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One way to change the properties of a material is to stretch it just a wee bit, so its atoms are farther apart but the bonds between them don't break. This extra distance affects the behavior of electrons, which determine whether the material is an insulator or a conductor of electricity, for instance.

But for an important class of complex oxide materials, stretching doesn't work so well; they're as brittle as ceramic coffee cups and would break.

Scientists at the Department of Energy's SLAC National Accelerator Laboratory and Stanford University have now found a way around this problem for a complex oxide known as LCMO. They created a super-thin, flexible membrane from the normally brittle material, used micromanipulators to stretch it on a tiny apparatus and glued it in place to preserve the stretch.

By applying gentle heat to melt the glue, they could release and stretch the same transparent membrane again and again and watch it flip from being an insulator to a conductor and back again. Stretching also changed its magnetic properties.

"We can really stretch and strain these things dramatically, by up to 8%," said Harold Hwang, a professor at SLAC and Stanford and an investigator with the Stanford Institute for Materials and Energy Sciences (SIMES). "This opens a whole new world of possibilities that will have an impact beyond this particular study."

The research team reported its findings in Science today.

New ways to float free and stretch

LCMO, or lanthanum calcium manganese oxide, is what's known as a quantum material because its electrons behave in unconventional and often surprising ways. Scientists want to be able to control and fine-tune this behavior for a new generation of electronics with applications in power transmission, transportation, computing, sensors and detectors.

Thin films of quantum materials are generally grown on the surface of another material. Four years ago, Hwang's group reported an easy way to detach those delicate layers so they could be studied in new ways.

One of the researchers who worked on that study, Seung Sae Hong, led this one as well. He used the new method to create and free small pieces of LCMO that were thinner than ever before - less than 20 nanometers thick. They were nearly transparent and surprisingly flexible.

Directly stretching such a small, fragile scrap would be difficult, but Hong got around that problem by putting it on a thin polymer film - kind of like a plastic bag from a grocery store - where it stuck of its own volition.

Then he clamped the polymer film on each of its four sides and used a micromanipulator to pull and stretch it - sometimes in one direction, sometimes in both directions at once. Once the LCMO was stretched, its polymer backing could be glued to another surface and taken to another instrument for examination with X-rays.

Flipping electronic states

"The experiments were quite tedious and difficult," said Hong, who is now an assistant professor at the University of California, Davis. "We'd look at the film, warm it to soften the glue and relax the stretch, manipulate it in some other way, freeze it in place and look at it again."

The researchers were able to directly measure the spacing between atoms and confirm that it increased with stretching. They also measured the electrical resistance of the LMCO and discovered that stretching flipped it from a metallic state that readily conducts electricity to an insulating state, which doesn't. Applying a strong magnetic field changed the magnetic state of the material and also flipped it back into being a metal.

"As a scientific tool this is really exciting," Hong said. "It opens opportunities for mechanically manipulating broad classes of materials in ways we couldn't do before. And it gives us ideas for how we might design flexible materials for electronic devices, including sensors and detectors that measure very small changes."

Researchers know that people are motivated to be vegetarian for different reasons -- the most common in western cultures being health, the environment and animal rights. But how compelling are these different factors for nonvegetarians?

University of California, Davis, researchers in the Department of Psychology surveyed 8,000 people of various ages and ethnicities, in two languages, in both the United States and Holland, to help determine why nonvegetarians decide to become vegetarian.

A paradox for advocacy efforts

The results showed that the main motivation for nonvegetarians to consider being vegetarian is health, with environmental and animal rights motives being less common. However, people who are most committed to a vegetarian diet were most motivated by the environment or animal rights.

"The most common reason people say they would consider being vegetarian has to do with health ... However, people driven primarily by health motives may be least likely to respond to vegetarian advocacy, in general," said Christopher J. Hopwood, professor of psychology and co-author of the paper. This creates a challenge for advocacy movements, he said: what motive should they target?

Should advocates target specific groups?

One possible solution would be to target different motives in different groups of people. The researchers found that health motives were associated with conventionality and masculinity, whereas people who cite environmental or animal rights motives tend to be curious, open to experience, likely to volunteer and interested in the arts. Based on these results, advocacy groups could target certain kinds of people -- maybe advertise health benefits at a gym or church service, but environmental or animal rights perspectives at a museum or concert, Hopwood said.

An international team, including Arizona State University researcher Gary Schwartz, have unearthed the earliest known skull of Homo erectus, the first of our ancestors to be nearly human-like in their anatomy and aspects of their behavior.

Years of painstaking excavation at the fossil-rich site of Drimolen, nestled within the Cradle of Humankind (a UNESCO World Heritage site located just 40 kilometers or around 25 miles northwest of Johannesburg in South Africa), has resulted in the recovery of several new and important fossils. The skull, attributed to Homo erectus, is securely dated to be two million years old.

Published this week in Science, the international team of nearly 30 scientists from five countries shared details of this skull -- the most ancient fossil Homo erectus known -- and other fossils from this site and discuss how these new finds are forcing us to rewrite a part of our species' evolutionary history.

