Culture

Analyzing data obtained with the Atacama Large Millimeter/submillimeter Array (ALMA), researchers found a galaxy with a spiral morphology by only 1.4 billion years after the Big Bang. This is the most ancient galaxy of its kind ever observed. The discovery of a galaxy with a spiral structure at such an early stage is an important clue to solving the classic questions of astronomy: "How and when did spiral galaxies form?"

"I was excited because I had never seen such clear evidence of a rotating disk, spiral structure, and centralized mass structure in a distant galaxy in any previous literature," says Takafumi Tsukui, a graduate student at SOKENDAI and the lead author of the research paper published in the journal Science. "The quality of the ALMA data was so good that I was able to see so much detail that I thought it was a nearby galaxy."

The Milky Way Galaxy, where we live, is a spiral galaxy. Spiral galaxies are fundamental objects in the Universe, accounting for as much as 70% of the total number of galaxies. However, other studies have shown that the proportion of spiral galaxies declines rapidly as we look back through the history of the Universe. So, when were the spiral galaxies formed?

Tsukui and his supervisor Satoru Iguchi, a professor at SOKENDAI and the National Astronomical Observatory of Japan, noticed a galaxy called BRI 1335-0417 in the ALMA Science Archive. The galaxy existed 12.4 billion years ago and contained a large amount of dust, which obscures the starlight. This makes it difficult to study this galaxy in detail with visible light. On the other hand, ALMA can detect radio emissions from carbon ions in the galaxy, which enables us to investigate what is going on in the galaxy.

The researchers found a spiral structure extending 15,000 light-years from the center of the galaxy. This is one third of the size of the Milky Way Galaxy. The estimated total mass of the stars and interstellar matter in BRI 1335-0417 is roughly equal to that of the Milky Way.

"As BRI 1335-0417 is a very distant object, we might not be able to see the true edge of the galaxy in this observation," comments Tsukui. "For a galaxy that existed in the early Universe, BRI 1335-0417 was a giant."

Then the question becomes, how was this distinct spiral structure formed in only 1.4 billion years after the Big Bang? The researchers considered multiple possible causes and suggested that it could be due to an interaction with a small galaxy. BRI 1335-0417 is actively forming stars and the researchers found that the gas in the outer part of the galaxy is gravitationally unstable, which is conducive to star formation. This situation is likely to occur when a large amount of gas is supplied from outside, possibly due to collisions with smaller galaxies.

The fate of BRI 1335-0417 is also shrouded in mystery. Galaxies that contain large amounts of dust and actively produce stars in the ancient Universe are thought to be the ancestors of the giant elliptical galaxies in the present Universe. In that case, BRI 1335-0417 changes its shape from a disk galaxy to an elliptical one in the future. Or, contrary to the conventional view, the galaxy may remain a spiral galaxy for a long time. BRI 1335-0417 will play an important role in the study of galaxy shape evolution over the long history of the Universe.

"Our Solar System is located in one of the spiral arms of the Milky Way," explains Iguchi. "Tracing the roots of spiral structure will provide us with clues to the environment in which the Solar System was born. I hope that this research will further advance our understanding of the formation history of galaxies."

These research results are presented in T. Tsukui & S. Iguchi "Spiral morphology in an intensely star-forming disk galaxy more than 12 billion years ago" published online by the journal Science on Thursday, 20 May, 2021.

FRANKFURT. As first pointed out by the German astronomer Karl Schwarzschild, black holes bend space-time to an extreme degree due to their extraordinary concentration of mass, and heat up the matter in their vicinity so that it begins to glow. New Zealand physicist Roy Kerr showed rotation can change the black hole's size and the geometry of its surroundings. The "edge" of a black hole is known as the event horizon, the boundary around the concentration of mass beyond which light and matter cannot escape and which makes the black hole "black". Black holes, theory predicts, can be described by a handful of properties: mass, spin, and a variety of possible charges.

In addition to black holes predicted from Einstein's theory of general relativity, one can consider those from models inspired by string theories, which describe matter and all particles as modes of tiny vibrating strings. String-inspired theories of black holes predict the existence of an additional field in the description of fundamental physics, which leads to observable modifications in the sizes of black holes as well as in the curvature in their vicinity.

