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Although boron nitride looks very similar to graphene in structure, it has completely different optoelectronic properties. Its constituents, the elements boron and nitrogen, arrange - like carbon atoms in graphene - a honeycomb-like hexagonal structure. They arrange themselves in two-dimensional layers that are only one atomic layer thick. The individual layers are only weakly coupled to each other by so-called van der Waals forces and can therefore be easily separated from each other.

Publication in Nature Materials

Physicists from Julius-Maximilians-Universität Würzburg (JMU) in Bavaria, Germany, in cooperation with the Technical University of Sydney in Australia have now succeeded for the first time in experimentally demonstrating so-called spin centers in a boron nitride crystal. Professor Vladimir Dyakonov, holder of the Chair of Experimental Physics VI at the Institute of Physics, and his team were responsible for this on the JMU side and carried out the crucial experiments. The results of the work have been published in the renowned scientific journal Nature Materials.

In the layered crystal lattice of boron nitride the physicists found a special defect - a missing boron atom - which exhibits a magnetic dipole moment, also known as a spin. Furthermore, it can also absorb and emit light and is therefore also called color center. To study the magneto-optical properties of the quantum emitter in detail, JMU scientists have developed a special experimental technique that uses the combination of a static and a high-frequency magnetic field.

A little luck is needed

"If you vary the frequency of the alternating magnetic field, at some point you hit exactly the frequency of the spin, and the photoluminescence changes dramatically," explains Dyakonov. A bit of luck is necessary, however, since it is difficuilt to predict at which frequencies one has to search for unknown spin states. Dyakonov and his team had discovered these centers in the 2D crystalline system, which had previously only been predicted theoretically. Among other things, they were able to demonstrate spin polarization, i.e. the alignment of the magnetic moment of the defect under optical excitation - even at room temperature.

This makes the experiments interesting for technical applications as well: Scientists around the world are currently working on finding a solid-state system in which the spin state can be aligned, manipulated on demand and later read-out optically or electrically. "The spin center we have identified in boron nitride meets these requirements," adds Dyakonov. Because it has a spin and additionally absorbs and emits light, it is a quantum bit that can be used in quantum sensing and quantum information. New navigation technology could also work with this technology, which is why space agencies such as DLR and NASA are conducting intensive research on this topic, too.

Material design by the Lego brick principle

For the basic scientist, the 2D materials are also exciting from another point of view. They have very special layer structure, combined with the only weak bonding of the layers to each other, offers the possibility of constructing different stacking sequences from different semiconductors. "If you then place a defect in one of these layers, we call it a spin probe, this can help to understand the properties of the adjacent layers, but also to change the physical properties of the entire stack," says Dyakonov.

In a next step, Dyakonov and his colleagues therefore want to produce, among other things, heterostructures made of multilayer semiconductors with a boron nitride layer as an intermediate layer. They are convinced: "If the atomically thin layers of boron nitride, which are 'decorated' with individual spin centers, can be produced and incorporated into a heterostructure, it will be possible to design artificial two-dimensional crystals based on Lego brick principles and investigate their properties."

CHAMPAIGN, Ill. -- Environmental concerns about hydraulic fracturing - aka "fracking," the process by which oil and gas are extracted from rock by injecting high-pressure mixtures of water and chemicals - are well documented, but according to a paper co-written by a University of Illinois at Urbana-Champaign environmental economics expert, the technique also poses a serious safety risk to local traffic.

New research from Yilan Xu ("E-Lan SHE"), a professor of agricultural and consumer economics at Illinois, shows that the growing traffic burden in fracking boomtowns from trucks hauling wastewater to disposal sites resulted in a surge of road fatalities and severe accidents.

"Fracking requires large amounts of water, and it subsequently generates a lot of wastewater," she said. "When trucks need to transport all that water within a narrow window of time to a disposal site, that poses a safety threat to other drivers on the road - especially since fracking occurs mostly in these boomtowns where the roadway infrastructure isn't built up enough to handle heavy truck traffic."

The study examined how fracking-related trucking affected the number of fatal crashes in the Bakken Formation in North Dakota from 2006-14, using the timing of fracking operations near certain road segments.

The researchers identified a causal link between fracking-related trucking and fatal traffic crashes, finding that an additional post-fracking well within six miles of the road segments led to 8% more fatal crashes and 7.1% higher per-capita costs in accidents.

"Our back-of-the-envelope calculation suggests that an additional 17 fatal crashes took place per year across the sampled road segments, representing a 49% increase relative to the annual crash counts of the drilling counties in North Dakota in 2006," Xu said. "That's a significant number when you're talking about a sparsely populated area like North Dakota.

"And besides the fatality and injury costs in fatal crashes quantified in our study, other costs may occur as well, including injury costs in nonfatal crashes and indirect expenditures on emergency services, insurance administrative costs, and infrastructure maintenance and replacement."

To lessen the negative impact on traffic fatalities as well as the severity of traffic accidents, the study proposes a tax that can be charged per well to internalize the costs of fracking-related trucking activities, similar to the impact fees implemented in energy-rich towns in Pennsylvania that yield hundreds of millions of dollars per year for the state.

"The tax could serve as an economic instrument that affects operators' drilling and fracking decisions and thus alleviate the hazard of the associated truck traffic indirectly," Xu said. "Likewise, a toll fee by miles driven by trucks could be collected on highways to absorb the negative impacts of fracking-related trucking."

The study also sheds light on more practical measures that local governments can undertake to curb the traffic risks associated with fracking.

"Since many fracking-induced fatal crashes take place in the daytime rush hours, local governments could adopt policies such as making a high occupancy vehicle lane for trucks carrying wastewater. An active traffic alert and warning system with live well-operations updates could also help drivers monitor traffic and avoid exposure to road hazards," she said.

