Culture

This is the main finding of new research involving more than 50,000 participants in 97 samples, published in the prestigious journal Proceedings of the National Academy of Sciences of the United States of America (PNAS).

The findings show that the more extreme choices and decisions of men can be both positive and negative.

"The question of whether men and women make systematically different choices and decisions is one on the most fundamental (and controversial) questions in psychological research," Associate Professor Stefan Volk from the University of Sydney Business School said.

"We found men were much more likely than women to be at the extreme ends of the behavioural spectrum, either acting very selfishly or very altruistically, very trusting or very distrusting, very fair or very unfair, very risky or very risk averse and were either very short-term or very long-term focused."

The findings could impact policies aimed at regulating extreme behaviours such as the recent GameStop trading frenzy after retail traders on Reddit heavily shorted the stock.

"Our research suggests policies aimed at reducing extreme behaviours should be more tailored towards men," said Dr Volk.

The researchers suggest the differences might have evolutionary roots, but there are also alternative explanations for the existence of what is often referred to as greater male variability.

"Parental investment theory explains that men, in contrast to women, invest less in parenting, are less selective in their partner choice and compete more for sexual partners," Associate Professor Volk explained.

"This evolutionary theorising suggests that men had to deviate from the average to stand out and be attractive to women to reproduce, while women were able to attract sexual partners without deviating from the average.

"Another explanation could be norms and expectations of acceptable gendered behaviour and that men's extreme behaviours are socially constructed and reinforced.

"This alternative theory suggests that the socially constructed patriarchy in many societies has managed to constrain women and the opportunity for them to display the same level of variability as men."

Associate Professor Stefan Volk, worked with an international team to examine sex differences in altruism, cooperation, trust, fairness and attitudes towards time and risk in economic decision-making. The researchers found systematic evidence for greater male variability.

He added these gender differences in variability are difficult to detect in research focused on gender differences in average behaviours. This is why they have been overlooked in most previous research, which traditionally focused on mean gender differences rather than the range of behaviours. But we need to look at differences in extreme behaviours to understand what might be driving those outliers.

The PNAS paper is the second in a series by Associate Professor Volk on greater male variability; the first was just published in the internationally leading psychological journal Psychological Science.

This earlier research involved two large-scale meta-analyses of economic decision-making studies and studies of organisational citizenship behaviour with more than 20,000 participants. While the researchers found no differences in the degree to which men and women behaved cooperatively on average, they did find strong evidence for greater male variability in cooperation.

Investigators from Trinity College Dublin, the Irish Mycobacteria Reference Laboratory, St James's Hospital, and the Department of Public Health HSE East believe tuberculosis (TB) care in Irish Prisons should be supported, considering the findings of their study which is published today (Tuesday, 1st June, 2021) in the International Journal of Tuberculosis and Lung Disease.

The study describes an investigation into a large outbreak of tuberculosis which occurred in an Irish prison in 2011. This resulted in 34 people contracting active TB from a single infectious case. The use of Whole Genome Sequencing enabled the investigators to track the course of onward transmission, and to link TB cases identified as recently as 2019 to the 2011 outbreak.

The outbreak resulted in litigation costs to the State of more than €5 million euro. The study found that in addition to the active TB cases, 50% of the prison staff tested as close contacts of cases may have developed Latent TB as a result of occupational exposure. This is an asymptomatic, non-infectious form of TB, which may progress to the active form of TB at a future date, in a small number of cases.

Professor Joe Keane, Clinical Medicine, Trinity College Dublin and St James's Hospital Dublin, and co-senior author of the study said:

"This report shows that tuberculosis is an issue in our prisons and will be followed by a 'test and educate' programme- that will mitigate the risk in congregate settings."

Professor Tom Rogers, Clinical Microbiology, Trinity, and formerly Clinical Director, Irish Mycobacteria Reference Laboratory (IMRL) based at St. James's Hospital, said:

" This report demonstrates the power of whole genome sequencing to enhance epidemiological investigations of TB outbreaks over prolonged periods of time. The IMRL has created a national database of TB genomes which will facilitate future public health investigations of TB in Ireland."

Dr Marcus Butler, vice-president, Irish Thoracic Society said:

"This study, along with recommendations from the CDC TB controllers association and a recent review of TB rates in prisons published by The Lancet Public Health, supports the need for improving early TB diagnosis and care in the Irish prison system, through a three-step approach:

1) A TB information and testing service in prisons

2) A Latent TB clinic at St James's Hospital Dublin

3) A National TB lead to oversee this as part of an integrated national TB control service

This integrated national service should comprise a national TB screening programme for high risk groups, investment in contact tracing and TB surveillance activities, and a TB education and awareness programme for healthcare professionals and the public."

Dr Mary O Meara, Specialist in Public Health Medicine , HSE East said:

"This report supports the need for augmenting the public health contact tracing response for infectious diseases such as tuberculosis."

Hydrogen peroxide (H2O2) is used to disinfect minor cuts at home and for oxidative reactions in industrial manufacturing. Now, the pandemic has further fueled demand for this chemical and its antiseptic properties. While affordable at the grocery store, H2O2 is actually difficult and expensive to manufacture at scale.

A team led by the University of Illinois Urbana-Champaign has demonstrated a more efficient and environmentally friendly method to produce H2O2, according to a recent study published in the Journal of the American Chemical Society.

"While the two ingredients--hydrogen and oxygen--are either inexpensive or freely available from the atmosphere, hydrogen peroxide is highly reactive and unstable, which makes it very hard to produce," said first author Tomas Ricciardulli, a graduate student in chemical and biomolecular engineering at UIUC.

Currently, producing H2O2 requires a complicated, multi-step process and large facilities. Moreso, this traditional method relies on an intermediate chemical (anthraquinone) that is derived from fossil fuels.