Physicists Dr Prashant Kocherlakota and Professor Luciano Rezzolla from the Institute for Theoretical Physics at Goethe University Frankfurt, have now investigated for the first time how the different theories fit with the observational data of the black hole M87* at the centre of the galaxy Messier 87. The image of M87*, taken in 2019 by the international Event Horizon Telescope (EHT) collaboration, was the first experimental proof of the actual existence of black holes after the measurement of gravitational waves in 2015.

The result of these investigations: The data from M87* are in excellent agreement with the Einstein-based theories and to a certain extent with the string-based theories. Dr Prashant Kocherlakota explains: "With the data recorded by the EHT collaboration, we can now test different theories of physics with black hole images. Currently, we cannot reject these theories when describing the shadow size of M87*, but our calculations constrain the range of validity of these black hole models."

Professor Luciano Rezzolla says: "The idea of black holes for us theoretical physicists is at the same time a source of concern and of inspiration. While we still struggle with some of the consequences of black holes - such as the event horizon or the singularity - we seem always keen to find new black hole solutions also in other theories. It is therefore very important to obtain results like ours, which determine what is plausible and what is not. This was an important first step and our constraints will be improved as new observations are made".

In the Event Horizon Telescope collaboration, telescopes from around the globe are interconnected to form a virtual giant telescope with a dish as big as the Earth itself. With the precision of this telescope, a newspaper in New York could be read from a street café in Berlin.

The chemical bisphenol F (found in plastics) can induce changes in a gene that is vital for neurological development. This discovery was made by researchers at the universities of Uppsala and Karlstad, Sweden. The mechanism could explain why exposure to this chemical during the fetal stage may be connected with a lower IQ at seven years of age - an association previously seen by the same research group. The study is published in the scientific journal Environment International.

"We've previously shown that bisphenol F (BPF for short) may be connected with children's cognitive development. However, with this study, we can now begin to understand which biological mechanisms may explain such a link, which is unique for an epidemiological study." The speaker is Carl Gustaf Bornehag, Professor and head of Public Health Sciences at Karlstad University. He is the project manager of the Swedish Environmental Longitudinal Mother and Child, Asthma and Allergy (SELMA) study, from which the data were taken.

External factors can cause changes in gene activity through an "epigenetic" mechanism. This means that individual genes are modified by means of "methylation". Increased methylation in a DNA segment makes it more difficult for the cellular machinery to read that specific part. As a result, expression of methylated genes is often impaired.

The scientists measured BPF levels in urine from pregnant women in the first trimester and subsequently monitored their children after birth. DNA methylation was measured in the children at age seven, and their cognitive ability was investigated. Since the fetus comes into contact with the mother's blood via the placenta, it is also exposed to substances in the mother's body.

The analyses demonstrated that in fetuses exposed to higher levels of BPF, methylation increases in a specific part of the GRIN2B gene, which has a key neurological role. Further, higher methylation was associated with lower IQ in the children. However, the study also found that there appears to be a sex difference in these children's susceptibility to BPF. The epigenetic link between BPF and cognition was observed only in boys.

"The fact that we've been able to identify DNA methylation as a potential mechanism behind BPF's effect on IQ adds an important piece of evidence in work to understand how environmental chemicals affect us on a molecular level," says Elin Engdahl, a researcher in environmental toxicology at Uppsala University and the article's lead author.

In the research group's previous study, they saw that the 25% of seven-year-olds who, during week 10 of the pregnancy, were exposed to the highest maternal levels of bisphenol F had a 2-point decline in full scale IQ compared to the 25% of children exposed to the lowest levels. This is a small difference that is inconspicuous in an individual child but, on the other hand, becomes clear on a population level.

A new study provides public health planning authorities with a method of calculating the number of COVID-19 isolation beds they would need for people experiencing homelessness based on level of infection in the city. The research holds promise for controlling spread of the virus - or future infectious diseases - in a population that is highly vulnerable and less likely than many others to access health care services.

The report, developed to support public health decision-making in Austin, Texas, was recently published by PLOS ONE. The paper's first author is an undergraduate student at The University of Texas at Austin, Tanvi Ingle, who harnessed her days in the pandemic lockdown to work with researchers in The University of Texas at Austin COVID-19 Modeling Consortium.