Moreover, the paper calls for the active involvement of the oil and gas industry to seek ways to improve their workplace safety and mitigate the traffic hazard of fracking to road users.

"Our findings suggest that oil and gas operators could redistribute the traffic loads over time to avoid concentrated water hauling during peak hours," Xu said. "In the long run, since a well may need to be fracked multiple times over its productive life, operators may improve the water supply system by constructing water wells serving multiple well pads via a piping system. They could also develop the onsite wastewater treatment and disposal facilities as opposed to trucking wastewater over long distances. Such measures would reduce the long-term transport costs and the associated traffic effects."

The findings should give local and federal policymakers information when conducting due diligence and evaluating the regional costs and benefits of shale energy development, Xu said.

"Our study provides an estimate based on the North Dakota experience where population density and traffic volume is relatively low, but our findings have implications for other regions planning future shale development."

SMU Office of Research & Tech Transfer - Can you imagine a world without personalised Spotify playlists, curated social media feeds, or recommended cat videos on the sidebars of YouTube? These modern-day conveniences, which were made possible by artificial intelligence (AI), also present a scary proposition - that the machines could end up knowing more about us than we ourselves do.

According to Gartner's 2019 CIO Agenda survey, 37 percent of Chief Information Officers (CIOs) globally have already deployed AI technology in their organisations. The rapid adoption of AI solutions brings to focus the way data - which could consist of sensitive, confidential and personal information - are being managed and used by organisations.

Speaking at the conference panel on 'AI and Data Protection: New Regulatory Approaches', Singapore Management University (SMU) Associate Professor Warren Chik gave his perspective on how to conceptualise trust in a digital age. "When it comes to matters such as personal data, we don't treat AI as god. Therefore, we cannot rely on faith, which is what religion requires. We need something more substantial than that," he said.

In his talk titled 'Artificial Intelligence and Data Protection in Singapore: Consumers' Trust, Organisational Security and Government Regulation', Professor Chik explained that to engender trust in a digital solution, it is crucial that users are being engaged on the issues involved. "People tend to fear the unknown, and it is hard to have trust in something that you don't know."

Moderated by Professor David Llewelyn, Deputy Dean of the SMU School of Law, the roundtable featured speakers Professor Ian Walden, Centre for Commercial Law Studies, Queen Mary University of London; Associate Professor Yip Man (whose paper was presented by Associate Professor Alvin See on her behalf); as well as commentators Mr KK Lim, Head of Cybersecurity, Privacy and Data Protection, Eversheds Harry Elias; and Mr Lanx Goh, Senior Legal Counsel (Privacy & Cybersecurity) & Global Data Protection Officer, Klook Travel Technology.

AI as an influencer

The ability of an AI system to conduct personal profiling could fundamentally change a user's digital personality, said Professor Chik, highlighting a cause of worry for many.

"While an AI holds specific information such as your name and address, it also forms its own knowledge of your identity, and who you are as a person," Professor Chik said, citing algorithms used by social media feeds to collect data on one's identity, interests and surfing habits. From that data, the system then creates a profile of who they think you are.

"These algorithms - which may be right or wrong - feed you information, articles and links, and as a result brings about an effect on your thinking. In other words, AI can mold human behaviour, and this is a risk that makes a lot of people uncomfortable," Professor Chik said. The threat is very real, he emphasised, noting that regulators have clearly identified a need to regulate the use of data in AI.

In Singapore, for instance, the Protection from Online Falsehoods and Manipulation Act (POFMA) carries criminal provisions on the creation, use and alteration of bots to spread false information.

Data protection legislation: a balancing act

In trying to regulate data, there are always two competing objectives when regulating the use, collection and processing of personal data. "The first objective is to protect the data subject, and the second is to promote innovation," said Professor See, who presented Professor Yip's paper on her behalf.

Of the different types of protection for data subjects that exist today, the most commonly available option is the use of contracts. Professor Yip's paper points out that "[t]he problem with trying to regulate data use through terms and conditions is that in most cases, people don't read [the legal fine print]". The consent given is therefore not genuine.

Professor Llewelyn, who moderated the roundtable, added that the meaning of consent is an issue that needs to be explored in greater depth. "If a consumer were to accept an online contract in full without reading it, can it be realistically said that he or she has agreed to all the terms and conditions, and given full consent?" he asked. "Perhaps there should be legal acknowledgement given to the automatic nature of the commitment made in such contracts."

A more critical limitation of the contract as protection for the data subject, is that the contract only governs the information that is shared between the two parties bound by the contract. For instance, if Facebook were to transfer a user's personal data to a third-party not bound by the contract, the third-party firm will not be obligated to protect the user's information.

Data protection by design

Singapore's Personal Data Protection Act (PDPA), which regulates personal data through the use of legislation, is described as light touch regime that takes a strongly balanced approach between the need for privacy protection and the interest of business innovation.

Professor Yip's paper recognises that there is some level of tension between the two objectives mentioned above. The issue at hand, therefore, is how to strike a balance between individual rights and privacy, and the competing interest of economic growth and innovation, she noted.

At the end of the day, the focus is on preventing, rather than trying to remedy a breach of data privacy. "It is about recognising the rights of the individual and the privacy of their data, and at the same time, the need for organisations to collect, use and disclose personal data for legitimate and reasonable purposes," Professor Yip's paper added.

Another solution that Professor Yip explored in her paper was the use of technology instead of law to protect data subjects. In some cases, privacy can be directly built into the design and operation of operation systems, work processes, network infrastructure and even physical spaces. She nevertheless highlights that this solution is not perfect because it is against the interest of businesses which leverage data to make profits to build robust privacy safeguards into their systems and business models.

