by providing a high-level view of the relationship between mentorship, prize giving, and ethnicity.

The research team concludes, as other researchers have in the past, that the Fields Medal should "return to its roots" in order to achieve its original goal of elevating marginalized voices.

Making people fear the coronavirus may motivate us to wash our hands, keep our distance and wear a face mask. But fear also takes a heavy toll on our mental health and is fertile ground for discrimination and prejudice. New research shows a different path.

When the coronavirus pandemic hit the world in the spring of 2020, feelings of being capable or efficacious against the virus were a key factor in driving compliance with the authorities' guidelines. This is the result of a new study based on large surveys across eight Western democracies, published in British Journal of Health Psychology.

The extent to which we personally felt informed and capable of acting clearly affected the extent of our behaviour to prevent infection, e.g. by keeping our distance and refraining from handshakes.

"These are important findings because they show a pathway to public compliance with pandemic health advice which is not driven by personal fear. Today, in the spring of 2021, many countries are hit by a third wave of infections and authorities may be tempted to induce fear to make people follow guidelines. Our findings provide policy makers with an alternative," says Michael Bang Petersen, one of three authors behind the study, and a professor of political science at Aarhus University, Denmark.

Tell us what to do, and we will do it

In fact, the study shows that when people feel capable of handling the crisis, the impact of fear is no longer important. Those who feel efficacious comply with the authorities' guidelines regardless of whether they are worried about the health of themselves and their families. And they also comply regardless of whether they trust their government and their fellow citizens.

"Our study shows that in the first stage of the pandemic, a sense of urgency emerged and made people put aside individual considerations and political differences. This sense caused people across the world to say: 'Tell us what to do, and we will do it,'" says Professor Michael Bang Petersen.

26,000 participants from the UK, the USA and six EU countries

The study is based on representative surveys conducted in Denmark, France, Germany, Hungary, Italy, Sweden, the United Kingdom and the United States of America. A total of 26,508 people participated from March to May 2020 as the early events were unfolding.

"The study provides a unique insight into behaviour during the first wave of an unprecedented crisis, which we can utilise both in the present and in the long term. Often, decision-makers are worried that the population will panic. But our data shows that authorities do not need to fear this. Instead, they should tell people as clearly as possible about the actual challenges and how people should act," Michael Bang Petersen concludes.

Drinking beetroot juice promotes a mix of mouth bacteria associated with healthier blood vessels and brain function, according to a new study of people aged 70-80.

Beetroot - and other foods including lettuce, spinach and celery - are rich in inorganic nitrate, and many oral bacteria play a role in turning nitrate to nitric oxide, which helps to regulate blood vessels and neurotransmission (chemical messages in the brain).

Older people tend to have lower nitric oxide production, and this is associated with poorer vascular (blood vessel) and cognitive (brain) health.

In the new study, by the University of Exeter, 26 healthy older people took part in two ten-day supplementation periods: one with nitrate-rich beetroot juice and another with nitrate-free placebo juice, which they drank twice a day.

The results showed higher levels of bacteria associated with good vascular and cognitive health, and lower levels of bacteria linked to disease and inflammation.

Systolic blood pressure dropped on average by five points (mmHg) after drinking the beetroot juice.

"We are really excited about these findings, which have important implications for healthy ageing," said lead author Professor Anni Vanhatalo, of the University of Exeter.

"Previous studies have compared the oral bacteria of young and older people, and healthy people compared to those with diseases, but ours is the first to test nitrate-rich diet in this way.

"Our findings suggest that adding nitrate-rich foods to the diet - in this case via beetroot juice - for just ten days can substantially alter the oral microbiome (mix of bacteria) for the better.

"Maintaining this healthy oral microbiome in the long term might slow down the negative vascular and cognitive changes associated with ageing."

The researchers ran tests to identify clusters (or "modules") of oral bacteria that tend to thrive together in similar conditions.

A module (Prevotella-Veillonella) that has been associated with inflammation was reduced after nitrate supplementation, including a decrease of Clostridium difficile (which can infect the bowel and cause diarrhoea).

Professor Vanhatalo stressed that more research is needed to confirm the findings and see whether similar effects are found in other groups.

"Our participants were healthy, active older people with generally good blood pressure," she said.
"Dietary nitrate reduced their blood pressure on average, and we are keen to find out whether the same would happen in other age groups and among people in poorer health.

"We are working with colleagues in the University of Exeter Medical School to investigate interactions between the oral bacteria and cognition to better understand the how diet could be used to delay cognitive decline in older age."

Much research has been conducted into the benefits of a healthy gut microbiome, but far less is known about the oral microbial community, which plays a crucial role in "activating" the nitrate from a vegetable-rich diet.