"Our model can help Austin and other cities ensure they have sufficient resources to protect populations experiencing homelessness during future disease outbreaks," said Lauren Ancel Meyers, director of the UT Austin COVID-19 Modeling Consortium and a professor of integrative biology. "Our calculations indicated how many hotel rooms would be needed to isolate individuals when they developed symptoms or were exposed to the virus. Given that this community generally has high contact rates, poor health care and lack of privacy, these isolation facilities were critical to preventing transmission and protecting this vulnerable population."

Projections based on the model were provided to the City of Austin during the beginning of the pandemic and helped the city finalize lease agreements for isolation facilities.

"The projections from the UT COVID-19 Modeling Consortium were invaluable to us in determining the potential impact and magnitude of support needed to prevent a catastrophic impact on people experiencing homelessness in Austin," said Dr. Mark Escott, the City of Austin's chief medical officer. "As a result, multiple area hotels were used as protective lodges to provide non-congregate sheltering to the most vulnerable members of our community."

Before the lockdown, the undergraduate first author, Ingle, served as a clinical volunteer with Dell Medical School at the C.D. Doyle Clinic, a student-run free clinic that provides care to people experiencing homelessness. When the lockdown hit, she responded to a campus-wide call for help from the newly formed UT COVID-19 Modeling Consortium. Ingle volunteered to lead a research project that could help the homeless population navigate the challenges of the pandemic.

"From my clinical experiences, I knew that the pandemic would be especially hard for people who experience homelessness since they face unique challenges in social distancing and accessing health care. Eager to help improve the situation, I collaborated with the consortium and the City of Austin to determine how many isolation rooms we should provide to help protect our unhoused neighbors from COVID-19," Ingle said.

Using the mathematical model of COVID-19 transmission developed by the consortium, the City of Austin could determine what proportion of people experiencing homelessness would need to be tested and how many of those individuals would test positive. With these parameters, they were then able to estimate the total number of individuals who would need an isolation room at any given time.

"This project was a way for me to see firsthand how clinical experiences inform scientific research that impacts public health outcomes," Ingle said. "Cities around the world will be able to adapt our framework to help shape public policies in the early stages of any pandemic."

"UT undergraduates have stepped up as researchers and leaders throughout the COVID-19 pandemic," Meyers said. "Tanvi is an inspiring example. Her calculations helped the City of Austin to protect some of its most vulnerable populations."

Scientists have discovered that the way in which neurons are connected within regions of the brain, can be a better indicator of disease progression and treatment outcomes for people with brain disorders such as epilepsy.

Many brain diseases lead to cell death and the removal of connections within the brain. In a new study, published in Human Brain Mapping, a group of scientists, led by Dr Marcus Kaiser from the School of Medicine at the University of Nottingham, looked at epilepsy patients undergoing surgery.

They found that changes in the local network within brain regions can be a better predictor of disease progression, and also whether surgery will be successful or not.

The team found that looking at connectivity within regions of the brain, showed superior results to the current approach of only observing fibre tract connectivity between brain regions. Dividing the surface of the brain into 50,000 network nodes of comparable size, each brain region could be studied as a local network with 100-500 nodes. These local networks showed distinct changes compared to a control group not suffering from epileptic seizures.

Using a non-invasive technique called diffusion tensor imaging - a special measurement protocol for Magnetic Resonance Imaging (MRI) scanners - the team of scientists demonstrated that fibres within and between brain regions are removed for patients.

However, they found that connectivity within regions was a better predictor of whether surgical removal of brain tissue was successful in preventing future seizures.

Explaining the work, Dr Kaiser, Professor of Neuroinformatics at the University of Nottingham, says: "When someone has an epileptic seizure, it 'spreads' through the brain. We found that local network changes occurred for regions along the main spreading pathways for seizures. Importantly, regions far away from the starting point of the seizure, for example in the opposite brain hemisphere, were involved.

"This indicates that the increased brain activity during seizures leads to changes in a wide range of brain regions. Furthermore, the longer patients suffered, the more regions showed local changes and the more severe were these changes."

The researchers at Nottingham, Newcastle, Qingdao, Shanghai, and Munich Universities, along with the company Biomax, evaluated the scans of 33 temporal lobe epilepsy patients and 36 control subjects.

Project partners used the NeuroXM™ knowledge management platform to develop a knowledge model for high-resolution connectivity with more than 50,000 cortical nodes and several millions of connections and corresponding automated processing pipelines accessible through Biomax's neuroimaging product NICARA™.