Decades ago, researchers proposed a simpler, cheaper, and 'greener' one-step alternative method where a catalyst (palladium-gold nanoparticles) drives the reaction instead. Bonus: the catalyst can be recycled to produce hydrogen peroxide over and over.

"However, hydrogen and oxygen also form water, and this proposed 'direct synthesis' method was known to synthesize 80 percent water and just 20 percent hydrogen peroxide," said lead author David Flaherty, a professor of chemical and biomolecular engineering at UIUC. "Scientists have fiercely debated the arrangement of palladium and gold atoms needed in nanoparticles to increase the selectivity for hydrogen peroxide and why this works."

A higher ratio of gold to palladium atoms in the catalyst produces more H2O2 and less water. The researchers found that a catalyst with a ratio of one palladium to 220 gold atoms generates almost 100 percent hydrogen peroxide, which is about the point of diminishing returns.

Significantly, the catalysts give stable performance over many days of use, continuously achieve these remarkable selectivities to H2O2, and do so using clean water as a solvent, which avoids the problematic and corrosive additives often used for this chemistry.

The organization of these atoms within the catalyst also counts: palladium atoms touching one another favor water formation, while palladium atoms surrounded by gold favor H2O2 formation.

What's more, they discovered the influence extends from the first ring of neighboring atoms that surround the palladium atom to the second layer of atoms, called the next nearest neighbors. More H2O2 is synthesized when both a given palladium atom's neighbors and next-nearest neighbors are all gold.

"We demonstrated how to create a very efficient and selective catalyst," said Flaherty, who is also a Dow Chemical Company Faculty Scholar. "While promising, there are still hurdles to overcome to adopt this method commercially."

The Flaherty research group is pursuing the development of nanoparticle catalysts with new compositions and reactors to enable hybrid chemical-electrochemical methods for this reaction. "Our ultimate goal is to develop feasible technology for distributed production of H2O2 which would open doors for many sustainable alternatives to traditional chemical processes."

The researchers also expect that their activities will reveal other key scientific concepts to electrify chemical manufacturing along the way.

Physicists at the University of Bath in the UK, in collaboration with researchers from the USA, have uncovered a new mechanism for enabling magnetism and superconductivity to co-exist in the same material. Until now, scientists could only guess how this unusual coexistence might be possible. The discovery could lead to applications in green energy technologies and in the development of superconducting devices, such as next-generation computer hardware.

As a rule, superconductivity (the ability of a material to pass an electrical current with perfect efficiency) and magnetism (seen at work in fridge magnets) make poor bedfellows because the alignment of the tiny electronic magnetic particles in ferromagnets generally leads to the destruction of the electron pairs responsible for superconductivity. Despite this, the Bath researchers have found that the iron-based superconductor RbEuFe4As4, which is superconducting below -236°C, exhibits both superconductivity and magnetism below -258°C.

Physics postgraduate research student David Collomb, who led the research, explained: "There's a state in some materials where, if you get them really cold - significantly colder than the Antarctic - they become superconducting. But for this superconductivity to be taken to next-level applications, the material needs to show co-existence with magnetic properties. This would allow us to develop devices operating on a magnetic principle, such as magnetic memory and computation using magnetic materials, to also enjoy the benefits of superconductivity.

"The problem is that superconductivity is usually lost when magnetism is turned on. For many decades, scientists have tried to explore a host of materials that have both properties in a single material, and material scientists have recently had some success fabricating a handful of such materials. However, so long as we don't understand why the coexistence is possible, the hunt for these materials can't be done with as fine a comb.

"This new research gives us a material that has a wide temperature range where these phenomena co-exist, and this will allow us to study the interaction between magnetism and superconductivity more closely and in great detail. Hopefully, this will result in us being able to identify the mechanism through which this co-existence can occur."

In a study published in Physical Review Letters, the team investigated the unusual behaviour of RbEuFe4As4 by creating magnetic field maps of a superconducting material as the temperature was dropped. To their surprise, they found the vortices (the points in the superconducting material where the magnetic field penetrates) showed a pronounced broadening near the temperature of -258°C, indicating a strong suppression of superconductivity as the magnetism turned on.

These observations agree with a theoretical model recently proposed by Dr Alexei Koshelev at Argonne National Laboratory in the USA. This theory describes the suppression of superconductivity by magnetic fluctuations due to the Europium (Eu) atoms in the crystals. Here, the magnetic direction of each Eu atom begins to fluctuate and align with the others, as the material drops below a certain temperature. This causes the material to become magnetic. The Bath researchers conclude that while superconductivity is considerably weakened by the magnetic effect, it is not fully destroyed.

"This suggests that in our material, the magnetism and superconductivity are held apart from each other in their own sub-lattices, which only minimally interact," said Mr Collomb.

"This work significantly advances our understanding of these rare coexisting phenomena and could lead to possible applications in the superconducting devices of the future. It will spawn a deeper hunt into materials that display both superconductivity and magnetism. We hope it will also encourage researchers in more applied fields to take some of these materials and make the next-generation computing devices out of them.

"Hopefully, the scientific community will gradually enter an era where we move from blue-sky research to making devices from these materials. In a decade or so, we could be seeing prototype devices using this technology that do a real job."

The American collaborators for this project were the Argonne National Laboratory, Hofstra University and Northwestern University.

In the deep waters that underlie the productive zones of the ocean, there is a constant rain of organic material called 'marine snow'. Marine snow does not only look like real snow but also behaves similarly: Large flakes are rare and fall quickly while highly abundant smaller flakes take their time. Scientists from Bremen and Kiel have now discovered that precisely those features explain why small particles play an important role for the nutrient balance of the oceans. These findings have now been published in Nature Communications and will aid in the further development of biogeochemical models that include the marine nitrogen cycle.