The high-resolution dating of Drimolen's fossil deposits demonstrates the age of the new skull to pre-date Homo erectus specimens from other sites within and outside of Africa by at least 100,000 to 200,000 years and thus confirms an African origin for the species.

The skull, reconstructed from more than 150 separate fragments, is of an individual likely aged between three and six years old, giving scientists a rare glimpse into childhood growth and development in these early human ancestors.

Additional fossils recovered from Drimolen belong to a different species -- in fact, a different genus of ancient human altogether -- the more heavily built, robust human ancestor Paranthropus robustus, known to also occur at several nearby cave sites preserving fossils of the same geological age. A third, distinctive species, Australopithecus sediba, is known from two-million-year old deposits of an ancient cave site virtually down the road from Drimolen.

"Unlike the situation today, where we are the only human species, two million years ago our direct ancestor was not alone," said project director and lead researcher from La Trobe University in Australia, Andy Herries.

Gary Schwartz, a paleoanthropologist and research associate with ASU's Institute of Human Origins, participated in the excavations and recovery of the new cranium, and as an expert in the evolution of growth and development, is continuing his work with the research team to analyze the many infant and juvenile specimens found at the site.

"What is really exciting is the discovery that during this same narrow time slice, at just around two million years ago, there were three very different types of ancient human ancestors roaming the same small landscape," said Schwartz.

"We don't yet know whether they interacted directly, but their presence raises the possibility that these ancient fossil humans evolved strategies to divvy up the landscape and its resources in some way to enable them to live in such close proximity." Schwartz is also an Associate Professor in the School of Human Evolution and Social Change.

The ability to date Drimolen's ancient cave deposits with such a high degree of precision, using a range of different dating techniques, allowed the team to address important broader questions about human evolution in this region of Africa.

Paper coauthor Justin Adams from Monash University (Australia) is a specialist in reconstructing paleohabitats based on the animals preserved at fossil sites, said the discovery now allows us to address what role changing habitats, resources, and the unique biological adaptations of early Homo erectus may have played in the eventual extinction of Australopithecus sediba in South Africa.

"The discovery of the earliest Homo erectus marks a milestone for South African fossil heritage," says project codirector and University of Johannesburg doctoral student Stephanie Baker.

Fieldwork will continue at Drimolen, expanding the excavations to include even more ancient components of the cave and to provide a more in-depth glimpse at the forces shaping human evolution in this part of the African continent.

While the COVID-19 pandemic has already resulted in mass layoffs in several industries, other essential industries will instead face critical workforce shortages, according to a new report. Social distancing, school and daycare closures, and measures to protect those people who are most at-risk limit the pool of workers firms can draw upon. How important will these constraints turn out to be, especially in essential industries?

To find out, researchers from McGill University, University of Rochester, and Stony Brook University provide a snapshot of the situation in the United States drawing on data from the Survey of Income and Program Participation, the American Community Survey, and the National Health and Interview Survey.

"To minimize the spread of the pandemic, state governments are increasingly restricting who can work outside the home to workers in essential industries. Roughly 60% of employment is in these industries," says Fabian Lange, a professor of economics at McGill University and Canada Research Chair in Labour and Personnel Economics. "Reducing the strain on the health care workforce will be essential as they stand on the front lines of the battle against the pandemic."

Childcare

According to the researchers, an important factor limiting the labour supply of people who can work outside the home is childcare. School and daycare closures have made it substantially more difficult for some employees to go to work. Because of social distancing, grandparents, friends, and neighbors are less able to pick up any of the slack.

Roughly a quarter of the U.S. workforce has young children at home and may therefore be constrained from full-time work. Rates are slightly higher in essential industries and highest in health care, where 5.6 million workers have at least one child under 12. Health care workers are also more likely to be single parents, and especially single mothers. It is therefore imperative to implement policies addressing childcare for health care workers to maintain labour supply in this crucial sector.

At-risk populations in the workforce

"Another limiting factor on labour supply could be attempts to limit outside contact for members of the household who are most at-risk. At-risk populations include those aged 65 and over, people with compromised immune systems, and people with underlying medical conditions," says Lange.

About one-fifth of the workforce is in an at-risk group or lives with someone who is more likely to suffer severe consequences from COVID-19. In health care, 25% of workers fall into this category. Overall, 18.5 million essential (non-health) workers and 4.6 million health care workers are in a high-risk group that limits their ability to participate in the labour force in order to protect themselves or a family member with underlying conditions.

Supply of health care workers

According to Lange, health care workers are subject to additional constraints. "They are under tremendous stress - not only because they face an increase in patients requiring intensive care, but also because of the likelihood that they themselves become infected."

The researchers note that one response has been to encourage former nurses and health care workers to return from retirement and other jobs. However, the reserve pool of potential health care workers is relatively small after accounting for the risks they face. The researchers estimate that if every one-time nurse not currently in nursing was recalled, this would increase the number of nurses by 27%. More broadly in health care, the potential pool could add up to 40% more workers. Nevertheless, two-thirds of these are either in a high-risk group or live in a household with a member from a high-risk group.

