Culture

(Jerusalem, July 10, 2020) -- When wild Egyptian fruit bats set out at night to forage in Israel's Hula Valley, they do so using advanced spatial memory and a flexible cognitive mapping of the fruit trees and other goals scattered in their foraging area. They seldom search randomly and their foraging patterns cannot be explained by simpler navigation mechanisms, a research team headed by Hebrew University of Jerusalem's Professor Ran Nathan has found.

The groundbreaking study, co-authored with Tel Aviv University Prof. Sivan Toledo, Hebrew U doctoral candidate David Shohami and other members of Nathan's group, is featured as the cover story for the current issue of Science magazine. It details the bats' cognitive map - the animals' mental representation of their own position relative to the surrounding environment - that helps them to move efficiently from any location to any of the many goals within their foraging area, even if the goal is out of their sight or smell range.

The existence of a cognitive map allows the bats to remember and return to favorable fruit trees, roosting caves and other goals. They use mapping and memory skills, rather than relying on path "directions" following numerous landmarks, specific cues originating from these goals, or simply finding these targets by chance.

To track the animals, the researchers had to overcome the limitations of GPS and other available wildlife tracking technologies. Although scientists have achieved key insights into animals' navigational capabilities from experiments on rats and other laboratory animals, limited battery size and the need to remotely retrieve data from GPS trackers prevented researchers from collecting large sets of data on wild animals in their natural habitats.

Alternative tracking methods such as radio telemetry have been used to track small wild animals, but they do not provide sufficiently detailed, long-term information on the movements, leaving researchers at an impasse.

"Up to now the technologies we had could not be used to track small wild animals in their natural habitats with enough detail required to test the existence of a cognitive map," says Prof. Nathan.

To solve the dilemma, Nathan teamed up with Toledo to develop an advanced "reverse-GPS" tracking system they called ATLAS. After a few years of development and refinement, Shohami used the system to collect a large dataset of 172 foraging Egyptian fruit bats comprising more than 18 million localizations collected over 3449 bat-nights across 4 years.

ATLAS movement data provided the means for detailed track analysis combined with translocation experiments and mapping of all fruit trees in the study area, spanning 88,200 hectares. The system provided researchers with detailed, accurate information from many individuals for relatively long periods at relatively low cost, showing that wild bats seldom search for food randomly, but instead repeatedly forage in goal-directed, long, and straight flights that include frequent shortcuts.

The team also ruled out alternative, non-map-based strategies by analyzing simulated tracks, time-lag embedding, and other analyses of the trajectory data.

The results present the most comprehensive evidence for a cognitive map from any wild animal studied since scientists first hypothesized the existence of a human-style cognitive map in 1948, says Nathan. Furthermore, the study marks a landmark for movement ecology, the academic discipline that Nathan pioneered in 2008 to study life on the move.

"Movement ecology has benefited from advances in tracking technology, but new ideas and novel insights have lagged behind. ATLAS has given us the keys to unlock previously unanswerable questions and will continue to shed light on a range of enigmatic natural phenomena," he says.

Solar-driven reduction of CO2 into energy-rich fuels, such as CO, HCOOH, and CH3OH, has been conceived as a highly promising approach to solve energy crisis and environmental pollution. Throughout the molecular photocatalytic systems, numerous catalysts, such as complexes of Re, Ru, Fe, Co and Ni, have been developed with detail study of their catalytic mechanism. In light of their relative mature study, more and more attention has begun to shift to accelerate electron transfer between catalyst and antenna molecules to promote CO2 reduction. At present, the research in this field focuses on the formation of composite systems between photosensitizers and catalysts through chemical bonds, hydrogen bonds, etc. This system shortens the distance between photosensitizers and catalysts, thus improving the electron transport capability between them. However, these studies still have many disadvantages, such as lack of flexibility and great influence from external factors. Accordingly, it's highly necessary yet remains great challenging to develop alternative strategy for dramatically boosting photocatalytic CO2 reduction.

At present, improving photosensitization ability of PSs for enhancing photocatalytic performance for CO2 reduction is still in its infancy. In this field, the frequently used PSs are confined to prototypical MLCT (metal-to-ligand charge transfer) complexes, such as Ru(bpy)32+ and Ru(phen)32+ (Phen = 1,10-phenanthroline), where their excited state lifetime was usually less than 1 μs (τ= 600 ns for Ru(bpy)32+ and 360 ns for Ru(phen)32+ in CH3CN). It will be a promising way to boost CO2 reduction via adjusting excited state population and lifetime of these PSs to improve their sensitizing ability.

In the present work, researchers put forward a new strategy to greatly boost photocatalytic CO2 reduction by improving photosensitization ability of PSs. A family of Ru(II)-based PSs Ru-2, Ru-3, and Ru-4 were prepared by selective addition of pyrene / pyrenyl ethynylene to 3- and 5-positions of Phen in Ru(Phen)32+ (Ru-1) (Fig. 1). As the triplet state energy level gradually decreased from Ru-1 with 3MLCT state to Ru-4 with 3IL state, the triplet lifetimes of these complexes were gradually prolonged and their excited state oxidation potentials became less negative, providing a platform to compare the effect of PSs with different sensitizing ability on photocatalytic CO2 reduction.