A team of scientists from the Max Planck Institute for Marine Microbiology, the Max Planck Institute for Meteorology and the GEOMAR - Helmholtz Centre for Ocean Research Kiel have been studying biogeochemical processes in the oxygen minimum zone of the eastern South Pacific off Peru, one of the largest low oxygen regions of the world ocean. The researchers focused on so-called marine snow particles of different sizes, which are composed of algal debris and other organic material, aiming to understand how these particles affect the nitrogen cycle in the oxygen minimum zone. Thereby, they solved a long-standing puzzle: How do the nutrients that are concentrated inside the particles reach anammox bacteria that live freely suspended in the water column.

Too much of a good thing can be bad

Oxygen minimum zones are regions of the ocean where little or no oxygen is dissolved in the water. As most animals need oxygen to breathe, they cannot survive in these water bodies. Not surprisingly, oxygen minimum zones are also referred to as marine dead zones. Oxygen minimum zones are a natural phenomenon, but have been found to be expanding in many regions of the ocean as a result of human activity. Global warming contributes to decreasing oxygen concentrations, as warm water stores less oxygen. Warmer surface water also mix less with the deep, cool water below, thus leading to stagnation and reduced ventilation.

Changes to the nitrogen cycle also have deleterious effects on ocean oxygen concentrations. Nitrogen is a vital nutrient that animals and plants need in order to grow. Normally rare in the ocean, nitrogen compounds that can be processed have become increasingly available in many coastal regions. Humans use large amounts of fertilizers with nitrogen compounds such as ammonium and nitrate for agriculture and these nutrients find their way into the ocean via rivers and the atmosphere in ever increasing amounts. This has severe consequences. The additional nutrients enhance phytoplankton growth. When the planktonic organisms die, they are decomposed by bacteria. During this process the bacteria consume oxygen, driving a decline in oxygen concentrations. Once oxygen is fully consumed, anaerobic microbial processes take over, during which microbes essentially "breathe" nitrogen compounds in place of oxygen, and as a result convert nitrate, nitrite and ammonium back to nitrogen gas and release it to the atmosphere.

Which factors drive the loss of nitrogen?

Combined, the anaerobic microbial respiration processes of anammox and denitrification in oxygen minimum zones lead to the loss of up to 40 percent of the oceans nitrogen. However the regulation of microbial nitrogen-loss processes in oxygen minimum zones is still poorly understood. This study is focused on the anammox process, i.e. anaerobic ammonium oxidation with nitrite. In their project, the researchers followed up on the observation that the anammox process is particularly high when organic material in the form of marine snow particles is especially abundant. Their hypothesis was that the organic material, which contains a large amount of fixed nitrogen, serves as a source of ammonium for the anammox reaction. Strangely enough, anammox bacteria do not seem to live on the marine snow itself, but in the water column. So how do these bacteria find their nutrients?

To unravel this puzzle, the scientists used underwater cameras to measure particle abundances over depth profiles at different stations in the oxygen minimum zone off Peru. "We observed that the anammox process occurs mainly in places where the smaller particles are abundant," says Clarissa Karthäuser, shared first author of the paper with Soeren Ahmerkamp. "This indicates that the smaller particles are more important for the anammox process than the larger ones - whereby small means that they are about the size of the width of a human hair and thus barely visible".

These small particles are very abundant in the water column and sink slowly, thus they stay in the oxygen minimum zone longer. Also, the organic material is packed more densely in smaller particles and as a result the small flakes transport a similar amount of material per particle as the larger clumps, which means that overall they transport significantly more nitrogen. "We estimated that the ammonium concentration around the particles is significantly increased," says Soeren Ahmerkamp. "This indicates two things: First, that the higher number and longer residence times of the smaller particles in the water column increase the likelihood that bacteria will encounter a small particle by chance. Secondly, the high ammonium concentrations in the boundary layer of the particle can then provide nourishment to the bacteria."

Important results for earth system models

The new findings are crucial for the improvement of Earth system models. "With this study, we have resolved an important aspect of the anammox process and thus made an important contribution to a better understanding of the nutrient balance in the oceans," says Marcel Kuypers, head of the Department of Biogeochemistry of the Max Planck Institute for Marine Microbiology in Bremen. "With this improved process understanding, we provide the link between particle-associated processes and N-cycling in oxygen minimum zones which can be adapted in biogeochemical Earth system models to better assess the effects of anthropogenic deoxygenation on the nitrogen cycle."

Philadelphia, June 1, 2021--Researchers at Children's Hospital of Philadelphia (CHOP) have developed a proof-of-concept treatment for blood disorders like sickle cell disease and beta-thalassemia that could raise hemoglobin levels by activating production of both fetal and adult hemoglobin. Using a viral vector engineered to reactivate fetal hemoglobin production, suppress mutant hemoglobin, and supply functional adult hemoglobin, the researchers developed an approach that could produce more hemoglobin through a single vector. The results were published in Haematologica.

"Until now, researchers have been exploring one of two approaches to treating blood disorders like sickle cell disease or beta-thalassemia: adding a functional copy of the adult hemoglobin gene, or increasing production of fetal hemoglobin," said senior author Stefano Rivella, PhD, Kwame Ohene-Frempong Chair on Sickle Cell Anemia and Professor of Pediatrics at CHOP. "In this study, we have done both simultaneously, which provides an opportunity to produce more hemoglobin per vector in these patients."

Sickle cell disease and beta-thalassemia are genetic blood disorders caused by errors in the genes for hemoglobin, a protein that is found in red blood cells and carries oxygen from the lungs to tissues throughout the body. In utero, the gamma-globin gene produces fetal hemoglobin, but after birth, this gene is switched off and the beta-globin gene is turned on, producing adult hemoglobin. Patients with sickle cell disease and beta-thalassemia have mutations in the beta-globin gene, which leads to mutant hemoglobin production and, as a consequence, serious health complications, ranging from delayed growth and jaundice to pain crises, pulmonary hypertension, and stroke.