Computer scientists at the University of Surrey have created a ground-breaking model that could improve our understanding of developmental disorders such as autism.

Scientists have long tried to better understand how the cerebral cortex and its layers develop, with pathologies such as autism, schizophrenia and epilepsy linked to this process.

In a paper published by the journal Cerebral Cortex, scientists from Surrey, Newcastle University, and Nottingham University detail how they developed and used a computational model to simulate cell division, cell migration and apoptosis (cell death) in the hope of understanding how these processes affect the development of the brain.

With the help of their computer model, the researchers reproduced a wide number of cerebral structures to study - from rats, to macaques, to humans.

The team also observed that slight changes in how cells perform division and apoptosis lead to the development of cortical structures found in neurodevelopmental disorders such as autism, polymicrogyria and subcortical band heterotopia.

Dr Roman Bauer, Engineering and Physical Sciences Research Council Research Fellow and lead author of the study from the University of Surrey, said: "We are working towards a comprehensive computational model of the cerebral cortex and how it develops - taking into account how neurons behave and organise themselves in our brains. It is clear to us that computational models have a crucial role to play in helping us to comprehensively understand the complex biological processes that lead to developmental disorders."

Marcus Kaiser, Professor of Neuroinformatics at the University of Nottingham and senior author of the study, said: "A large proportion of nerve cells dies before birth, but it was unclear why these cells are just born to die at such an early stage. The team's results showed that cell death plays an essential role in developing the brain, as it influences the thickness of the cortex's layers, variety and layer cell density."

The first online advertisement was a banner for AT&T that appeared on the HotWired.com website in 1994, when there were just 30 million internet users worldwide. Today, 57% of the world's population has access to the internet and advertising technology has advanced to the point that by 2018 the digital advertising market in Europe alone was worth 55 billion euros. Of this amount, 16.8 billion euros is accounted for by programmatic advertising, which uses artificial intelligence to automate much of the buying and selling of internet advertising.

A new report, published by Open Evidence, a spin-off of the UOC, whose authors include Francisco Lupiáñez, a member of the UOC's Faculty of Information and Communication Sciences and a partner and director of Open Evidence, examines the current situation and the challenges for online advertising. The results reveal an online market that is increasingly dominated by just a few companies (e.g., Google, Facebook) which occupy strategic roles throughout the advertising chain, affecting free competition. Among these challenges, the authors point to "the opacity and lack of transparency" in the market and the need to tackle this issue by combining self-regulation in the sector with domestic and international regulatory measures.

The personalization of advertising

The automation of the advertising market has enabled a better fit between supply and demand, allowing digital media publishers to sell advertising space and advertisers to easily reach large audiences on many websites. The system is based on users' data which is collected by browsers and cookies, i.e. small fragments of code that are stored on devices and record information including demographic details and online behaviour, such as the type of website visited and purchases made. This data is sold to advertisers, who can then use it to personalize advertising messages and show them at the best time and place.

This personalization of advertising activity has gone hand-in-hand with the growth of Google and Facebook, which headed the sector in 2017 with 33% and 16.2% of global revenues, respectively. "Both companies, and, to a lesser extent, Amazon, profit greatly from users' data and from providing a vast inventory of advertisements through their websites and services that can be monetized, generating most of their advertising revenues". The researchers note that "83.9% of Facebook's revenues and 98.5% of Google's revenues in 2019 were generated from advertising services".

Potentially anti-competitive practices

The report also states that this market leadership allows Google and Facebook to benefit from economies of scale and network effects, thanks to the interdependence of their services. It also details how a single company can operate "simultaneously as both buyer and seller". Google, for example, is involved on both the demand side for advertising space, through its DV360 campaign manager, and on the supply side, through its AdX exchange platform. At the same time, it also has a key role in support technologies such as website analytics and as a shopwindow for advertisements via its search engine.

All these advantages, argue the researchers, mean these platforms may potentially engage in "anti-competitive practices" such as favouring their own products, using their market power in new sectors, or acting as a barrier to access, by charging higher rates to advertisers, publishers or providers of complementary services, for example.

Technological complexity, opacity and fraud

The report highlights the opacity of the online advertising market as one of the gravest issues among the consequences of this type of practice. This lack of transparency is due "in part to the complexity of programmatic advertising, but also to the practices of the online platforms". Within these platforms, so-called "walled garden" companies like Amazon and Facebook can use their dominant positions to limit the release of information on the cost, revenues and effectiveness of advertising placement. These activities make it "very difficult to know how the money is spent and where the advertisements appear, leading advertisers and publishers to question the effectiveness of the online advertisement and hindering decision-making".