AMES, Iowa - The Earth of 3.2 billion years ago was a "water world" of submerged continents, geologists say after analyzing oxygen isotope data from ancient ocean crust that's now exposed on land in Australia.

And that could have major implications on the origin of life.

"An early Earth without emergent continents may have resembled a 'water world,' providing an important environmental constraint on the origin and evolution of life on Earth as well as its possible existence elsewhere," geologists Benjamin Johnson and Boswell Wing wrote in a paper just published online by the journal Nature Geoscience.

Johnson is an assistant professor of geological and atmospheric sciences at Iowa State University and a recent postdoctoral research associate at the University of Colorado Boulder. Wing is an associate professor of geological sciences at Colorado. Grants from the National Science Foundation supported their study and a Lewis and Clark Grant from the American Philosophical Society supported Johnson's fieldwork in Australia.

Johnson said his work on the project started when he talked with Wing at conferences and learned about the well-preserved, 3.2-billion-year-old ocean crust from the Archaean eon (4 billion to 2.5 billion years ago) in a remote part of the state of Western Australia. Previous studies meant there was already a big library of geochemical data from the site.

Johnson joined Wing's research group and went to see ocean crust for himself - a 2018 trip involving a flight to Perth and a 17-hour drive north to the coastal region near Port Hedland.

After taking his own rock samples and digging into the library of existing data, Johnson created a cross-section grid of the oxygen isotope and temperature values found in the rock.

(Isotopes are atoms of a chemical element with the same number of protons within the nucleus, but differing numbers of neutrons. In this case, differences in oxygen isotopes preserved with the ancient rock provide clues about the interaction of rock and water billions of years ago.)

Once he had two-dimensional grids based on whole-rock data, Johnson created an inverse model to come up with estimates of the oxygen isotopes within the ancient oceans. The result: Ancient seawater was enriched with about 4 parts per thousand more of a heavy isotope of oxygen (oxygen with eight protons and 10 neutrons, written as 18O) than an ice-free ocean of today.

How to explain that decrease in heavy isotopes over time?

Johnson and Wing suggest two possible ways: Water cycling through the ancient ocean crust was different than today's seawater with a lot more high-temperature interactions that could have enriched the ocean with the heavy isotopes of oxygen. Or, water cycling from continental rock could have reduced the percentage of heavy isotopes in ocean water.

"Our preferred hypothesis - and in some ways the simplest - is that continental weathering from land began sometime after 3.2 billion years ago and began to draw down the amount of heavy isotopes in the ocean," Johnson said.

The idea that water cycling through ocean crust in a way distinct from how it happens today, causing the difference in isotope composition "is not supported by the rocks," Johnson said. "The 3.2-billion-year-old section of ocean crust we studied looks exactly like much, much younger ocean crust."

Johnson said the study demonstrates that geologists can build models and find new, quantitative ways to solve a problem - even when that problem involves seawater from 3.2 billion years ago that they'll never see or sample.

And, Johnson said these models inform us about the environment where life originated and evolved: "Without continents and land above sea level, the only place for the very first ecosystems to evolve would have been in the ocean."

Researchers at Karolinska Institutet in Sweden have analysed all cell types in the human ovary and found that the hotly debated so-called egg stem cells do not exist. The results, published in Nature Communications, open the way for research on improved methods of treating involuntary childlessness.

The researchers used single-cell analysis to study more than 24,000 cells collected from ovarian cortex samples of 21 patients. They also analysed cells collected from the ovarian medulla, allowing them to present a complete cell map of the human ovary.

One of the aims of the study was to establish the existence or non-existence of egg stem cells.

"The question is controversial since some research has reported that such cells do exist, while other studies indicate the opposite," says Fredrik Lanner, researcher in obstetrics and gynaecology at the Department of Clinical Science, Intervention and Technology at Karolinska Institutet, and one of the study's authors.

The question of whether egg stem cells exist affects issues related to fertility treatment, since stem cells have properties that differ from other cells.

"Involuntary childlessness and female fertility are huge fields of research," says co-author Pauliina Damdimopoulou, researcher in obstetrics and gynaecology at the same department. "This has been a controversial issue involving the testing of experimental fertility treatments."

The new study substantiates previously reported findings from animal studies - that egg stem cells do not exist. Instead, these are so-called perivascular cells.

The new comprehensive map of ovarian cells can contribute to the development of improved methods of treating female infertility, says Damdimopoulou.

"The lack of knowledge about what a normal ovary looks like has held back developments," she says. "This study now lays the ground on which to produce new methods that focus on the egg cells that already exist in the ovary. This could involve letting egg cells mature in test tubes or perhaps developing artificial ovaries in a lab."

The results of the new study show that the main cell types in the ovary are egg cells, granulosa cells, immune cells, endothelial cells, perivascular cells and stromal cells.

Want to learn to code? Put down the math book. Practice those communication skills instead.

New research from the University of Washington finds that a natural aptitude for learning languages is a stronger predictor of learning to program than basic math knowledge, or numeracy. That's because writing code also involves learning a second language, an ability to learn that language's vocabulary and grammar, and how they work together to communicate ideas and intentions. Other cognitive functions tied to both areas, such as problem solving and the use of working memory, also play key roles.

"Many barriers to programming, from prerequisite courses to stereotypes of what a good programmer looks like, are centered around the idea that programming relies heavily on math abilities, and that idea is not born out in our data," said lead author Chantel Prat, an associate professor of psychology at the UW and at the Institute for Learning & Brain Sciences. "Learning to program is hard, but is increasingly important for obtaining skilled positions in the workforce. Information about what it takes to be good at programming is critically missing in a field that has been notoriously slow in closing the gender gap."