The photocatalytic process was dominated by oxidation mechanism for Ru-1 - Ru-4-containing system (Fig. 2). From the view of kinetics, long-lived triplet state of PSs greatly contributed to intermolecular electron transfer / energy transfer. Thus stern-volmer quenching constants of PSs by C-1 were in the order of 4.4 × 103 M-1 for Ru-4 > 3.2 × 103 M-1 for Ru-3 > 9.6 × 102 M-1 for Ru-2 > 3.8 × 102 M-1 for Ru-1, which was proportional to their excited state lifetimes (Fig. 2D). From the thermodynamics viewpoint, excited state oxidation potentials of PSs determine the driven force of electron transfer from excited PSs to C-1. As shown in Fig. 2F, the absolute value of excited state oxidation potential was in the order of Ru-4

This work provides a new insight for dramatically boosting photocatalytic CO2 reduction via improving photosensitization.

E-cigarettes are highly addictive nicotine products with unclear health impacts, particularly on young people. Instagram is a visual social media platform which is wildly popular, particularly with young people. Researchers interested in public health at Aalto university in Finland studied how vaping is represented on the platform. By using artificial intelligence, they were able to analyse hundreds of thousands of posts from a 6-month period last year, and found that a large portion of posts are promoting controversial flavoured e-liquids to young audiences.

The research worked by downloading every image on Instagram that had a caption including "#vaping" on the network for June to November 2019. 'We knew this would be predominantly promotional material,' said Dr Aqdas Malik from the department of computer science who studies public health and the internet, 'but we were interested in what types of images these would be, and who was posting them.' In the end, they generated a database of over half a million pictures, which they then sorted using a neural network, which grouped the images into categories of pictures with similar features.

What the neural network showed was that 40% of the images - the largest proportion out of the 6 categories - were of vaping e-liquids. These were predominantly posted by Instagram profiles listed as business accounts. The prominence of posts about e-liquids is interesting from a public health perspective because, although many e-cigarette brands market themselves as "smoking cessation" devices, it has been shown by other studies that flavoured liquids are strongly linked to adolescent users taking up vaping in the first place. The USA banned the sale of flavoured liquids at the beginning of this year specifically to help tackle the huge growth of teenage vaping, and other countries are looking to do the same.

'While print and broadcast media has clear rules and regulations about what can and cannot be advertised, and what constitutes advertising, we don't see this on social media,' said Dr Malik. 'I think we need stricter laws and rules on how we allow these products to be seen on these networks. Any 12-year-old with a phone can get an account and bypass the age-rules for seeing what's posted here, and the potential health implications are significant.' 60% of all the posts using the #vaping hashtag were from business accounts. Over 70% of Instagram users are under 35, and over 35% of its users are under 24 years old. 'It's a huge grey area in terms of advertising regulations, especially regarding promotion towards younger audiences' Dr Malik said.

Researchers at the Francis Crick Institute have characterised the structure of the SARS-CoV-2 spike protein as well as its most similar relative in a bat coronavirus. The structures provide clues about how the spike evolved and could help inform vaccine design.

A characterising feature of SARS-CoV-2, the virus that causes COVID-19, is the protein spikes which cover the surface, which the virus uses to bind with and enter human cells.

Analysing the structure of these spikes could provide clues about the virus' evolution. It is not yet known how SARS-CoV-2 evolved to infect humans and whether this happened directly from coronaviruses in bats or via an intermediary species.

In their study, published in Nature Structural & Molecular Biology, the researchers characterised the spike protein in high resolution using a technique called cryo-electron microscopy, which allowed them to achieve a greater level of detail than previously reported structures. They then compared this structure to the spike protein of a bat coronavirus, RaTG13, which has the most similar spike to that of SARS-CoV-2.

While the spikes as a whole were over 97% similar, the researchers found a number of significant differences at the location where SARS-CoV-2 binds with a receptor on human cells, called ACE2, and at the surfaces that keep the subunits of the spike together.

These differences mean the spike of SARS-CoV-2 is more stable and is able to bind around 1,000 times more tightly to a human cell than this bat virus.

Based on their findings, the researchers suggest it is unlikely that a bat virus similar to RaTG13 could infect human cells. This supports the theory that SARS-CoV-2 is the result of different coronaviruses coming together and evolving over time, potentially also through several host species.

Antoni Wrobel, co-lead author and postdoctoral training fellow in the Structural Biology of Disease Processes Laboratory at the Crick, says: "The spike is the entry key that allows SARS-CoV-2 into human cells. Changes in the virus' genome, which affect the spike's structure, therefore have potential to make the virus either more or less able to enter the host's cell."

"At some point in the evolution of this virus, it seems to have picked up changes, like the differences we found, which made it able to infect humans."

Donald Benton, co-lead author and postdoctoral training fellow in the Structural Biology of Disease Processes Laboratory at the Crick, says: "The exact process of how SARS-CoV-2 evolved remains unclear and is something many researchers are trying to piece together. Our work provides a piece of this puzzle, as it suggests that the virus did not come straight from the bat coronaviruses currently known."