Current research has focused on treating these blood disorders by either increasing fetal hemoglobin, which is not mutated in these conditions, or adding back a functional copy of adult hemoglobin via gene therapy, using an engineered vehicle known as a viral vector to supply new genetic material. However, there are limitations to both of these approaches, and neither has been established as a fully curative approach.

In order to increase hemoglobin levels in one therapy, the researchers - led by co-first authors Danuta Jarocha, PhD and Silvia Lourenco, PhD - combined the two tactics into a single gene therapy vector. To do so, they focused on a transcription factor called BCL11A, which effectively operates the switch that turns off the production of fetal hemoglobin and turns on the production of adult hemoglobin. The researchers hypothesized that if they could use an engineered vector to repress BCL11A, which would keep fetal hemoglobin production turned on and turn off the production of mutant adult hemoglobin, while also adding back a functional copy of the beta-globin gene, they could induce greater hemoglobin production.

Working in cell lines of patients with sickle cell disease and beta-thalassemia, the researchers tested their vector - which included a gene coding for adult hemoglobin and a microRNA sequence that would target BCL11A - and found that the vector was able to elevate fetal and adult hemoglobin simultaneously in vitro. Although BCL11A was not completely knocked down, the suppression was sufficient to reduce production of the mutant adult hemoglobin. By elevating both fetal and functional adult hemoglobin, the vector was able to induce more functional hemoglobin production than that of a vector expressing beta-globin alone.

"Future studies will evaluate this approach using an even stronger vector that we developed in our lab and published on recently," Rivella said. "Combining these two technologies, we hope to make an even more powerful vector that can provide curative levels of hemoglobin to these patients."

This research was supported by the CuRED Frontier Program at CHOP, which is dedicated to finding new and improved curative therapies for blood disorders like sickle cell disease and beta-thalassemia.

Getting enough sleep can be a real challenge for shift workers affecting their overall health. But what role does being an early bird or night owl play in getting good rest? Researchers from McGill University find a link between chronotype and amount of sleep shift workers can get with their irregular schedules.

"Some people seem to be hardwired to sleep early, while others tend to sleep late. This preference, called chronotype, is modulated by our circadian system - each person's unique internal timekeeper," says lead author Diane B. Boivin, a Professor in the Department of Psychiatry at McGill University.

Their study published in Sleep is the first to examine the relationship between chronotype and sleep behaviour in shift workers during morning, evening, and night shifts. To investigate this relationship, the researchers tracked 74 police officers as they worked their usual shifts. For close to a month, the officers wore a watch-like device, allowing researchers to measure their sleep.

Not all shifts created equal

"Our results suggest that the effect of chronotype on sleep duration and napping behavior depends on the shift type. On average early risers sleep 1.1 hours longer on morning shifts, while night owls sleep two hours longer on evening shifts," says co-author Laura Kervezee, a former Postdoctoral Fellow at The Douglas Research Centre affiliated with McGill University.

The power of naps

While shift workers take naps to reduce the effect of their irregular schedules on their sleep, the researchers found this behaviour was more prominent during night shifts in early risers. Generally, early risers slept less after night shifts compared to night owls - but they also took more naps prior to their night shifts, so their total daily sleep was similar.

The findings could help design strategies to improve sleep in workers with atypical schedules, the researchers say. Such strategies could include work schedules that consider chronobiological principles.

"People involved in shift work experience an increased risk of sleep disturbances and fragmented sleep periods. Since sleep is essential for optimal performance, health, and well-being, it's important to develop strategies to get better rest," says Boivin, who is also the Director of the Centre for Study and Treatment of Circadian Rhythms at The Douglas Research Centre.

As next steps, the researchers hope to study the impact of chronotype and shift work on other health outcomes.

Algorism plays a significant role in predicting future states of a system. Particularly, non-Markov chain algorithm has been widely applied in epidemic spreading processes, social and man-made memory networks, the environment-related quantum entangled states, and artificial algorisms such as face pose tracking. Traditionally, a large number of memories and computing cells are integrated to achieve these goals by software algorisms, showing high complexity. In the paper published in Science Bulletin, a group led by Bilu Liu and Hui-Ming Cheng from Tsinghua-Berkeley Shenzhen Institute (TBSI) of Tsinghua University has realized a non-Markov chain algorithm in a single resistive random access memory (RRAM) based on 2D mineral material for the first time and revealed the related mechanism.

The researchers found that 2D mica is an excellent ionic conductor, the internal potassium ions (K+) in which controllably migrates under the stimulation of a cyclic electric field to induce resistance switching (RS) phenomena. It is interesting that the related RRAM device exhibits both single-window and bipolar RS behaviors, which is modulated by the strength of the electric field. The migration of the intrinsic K+ contributes to the high on/off ratio of 103, long retention time of more than 108 s, high stability and reliability of the 2D mica-based RAAM, superior to the ones relied on the conduction of external ions.

Accordingly, the authors have successfully achieved the non-Markov chain algorithm in a 2D mica-based RRAM with three states (Figure 1). Different polarities of the input voltages were applied to stimulate the device and produce certain passing paths. By this way, the output signal of the device is not only related to the current input voltage but also the previous state, and a multi-path non-Markov chain is realized. This research reveals the controllable ion transport in 2D layer mineral materials and provides a guideline to design and engineer the related functional devices for realization of algorithms in future.