Project manager Dr Markus Butz-Ostendorf from Biomax: "Our software can be easily employed at hospitals and can also be combined with other kinds of data from genetics or from other imaging approaches such as PET, CT, or EEG."

Commenting on the fact that local changes were more informative of surgery outcome, Professor Yanjiang Wang, who is one of the corresponding authors, and Ms Xue Chen, both from China University of Petroleum (East China), explained: "Local connectivity was not only better in overall predictions but particularly successful in identifying patients where surgery did not lead to any improvement, identifying 95% of such cases compared to 90% when used connectivity between regions".

The University of Maryland (UMD) co-published a new review paper in the Annual Review of Resource Economics to examine pollinators from both an economic and ecological perspective, providing much needed insight into the complexities of valuing pollination. Pollinators are not only a critical component of a healthy ecosystem, but they are also necessary to produce certain foods and boost crop yields. While native and wild pollinators (whether they be certain bee species, other insects and animals, or just the wind) still play an important role, managed honey bee colonies are commercially trucked around the U.S. to meet the need for pollination services in agricultural products. Recent reports of parasites, disease, and other concerns in colonies call into question the resilience of the managed honey bee rental markets, as well as how those managed bees are interacting with native pollinators. This recent collaboration with the University of California, Santa Barbara (UCSB), and the University of North Texas (UNT) highlights the importance of characterizing the economic value of pollination services, including that of managed and wild pollinators, both for the sustainability of honey bee markets and the protection of overall ecosystem health.

"Many people don't realize that honey bees are not native to the U.S., or that they are actually a form of agricultural livestock rented out largely for their pollination services," says Erik Lichtenberg, professor in Agricultural and Resource Economics at UMD. "It used to be that you raised bees for honey, but today, pollination services account for the largest share of commercial beekeeper income, with honey as a secondary product. Agriculture is always integrated into an ecosystem, and we typically think about the managed parts without the ecosystem parts. But when we are thinking about resilience and things like climate change which is changing the ecosystem, then we have to reckon with the parts that we've tended to ignore. Getting a more holistic sense of the health of pollinators and the true resilience of the rental market is very important."

Researchers have historically struggled to put a value on pollination services, largely because of the many complex inputs into the system like wind, native versus managed pollinator interactions, weather, and even quality or health of the bees due to emerging diseases and invasive pests like varroa mites -- in addition to inputs provided by farmers. With these complexities in mind, Erik Lichtenberg teamed up with Kathy Baylis, economist and professor in geography at UCSB, and Elinor Lichtenberg, ecology professor at UNT, to take an interdisciplinary approach to reviewing the economics of pollination.

"As a pollination ecologist, it was exciting to collaborate with economists to write this review," says Elinor Lichtenberg. "One of our goals was to help ecologists understand the economics, and economists understand the ecological considerations and constraints involved. This will help develop solutions that benefit both wildlife and farmers."

Elinor Lichtenberg did her undergraduate work in biology at UMD, also spending a year working with Daniel Gruner and Dennis vanEngelsdorp in Entomology. Baylis also collaborates with vanEngelsdorp and the Bee Informed Partnership (BIP), a UMD-led nonprofit organization that conducts a nationwide annual survey each year since 2006 to assess managed honey bee health and colony loss.

"Colony collapse disorder was big in the media in 2006 when beekeepers started seeing so many of their bees dying, so people wanted to know why," explains Baylis. "With our increased reliance on managed honey bees for pollination, it really raised concerns about the resilience of the system we have in place, or the lack thereof. As it turns out, the pollination market and associated fees are quite responsive to colony health, and beekeepers have been able to meet that demand so far. The price signals are working, but there are many things that aren't really priced in yet. So a big part of this paper is to highlight the linkages where we know things are being captured, and the values that aren't being captured but should be."

Erik Lichtenberg adds, "If we are thinking about the resilience of the system of migratory managed pollination services, a lot of that system is still hidden. We see the tip of the iceberg, but we don't see what is underneath the waterline, so we'd like to take our analytical submarine and check out what's down there."