Steve Gamblin, group leader of the Structural Biology of Disease Processes Laboratory at the Crick says: "The world was caught off guard by SARS-CoV-2. Examining the structure of this virus, and its likely precursor, helps us understand where it came from, and how it interacts with human cells."

The Crick researchers will continue to study the structure of the virus, with a view to finding further clues as to its evolutionary path.

The spike protein structures are open-access, so other researchers can use these in their work and to aid with drug discovery and vaccine design.

A new study from McGill University shows that increases in the concentrations of blood sodium can have an influence on the biological clock of mice, opening new research avenues for potentially treating the negative effects associated with long distance travel or shift work.

The findings, published in Nature by former McGill PhD student Claire Gizowski and Charles Bourque, a professor in McGill's Department of Neurology-Neurosurgery, are the first to show that injecting mice with a salt solution leads to the activation of neurons associated with the brain's master circadian clock - the suprachiasmatic nucleus (SCN).

Our biological clock - or circadian rhythm - adapts our body's cells and organs to changing requirements at different times of day. Prolonged disruption of these rhythms because of jetlag or shift work can lead to adverse health effects.

Though it is well established that light is the primary factor regulating our body's biological clock, it was unknown if or how physiological factors could regulate the SCN.

"Our study is the first to show that the SCN is listening to physiological signals and that such signals can in fact regulate clock time," says Bourque.

Gizowski and Bourque were able to show that salt-sensitive neurons found in a specific region of the brain - the organum vasculosum of the lamina terminalis - are capable of activating the brain's master circadian clock at a time of day when it is normally silent.

"This suggests that there could be ways by which we could speed up the clock, which could be useful to adapt more quickly to the time change associated with long distance travel, or when our work schedule is shifted by several hours," explains Gizowski.

The researchers now hope to establish if natural increases in blood sodium levels - through eating - have the same effect and whether or not these also occur in humans.

"One concern is that although ingestion of small amounts of salt is pleasant and not dangerous, it can be toxic when consumed in large amounts," Bourque adds. "Much more work is needed to examine if this finding is applicable to humans in a safe and practical way."

Researchers at the University of Westminster and City University of London analysing the music record choices of guests on BBC Radio 4's Desert Island Discs programme has found that the music we listen to between the age of 10 and 30 define us for the rest of our lives.

Music from this time which the researchers call 'self-defining period' connects an individual to the people, places, and times that are significant to their identity. The study reveals that people imagining themselves in isolation not only prefer music reminding them of a time when they were aged between 10 and 30, but also they are most likely to choose music that reminds them of an important person playing to the sense that someone is with them, or an important turning point in their life as a powerful way to strengthen their sense of self.

In Britain's longest running radio programme guests are invited to imagine they are being cast away to a desert island and are asked to choose eight records to take with them. The researchers analysed the responses of 80 Desert Island Discs guests to reveal how people choose music that is important to them and whether they are more likely to select music from a particular time in their life if they can choose anything they like.

Half of all musical choices were seen to be important between the ages of 10 and 30, a period that has been commonly known as the 'reminiscence bump'. However, this new study reveals that it is more helpful to think of this period as a 'self-defining period' because it is characterised by enduring memories that support our sense of who we are. They suggest that listening to music is typically a key feature of this age and that music is also intrinsically linked to the developing self.

The power of music in identity formation is well-demonstrated through the reasons why people select certain records on Desert Island Discs. The most frequent reason for choosing a song (17%) was that it reminded the guest of their relationship with a specific person, such as a parent, partner or a friend, followed by a memory of a period of time (16.2%) such as reminding someone of their childhood or "remembering playing this at home over and over again". The third most popular explanation for choosing a record was the song's connection to specific memories relating to the formation of identity through life-changing moments (12.9%). Such reason was given by Bruce Springsteen, who said that the Beatles song "I want to hold your hand" had inspired him to pick up the guitar and start a band.

Professor Catherine Loveday, Neuropsychologist at the University of Westminster and Lead Researcher, said: "Guests frequently chose songs because they were related to important memories that occurred during teenage years. This extends previous findings by showing that music from this time has particular meaning, primarily because it relates to memories from this very important developmental period of our life. Unlike previous studies, this study shows that this occurs even in a completely naturalistic setting, where people are not constrained by experimental settings and have a completely free rein on their musical choices.

"Because the premise of the programme is that people imagine themselves in isolation, this research has relevance to anyone who becomes isolated, including during lockdown measures in the current coronavirus pandemic, or who becomes displaced from their everyday environment, such as residents in care homes, refugees or hospital patients."

Working with an international team, the researchers are now working on a new study that invites people to create and share their own Deserts Island Disc experience. The survey will provide important new insights into the benefits of music and reminiscence and can be accessed from http://instrumentaljourneys.com/diy-desert-island-discs

A survey conducted in the U.K. suggests that social and physical distancing measures put in place during the Covid-19 pandemic significantly impacted people's perception of how quickly time passed compared to their pre-lockdown perceptions. Ruth S. Ogden of Liverpool John Moores University, U.K., presented these findings in the open-access journal PLOS ONE on July 6, 2020.