About the report

"Labour Supply in the time of COVID19" is authored by Lisa Kahn (University of Rochester), Fabian Lange (McGill University), and David Wiczer (State University of New York at Stony Brook).

Link: http://fabianlange.ca/linked_files/papers/NOWcasting.pdf

About McGill University

Founded in Montreal, Quebec, in 1821, McGill University is Canada's top ranked medical doctoral university. McGill is consistently ranked as one of the top universities, both nationally and internationally. It is a world-renowned institution of higher learning with research activities spanning two campuses, 11 faculties, 13 professional schools, 300 programs of study and over 40,000 students, including more than 10,200 graduate students. McGill attracts students from over 150 countries around the world, its 12,800 international students making up 31% of the student body. Over half of McGill students claim a first language other than English, including approximately 19% of our students who say French is their mother tongue.

LA JOLLA, CA -- A prevalent heart protein known as cardiac myosin, which is released into the body when a person suffers a heart attack, can cause blood to thicken or clot--worsening damage to heart tissue, a new study shows.

A team led by John H. Griffin, PhD, a professor in the Department of Molecular Medicine at Scripps Research, made the unexpected finding after a series of experiments spanning three years and involving researchers from multiple collaborating institutions.

Though blood clotting is the root cause of many life-threatening cardiac events, including heart attack and stroke, scientists didn't know until now that cardiac myosin was implicated in that process. The protein's primary job is to provide the muscle-motor action that pumps blood.

"The real breakthrough of this study is that we've discovered another major biologic activity of cardiac myosin. No one had suspected it was acting as a procoagulant factor," Griffin says. "Our findings bridge research in hematology and cardiology, showing there's another potentially very important factor influencing the health outcomes of people with cardiac disease."

Blood coagulation is essential to prevent bleeding after an injury. The most abundant procoagulant protein in the human body is collagen, but it's not usually exposed to blood. Upon blood vessel and tissue damage, many procoagulant factors, including collagens, cause blood to turn from a liquid into a gel, forming a blood clot and reducing blood loss. However, procoagulants must strike the right balance between stopping bleeding and preventing excessive clotting, as occurs in conditions such as deep vein thrombosis or when a blood clot causes a stoke.

"Just as with inflammation, a little coagulation is good, but too much is dangerous," Griffin says. "While a small amount of cardiac myosin might help reduce bleeding in the heart, an excess of the protein may worsen the injury by promoting blood clots that cut off oxygen and exacerbate damage to heart tissue."

Indeed, Griffin and his collaborators, including Tobias Eckle, MD, PhD, of the University of Colorado, found that excess cardiac myosin doubled heart damage when administered to mice who experienced controlled heart attacks.

The study appears in the April 2020 issue of the American Heart Association journal Arteriosclerosis, Thrombosis, and Vascular Biology.

Griffin and his team are now working with scientists at Calibr, the drug discovery and development division of Scripps Research, to create a therapeutic compound that would target the procoagulant activity of cardiac myosin, reducing tissue damage caused by a heart attack.

Anticoagulant drugs already exist, ranging from over-the-counter medications like aspirin to widely prescribed drugs such as coumadin and warfarin. A newer class of drugs, known as direct oral anticoagulants (commonly referred to as DOACs), also have emerged to address the great need for blood clotting medications. But many of these existing drugs can cause excessive bleeding or other side effects because they act on the entire body's coagulation system, not just blood clotting in the heart.

Griffin envisions an anticoagulant medicine that targets only cardiac myosin-driven coagulation. Such a drug could theoretically be administered to patients in the hospital immediately after an acute cardiac event.

"Cardiovascular disease is the leading cause of death for men, women and people of most racial and ethnic groups in the United States," Griffin says. "New and better medicines are needed for those at risk of disease, and cardiac myosin gives us a promising avenue to pursue."

The oldest known animals and plants preserved in amber from Southern Gondwana are reported in Scientific Reports this week. Gondwana, the supercontinent made up of South America, Africa, Madagascar, India, Antarctica and Australia, broke away from the Pangea supercontinent around 200 million years ago. The findings further our understanding of ecology in Australia and New Zealand during the Late Triassic to mid-Paleogene periods (230-40 million years ago).

Jeffrey Stilwell and colleagues studied more than 5,800 amber pieces from the Macquarie Harbour Formation in Western Tasmania, dating back to the early Eocene Epoch (~54-52 million years ago) and Anglesea Coal Measures in Victoria, Australia, from the late middle Eocene (42-40 million years ago). The authors report a rare "frozen behaviour" of two mating long-legged flies (Dolichopodidae). The specimens also include the oldest known fossil ants from Southern Gondwana and the first Australian fossils of 'slender springtails', a tiny, wingless hexapod. Other organisms preserved in the amber include a cluster of juvenile spiders, biting midges (Ceratopogonidae), two liverwort and two moss species.