Published online March 2 in Scientific Reports, an open-access journal from the Nature Publishing Group, the research examined the neurocognitive abilities of more than three dozen adults as they learned Python, a common programming language. Following a battery of tests to assess their executive function, language and math skills, participants completed a series of online lessons and quizzes in Python. Those who learned Python faster, and with greater accuracy, tended to have a mix of strong problem-solving and language abilities.

In today's STEM-focused world, learning to code opens up a variety of possibilities for jobs and extended education. Coding is associated with math and engineering; college-level programming courses tend to require advanced math to enroll and they tend to be taught in computer science and engineering departments. Other research, namely from UW psychology professor Sapna Cheryan, has shown that such requirements and perceptions of coding reinforce stereotypes about programming as a masculine field, potentially discouraging women from pursuing it.

But coding also has a foundation in human language: Programming involves creating meaning by stringing symbols together in rule-based ways.

Though a few studies have touched on the cognitive links between language learning and computer programming, some of the data is decades old, using languages such as Pascal that are now out of date, and none of them used natural language aptitude measures to predict individual differences in learning to program.

So Prat, who specializes in the neural and cognitive predictors of learning human languages, set out to explore the individual differences in how people learn Python. Python was a natural choice, Prat explained, because it resembles English structures such as paragraph indentation and uses many real words rather than symbols for functions.

To evaluate the neural and cognitive characteristics of "programming aptitude," Prat studied a group of native English speakers between the ages of 18 and 35 who had never learned to code.

Before learning to code, participants took two completely different types of assessments. First, participants underwent a five-minute electroencephalography scan, which recorded the electrical activity of their brains as they relaxed with their eyes closed. In previous research, Prat showed that patterns of neural activity while the brain is at rest can predict up to 60% of the variability in the speed with which someone can learn a second language (in that case, French).

"Ultimately, these resting-state brain metrics might be used as culture-free measures of how someone learns," Prat said.

Then the participants took eight different tests: one that specifically covered numeracy; one that measured language aptitude; and others that assessed attention, problem-solving and memory.

To learn Python, the participants were assigned 10 45-minute online instruction sessions using the Codeacademy educational tool. Each session focused on a coding concept, such as lists or if/then conditions, and concluded with a quiz that a user needed to pass in order to progress to the next session. For help, users could turn to a "hint" button, an informational blog from past users and a "solution" button, in that order.

From a shared mirror screen, a researcher followed along with each participant and was able to calculate their "learning rate," or speed with which they mastered each lesson, as well as their quiz accuracy and the number of times they asked for help.

After completing the sessions, participants took a multiple-choice test on the purpose of functions (the vocabulary of Python) and the structure of coding (the grammar of Python). For their final task, they programmed a game -- Rock, Paper, Scissors -- considered an introductory project for a new Python coder. This helped assess their ability to write code using the information they had learned.

Ultimately, researchers found that scores from the language aptitude test were the strongest predictors of participants' learning rate in Python. Scores from tests in numeracy and fluid reasoning were also associated with Python learning rate, but each of these factors explained less variance than language aptitude did.

Presented another way, across learning outcomes, participants' language aptitude, fluid reasoning and working memory, and resting-state brain activity were all greater predictors of Python learning than was numeracy, which explained an average of 2% of the differences between people. Importantly, Prat also found that the same characteristics of resting-state brain data that previously explained how quickly someone would learn to speak French, also explained how quickly they would learn to code in Python.

"This is the first study to link both the neural and cognitive predictors of natural language aptitude to individual differences in learning programming languages. We were able to explain over 70% of the variability in how quickly different people learn to program in Python, and only a small fraction of that amount was related to numeracy," Prat said. Further research could examine the connections between language aptitude and programming instruction in a classroom setting, or with more complex languages such as Java, or with more complicated tasks to demonstrate coding proficiency, Prat said.

An improved mobile phone app will help identify women who need special treatments at the right time and reduce emotional and financial burden on families and the NHS.

A team of researchers from the Department of Women & Children's Health, King's College London, supported by Guy's and St Thomas' Charity, the National Institute for Health Research and Tommy's have created a user-friendly mobile phone application, QUiPP v2, that will allow doctors to quickly calculate a woman's individual risk of preterm birth. This will help them to make sure women who need special treatments get them at the right time, but it also helps them to reassure women when their risk is low.

When babies are born early, before 37 weeks of pregnancy, they are more likely to die, or have physical, developmental and emotional problems. This can result in a huge emotional and financial burden for families and substantial cost for the NHS and care services.

Some women are known to be more likely to have their babies early, and some have symptoms of labour too early in pregnancy. If identified, these women can be given extra monitoring and/or special treatments that aim to prevent early delivery and ensure the infants have the best chance of surviving without long-term problems.

QUiPP v2 calculates the risk based on a woman's individual risk factors, such as previous preterm birth, late miscarriage or symptoms, along with clinical test results that help to predict preterm birth (i.e. fetal fibronectin tests and cervical length measurements). The app then produces a simple individual % risk score.

In two papers, published in Ultrasound in Obstetrics and Gynecology, the authors show how they developed and tested the complicated algorithms (mathematical calculations) incorporated in the app which calculate the simple % risk.

"We are delighted to be able to share the findings of our work which shows that the QUiPP app is very reliable in predicting preterm birth in women at risk. This should mean that women who need treatments are offered them appropriately, and also that doctors and women can be reassured when these treatments are not needed, which reduces the possibility of negative effects and unnecessary costs for the NHS," said lead author Dr Jenny Carter, Senior Research Midwife, Department of Women & Children's Health at King's College London.