Previous research suggests that one's perception of how quickly time passes can vary according to one's emotions, the number of daily tasks one must perform, and other factors. However, most of that research has been limited to normal day-to-day life. Social and physical distancing measures put in place during the Covid-19 pandemic provide a unique opportunity to examine how significant changes to life's daily routine impact time perception.

Ogden prepared an online questionnaire asking participants to rate on a sliding scale how quickly they felt time was passing compared to normal, both over the course of a single day and over a full week. The questionnaire also evaluated people's emotional state, task load, and satisfaction with levels of social interaction. The final analysis included 604 participants in the U.K. who answered the questionnaire between April 7 and April 30, 2020.

Ogden found that more than 80 percent of participants experienced changes to how quickly they perceived time passing during lockdown compared to pre-lockdown. Those who were older or less satisfied with their current levels of social interaction were more likely to experience slower passage of time over the course of a day or week. Slower passage of time over the course of a day was also associated with higher stress and a lower task load.

These findings suggest that significant changes to life's daily routine distort perception of time. Future research could look deeper into the effects of specific factors, such as whether social satisfaction influences perception of time during normal daily life, or if its significance in this study is due to the unique social impacts of the Covid-19 lockdown.

Author Ruth Ogden notes: "80% of people experienced distortion to the passage of time during the lockdown. Lockdown passing more slowly than normal was associated with older age and reduced satisfaction with social interactions."

In a recent study of genes involved in brain functioning, their previously unknown features have been uncovered by bioinformaticians from the Moscow Institute of Physics and Technology and the Institute of Mathematical Problems of Biology, RAS. The findings are reported in PLOS One.

DNA is the molecule that stores information about the structure and functioning of living organisms. This "book of life" is a carefully arranged nucleotide-by-nucleotide record on every protein and RNA synthesized in a cell. Each DNA fragment corresponding to a particular protein is called a gene, and the pattern for translating a DNA sequence into the amino acid sequence of the associated protein is known as the genetic code.

Back in the 1960s, biologists discovered the basic properties of the genetic code, including its so-called triplet nature: Each amino acid is encoded by a codon -- a sequence of three nucleotides. For example, the sequence adenine-thymine-guanine encodes the amino acid called methionine, which usually begins the proteins of all living beings at the stage of synthesis.

Since the genetic code was discovered, scientists have learned a lot about gene structure. For example, they found that a kind of fragmentation was characteristic for the genes of eukaryotes -- organisms whose cells have a nucleus. Namely, genes contain noncoding regions referred to as introns. They are removed from the sequence in a process called splicing. The remaining regions that actually encode parts of the protein are termed exons.

Researchers have proposed a number of hypotheses as to how long ago and in what way introns originated, and what their functions are. For one thing, introns enable alternative splicing. This refers to the selective joining of certain exons but not others. The consequence is that more than one protein sequence can be produced based on the template of a single gene. As a result, the number of distinct proteins in cells is far greater than the number of genes.

Another intron-enabled process important for gene evolution is exon shuffling. This involves a kind of atypical recombination, where a foreign exon can become incorporated into a gene where it does not belong, giving rise to a new gene.

The currently available full-genome sequences of many organisms have made it possible to study the evolution of introns in detail. They are now known to vary in length from several dozen pairs to 10,000 times as many. Introns are also distinguished by phase, depending on where they occur relative to a codon. Phase 0 introns are found in between codons, whereas phases 1 and 2 occur immediately after the first or second nucleotide in the codon, respectively.

Now a team of bioinformaticians from MIPT and IMPB RAS has examined the relation between intron phase and length in humans and mice.

"No one had thought of investigating a potential link between intron length and phase before us. Common sense says there shouldn't be any connection at all, similarly to how a person's height has nothing to do with their eye color," commented Eugene Baulin, a researcher at the Applied Mathematics Lab at IMPB RAS, and the Algorithms and Programming Technologies Department at MIPT.

To their surprise, the study's authors identified a group of genes containing an unusually large number of phase 1 introns that were over 50,000 nucleotide pairs long. Moreover, these turned out to be genes involved in nerve impulse transmission in the brain.

A detailed analysis of numerous scientific publications enabled the team to put the fragments of knowledge together and arrive at a unified understanding. It turned out that in most cases, the phase 1 introns in the group of genes in question resulted from the presence of a particular amino acid sequence at the beginning of the protein. This so-called signal peptide serves to direct the protein to where it should perform its function. In the case of nerve cell receptors, that means to the plasma membrane.

As for the introns being fairly long, this also indirectly has to do with the signal peptide. In such proteins, the signal peptide is always located at the beginning of the molecule, and the DNA region encoding it is found at the start of the gene. And it is precisely there, at the beginning of a gene, that long introns tend to occur, because they contain regulatory DNA sequences important for the protein's synthesis.

The study reveals a clear and complete picture of how exon shuffling works and what role long phase 1 introns play in it. "That mechanism speeds up the evolution of intercellular and membrane proteins in animals, particularly the younger ones [evolutionary speaking], and these are the proteins that enable nerve impulse transmission in brain cells," Baulin added.