The authors also studied deposits found at locations in southeastern Australia, Tasmania and New Zealand. These include the oldest reported amber from Southern Pangea dating back to 230 million years ago, 96-92 million year old deposits from forests near the South Pole and an intact fossil of an insect called a felt scale (Eriococcidae) from 54-52 million years ago.

The findings provide new insights into the ecology and evolution of Southern Gondwana and indicate that there may be a vast potential for future, similar finds in Australia and New Zealand.

Nicotinamide, a form of vitamin B3, can inhibit aggressive cell transformations during wound healing and may be key to the development of therapies to treat fibrotic eye diseases that impair vision, according to a new Mount Sinai study published on Thursday, April 2, in Stem Cell Reports.

The findings apply to a condition in which cells in the retinal pigment epithelium, a layer that supports the retina, transform and develop the characteristics of more aggressive cells known as mesenchymal cells. The condition can be triggered by aging, diabetes, or injury to the eye. This causes development of fibrous membranes that resemble damaging cells found in retinal scar tissue, and can lead to retinal detachment.

The researchers found that nicotinamide not only inhibits these cell transformations, but can also reverse that cell transition and slow down the development of eye diseases that may lead to vision loss or blindness.

When applying nicotinamide as a therapy to human adult cells in vitro, the researchers found that the vitamin B derivative slowed down the aggressive cellular transformation and could promote the opposite transition, from mesenchymal to epithelial, helping to preserve the cell's original identity.

"This is the first study that shows how nicotinamide can inhibit invasive wound healing, but also reverse the development of membranes associated with scar tissue," said Timothy Blenkinsop, PhD, co-lead investigator of the study and Assistant Professor of Cell, Developmental and Regenerative Biology at the Icahn School of Medicine at Mount Sinai. "This discovery helps evolve our understanding of wound healing, as well as good inflammation versus bad inflammation. Good inflammation essentially nudges the system into a regenerative response, while bad inflammation can create harmful scar tissue formation. This is an exciting time to understand how this compound can be used to treat and reverse not only fibrotic diseases of the retina but other diseases too."

The researchers also identified epigenetic and molecular changes that occur during the cell transition process. Nicotinamide therapy resulted in widespread changes in the DNA sequence of the cells, eliciting changes in more than 40,000 identified chromosomal regions. The scientists observed that nicotinamide was associated with massive reorganization of the cell patterns, especially with inducing enhancer elements that lead the cell stage change in the retina. It activated regulatory elements in cells, including transcriptional factors that are prominent regulators of cell transformation.

Sally Temple, PhD, co-lead investigator of the study and Scientific Director at Neural Stem Cell Institute, said the study paves the way to develop new forms of treatment for patients. "Now we know the epigenetic landscape that is associated with the changes activated by nicotinamide, which gives deeper insights into cell transformations and provides an opportunity to explore a pathway for new therapeutic approaches for any condition or complication associated with wound healing."

Published in Communications Biology, the study explored the molecular interactions that occur in our response to varying levels of nutrients, otherwise known as nutrient-sensing pathways, as we grow older.

Using a combination of laboratory-based techniques and analysis of data on people's memory, diet and level of physical exercise, researchers identified a number of genes that are active in nutrient-sensing pathways and demonstrated these genes also show associations to performance on memory tasks in data from over 2000 individuals. The study identified that the genes ABTB1 and GRB10 were both influential in nutrient sensing pathways and showed association to memory.

Advances in medicine and healthcare over the past century have led to increased life expectancies. However, ageing is still accompanied by frailty and a decline in our thought processes. This level of decline varies enormously across individuals and an improved understanding of what influences these ageing mechanisms could help develop strategies to increase "healthspan", which is the period of time free from debilitating disease.

Previous studies have indicated that neural stem cells (NSCs) in the hippocampal part of the brain play an important role in the decline of our thought process and memory over time. NSCs are cells that keep dividing as long as they are alive and either make more NSCs or cells that have a specialist function in the brain. The maintenance of these NSCs is important in memory and is affected by environmental factors such as diet and exercise, potentially explaining some of the variation in how ageing affects different people.

Although the role of nutrient-sensing-pathways in ageing and the maintenance of stem cells in the brain has been investigated in animal models, no human studies have so far investigated their role in NSCs in the hippocampus.

The study aimed to explore whether nutrient-sensing pathways can provide the molecular basis for the association between lifestyle and ageing. These pathways have been implicated in stem cell maintenance, suggesting they could also be involved in the interaction between lifestyle, NSCs and cognition. Using a novel back-translation approach which uses laboratory-based experiments on NSCs to inform analysis of epidemiological data rather than vice versa the researchers showed that variations in ABTB1 are associated to performance on a standard memory task and that variation in the gene GRB10 is an important player in determining the association between Mediterranean diet and memory performance. The study also identified an interaction between exercise levels and the SIRT1 genotype which led to different performances on memory tasks.

Lead author, Chiara de Lucia, from the Institute of Psychiatry, Psychology & Neuroscience (IoPPN), King's College London said: 'Our study shows that nutrient-sensing pathways play an important role in memory and suggests that the ABTB1 and GRB10 genes are likely molecular links for the association between diet, the ageing of neural stem cells and our memory ability. Identifying these genes as the missing links between these three important variables could inform new approaches to help improve the ageing process through targeted changes in diet and exercise and ultimately in developing new drugs in the future.'