The authors have recently completed the EQUIPTT trial, where they evaluated whether QUiPP improves appropriate targeting of care. Results of this trial are expected later on this year.

Patient Safety Minister, Nadine Dorries said: "The joy a newborn brings can be cruelly contrasted alongside the fear when a baby is born too soon. Being able to identify mothers at risk of a pre-term birth as early as possible can help clinicians to intervene sooner, improve safety and ultimately save lives.

"We want the NHS to be the safest place in the world to give birth and the harnessing of promising digital innovations such as this is another stepping stone on this shared journey."

The team will continue to collect data (which will be used to update the algorithms in the future) through the ongoing UK wide PETRA study, and through the Preterm Clinical Network Database which is a global clinical registry of care given to women at risk of preterm birth.

(San Antonio, TX -- March 2, 2020) The physical and mental sensations we associate with feeling sick are a natural biological response to inflammation within the body. However, the strength and severity of these sensations go beyond biology and may be affected by gender, ethnicity and various social norms we've all internalized. These are the latest research findings, according to social scientists at UTSA, who have discovered a link between a person's culture and how one classifies being ill.

Social scientists think that a person's values may shape internal views on "socially appropriate sickness." This has implications for how different individuals may take more action in dealing with illness rather than spreading further disease.

Eric Shattuck, a biological anthropologist with UTSA's Institute for Health Disparities Research; sociology professor Thankam Sunil, who is director of the IHDR; and Xiaohe Xu, chair of UTSA's Department of Sociology, found that sickness expression is affected by gender, income and cultural values.

Specifically, study participants who (1) earned less than the U.S. median household income, (2) claimed to be stoics with a high tolerance for pain or (3) had symptoms of depression were more likely to express being sick. In men with stronger family bonds, feeling sick was also more likely to be reported.

"It's ironic. You think that being a stoic would mean that you are more likely to be reserved, but according to our survey, it has the opposite effect," said Shattuck. "Stoics could own up to being ill as a bragging right and maintain a disease for longer than is necessary."

According to the researchers, stoics--regardless of gender--and individuals with household incomes lower than $60,000 were more likely to claim being ill.

"In regard to lower income levels, perhaps those individuals were more likely to claim to have been sick because they didn't necessarily have the means to seek medical attention and, therefore, symptoms became severe," added Shattuck. "This perhaps made them remember the illness."

The researchers also pointed that men with stronger family ties were more likely to report stronger sickness sensations over the past year.

"It could be that family support allows men to feel more cared for and therefore rely on that social safety net," said Shattuck.

The researchers analyzed the self-reported surveys of 1,259 respondents who claimed to have been sick with influenza or the common cold in the past year. Participants were also asked to rate their current feelings of sickness from "not sick" to "severely sick" using a Likert-type scale in order to control for any possible compounding effect.

Sickness behavior, including lethargy, social withdrawal and appetite changes, is "one of the responses that all living creatures from ants to bees to humans seem to have in common. Yet socioeconomic and cultural norms play a part with us," said Shattuck. "For example, other researchers have shown that the majority of individuals who work in many fields, including medicine, are often likely to show up to work while being sick. If you think about it, this is about work culture and it has consequences."

The next step for the researchers is to repeat the study with individuals who are actively sick versus those that had to recall an illness. Areas of future investigation will explore how the severity of an illness affects reporting being sick.

"Maybe people are more comfortable reporting being sick when it's a common cold," Shattuck said, "but what about those stigmatized infections, such as HIV. What about the coronavirus? How are infectious diseases claimed using a cultural or economic lens?"

It becomes annoyingly easy to knock over a shampoo bottle when it's nearly empty. This is an easily observed and curiosity-provoking phenomenon that, according to Lehigh University physics professor Jerome Licini, yields insights into center-of-mass and impacts.

"The physics of that is pretty interesting and easy to understand," says Licini who, along with first-year physics major Allen Zijun Yuan, wrote a paper on the phenomenon that was recently published in The Physics Teacher. In the paper, they find the center-of-mass of a shampoo bottle, discuss its stability on a tilted surface, and demonstrate its sensitivity to impacts using a simple experiment involving a tennis ball and a protractor.

They write: "An object placed on a tilted surface and released will tip over if the horizontal position of the center of mass lies outside the geometric outline of the base of the object. This means that an object with a low center of mass will be stable for larger incline angles. Students are often surprised to see that the altitude of the center of mass of a shampoo bottle is a nonlinear function of the fraction occupied by the contents. This can, however, be seen in a straightforward manner by recognizing that for a plastic bottle, the mass of the liquid contents is usually far greater than the mass of the bottle. When the bottle is either completely full or completely empty, the center of mass must be approximately at the geometric center of the bottle, but the center of mass gets significantly lower in altitude for small liquid levels in between those two extremes."

Yuan developed a demonstration to show the effect of impact and, it turns out, even more extreme than just looking at angle.

A five-minute video of this demonstration is available can be viewed here. The experiment that uses a tennis ball, protractor and shampoo bottles with varying degrees of fullness to show the effects of impact starts at 2:40.

As Licini explains in the video, using a full bottle of shampoo: "So, what we have here is a tennis ball mounted on a string that can draw back to different angles. You put a protractor over here to measure that launch angle. And watch what happens as it impacts this shampoo bottle. So, you can see that for an angle of ten degrees, nothing happens. For an angle of 15 degrees, the bottle's still stable. It takes an angle of about 23 degrees in order to give this bottle enough rotational energy or angular momentum, in order to raise the center of mass above the stability point, and topple [the bottle]."