Currently, the system involves a migration route that is similar to that of farmed labor. Managed honey bee colonies start their year in central California pollinating almonds, plums, prunes, and other early blooming crops, and then are transported slowly up north to later blooming crops like apples, cucumbers, squash, and even pumpkins. The route moves up to the Pacific Northwest and then ends with the bees "summering" in the Northern Plains region to forage and recharge. This system has become increasingly important as agriculture has become more specialized and mechanized, with less habitat for native pollinators and more consumer demand for insect-pollinated crops. But, as the researchers explain, there is so much about the system we just don't understand.

"When problems like colony collapse disorder arise, to me, it feels like we are always trying to attach band aids to different parts of the dike wherever we see a crack without seeing the whole necessarily," says Baylis. "And that's a big purpose of the paper is trying to at least sketch out what the whole thing might look like."

Some of the biggest unknowns identified are the protection of forage lands and habitat for native and managed honey bee colonies, how to manage the surrounding landscape to optimize pollination services and pollinator health, and especially understanding the interactions between wild and managed pollinators. Interactions may be positive, as with native pollinators reaching higher branches in high winds while honey bees stick to lower branches, or they can be negative, like the spread of disease from managed to wild pollinators. All these inputs are especially important when considering the costs and benefits of conserving wild pollinator habitat.

"Economists and ecologists both recognize the importance of putting an economic value on inputs like clean water, clean air, biodiversity, and natural pollination, because these natural products that aren't bought and sold in the market otherwise get a default value of zero placed on them," says Baylis. "We know that is wrong, so hopefully this can draw attention to that issue. We've identified a lot of gaps here, and it is important not just for the space of bees, but more broadly for issues where part of the ecological system is managed and monetized, and other parts are not. This speaks to how we can develop a system that is responsive, resilient, and also sustainable."

Erik Lichtenberg adds, "We are excited about the follow-on work that we've identified to do. There is a lot of fascinating work to be done in this area, and we hope this review inspires people to think creatively about some of the issues we've raised."

BATON ROUGE, Louisiana - A diet that improves the biomarkers of metabolic health, and that could potentially slow the aging process, has moved a step closer to reality.

"We've known for years that restricting the amino acid methionine in the diet produces immediate and lasting improvements in nearly every biomarker of metabolic health," said Thomas W. Gettys, PhD, Professor and Director, Nutrient Sensing and Adipocyte Signaling Laboratory at Pennington Biomedical Research Center. "The problem is that methionine-restricted diets have been difficult to implement because they taste so bad."

Until now. Restricting methionine normally involves diets formulated with elemental (e.g., individual) amino acids. Individual amino acids are the building blocks of proteins. But diets made from elemental amino acids taste bad, and few are willing to tolerate the regimen.

A palatable solution emerged from a collaboration between Dr. Gettys' lab and food scientists at LSU who developed the methods to selectively delete methionine from casein, the main protein in milk and cheese. Dr. Gettys' lab then conducted the proof-of-concept testing to establish that oxidized casein could be used to implement methionine restriction without the objectionable taste of the standard elemental diet.

More than two-thirds of Americans are overweight or have obesity. More than 40 percent of adults have prediabetes or type 2 diabetes.

"A diet that offsets all the major components of metabolic disease would have an enormous impact on the nation's health, and the world's," said Han Fang, PhD, a Postdoctoral Researcher in Dr. Gettys' lab, and the lead author of the study.

A palatable, methionine-restricted diet could also ease a major frustration for those struggling to manage their weight. Each year, millions of people improve their metabolism and lose weight by reducing how much they eat. But eventually, most people gain back those pounds.

"Calorie restriction is an effective weight-management tool. But for most people it is also very, very difficult to follow long-term," said Pennington Biomedical Executive Director John Kirwan, PhD. "This struggle is one of the major reasons our scientists explore every avenue to find solutions to the obesity epidemic."

Although the oxidized casein diet represents a major advance, Gettys and his team say more research is needed. Their study, published in the journal iScience, involved mice. Translating the results to produce a methionine-restricted human diet, which is far more complex and involves multiple sources of protein, will be challenging.

In the short term, a practical solution may be to develop a palatable group of modified proteins to serve as the basis of a therapeutic diet. People would follow the diet for a limited period while under medical supervision.

New research led by the University of Kent's School of Psychology has found that some brain activity methods used to detect incriminating memories do not work accurately in older adults.