Siberian jays are group living birds within the corvid family that employ a wide repertoire of calls to warn each other of predators. Sporadically, however, birds use one of these calls to trick their neighbouring conspecifics and gain access to their food. Researchers from the universities of Konstanz (Germany), Wageningen (Netherlands), and Zurich (Switzerland) have now examined how Siberian jays avoid being deceived by their neighbours. The study, published in the journal Science Advances, shows that these birds have great trust in the warning calls from members of their own group, but mainly ignore such calls from conspecifics of neighbouring territories. Thus, the birds use social information to differentiate between trustworthy and presumably false warning calls. Similar mechanisms could have played a role in the formation of human language diversity and especially in the formation of dialects.

Deception and lies

Deception and lies are surprising aspects of human communication and the use of language in which false information is intentionally communicated to others, allowing an individual to gain an advantage over the recipient of such false information. However, language is actually highly pro-social and cooperative and is mainly used to share reliable information. Thus, language can only function properly and be maintained if deception is kept to a minimum or other mechanisms are in place to recognize and avoid deception.

People do judge the reliability of communication partners based on personal experience. "If someone repeatedly lies to you, you will most likely stop trusting this person very quickly," says Dr Michael Griesser, a biologist at the University of Konstanz. Griesser authored the study together with Dr Filipe Cunha, whose doctoral thesis he supervised. But do we observe deception in animals as well, and, if so, which mechanisms do animals use to avoid being deceived?

Warning calls of the Siberian jay

Indeed, a number of species are able to deceive their conspecifics, including some species of primates and birds like the Siberian jay (Perisoreus infaustus). Siberian jays live in territorial groups and have an elaborate communication system: A wide range of calls allow them to warn each other of the presence of different predators as well as the behaviour of their fiercest enemy, the hawk.

Occasionally, however, neighbours intruding into a group's territory use the same calls that would otherwise indicate the presence of a perched hawk for a different purpose. Their aim is to deceive the members of the group about the presence of the predator, thus scaring them away to get access to their food. "It is a commonly observed phenomenon in the animal kingdom that warning calls are used to deceive others. Clearly, the recipients of the false information potentially pay a high price if they ignore the warning," says Cunha.

Only trust those you know?

To find out how Siberian jays identify and respond to this type of deception, the researchers examined a population of wild Siberian jays in northern Sweden. They attracted experienced individuals to a feeding site and recorded video footage of what happened. As soon as such an experienced individual visited the feeder, a loudspeaker played recordings of Siberian jays' warning calls designating a perched hawk. These calls were recordings from former members of the visitor's own group, birds from neighbouring territories, or birds that the visitor had never encountered before. Using the video recordings, the researchers measured how long it took the visitor to leave and return to the feeder.

These "playback experiments" demonstrated that experienced Siberian jays responded quicker and took longer to return to the feeder when hearing warning calls of a former member of their own group than when exposed to warning calls of neighbouring groups or previously unknown individuals. "Siberian jays thus have a simple rule to avoid being tricked: They only trust the warning calls from members of their own group, meaning cooperation partners. Familiarity alone is not enough, otherwise the birds would also have trusted the calls of their neighbours," Griesser explains.

Deception as a possible factor in language and dialect formation

Michael Griesser draws a comparison to humans and their languages and dialects. Just like Siberian jays, humans preferentially trust others who belong to the same group as themselves and therefore more likely are cooperation partners. "It could thus very well be the case that vulnerability to deception has been a driver of the rapid diversification of human languages and facilitating the formation of dialects as they allow the identification of local cooperation partners," Griesser considers.

A college education is estimated to add $1 million to a person's lifetime earning potential, but for some students the path to earning one is riddled with obstacles. That journey is even more difficult for students who have been in the foster care system or experienced homelessness, according to a new study from the University of Georgia.

But the more college administrators and faculty know about these students' problems, the more they can do to ease the burden.

Getting into universities in the first place can frequently be a challenge for students who've had unstable home lives, said David Meyers, co-author of the study.

"Research tells us that every time a student moves from one foster care placement to another, they lose six months of educational progress," said Meyers, a public service associate in the J.W. Fanning Institute for Leadership Development. "That's a pretty serious setback. It's a challenge for them to participate in after-school activities or athletics. Their college resume is not going to be as strong as those students who don't face those same challenges."

It's a similar struggle for students who've experienced homelessness. For those who beat the odds, getting into college is just the start of a whole new set of hurdles. The added stressors of having to figure out how to pay for courses, books and housing once they get there--something many of their classmates don't have to think about--take a tremendous toll.

"Having to act like an adult when you're still a kid presents huge challenges for students trying to get into college," said Kim Skobba, co-author of the paper and an associate professor in the College of Family and Consumer Sciences. "But then when you get to college, you're still on your own."

Entirely on their own

The study, published in the Journal of Adolescent Research, focuses on the experiences of 27 college students, all attending four-year institutions, who had been in foster care, experienced homelessness or both. The researchers conducted a series of three in-depth interviews with each participant over the course of one academic year, and several clear themes emerged.

These students all had to "get by" largely on their own. They often were without parental guidance or support during high school, and in college they were entirely on their own. Many took jobs, sometimes going to school full time while also working full or nearly full-time hours.

One student described having six classes while also working 40 hours a week, saying, "I kept breaking down. ... I was staying up to about 2 or 4 in the morning doing homework and waking up at 7." (This type of experience was more common among students who had been homeless than those who were in foster care at the time of their high school graduation.)

One of the biggest expenses for all the students in the study was paying for and maintaining stable housing. Eleven of them experienced at least one period of homelessness since beginning college, living in their cars or couch surfing.

Another constant issue was finding money for books and food. Even with scholarship support, many of the students would ask professors whether the book was essential for success in their course and if so would borrow a friend's book or even one of the professor's copies, if possible.

Perhaps not surprisingly, these stressors made it difficult for students to focus on their academics.