People who seek novel and powerful sensations and are more prone to taking risks -- and who perceive bitter tastes more intensely -- are more likely to prefer bitter, pale-ale-style beers and drink them more often, according to Penn State sensory researchers, who conducted a study that involved blind taste tests and personality assessments.

The results of the study, which involved more than 100 beer consumers, were unexpected, explained researcher John Hayes, associate professor of food science, because previous research typically indicates that greater perceived bitterness leads to decreased intake of bitter foods and drinks.

"Traditionally, most researchers find that people who experience bitterness more intensely avoid bitter food or drink -- so with heightened bitterness, they like it less, and therefore consume it less," he said. "But here, we find that people who seek higher sensations and are more risk-taking, they like bitter beer such as India pale ales, if they also have greater bitter taste perception."

The connection between food liking and personality has been seen before, noted Hayes, director of Penn State's Sensory Evaluation Center. In a study spearheaded by one of his former doctoral students, his research group in the College of Agricultural Sciences found robust links between the liking of spicy foods and the high-sensation-seeking, risk-taking personality traits. Studies done in Mexico and Italy also have revealed similar findings.

These results highlight the importance of considering personality traits such as sensation seeking when considering the relationship between bitterness perception and the liking and intake of bitter food and beverage products, said lead researcher Molly Higgins, who will receive her doctoral degree in food science this August.

"Our data contradict the classic view that bitterness is merely an aversive sensation that limits intake. We found that increased bitterness perception does not always lead to decreased liking and intake -- rather, it's a positive attribute in some products for some consumers."

In Higgins' study, 109 beer consumers rated liking and intensity of two pale ales and a lager, and the intensity of two bitter solutions -- quinine, the compound that makes tonic water bitter, and hops extract Tetralone -- under blind laboratory conditions. Participants also completed intake and personality questionnaires. A liking ratio for each beer was calculated from each participant's liking for that specific beer and their total liking for all beers.

Participants, about half men and half women, most in their 30s, were classified as weekly, monthly or yearly pale-ale consumers using intake data. Using intensity ratings, personality measures and other parameters, the researchers developed models to predict liking ratios and beer-intake frequency.

A lager beer and two pale-ale-style beers were chosen as the test stimuli. The specific beer samples were selected by research staff following benchtop tasting of various commercial pale-ale-style beers sold in Pennsylvania. To represent the range of bitterness in commercial pale ales, researchers selected one pale ale that was strongly bitter and one that was moderately bitter.

To represent a lager-style beer with low bitterness, research staff selected Budweiser. The pale-ale-style beers used in the study were Founder's All-Day IPA Session Ale as the moderately bitter ale, and Troeg's Perpetual IPA Imperial Pale Ale, as the strongly bitter ale.

A significant interaction between sensation seeking and quinine bitterness was found for the liking ratio of the imperial pale ale, Higgins pointed out. But the relationship was not straightforward.

"The interaction revealed liking of the pale ale increased with sensation seeking but only if quinine bitterness was also high," she said. "Intake models showed increased odds of frequent pale-ale intake with greater quinine bitterness and lower liking for lager beer. These data suggest liking and intake of pale ales is positively related to sensation seeking and bitter taste perception."

The findings, recently published in Food Quality and Preference, suggest that further research on the relationship between personality traits and the liking and intake of bitter foods and beverages may lead to new strategies to promote consumption of healthy bitter foods, Higgins contended.

"Avoidance of bitter foods can impact health negatively, because bitter foods such as cruciferous vegetables, green tea and grapefruit contain healthy compounds like flavonols, which are reported to have antioxidant and anticarcinogenic properties," she said.

Alyssa Bakke, staff sensory scientist in food science, also was involved in the research.

Summary: Current research indicates that unhealthy lifestyle choices, including smoking and lack of exercise, along with emotional stressors like social isolation and interpersonal conflicts are important risk factors for developing upper respiratory infections. It is possible these same factors also increase the risk of contracting COVID-19.

Unhealthy lifestyle choices, like smoking and avoiding exercise, are known risk factors for certain cancers and cardiovascular disease. A growing body of research reveals that these risk factors and a lack of supportive social connections can also increase the risk of developing respiratory infections, like the common cold and influenza.

A new article published in the journal Perspectives on Psychological Science explores how lifestyle, social, and psychological factors also may increase the risk of contracting COVID-19.

"We know little about why some of the people exposed to the coronavirus that causes COVID-19 are more likely to develop the disease than others," said Sheldon Cohen, a professor of psychology at Carnegie Mellon University and one of the authors on the paper. "Our research on psychological factors that predict susceptibility to other respiratory viruses may provide clues to help identify factors that matter for COVID-19."

Through a series of studies spanning more than 30 years, Cohen and his team examined how lifestyle, social, and psychological factors affect whether or not healthy adults exposed to respiratory viruses become ill. This work focused on eight viral strains that cause the common cold and two that cause influenza.

"In our work, we intentionally exposed people to cold and influenza viruses and studied whether psychological and social factors predict how effective the immune system is in suppressing infection, or preventing or mitigating the severity of illness," said Cohen. "We found a strong correlation between social and psychological stressors and increased susceptibility."