Conducting the experiment with a shampoo bottle that is 30 percent full, Licini says: "When we have our bottle with the lowest center of mass about filled to 30 percent, again it's still fairly stable. At five degrees, it bounces off no problem. At ten degrees, there's impact but still it rocks and then comes back to stability. That's because the center of mass is low. It takes an angle of about thirteen degrees in order to finally knock that bottle over."

Then, finally, using the empty shampoo bottle, Licini explains: "But the empty bottle is much more annoying than all that. Because the mass is so light, that means it's going to have a large response to impact. And, because the center of mass is so high [above the base], it's going to topple over easily. So, in this case, it only takes an angle of about three degrees in order to knock that bottle over. So, much less stable than any of the other configurations."

"We constructed a demonstration to produce impacts from a pendulum bob," write the authors. "A tennis ball of mass 57.7 g striking the bottle at an altitude of 13.7 cm turned out to be a good match of mechanical impedance and center of percussion. A string was tied to the tennis ball so its center would travel in an arc of radius 37 cm, and a protractor was mounted to determine the release angle of the pendulum, with 0° indicating the point of impact when the string was vertical ...The launch angles required for the impact to tip the bottle could be determined to ±0.5°and were approximately 20.5° for a full bottle, 12.0° for the maximum stability level, and only 3.0° for the completely empty bottle. The initial potential energy of the tennis ball at these angles is given by mgl[1 ? cos(θ)] and yields corresponding values of 13.2 mJ, 4.6 mJ, and 0.3 mJ, illustrating the drastic decrease of energy required to tip the empty bottle."

MEDFORD/SOMERVILLE, Mass. (March 2, 2020)-- Using more than 30 years of earth satellite images, scientists at Tufts University and the non-profit conservation organization Defenders of Wildlife have discovered that habitat loss for imperiled species in the U.S. over this period was more than twice as great on non-protected private lands than on federally protected lands. As wildlife face a host of survival threats ranging from habitat destruction to global climate change, the study, published today in Frontiers in Ecology and the Environment, provides evidence that federal land protection and listing under the U.S. Endangered Species Act are effective tools for stemming losses in species habitat.

Habitat loss and modification are the primary drivers of global losses in biodiversity, leading to reductions in population size and reproductive rates for many common and endangered species. Scientists have worked to identify the most effective mechanisms for preventing future habitat loss around the globe, yet most studies have had limited geographic scope or focused on only one or a limited range of species.

With a goal of understanding on a national level how land jurisdictions and conservation policies translate to habitat protections on the ground, the study authors collected large scale data on habitat extent across the U.S. for 24 vertebrate species, chosen from among those listed under the Endangered Species Act (ESA) or the International Union for Conservation of Nature's Red List. The species examined have ranges that include both federal and non-federally owned lands, covering 49% of the country from coast to coast and including all major ecosystems in the continental U.S.

Using national databases of wildlife habitat, the researchers mapped out the 24 species' ranges, and tracked habitat change in those ranges over time using the Google Earth Engine LandTrendr algorithm. The data revealed that imperiled species lost the least habitat (3.6%) on federally protected lands and lost the most habitat (8.6%) on private lands lacking any protections. State lands and lands protected by non-governmental organizations had losses of species habitat similar to one another (4.6% and 4.5%, respectively), but still greater than losses on federal land.

Since the study covered more than 30 years of data (1986 to 2018), the researchers were also able to observe other residual effects over time, such as the relative impact of protected vs. non-protected lands before and after a species is placed on the ESA or Red List. The authors found evidence that the ESA contributed to habitat protections on federal lands, with species losing less habitat after they were listed than before.

"By zooming out to the national level, the study provided us with a unique opportunity to examine whether certain regulations and jurisdictions were more effective in protecting habitats of endangered species," said Michael Evans, senior conservation data scientist at the Center for Conservation Innovation at Defenders of Wildlife and co-author of the study. "For example, we found that habitat preservation was linked more closely to federal protected land status and ESA protection, regardless of agency-specific regulations. Regulations for protection are different outside of federal lands, where reporting of environmental impacts is required, but minimization of these impacts may not be required."

The authors noted that the differences in how conservation laws and protections are applied in different contexts may not ultimately serve the ESA's intended goal of species preservation. Species not only inhabit federally managed areas, but their ranges can also extend into state and privately-owned land, and even state-owned lands were not as effective as federal lands in protecting species from habitat loss.

Even if a species' range is contained within federally protected land, that protection can be compromised. "We know from research conducted by other scientists that development surrounding protected areas can reduce the effectiveness of those protections for animals," said Adam Eichenwald, biology graduate student in the laboratory of professor Michael Reed at Tufts and first author of the study. "Not only that, but global climate change can force species to move, which we worry may eventually result in areas designed to protect species without any of their protected occupants."

"At a time when the planet faces a looming extinction crisis, we need every tool available to protect species and their habitats," said Jacob Malcom, director of the Center for Conservation Innovation at Defenders of Wildlife and a co-author on the study. "This research illustrates the critical importance of America's federal lands system for conserving wildlife habitat and the urgent need for better protections on other land ownerships. Biodiversity and the services it provides to society can be conserved through concerted effort and transformative change; protecting habitats must be an essential part of that effort."

The threat to insects and other small creatures from rainforest clearance and the consequences for the environment in tropical regions are recognised. What has not been studied so far is whether, and how, the oil palm plantations are able to sustain the populations of tiny below-ground animals that work to keep the soil healthy. In a new study led by the University of Göttingen, scientists have discovered high levels of biological activity in regions above ground level that may serve as oases for soil organisms. They identified that the suspended soil in the gaps where the frond grows out of the palm trunk may in fact provide novel microhabitats where soil creatures can thrive. The research was published in Frontiers in Ecology and the Environment.