"It takes a mental and emotional toll on these students," Meyers said. "We think about it in financial terms, but it really, I think, also shows up in sort of this constant emotional challenge. Being thoughtful, being vigilant, never really having the luxury of being able to set it aside."

Finding solutions

Institutions like UGA are taking steps to address this issue, with programs that provide emotional support while connecting students to resources they might otherwise not know exist.

Embark@UGA, for example, is the campus-based component of Embark Georgia, an effort led by Meyers and Lori Tiller, a colleague at the Fanning Institute. The program is a statewide network that connects the University System of Georgia and Technical College System of Georgia to the Division of Family and Children Services, the Georgia Department of Education, and numerous nonprofit and community organizations seeking to increase college access and retention for students who have experienced foster care or homelessness.

Through Embark, each USG university and technical college campus and every high school in Georgia has a point of contact to help identify and provide resources to homeless and former foster students who need help.

Additionally, scholarships like Let All the Big Dawgs Eat, which provides a food stipend for students, have also helped narrow the gap. UGA also has made a point to start using free online textbooks in many courses.

But not all schools have the same resources.

"Expanding programs at the federal level that would serve students who've been in foster care or homeless would really help close that gap," Skobba said. "We also don't want them taking out huge loans because that's not a good financial situation long term. And some kind of financial aid grant program serving this group would make a huge difference."

Another big help? Understanding and awareness from professors that not all students are able to spend hundreds of dollars on textbooks or don't have a personal laptop to use for class assignments.

"I think I was already a pretty flexible understanding professor, but just realizing that if you're working 40 hours because that's what it takes to stay in school, some things are going to drop from time to time," Skobba said. "Having a little bit of breathing room in your syllabus and assignments is probably beneficial to all students, but it's going to be especially helpful for this group of students."

GAINESVILLE, Fla. --- Scientists have long known that frogs are oddballs when it comes to teeth. Some have tiny teeth on their upper jaws and the roof of their mouths while others sport fanglike structures. Some species are completely toothless. And only one frog, out of the more-than 7,000 species, has true teeth on both upper and lower jaws.

Now, the first comprehensive study of tooth evolution in frogs is bringing the group's dental history into focus. Florida Museum of Natural History researchers analyzed CT scans of nearly every living amphibian genus to reveal that frogs have lost teeth over 20 times during their evolution, more than any other vertebrate group. Some frog species may have even re-evolved teeth after losing them millions of years before.

Researchers also found a correlation between the absence of teeth in frogs and a specialized diet on small insects, such as ants and termites. Their analysis of frogs' amphibian relatives, the salamanders and obscure wormlike animals known as caecilians, showed these groups retained teeth on both upper and lower jaws throughout their evolutionary history.

"Through this study, we have really been able to show that tooth loss in vertebrates is largely a story about frogs, with over 20 independent losses," said lead study author Daniel Paluh, a Ph.D. candidate in the University of Florida's department of biology. "Only eight other groups of living vertebrates, including seahorses, turtles, birds and a few mammals, have also evolved toothlessness."

Teeth first evolved more than 400 million years ago, quickly conferring a competitive advantage to animals that had them and leading to the diversification of sharks, bony fish and ultimately the vertebrates that first roamed onto land.

Throughout their long history, teeth have been an important component of vertebrate evolution, yet some groups have done equally well without them. Birds lost their teeth around 100 million years ago with the advent of the beak, and both the largest known vertebrate, the blue whale, and the smallest, a frog from New Guinea, are entirely toothless.

Few researchers have focused on studying frog teeth, however, for the simple reason that they're incredibly small.

"If you open a frog's mouth, chances are you will not see teeth even if they have them, because they're usually less than a millimeter long," or smaller than the tip of a pencil, Paluh said.

That hasn't stopped some people from trying. In his study of the relationships between frog species, the famous 19th-century paleontologist Edward Cope lumped all toothless frogs into the same group, which he called Bufoniformia.

Researchers using modern genetic techniques have since shown that species in Bufoniformia aren't actually closely related, suggesting that the loss of teeth occurred more than once in frog evolution. But there the story stalled.

In the past, accurately determining which frogs had teeth would have required laborious work that irrevocably damaged or destroyed portions of preserved specimens. Frogs are also a highly diverse group, making a comprehensive assessment of their teeth a difficult task.

But Paluh and his colleagues had one major advantage: The Florida Museum leads a massive multi-institutional effort to CT scan 20,000 vertebrate specimens, giving researchers the ability to study animals in ways not previously possible.

The project, called oVert, allows anyone with an Internet connection to access 3D models derived from the scans, which depict distinct features of an organism, including bones, vasculature, internal organs, muscle tissue - and teeth. For Paluh, it meant he could virtually peer into the gape of a frog.

Working remotely during COVID-19 lockdowns, Paluh and fellow members of the museum's Blackburn Lab used oVert scans to carry out the study. To get the clearest picture of changes in teeth over time, the researchers included representatives of all amphibian groups. They analyzed patterns of tooth loss through time using a previously published map of evolutionary relationships between amphibians based on genetic data.

The study provides a powerful example of the research that can be accomplished with open-access data, said David Blackburn, Florida Museum curator of herpetology, Paluh's adviser and senior author of the study.

"We effectively crowdsourced the data collection across our lab, including people that were not in the U.S. at that time," Blackburn said.

Their results showed that far from losing teeth once during their evolution, as suggested by the now-debunked idea of the Bufoniformia, frogs have undergone "rampant tooth loss," Paluh said, with toothlessness popping up in groups as distantly related as toads and poison dart frogs.

The team also noted a tight correlation between the presence or absence of teeth in frogs and their eating habits. While dietary information is scant for many species of frogs, the researchers uncovered a connection between a diet of tiny insects and a lack of teeth.