Senior author, Sandrine Thuret from the IoPPN said: 'Finding the means to prevent or slow down the processes that drive the decline of our thought processes during ageing is one of the great endeavours of the 21st century. To our knowledge this is one of the first studies looking at these relationships with human data and adopting this back-translation approach which uses lab-based experiments to inform research on large datasets, allowing for a more targeted approach.'

'Our findings suggest that changes in lifestyle may be able to delay a decline in memory and thinking but that the effectiveness of these approaches will depend on the genetic makeup of each person. For example, adherence to a diet such as the Mediterranean diet may be most beneficial for people with a specific GRB10 mutation while increased exercise may be a better approach for participants with specific SIRT1 variations. Future research should look to replicate these findings on a larger dataset which would allow for the testing of 3-way interactions between diet, exercise and memory to gain a more comprehensive understanding of how these relate to one another.'

Researchers analysed the molecular and genetic mechanisms by exposing human NSCs to serums from either young or old individuals and to chemicals whose effects mimic the ageing process. The genes identified from the in vitro analysis as important in nutrient-sensing-pathways were then associated with genetic data from over 2000 individuals from the TwinsUK cohort and data on performance on the Paired Associates Learning(PAL) task which assesses visual memory and learning, healthy eating, Mediterranean diet, calorie intake and physical activity.

TORONTO, April 2, 2020 - Women academics are less likely than men to comment on published research, limiting scholarly debate, a new study co-authored by York University sociologist Professor Cary Wu, shows. According to the study, women are also relatively less likely to comment on their male counterparts, published research.

"Gendered patterns in academic commenting could impede scholarly exchange between men and women and further marginalize women within the scientific community," cautioned Wu, of the Faculty of Liberal Arts & Professional Studies. "And gender inequality is still deeply felt, despite the welcoming atmosphere today for women in academia."

Wu and his co-authors Professors Sylvia Fuller (University of British Columbia); Zhilei Shi (Zhongnan University of Economics and Law in Beijing, China); and Rima Wilkes (University of British Columbia), reviewed comments in two major scientific journals for this study.

They collected and hand coded author information from all comment letters and corresponding science and social science research articles published over the past 16 years in reputable scientific journals - Science and Proceeding of the National Academy of Sciences of the United States of America (PNAS.)

"Though time-consuming, this method allows for more accurate coding of gender information for the authors," said Wu, adding that the team also searched authors' profiles online to obtain images for the gender variable.

Published in PLOS ONE, the study supports the theory that women are disadvantaged across the stages of academic publishing, including collaboration, peer-reviewing, readership, citation and in media coverage.

York University champions new ways of thinking that drive teaching and research excellence. Our students receive the education they need to create big ideas that make an impact on the world. Meaningful and sometimes unexpected careers result from cross-disciplinary programming, innovative course design and diverse experiential learning opportunities. York students and graduates push limits, achieve goals and find solutions to the world's most pressing social challenges, empowered by a strong community that opens minds. York U is an internationally recognized research university - our 11 faculties and 25 research centres have partnerships with 200+ leading universities worldwide. Located in Toronto, York is the third largest university in Canada, with a strong community of 53,000 students, 7,000 faculty and administrative staff, and more than 300,000 alumni.

As part of their efforts to slow the outbreak of coronavirus, governments, research institutions and industry are developing contact tracing apps to record interactions between people. The apps warn users if one of the people they have been recorded as being in contact with is later diagnosed with COVID-19 so they can take appropriate steps like self-isolation.

Such apps could prove useful in avoiding long-term confinement measures. However they collect sensitive information like location data, Bluetooth-enabled proximity information, and whether individuals are infected.

Now, a new white paper by Imperial College London's Dr Yves-Alexandre de Montjoye has outlined eight questions that should be asked to understand how protective of privacy an app is.

Dr de Montjoye, of Imperial's Department of Computing, said: "We need to do everything we can to help slow the outbreak. Contact tracing requires handling very sensitive data at scale, and solid and proven techniques exist to help us do it while protecting our fundamental right to privacy. We cannot afford to not use them.

"Our questions are intended for governments and citizens to help evaluate the privacy of apps. They could also for app developers when planning and evaluating their work."

The questions were developed by a team including Imperial PhD students Florimond Houssiau, Andrea Gadotti, and ENS Lyon's Florent Guepin.

The questions

1. How do you limit personal data gathered by the app developers?

Dr de Montjoye (YDM): "Large-scale collection of personal data can quickly lead to mass surveillance. We should ask how much data the app gathers - like the whole disease trajectory and real-life social network of infected users."

2. How do you protect the anonymity of every user?

YDM: "Special measures should be put in place to limit the risk that users can be re-identified by app developers, other users, or external parties. Because location traces are unique, they might easily be linked back to a person."