Intriguingly, the researchers also found that social integration and social support offer a protective shield against respiratory infection and illness.

Until now, the only tactics to slow the spread of coronavirus have been behavioral changes that reduce the probability of being exposed to the virus, such as stay-at-home measures and social-distancing requirements. These same behaviors, however, are often associated with interpersonal stressors, like loneliness, loss of employment, and familial conflict. According to the researchers, these stressors may be powerful predictors of how a person will respond if exposed to coronavirus because of the stressors' direct physiological effects on immunity and their psychological factors, which are thought to have their influence through the mind-body connection.

Cohen's work demonstrates that psychological and social stressors are associated with an overproduction of proinflammatory chemicals known as cytokines in response to cold and influenza viruses. In turn, this excess of inflammation was associated with an increased risk of becoming ill.

Similarly, research on COVID-19 has shown that producing an excess of proinflammatory cytokines is associated with more severe COVID-19 infections, suggesting that a stress-triggered excessive cytokine response might also contribute to excessive inflammation and symptoms in COVID-19 patients.

Cohen and his colleagues acknowledge that, as of now, there are no firmly established links between behavioral and psychological factors and the risk for disease and death in persons exposed to the corona virus that causes COVID-19. However, their prior body of research may be relevant to the current pandemic because, they note, the most potent predictors of disease, interpersonal and economic stressors, are the types of stressors that are commonly experienced among those who are isolated or in quarantine.

"If you have a diverse social network (social integration), you tend to take better care of yourself (no smoking, moderate drinking, more sleep and exercise)," said Cohen. "Also if people perceive that those in their social network will help them during a period of stress or adversity (social support) then it attenuates the effect of the stressor and is less impactful on their health."

Some mandarin fish species (Sinipercidae) are pure fish-eaters, which feed exclusively on living juvenile fish - also of their own species. A research team led by the Chinese Huazhong Agricultural University (HZAU) and the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB) has described the genome of four mandarin fish species and thus also identified genes for cannibalistic eating behaviour. Knowledge of the connections between the genome and feeding behaviour is of interest for sustainable aquaculture.

Most fish larvae feed on easily digestible, small zooplankton. Not so some species of mandarin fish. These are pure "fish-eaters" already after hatching and feed on young fish of other fish species and on conspecifics. This cannibalism leads to a high mortality rate of juvenile fish and to economic losses in aquaculture.

32 genes make the difference to cannibals

The researchers compared the genome sequences of different species of mandarin fish and were thus able to trace the evolution of 20,000 genes over a period of 65 million years. They were able to link many genes with species-specific characteristics. "For 32 of these evolving genes, we were able to experimentally demonstrate different gene expression in mandarin fish species that are common to other food and in pure fish-eating species," explains Ling Li, one of the first authors of the study and guest scientist from HZAU at the IGB.

Rapid evolutionary adaptation in predatory behaviour

Mandarin fish are aggressive predators. During the complex genome analysis, the researchers identified so-called candidate genes that are associated with particularly high aggression and affect behaviour. "Our genome analyses show the evolutionary development of mandarin fish. They have adapted rapidly to changing environmental conditions, especially with regard to their feeding behaviour. Today, some mandarin fish species are more aggressive predators than others due to their genetic predisposition," says Prof. Xu-Fang Liang from HZAU.

"Research on the relationship between the genetic code and feeding behaviour is an important basis for the sustainable aquaculture of these fish. In future, fish farmers will be able to use marker based selection to choose fish for breeding where the genome indicates less predatory behavior - and thus reduce losses," summarises Dr. Heiner Kuhl, leading bioinformatician of the project from the IGB.

High-throughput genome research at IGB

The reference genome for Siniperca chuatsi is one of the highest quality fish genomes to date. It was analysed using third-generation sequencing techniques and has very high sequence continuity and almost complete reconstruction of the 24 chromosomes. The high-quality reference genome enabled the cost-efficient sequencing of three other species from the Sinipercidae family by means of comparative genomics. This approach to create genome sequences for entire taxonomic families of organisms could serve as a blueprint for large-scale genomic projects.

The IVY Research Network has completed initial studies evaluating the epidemiology of COVID-19 in health care workers and patients.

Among 249 front-line health care workers who cared for COVID-19 patients during the first month of the pandemic in Tennessee, 8% tested positive for COVID-19 antibodies by serology testing, suggesting they had contracted COVID-19 in the first several weeks of taking care of COVID-19 patients. Among these health care workers with positive serology results, 42% reported no symptoms of a respiratory illness in the prior two months. This suggests that front-line health care workers are at high risk for COVID-19 and that many health care workers with the virus may not have typical symptoms of a respiratory infection. These results were published in the journal Clinical Infectious Diseases on July 6.

"Our results suggest that screening health care workers for COVID-19 even when they don't have any symptoms could be important to prevent the spread of the virus within hospitals," said Wesley Self, MD, associate professor of Emergency Medicine at Vanderbilt University Medical Center and lead investigator for the IVY Network.