The rapid expansion of oil palm plantations throughout Southeast Asia due to increasing global food demand has knock-on effects for the environment. Rainforests may be cleared resulting in major losses of soil structure, fertility and biodiversity. In the soil, many creatures are important for ecosystem functions: making nutrients available, forming soil structures, and providing other services such as decomposition, pollination and pest-control. To find out about the biological activity in soil in oil palm plantations, researchers from the University of Göttingen examined soil communities in six different microhabitats in a 16-year-old oil palm plantation in Sumatra, Indonesia. Scientists from the Collaborative Research Centre EFForTS (Ecological and Socioeconomic Functions of Tropical Lowland Rainforest Transformation Systems) collected 9,205 individuals of macrofauna (earthworms and large arthropods such as ants, fly larvae and millipedes), 40,229 of mesofauna (small arthropods such as springtails and mites), 2,895 nematodes, and 4,467 testate amoebae (single-celled microorganisms that have a protective shell around them).

"Since many oil palm plantations may be with us to stay, it is imperative to get a better understanding of soil biodiversity across microhabitats," explains Dr Anton Potapov from the University of Göttingen. "This will help farmers and plantation-owners to develop more sustainable methods that can preserve ecosystem functioning." One of the microhabitats the researchers studied is formed from the accumulation of dead leaves and other detritus in the gaps at the base of palm fronds. The detritus forms soil-filled crevices suspended above the ground, which make little corners and recesses for soil life. The scientists' analysis showed there were far more active soil dwellers in these suspended soils than below ground.

"It is important to realize that high activity in the suspended soil does not compensate for the degradation of soil below ground," adds Dr Valentyna Krashevska. "But now we can take advantage of this knowledge and better preserve suspended soil during plantation management, which may partly offset the damage caused by oil palm agriculture to soil-borne processes and biodiversity."

Innovative, Indigenous-led health care partnerships and cultural healing practices have shown improved health outcomes and access to care, and have become important features of the medical landscape in Canada, according to a new analysis in CMAJ (Canadian Medical Association Journal).

Indigenous-led heath care partnerships incorporate traditional Indigenous knowledge as key in their approach to treatment and healing for Indigenous patients.

The article reflects a collaboration between Elders David Courchene and Burma Bushie, community physician Dr. Sabina Ijaz, and health researchers Dr. Andrew Hatala and Ms. Lindsay Allen from the University of Manitoba's Rady Faculty of Health Sciences.

"Addressing health inequities requires a deeper understanding of the diversity within and across First Nations, Inuit and Métis communities, as well as how different models of Indigenous-led health partnerships can respond to context-specific service needs," write the authors.

Canadian physicians often lack training in how to support the holistic cultural, emotional and spiritual dimensions of Indigenous patients' illnesses and well-being. Healers, Elders and others skilled in Indigenous cultural worldviews and experiences are therefore needed in medical partnerships, decision-making and patient care.

"A largely biomedical approach to health fails to address Indigenous patients' myriad, unique needs in an integrated, holistic manner," say Elders and coauthors David Courchene, founder of the Turtle Lodge Central House of Knowledge and cofounder and member of the Elders' council, along with Elder Burma Bushie and other community leaders, of Giigewigamig Traditional Healing Centre.

Turtle Lodge and the Giigewigamig Traditional Healing Centre have pioneered Indigenous-led approaches to health care, which are described along with examples of other health service partnerships in Canada and other countries.

"If the swell of efforts of Elders, Knowledge Keepers and healers can be supported by the larger medical community, and if barriers to full health care rights for Indigenous Peoples can be lessened or removed," the authors conclude, "then systemic racism can be overpowered and health equity can be more easily approached."

A practice article provides 5 things to know on how drugs can interact with cannabinoids in CMAJ (Canadian Medical Association Journal).

1. The antifungal drug ketoconazole was shown to nearly double cannabinoid levels. Similar effects might be seen with commonly used drugs, such as macrolide antibiotics, increasing the chance of cannabinoid-related adverse effects.

2. Cannabinoids can affect levels of other drugs, increasing levels and the risk of adverse effects.

3. Smoking marijuana regularly can increase clearance of some drugs.

4. Marijuana can have additive effects with certain drugs, and may cause tachycardia (rapid heartbeat), high blood pressure and depression of the central nervous system.

5. Although more research is needed, potentially serious interactions with marijuana can occur with the blood thinner warfarin and specific drugs used for asthma and seizure control.

Patients and physicians should be aware of these potential interactions and effects.

Cases of potentially deadly brain damage as a result of stroke could be reduced after new research identified a pathway in the brain that causes swelling, and which responds to an innovative treatment.

Research led by the University of Exeter, and published in Nature Communications, has discovered how a malfunction in the way key proteins are transported within the brain after a stroke can lead to swelling, which can cause severe damage.

The international team has developed a compound which effectively treats this pathway in laboratory tests, paving the way for a new treatment. This could potentially provide an alternative, more effective way to treat brain swelling, for which currently there are limited treatment options.

The work was developed by a consortium of experts in Signalling Transduction (Dr Jinwei Zhang, University of Exeter, UK), Medicinal Chemistry (Professor Xianming Deng, Xiamen University, China), Neurosurgery and Cellular and Molecular Physiology (Dr Kristopher T. Kahle, Yale School of Medicine, USA) and Neurology (Professor Dandan Sun, Veterans Affairs Pittsburgh Healthcare System and University of Pittsburgh, USA).