3. Does the app reveal to its developers the identity of users who are at risk?

YDM: "The goal of contact tracing is to warn people who are at risk, so there's no need for app developers to know who these people are."

4. Could the app be used by users to learn who is infected or at risk, even in their social circle?

YDM: "Personal health data is very sensitive. Digital contact tracing should warn those who are at risk without revealing who might have infected them."

5. Does the app allow users to learn any personal information about other users?

YDM: "Having access to small amounts of information could help users identify who is infected, so apps shouldn't disclose information on a user's location or social networks to other users."

6. Could external parties exploit the app to track users or find out who's infected?

YDM: "Apps should consider the risk of external adversaries, including well-resourced ones. External entities could install Bluetooth trackers to cover a city, or install malicious code on phones, and record the identifiers that they observe in specific locations. This can be avoided by regularly changing and re-anonymising identifiers like location data."

7. Do you put in place additional measures to protect the personal data of infected and at-risk users?

YDM: "The app design may require revealing more personal information about users who are infected or exposed, but these are often the people who are more vulnerable and at risk. It's important to consider what additional measures can be taken to protect their information."

8. How can users verify that the system does what it says?

YDM: "Large-scale contact tracing is too sensitive an issue to rely on blind trust. Technical measures should be used to guarantee public scrutiny on the functioning of the app. Transparency of the system (app code, protocol, what is being broadcast, etc) is fundamental to guarantee privacy. This requires that the app be open source and app versions distributed on mobile app stores be verifiable, enabling developers to confirm that they're running the public, auditable code."

Privacy a 'crucial component' going forward

Contact tracing apps are being developed around the world and some are already available. If they are proven useful, governments, health authorities, and users will have to evaluate the different approaches and decide whether to adopt them. Privacy, say the researchers, is a crucial component in this decision.

Co-author Florimond Houssiau, also from Imperial's Department of Computing, said: "These questions are meant to be a starting point for an informed conversation on privacy in contact tracing apps."

The questions do not cover every potential vulnerability of contact tracing protocols, like security issues. Co-author Andrea Gadotti said: "Our questions focus on privacy, but the security side is equally important. This means, for example, encrypting the apps, evaluating how mobile malware could affect the app's behaviour, and assessing the resilience of the app developer servers against intrusion."

"Evaluating COVID-19 contact tracing apps? Here are 8 privacy questions we think you should ask." by Dr de Montjoye et al., published 2 April 2020.

WASHINGTON, April 2, 2020 -- Cold brew may be the hottest trend in coffee-making, but not a lot is known about how this process alters the drink's chemical characteristics. Scientists now report that the content of potentially health-promoting antioxidants in coffee brewed without heat can significantly differ from a cup of joe prepared with the same beans in the traditional way, particularly for dark roasts.

The researchers are presenting their results through the American Chemical Society (ACS) SciMeetings online platform.

A brand-new video on the research is available at http://www.acs.org/philly-2020-coffee.

"This study can inform coffee enthusiasts about how they may want to craft their own coffee at home, based on science and on analytical chemistry," says Meghan Grim, an undergraduate student who worked on the project.

"After I first tried cold-brew coffee, I wanted to make it at home, but it didn't turn out too great," says Niny Z. Rao, Ph.D., the project's principal investigator. With her collaborator, Megan Fuller, Ph.D., Rao looked into the scientific literature to learn what she had done wrong. "It turns out there weren't any studies on cold-brew coffee at the time," Rao says, "so we decided to do some."

In the cold-brew process, ground coffee is mixed with room-temperature or colder water and steeped for as long as two days, sometimes in a refrigerator. It can be drunk cold or hot. In hot brewing, ground coffee is mixed with boiling or near-boiling water and steeped at most for a few minutes. In either case, the coffee grounds are sometimes pressed, and the beverage is then filtered to remove the grounds.

The researchers, who are at Thomas Jefferson University, previously assessed acidity and antioxidants in hot- and cold-brew java from lightly roasted beans. In another project, they analyzed the effect of medium and dark roasting, and of medium and coarse grinding, on a few coffee attributes. Now they're taking a deeper dive by roasting Columbian beans at five different temperatures -- from light roasting at 174 C to dark roasting at 209 C -- and studying the impact on acidity, antioxidants and other natural chemicals in hot- and cold-brew coffee.

With the lighter roasts, Rao's team finds that the content of caffeine and antioxidants is pretty similar in hot and cold brews. However, significant differences show up with the darker roasts. "Hot brewing extracts more antioxidants from the grind than cold brew, and this difference increases with the degree of roasting," Rao says. So hot-brew of dark roasts produces a potentially healthier drink. Hot brew also contains more of certain kinds of acids and total dissolved solids. The pH is about the same for both hot and cold brews at equivalent roast, though both become less acidic as roasting temperature increases.

"My advice to consumers has always been to drink what they like," Rao says. "But if you want to craft a coffee beverage with antioxidants or acidity in mind, you may want to pay attention to roast. If you want a low-acid drink, you may want to use a darker roast. But remember that the gap between the antioxidant content of hot- and cold-brew coffee is much larger for a darker roast."