Investigator Bo Stubblefield, MD, instructor of Emergency Medicine, added, "We are continuing to study COVID-19 in front-line health care workers across the country to better understand what may be done to decrease their risk of infection, such as using specific types of personal protective equipment."

In a separate study, the IVY investigators studied 350 patients across 11 medical centers in the U.S. who tested positive for COVID-19; 54% of these patients reported no close contact with another person known to have COVID-19 in the two weeks before getting sick.

"With over half of COVID-19 patients not identifying a clear source of their infection, this study reinforces the need for practical measures to reduce the spread of the virus, such as social distancing and the use of face coverings when out in public," Self said.

Additionally, 40% of COVID-19 patients in the study remained symptomatic two weeks after a positive COVID-19 test, showing that patients with COVID-19 tend to remain ill longer than with other respiratory infections, such as influenza. The results were published by the journal Morbidity and Mortality Weekly Report on June 30.

The IVY Network is a collaborative research group of multiple medical centers in the U.S led by Vanderbilt University Medical Center. It is funded by Centers of Disease Control and Prevention (CDC) to conduct research on severe respiratory infections, including COVID-19 and influenza.

URBANA, Ill. - Genetically speaking, the loaf of bread you stress-baked during the COVID-19 shutdown is more complex than you think. Wheat's 16 billion genes, organized in not one but three semi-independent genomes, can overlap or substitute for one another, making things extremely tricky for geneticists trying to enhance desirable traits in the world's most widely grown crop.

One of those traits is herbicide tolerance. Many cereal crops, including wheat, have a natural ability to detoxify certain herbicides applied to weeds in their midst. Under optimal conditions, weeds die, but the crops stand tall. If scientists can identify the genes involved, they could potentially amplify expression of those genes to make the detoxification process more effective under a range of environmental conditions.

In a new University of Illinois study published in Scientific Reports, scientists take advantage of wheat's flexible genetic makeup to identify chromosomal regions that help detoxify synthetic auxin herbicides.

"In the 1950s, scientists came up with a process called 'alien substitution' where you can replace chromosomes from one of the three wheat genomes with chromosomes from a wheat relative, such as Aegilops searsii. The chromosomes are similar enough that the plant can still grow and still looks pretty much like wheat," explains Dean Riechers, professor in the Department of Crop Sciences at Illinois and co-author on the study. "The benefit is that the relative might not have the same traits as wheat, so the alien substitution line will help pinpoint where genes of interest are located."

The method is now so commonplace in wheat research that scientists can simply obtain seeds for wheat plants with Aegilops searsii chromosomes, denoted as the S genome, subbing in for each of the seven wheat chromosomes across all three of its genomes (A, B, and D). These are known as alien substitution lines, and Riechers and doctoral student Olivia Obenland used them to determine that synthetic auxin tolerance in wheat likely resides somewhere on chromosome 5A.

"Although the method is common for finding genes for pathogen resistance and other useful genes in wheat, ours is the only research group to have used this method to search for herbicide tolerance," Riechers says. "We've basically shortened the list from 21 chromosomes down to one, so now we know where to focus our future gene discovery efforts."

Obenland grew all 21 alien substitution lines in the greenhouse, along with wheat cultivar 'Chinese Spring' and Aegilops searsii, and sprayed them all with high rates of the synthetic auxin herbicide halauxifen-methyl. She then compared the biomass of the treated plants to untreated controls.

The researchers expected and observed minimal injury in 'Chinese Spring,' thanks to its ability to naturally detoxify the chemical. But Aegilops searsii turned out to be highly sensitive to halauxifen-methyl, as were wheat plants with alien substitutions at chromosome 5A.

"By subbing 5A with the 5S chromosome of the alien species, we took away wheat's natural halauxifen-methyl tolerance and made it sensitive," Obenland says.

Plants with the substitution at chromosome 5B also showed some sensitivity, but only when the herbicide was applied at the highest rate. Although this means 5B likely possesses genes involved in synthetic auxin detoxification as well, the results so far point to 5A as the key player. Interestingly, chromosome 5D in wheat's third (D) genome doesn't seem to play a major role, according to the research.

The next step is to scour chromosome 5A for specific genes that could be involved in herbicide tolerance. Obenland and Riechers are already working on it, and although they've identified some interesting genes related to those they've found in resistant waterhemp, they're not ready to release those results without further molecular tests.

"Ultimately, we hope to broaden and deepen our understanding of wheat's natural tolerance to halauxifen-methyl, as well as other synthetic auxin herbicides, and this is a great first step. And it is very satisfying to apply existing genetic tools to address a new scientific problem," Riechers says.

DOE and USDA researchers use new global models to study how environmental controllers affect soil organic carbon, changes in which can alter atmospheric carbon concentrations and affect climate. Predictions could benefit industry mitigation plans.

Nature provides a myriad of ways to keep check on its health. One of the more successful indicators is the status of its soil organic carbon, or the concentration of carbon in the organic fraction of soil that consists of decaying vegetation or animal products. A small change in carbon levels can dramatically alter atmospheric carbon concentrations and affect climate.