"Having those teeth on the jaw to capture and hold on to prey becomes less important because they're eating really small invertebrates that they can just bring into their mouth with their highly modified tongue," said Paluh. "That seems to relax the selective pressures that are maintaining teeth."

Some species of poison dart frogs, for example, have evolved to feed mostly on ants and mites that produce toxic compounds, using their sticky, projectile tongues to scoop up their prey and swallow it whole. The frogs are able to store the toxins from their food source and repurpose them for their own use, secreting the compounds through their skin to ward off predators. And the turtle frog, a toothless burrowing species in Australia, tunnels through the maze of underground passages inside termite nests, hunting the insects that constructed them.

Teeth seem to be superfluous for mammals that feed on ants and termites as well. Pangolins and anteaters, which have highly specialized tongues for probing ant and termite nests, are both toothless.

Many questions remain about frogs' tooth biology, including how the genes that regulate their tooth production turn on and off. It's also unclear whether the serrated toothlike structures in frogs that regained these features are actually real teeth, Paluh said. To determine that, scientists will need to take a more in-depth look at these structures, looking for the presence of enamel and other key defining features.

Innovative techniques, such as those used in the oVert project, are beginning to underscore knowledge gaps and limitations like these, but they also open up the field to new discoveries, Blackburn said.

"We now have lots of new questions in my lab inspired by the surprising things turning up from 3D imaging from the oVert project, and those will lead us both back into museum collections and to the field to see what these animals are doing in the wild."

DANVILLE, Pa. - Among people who have strokes and COVID-19, there is a higher incidence of severe stroke as well as stroke in younger people, according to new data from a multinational study group on COVID-19 and stroke, led by a team of Geisinger researchers.

The COVID-19 Stroke Study Group's latest report, published in the journal Stroke, focused on a group of 432 patients from 17 countries diagnosed with COVID-19 and stroke. Among this group, the study found a significantly higher incidence of large vessel occlusion (LVO) -- strokes caused by a blockage in one of the brain's major arteries that are typically associated with more severe symptoms. Nearly 45% of strokes in the study group were LVOs; in the general population, 24 to 38% of ischemic strokes are LVOs.

The study group also had a high percentage of young patients who had strokes: more than a third were younger than 55, and nearly half were younger than 65. Pre-pandemic general population data showed 13% of strokes occurred in people under 55, and 21% in people younger than 65.

The data showed that that less-severe strokes, mostly in critically ill patients or overwhelmed health centers, were underdiagnosed. This finding is significant, the research team said, as minor or less-severe stroke may be an important risk factor for a more severe stroke in the future.

"Our observation of a higher median stroke severity in countries with lower healthcare spending may reflect a lower capacity for the diagnosis of mild stroke in patients during the pandemic, but this may also indicate that patients with mild stroke symptoms refused to present to the hospitals," said Ramin Zand, M.D., a vascular neurologist and clinician-scientist at Geisinger and leader of the study group.

Throughout the pandemic, people with COVID-19 have reported symptoms involving the nervous system, ranging from a loss of smell or taste to more severe and life-threatening conditions such as altered mental state, meningitis and stroke. A group of Geisinger scientists and a team of experts from around the world formed the COVID-19 Stroke Study Group shortly after the pandemic began to study the correlation between COVID-19 infection and stroke risk.

Results from the first phase of the study, which included data on 26,175 patients, indicated an overall stroke risk of 0.5% to 1.2% among hospitalized patients with COVID-19 infection. The finding demonstrated that, even though there were increasing reports of patients with COVID-19 experiencing stroke, the overall risk is low.

"Our initial data showed that the overall incidence of stroke was low among patients with COVID-19, and while that hasn't changed, this new data shows that there are certain groups of patients -- for example, younger patients -- who are more affected," said Vida Abedi, Ph.D., a scientist in the department of molecular and functional genomics at Geisinger. "We hope these findings highlight new research directions to better identify patients at risk and help improve the quality of care."

Mass of human chromosomes measured for the first time

The mass of human chromosomes, which contain the instructions for life in nearly every cell of our bodies, has been measured with X-rays for the first time in a new study led by UCL researchers.

For the study, published in Chromosome Research, researchers used a powerful X-ray beam at the UK's national synchrotron facility, Diamond Light Source, to determine the number of electrons in a spread of 46 chromosomes which they used to calculate mass.

They found that the chromosomes were about 20 times heavier than the DNA they contained - a much larger mass than previously expected, suggesting there might be missing components yet to be discovered.

As well as DNA, chromosomes consist of proteins that serve a variety of functions, from reading the DNA to regulating processes of cell division to tightly packaging two-metre strands of DNA into our cells.

Senior author Professor Ian Robinson (London Centre for Nanotechnology at UCL) said: "Chromosomes have been investigated by scientists for 130 years but there are still parts of these complex structures that are poorly understood.

"The mass of DNA we know from the Human Genome Project, but this is the first time we have been able to precisely measure the masses of chromosomes that include this DNA.

"Our measurement suggests the 46 chromosomes in each of our cells weigh 242 picograms (trillionths of a gram). This is heavier than we would expect, and, if replicated, points to unexplained excess mass in chromosomes."

In the study, researchers used a method called X-ray ptychography, which involves stitching together the diffraction patterns that occur as the X-ray beam passes through the chromosomes, to create a highly sensitive 3D reconstruction. The fine resolution was possible as the beam deployed at Diamond Light Source was billions of times brighter than the Sun (ie, there was a very large number of photons passing through at a given time).

The chromosomes were imaged in metaphase, just before they were about to divide into two daughter cells. This is when packaging proteins wind up the DNA into very compact, precise structures.

Archana Bhartiya, a PhD student at the London Centre for Nanotechnology at UCL and lead author of the paper, said: "A better understanding of chromosomes may have important implications for human health.