One of the biggest challenges in all these projects is reproducibility. "We have performed experiments in which we're using the same beans, the same machine, the same settings, and it comes out not quite the same as the previous batch," Rao says. "The same goes for brewing. To create a cup that's consistent every time is really difficult. I have a lot of respect for the baristas who can do that." To approach that level of perfection, the researchers became like drill sergeants, carefully standardizing their processes. They developed a procedure for when the water should be added to the ground coffee, how to pour the water and for how long, how to shake the solution, how to press the brewed coffee and how to analyze it. They set time limits for each step, with margins of just a few seconds. This rigor produced much more reproducible results.

The team has now begun comparing the impact of the two brewing processes and degree of roast on furans, flavor compounds present in raw coffee beans that are also generated through roasting. Such compounds are particularly important in cold-brew joe, which doesn't have the same distinct aroma as the hot drink because it lacks steam to carry volatile organic compounds to the nose.

A new study in Nature Communications proposes a method to extend polygenic scores, the estimate of genetic risk factors and a cornerstone of the personalized medicine revolution, to individuals with multiple ancestral origins. The study was led by Dr. Davide Marnetto from the Institute of Genomics of the University of Tartu, Estonia and coordinated by Dr. Luca Pagani from the same institution and from the University of Padova, Italy.

"The information contained in our DNA is a mosaic of genetic instructions inherited from our ancestors, and in many societies one's ancestors often come from the opposite corners of the world." says Dr. Davide Marnetto, first author of the study. The contribution of one's ancestry, or ancestries, to the total risk of developing a specific disease or presenting a given trait is a long standing question of medical genomics. Nevertheless, most of the genotype/phenotype association data come from relatively uniform populations, in order to have a simplified and clearer picture. But what can be done when dealing with individuals who derive their ancestry from two or more distantly related populations?

"The latest developments of personalized medicine needed an extra step to be applied to individuals with more diverse origins, and here we tried to combine knowledge from homogeneous populations into a model that could work for recently admixed individuals" continues Dr. Marnetto.

To separate the various genomic components of each individual, Marnetto and colleagues applied methods from molecular anthropology and population genomics. "This research is a welcomed example of deep synergy between evolutionary/population genetics framework and medically oriented large scale genomics science, which is one of the focuses of our institute." says Dr. Mait Metspalu who is heading the institute of Genomics at the University of Tartu.

"Our work provides a solid proof of principle on the feasibility of using population genetic and molecular anthropology to boost the potential of personalized medicine. I hope our work can bring individuals of mixed ancestry one step closer to the benefits of personalized and predictive healthcare" concludes Dr. Luca Pagani, the research coordinator.

A newly developed wireless biologging network (WBN) enables high-resolution tracking of small animals, according to a study published April 2 in the open-access journal PLOS Biology by Simon Ripperger of the Leibniz Institute for Evolution and Biodiversity Science, and colleagues. As noted by the authors, WBNs could close an important gap in biologging: the fully automated tracking and proximity-sensing of small animals, even in closed habitats, at high spatial and temporal resolution.

Recent advances in animal tracking technology have ushered in a new era in biologging. By collecting data of unprecedented quantity and quality, automated methods have revolutionized numerous fields, including animal ecology, collective behavior, migration, and conservation biology.

However, satellite communication for localization or data access requires a lot of power, and heavy transmitters greatly limit the ability to track smaller vertebrate species. To address this problem, Ripperger and colleagues developed their WBN -- a system that enables high-resolution tracking of animals weighing as little as 20 grams. These smaller species make up a large proportion of birds and mammals, so WBNs will give researchers new capabilities to address a wide range of questions in animal behavior and ecology.

As reported in the study, WBN is a scalable, flexible system that offers a temporal resolution of seconds, allows automated recording of movement trajectories even in structurally complex habitats such as woodland, and is an ultra-low-power solution for remote data access over distances of several kilometers.

The researchers deployed WBN to study wild bats, creating social networks and flight trajectories of unprecedented quality. To do this, wireless localization nodes are placed in the area of study, and light-weight mobile nodes are attached to the animals. In one example, the authors planted 17 localization nodes in a 1.5-hectare area of German forest, and glued mobile nodes to the fur on the backs of 11 mouse-eared bats, allowing them to track their flights and interactions.

According to the authors, WBNs will greatly benefit biologging of small animal species that move over smaller and more predictable spatial scales, especially inside habitats where signal transmission is constrained. Such setups will allow studies on the effects of social network dynamics on phenomena such as transmission of social information and pathogens, and key ecosystem functions such as pollination and seed dispersal.

Ripperger adds: "Key to success in this project was the close collaboration among biologists, computer scientists, and electrical engineers. Thanks to the high level of miniaturization of the animal-borne tags, we can now collect data of unprecedented quantity and quality that allows us studying the behavior of small animals in much greater detail. For example, we learned from proximity sensing in the wild that noctule bat mothers guide their offspring to novel roosts and that social relationships in vampire bats that formed in the lab persist in the wild. In the future, we plan to expand our work to other taxonomic groups - a method that allows tracking bats is also likely to work for other small animals such as reptiles or songbirds."