“Soil organic carbon is important to study because it is the soil property that provides numerous ecosystem services to humanity, such as deactivating pollutants, conserving biodiversity, conserving and purifying water, increasing soil fertility, and mitigating climate change impacts,” said Umakant Mishra, a geospatial scientist at the U.S. Department of Energy’s (DOE) Argonne National Laboratory.

“We believe that the scaling functions we developed in this research … can improve the spatial representation of soil organic carbon in land surface within Earth system models.” — Umakant Mishra, Argonne geospatial scientist

A collaboration between the U.S. Department of Agriculture and several DOE National Labs, including Argonne, set out to predict and model the effect of environmental controllers, or soil-forming factors — climate, organisms, topography, parent material and time — on soil organic carbon at different spatial scales across the continental United States.

The results of the soil organic carbon study are intended to reduce uncertainty in predicting global carbon climate feedbacks and associated climate changes. They also could provide more certainty as to how future climate extremes may impact the activities of numerous industries, from agriculture and crop insurance industries to natural resource conservation industries.

Researchers, for the first time, were able to generate scaling algorithms to account for such a large geographic region by using a large set of recently available field observations, a large number of environmental factors and a machine learning algorithm — an artificial intelligence method that learns from specific data to progressively improve predictions of new, similar data.

In this case, scale refers to the area across which soil organic carbon properties are assumed to be similar, and scaling takes information collected from one spatial scale and applies it to another. With the region broken down into a pattern of grid cells, the spatial scale used in this research ranged from a finer resolution of 100 m to a more course 50 km between grid centers.

“The soil organic carbon content differs in different sampling locations, that’s why we need to sample at representative locations if we intend to capture the spatial heterogeneity of soil properties in the study area,” Mishra said.

The scaling algorithms that he and his collaborators created as part of the research are important to Earth system models, like the DOE’s Energy Exascale Earth System Model, in addition to predicting changes in climate more accurately.

Scaling, Mishra noted, is an issue which has traditionally been ignored in biogeochemical/natural sciences, where it was believed that properties or processes associated with one spatial scale can be applied at both smaller or larger scales. In reality, however this is not the case.

Current Earth system models, which are used to predict the future global carbon climate feedbacks and associated climate changes, operate at coarse spatial scales (50-100 km) and are currently unable to represent environmental controllers and their effect on soil organic carbon in a manner consistent with field observations.

“The control of environmental factors on soil organic carbon is not consistent with the observations in the current land surface models,” he added. “We believe that the scaling functions we developed in this research, which are drawn from numerous samples across a large geographical area, can improve the spatial representation of soil organic carbon in land surface within Earth system models.”

Among the results of the team’s recent work, models showed that topographic and soil attributes were significant controllers of soil organic carbon at finer scales. At the coarser end of the scale, climatic and land use factors served as important controllers.

DALLAS, July 9, 2020 -- Older, critically ill patients with COVID-19 who received a combination of the antiretroviral medications lopinavir and ritonavir experienced bradycardia, a slow heart rate, more often, according to new research published today in Circulation: Arrhythmia and Electrophysiology, an American Heart Association journal.

The combination of antiretroviral medications lopinavir (LPV) and ritonavir (RTV) have been previously used to treat patients with SARS-Cov-1 and MERS-Cov, as well for HIV-1 patients. Among HIV-1 patients, a risk of bradycardia was also reported.

In this small, preliminary, prospective study, researchers recorded the risk of bradycardia in critically ill COVID-19 patients treated with this combination of medications. Bradycardia is classified as a heart rate below 60 beats per minute for a period of more than 24 hours. Bradycardia can cause problems if the slow heart rate leads to a decrease in blood flow to the body. This can lead to heart failure, fainting, chest pain and low blood pressure. In some people, bradycardia does not cause any symptoms.

The study included 41 patients with COVID-19 admitted to the intensive care unit at Amiens University Hospital, in Amiens, France, who were treated with 200 mg LPV and 50 mg RTV twice daily for 10 days. All patients received continuous electrocardiogram (ECG) monitoring.

Among the patients who received the LPV/RTV treatment:

22% experienced bradycardia for more than 24 hours;

bradycardia occurred at least 48 hours after initiation of treatment, indicating that the medications may have caused bradycardia;

a blood test measuring the concentration of ritonavir (RTV plasma concentration) at 72 hours after receiving the treatment showed higher concentrations of RTV in the patients who had bradycardia;

no correlation was found between RTV plasma concentration, LPV plasma concentration and mean heart rate at 3-days after LPV/RTV treatment began;

patients experiencing bradycardia were on average older than patients receiving the treatment who did not experience bradycardia (ages 62-80 vs. 54-68, respectively); and,

bradycardia resolved after LPV/RTV were discontinued or doses were reduced.

Researchers noted, "[LPV and RTV] have complex pharmacokinetic characteristics [how the body processes a medication] ... Bradycardia could be a sign of severe cardiological or neurological impairment since it is associated with lymphopenia [lower than normal number of white blood cells] that seems to reflect the severity of COVID-19 infection. Intensivists should be aware of this potential side effect in order to closely monitor LPV/RTV plasma levels, notably in elderly patients."