Stroke is typically caused by a blood clot in the brain and can lead to death within minutes. In the UK alone, more than 100,000 strokes occur each year, averaging one every five minutes. Currently. Two thirds of stroke survivors leave hospital with a disability, according to the Stroke Association.

A stroke can damage cell volume regulation in the brain, resulting in swelling, a complication that is severe and difficult to treat, currently addressed by the highly invasive surgical procedures of removing part of the skull or inserting a shunt of cerebral spinal fluid. Shunts are particularly susceptible to malfunction and infection, and therefore often require patients to endure a number of repeat operations.

The compound, called ZT-1a, targets a pathway that controls proteins that act as transporters of ions and water in and out of cells. It works by stopping enzymes that activate proteins which bring too much water into the brain. It was tested on mice and rats which had stroke or hydrocephalus, a condition which causes fluid on the brain. These studies indicate that the compound may be able to stop brain swelling, potentially reducing cases of brain injury and death.

Dr Jinwei Zhang, Lecturer at the University of Exeter Medical School, led a team including collaborators in China and the US, that has developed the compound. He said: "Brain swelling after a stroke is a common and devastating problem for individuals and their families. Our discovery could address the urgent need for treatment that could provide an effective alternative to invasive surgery. The drug is still in the laboratory and requires further development. So far it shows promise in effectively reducing brain swelling in stroke, and other brain injuries such as drowning, choking or heart attack."

Researchers from Chalmers University of Technology, Sweden, have made a new contribution to the ongoing search into the possibility of life on Titan, Saturn's largest moon. Using quantum mechanical calculations, they have shown that azotosomes, a proposed alternative to cell membranes, could not form under the conditions there. Their research is published in the journal Science Advances.

Titan, Saturn's largest moon, has a dynamic surface, with seasonal rainfall, and lakes and seas at its polar regions, as well as a dense, nitrogen-rich atmosphere. These similarities to Earth have led many to consider the possibility of life there. The liquids on Titan are not water, however, but seas of methane and ethane, and the surface temperature is around -180C. Lipid membranes, of the type common to life on Earth, could not function under such conditions. This has led researchers looking for signs of life on Titan to contemplate alternative forms of cell membrane that could tolerate these extremes. One such alternative form, suggested by a team from Cornell University, is called an 'azotosome'.

The idea of azotosomes has gained traction in the field of astrobiology, and it has been shown computationally that such structures would survive the conditions on Titan. The azotosome was proposed to be formed from the organic compound acrylonitrile - which was later confirmed to exist on Titan.

"Titan is a fascinating place to test our understanding of the limits of prebiotic chemistry - the chemistry that precedes life. What chemical, or possibly biological, structures might form, given enough time under such different conditions? The suggestion of azotosomes was a really interesting proposal for an alternative to cell membranes as we understand them," says Martin Rahm, Assistant Professor at the Department of Chemistry and Chemical Engineering at Chalmers University of Technology.

"But our new research paper shows that, unfortunately, although the structure could indeed tolerate the extremes of Titan, it would not form in the first place," he explains.

Using advanced quantum mechanical calculations, the researchers compared the energy of the proposed azotosome membrane embedded in methane with that of the molecular crystal form of acrylonitrile - its molecular ice. They discovered that each building block added to the azotosome increased its energy significantly, making its formation progressively less likely thermodynamically. They conclude therefore that while azotosomes could survive on Titan, they would not self-assemble under such conditions. Instead, acrylonitrile would crystallise into its molecular ice.

Despite the 'negative' results of their work, Martin Rahm sees the study, which was done together with PhD student Hilda Sandström, as providing highly valuable information for ongoing research in astrobiology.

"With this work we hope to contribute to the ongoing discussion on the limits of chemistry and biology in environmental extremes. Though we have shown that acrylonitrile is not a viable building block for workable cell membranes on Titan, we now have a better understanding of the environmental limits for cell membranes. Titan is a highly interesting and unique environment with many unanswered questions and possibilities left to explore," he explains.

Their work is also an important step forward in demonstrating the potential of computational astrobiology, which offers the chance to evaluate, prior to experiments or sampling, whether or not a particular structure or process might be a biosignature, a marker for potential biology.

Interest in astrobiology on Titan is very high in the scientific community - so much so that in 2026, NASA will launch the billion-dollar Dragonfly spacecraft, which will make the 8-year journey to Titan to investigate its surface. It will spend around 3 years flying to different locations around the moon, assessing the conditions for habitability, prebiotic chemistry, and looking for signs of past and present life.

Read the article "Can polarity-inverted membranes self-assemble on Titan?" in the journal Science Advances.

The likelihood of life on Titan and other similar worlds

While stressing that life under the extreme conditions found on Titan and other such worlds is highly unlikely, the researchers do, however, consider another possibility. They hypothesise that perhaps cell membranes are not a necessity for life everywhere, as we see they are on our Earth.

One crucial function of cell membranes on Earth is to protect the contents of a cell from being diluted and destroyed in larger bodies of liquid water. However, on the surface of Titan, any hypothetical life-bearing biomolecule would exist in the solid state, due to the low temperature, and never risk such destruction by dissolution.

Because hypothetical biomolecules on Titan would be immobile, they would need to rely on the diffusion of small energetic molecules, such as hydrogen gas or acetylene, to reach them before they could grow or replicate. Such molecules would need to be transported through the surrounding atmosphere or through liquid hydrocarbons, and a membrane would, in this case, hinder the desired diffusion. A membrane would likely be a similar obstacle in the opposite direction, for the necessary removal of waste products from the biomolecule's metabolism.

"One can therefore ask what the benefit would be from having cell membranes under such different conditions?" explains Martin Rahm.