Researchers have found strong evidence that the risk for armed conflict is higher after a climate-related disaster, but only in vulnerable countries.

Lead author Tobias Ide from the University of Melbourne said the disasters include storms, floods and droughts - the frequency and intensity of which will increase in the future, due to climate change.

"Bushfires in Australia will not spark a civil war as the state is democratic and able to provide relief," said DECRA Fellow Dr Ide. "But when it comes to droughts in Nigeria or storms in Pakistan, where you have large marginalised populations and little state presence, the picture may well change."

The paper, published today in the Global Environmental Change journal, provides invaluable evidence for policy makers such as the United Nations Security Council, which has been called on to invest in climate adaptation and risk reduction for the millions of people already suffering from the effects of climate change.

"The question 'Will a warming world also be a world with more violent and armed conflicts?' has been a very real one for political leaders and civil societies across the world," Dr Ide said. "Climate change makes tense social and political situations even worse, so climate-change disasters may act like a 'threat multiplier' for violent conflicts.

"Only countries with large populations, the political exclusion of ethnic groups and relatively low levels of economic development, are susceptible to disaster-conflict links. Measures to make societies more inclusive and wealthier are, therefore, no-regrets options to increase security in a warming world."

Research on the effects of climate change have on armed violence have previously been open to interpretation but Dr Ide and his colleagues say their study shows that climate-related disasters enhance armed conflict risks.

"We find that almost one third of all conflict onsets in vulnerable countries over the recent decade have been preceded by a climate-related disaster within seven days," said co-author Carl-Friedrich Schleussner from Climate Analytics. "This does, however, not mean that disasters cause conflicts, but rather that occurrence of disasters increase the risks of an outbreak."

Dr Ide added: "If we look at what happened in Mali when a severe drought occurred in June 2009, we can see that the militant Al-Qaeda in the Islamic Maghreb (AQIM) group exploited the resulting state weakness and desperation of local people to recruit fighter and expand its area of operation. The Philippines were another country where recurrent disasters weakened government structures in contested regions, hence opening a space for rebel groups."

In the large majority of cases, opportunity factors drove the onset of armed violence. Rather than aggrieved populations, rebels exploited the temporary weakness of the state after a disaster, to stage attacks.

Michael Brzoska, a co-author and Associate Senior Researcher from the University of Hamburg, said: "The most surprising result of our study for me was the prevalence of opportunities for armed violence over those related to grievances in post-disaster situations."

The study employed an innovative approach combining different research methods. "For the first time, we brought together statistical analysis on the global level with case study assessments allowing us to assess the robustness of our findings as well as to compare the individual circumstances of each case," said co-author Jonathan Donges from the Potsdam Institute for Climate Impacts Research.

You wait ages for a pterosaur and then four come along at once.

Hot on the heels of a recent paper discovering three new species of pterosaur, University of Portsmouth palaeobiologists have identified another new species - the first of its kind to be found on African soil.

Pterosaurs are the less well-known cousins of dinosaurs. They had adept flying ability - some as large as a fighter jet and others as small as a model aeroplane.

The new species belongs to a group of pterosaurs called tapejarids from the Cretaceous period. Tapejarids were small to medium-sized pterosaurs with wingspans perhaps as wide as four metres, most of which had large, broad crests sweeping up from the front of the skull.

They are well known in Brazil and China, and specimens have also been discovered in Europe, but this is the first time the flying reptile has been found in Africa.

It differs from the three recent species discovered as this one had no teeth - it was 'edentulous'.

Professor David Martill, from the University's School of the Environment, Geography and Geosciences, led the study. He said: "The study of Moroccan material shows that we are still far from having found all the paleontological treasures of North Africa. Even fragmentary fossils, like the jaw piece of the new pterosaur, can give us important information about the biodiversity of the past."

PhD student Roy Smith, one of the co-authors, said: "I feel very privileged to be part of such an exciting discovery. Working in the Sahara was a life-changing experience, and discovering a new species of pterosaur is the icing on the cake."

The new pterosaur has been named Afrotapejara zouhrii to honour the Moroccan palaeontologist Professor Samir Zouhri. Originally a mammal specialist, Zouhri also contributed to several discoveries of prehistoric reptiles in Morocco, including dinosaurs and pterosaurs.

Professor Martill said: "The opportunity to illuminate the diversity of pterosaurs in Africa while honouring a colleague does not happen every day."

The research team included Dr David Unwin from the University of Leicester and Dr Nizar Ibrahim from the University of Detroit Mercy.

Palaeontologist Dr Ibrahim, said: "Samir Zouhri has played an important role in the development of Moroccan palaeontology, not only through his publications, but also because he organised scientific conferences in Morocco and edited an entire volume for the Geological Society of France on the subject of vertebrate palaeontology in Morocco."

The fossil material is part of the collections of the Faculty of Sciences Aïn Chock, Casablanca Hassan II University and the paper was published in Cretaceous Research.