"A vast amount of study of chromosomes is undertaken in medical labs to diagnose cancer from patient samples. Any improvements in our abilities to image chromosomes would therefore be highly valuable."

Each human cell, at metaphase, normally contains 23 pairs of chromosomes, or 46 in total. Within these are four copies of 3.5 billion base pairs of DNA.

Scientists have revealed a potential mechanism for how traumatic brain injury leads to neurodegenerative diseases, according to a study in fruit flies, and rat and human brain tissue, published today in eLife.

The results could aid the development of treatments that halt the progression of cell damage after brain injury, which can otherwise lead to neurological diseases such as amyotrophic lateral sclerosis (ALS), and Alzheimer's and Parkinson's disease.

Repeated head trauma is linked to a progressive neurodegenerative syndrome called chronic traumatic encephalopathy (CTE). Postmortem tissues from patients with CTE show dysfunctional levels of a molecule called TDP-43, which is also found in ALS, Alzheimer's disease and frontotemporal dementia.

"Although TDP-43 is a known indicator of neurodegeneration, it was not clear how repeated trauma promotes the build-up of TDP-43 in the brain," explains first author Eric Anderson, Postdoctoral Research Associate at the Department of Pediatrics at the University of Pittsburgh, Pennsylvania, US. "We have shown that repetitive brain trauma in fruit flies leads to a build-up of TDP-43. In this study we measured the changes of proteins in the fruit fly brain post injury to identify the molecular pathways that cause this."

From an analysis of 2,000 proteins, the team identified 361 that significantly changed in response to injury. These included components of the nuclear pore complex (NPC) involved in nucleocytoplasmic transport - the shuttling of important cargoes between the cell nucleus and the rest of the cell.

They found that a family of molecules that make up the NPC called nucleoporins (Nups) were increased in both larval and adult flies after injury. When they looked at the distribution pattern of Nups around the edge of the nucleus in fruit fly nerve cord cells, they found it was altered after brain trauma: there were gaps in the nuclear membrane and clumps of Nups. They also found changes in a key enzyme involved in transporting molecules in and out of the nucleus in injured brains. As a result, the transport of fluorescently labelled cargo in and out of the nucleus was impaired.

Having established that brain injury impairs the transport machinery between the nucleus and the rest of the cell, the team looked at whether the build-up of Nups leads to the aggregation of TDP-43 seen in neurodegenerative diseases. They created fruit flies that produce excess Nup protein and then stained the brain cells for the fruit fly version of TDP-43, called Tbph. They found a significant increase in the number of Tbph deposits in brains that had too much Nup compared with normal brains. Moreover, these high levels of Nups were also toxic to the flies, causing decreased motor function and reducing the distance they could climb in a certain timeframe. When the level of Nups was reduced in cells after injury, this improved the flies' climbing ability and lifespan, highlighting an avenue to explore for new treatments.

Finally, the team looked at whether the increased build-up of a Nup molecule (Nup62) was also seen in human brain tissue after injury. They examined postmortem brain tissue from patients with mild and severe CTE matched to healthy tissue from people of the same age. All mild and severe patients were involved in sports, while healthier cases were not. They found that Nup62 was present in large amounts in the wrong place in patients with mild and severe disease, but not in the healthy group, and the degree of Nup62 aggregation increased with the severity of disease. They also saw similar changes in the distribution of Nup62 in a rat model of traumatic brain injury.

"Our study reveals that traumatic brain injury can disrupt nuclear transport machinery of the cells, which plays an essential role in normal cell functions such as communication," concludes senior author Udai Pandey, associate professor of pediatrics, human genetics and neurology at the University of Pittsburgh School of Medicine. "This suggests that the accumulation of neurodegenerative hallmark proteins caused by injury begins with these nuclear transport defects, and that targeting these defects could be a strategy for preventing trauma-induced neurological disorders."

A new study led by Kent Business School, University of Kent, finds that whilst the mumpreneur identity may enable women to participate in the business world and be recognised as 'proper' entrepreneurs, this success is dependent on alignment with the conventional masculine norms of entrepreneurship.

These conventional masculine behaviours include working long hours and an ongoing dedicated commitment to the success of a business.

Published in the International Small Business Journal and based on an interview study of women business owners, the study highlights the interviewees' belief that entrepreneurship and motherhood are compatible but challenges the claim in existing research that mumpreneurship represents a new feminised identity and a different way of doing business.

The study conceptualises the mumpreneur as the hybrid combination of masculine and feminine behaviours, examining the tensions that emerge in simultaneously running a business and a family, and considering if these are managed through the curtailment of entrepreneurial activity.

The study found that for those women who see themselves as entrepreneurial mums, entrepreneurial curtailment is not an option and conventional masculine behaviours are valued higher than the feminine in the context of successful business development.

The consequences of this hybrid behaviour are significant:

To be identified as a 'normal' entrepreneur, feminine behaviours are accepted alongside masculine commitment to business, so long as they are not disruptive of the latter.

Mumpreneurs must balance both behaviours yet avoid engaging in excessive feminine conduct that may restrict business development or devalue their entrepreneurial activities.

Mumpreneurs perceived as 'too feminine' in their business activities are marginalised as unengaged in 'proper' entrepreneurship, creating a hierarchy of business identities.

Patricia Lewis, Professor of Management at the University of Kent and Principal Investigator said: 'The mumpreneur identity has undoubtedly had a positive impact on the way women's entrepreneurship is viewed. Nevertheless, our study demonstrates that it has not disrupted the dominant discourses of masculine entrepreneurship or gendered power relations in the field. Women are still in a position of being committed to both sides of the balance between business and motherhood but are devalued as entrepreneurs when devoting time to their children rather than business.'