Fraud is another effect of this opacity in the value chain of advertising technology, including dependence on algorithms and the large number of intermediary businesses. According to 2017 figures published in the report, fraud cost advertisers around 13.6 billion euros globally.

International cooperation between regulatory authorities

The study's conclusions also set out a number of solutions to these issues, including responses at public policy level and at the level of the sector and the companies involved. With regard to the issues of competition and transparency, these include measures such as "the creation of units within the regulatory authorities to deal specifically with digital platforms, with control and executive powers; the establishment of codes of conduct; regulatory reforms on disclosure and interoperability, and, if necessary, anti-trust measures". Given the transnational nature of the platforms, the researchers also recommend "cooperation between regulatory authorities to share learning, improve cross-border regulation and coordinate measures".

The report also examines various self-regulatory initiatives within the industry, such as the development of standards and practices for measuring and ensuring the quality of advertisements, guidelines for improving transparency on tariffs and programmes governing users' privacy and consent. Finally, it emphasizes that no measure is sufficient "in itself", but "a better implementation of existing initiatives and a combination of the proposed measures could be effective in tackling the problems identified in this sector".

A team of scientists has been using DESY's X-ray source PETRA III to analyse the structural changes that take place in an egg when you cook it. The work reveals how the proteins in the white of a chicken egg unfold and cross-link with each other to form a solid structure when heated. Their innovative method can be of interest to the food industry as well as to the broad field of research surrounding protein analysis. The cooperation of two groups, headed by Frank Schreiber from the University of Tübingen and Christian Gutt from the University of Siegen, with scientists at DESY and European XFEL reports the research in two articles in the journal Physical Review Letters.

Eggs are among the most versatile food ingredients. They can take the form of a gel or a foam, they can be comparatively solid and also serve as the basis for emulsions. At about 80 degrees Celsius, egg white becomes solid and opaque. This is because the proteins in the egg white form a network structure. Studying the exact molecular structure of egg white calls for energetic radiation, such as X-rays, which is able to penetrate the opaque egg white and has a wavelength that is no longer than the structures being examined.

"To understand the structural evolution in detail, you have to study the phenomenon on the micrometre scale," explains Nafisa Begam, the lead author of the first study, who is an Alexander von Humboldt fellow in Schreiber's group. The scientists used so-called X-ray photon correlation spectroscopy (XPCS) with a specific geometry allowing them to determine the structure and the dynamics of the proteins in the egg white.

For their experiments on the P10 beamline at PETRA III the scientists used a chicken egg from a supermarket and filled the egg white into a quartz tube with a diameter of 1.5 millimetres. "Inside, the egg white was heated in a controlled manner while we analysed it with the help of the X-rays," explains DESY co-author Fabian Westermeier. "The X-ray beam was expanded to 0.1 by 0.1 millimetres, to keep the radiation dose below the damage threshold of the protein structures."

The measurements reveal the protein dynamics in the egg white over a period of about a quarter of an hour. During the first three minutes, the protein network grew exponentially, reaching a plateau after about five minutes, at which virtually no more protein links were formed. At this time, the average mesh size of the protein network was about 0.4 micrometres (thousandths of a millimetre).

In the second study, the team used the XPCS technique to investigate the self-organisation of protein solutions into domains with, respectively, high and low protein concentration, as an example of structure formation in cell biology. In the process, they were able to follow the temperature-dependent dynamics over time. "At high protein densities, mobility decreases, which slows down the phase separation. This is important for the special dynamics of the system," reports lead author Anita Girelli from Schreiber's group.

The studies, which were funded by the German Federal Ministry of Education and Research (BMBF), not only reveal new details about the structural changes occurring in egg whites, but also prove the experimental concept, which can be used for other samples too, as demonstrated by the second study. "Successfully applying X-ray photon correlation spectroscopy opens up a new way to study the dynamics of biomolecules, which is essential if we are to understand them properly," Schreiber comments.

DESY is one of the world's leading particle accelerator centres and investigates the structure and function of matter - from the interaction of tiny elementary particles and the behaviour of novel nanomaterials and vital biomolecules to the great mysteries of the universe. The particle accelerators and detectors that DESY develops and builds at its locations in Hamburg and Zeuthen are unique research tools. They generate the most intense X-ray radiation in the world, accelerate particles to record energies and open up new windows onto the universe. DESY is a member of the Helmholtz Association, Germany's largest scientific association, and receives its funding from the German Federal Ministry of Education and Research (BMBF) (90 per cent) and the German federal states of Hamburg and Brandenburg (10 per cent).