Findings show that concealed information tests relying on electrical activity of the brain (electroencephalography [EEG]) are ineffective in older adults because of changes to recognition-related brain activity that occurs with aging.

EEG-based forensic memory detection is based on the logic that guilty suspects will hold incriminating knowledge about crimes they have committed, and therefore their brains will elicit a recognition response in the EEG when confronted with reminders of their crimes.

The team of researchers at Kent led by Dr Robin Hellerstedt and Dr Zara Bergström conducted the study with 30 participants under the age of 30 and 30 participants over the age of 65. All participants undertook a concealed information test to detect if they recognised details from a mock crime they had just committed, which would indicate criminal guilt. However, only young adults showed a strong EEG recognition response to reminders of the crime, with such responses being absent in the older group. This failure to detect memories with EEG brain activity occurred even though the older group had the same knowledge about the crime as the younger group, and had just as good general recognition memory ability.

The research published by Cortex therefore suggests that EEG-based forensic memory detection tests have limited practical applications with less validity in older adults than younger populations.

Dr Bergström said: 'Our research demonstrates that EEG-based forensic memory detection in older age is impaired, even with methods that compensate for potential age differences in frequency, timing and location of brain responses.

'Further investigation is needed to examine the ability of these tests to detect concealed memories of real crimes, and whether memory detection in older age is a reflection of permanent changes in brain functioning or is influenced by motivational processes that can vary across situations. Findings could have implications for processes within the criminal justice system, such as the use of polygraph techniques, which may be vulnerable to similar limitations.'

Deaths caused by indirect effects of the pandemic emphasize the need for policy changes that address widening health and racial inequities.

More than 15 months into the pandemic, the U.S. death toll from COVID-19 is nearing 600,000. But COVID-19 deaths may be underestimated by 20%, according to a new, first-of-its-kind study from Boston University School of Public Health (BUSPH), the University of Pennsylvania, and the Robert Wood Johnson Foundation.

Published in the journal PLOS Medicine, the study uses data from the National Center for Health Statistics (NCHS) and the Centers for Disease Control and Prevention (CDC) to estimate the number of deaths in 2,096 counties from January to December 2020 above what would be expected in a normal year, or "excess deaths." For every 100 excess deaths directly attributed to COVID-19, there were another 20 excess deaths not attributed to COVID-19. In other words, 20 out of every 120 excess deaths, or 17%, were not directly attributed to COVID.

The researchers found that the proportion of these excess deaths not directly attributed to COVID-19 was higher in counties with lower average socioeconomic status and less formal education, as well as in counties located in the South and West. Counties with more non-Hispanic Black residents--who were already at high risk of dying directly from COVID-19--also reported a higher proportion of excess deaths not assigned to COVID-19.

"Our findings suggest that the impact of the COVID-19 pandemic on mortality has been substantially underestimated in many communities across the US," says study lead author Dr. Andrew Stokes, assistant professor of global health at BUSPH. "Several factors, including severe testing shortages, overwhelmed health care systems, and a lack of familiarity with the clinical manifestations of COVID-19 has likely led to significant underreporting of COVID-19 on death certificates, especially early in the pandemic. Official COVID-19 death tallies also fail to capture the pandemic's profound social and economic consequences, including the downstream effects of interruptions in receiving health care, loss of employment, evictions, and social isolation and loneliness."

In addition to deaths directly from the coronavirus that were not recorded as such, some of the excess deaths are likely from indirect consequences of the COVID crisis, including fear of going to the hospital for another condition, or any number of issues caused or exacerbated by the toll that COVID has taken on the economy and on mental health.

"Counties with high levels of COVID-19 mortality also had exceptionally high levels of mortality in 2020 from other causes of death. This result suggests that the epidemic is responsible for many more deaths than are attributed to COVID-19 alone," says study senior author Dr. Samuel H. Preston, professor of sociology at the University of Pennsylvania.

"Racial and socioeconomic inequities in U.S. mortality have widened significantly as a result of the COVID pandemic, especially when considering total excess deaths. To protect public health, policymakers must act decisively to address structural racism and reduce income inequality," says study co-author Dielle Lundberg, a research fellow at BUSPH.

Overall, the study makes clear that county-level measures of direct COVID-19 mortality were not accurate measures of excess mortality in many US counties.

"A more complete accounting of COVID-19 deaths in local communities using excess deaths could lead to increased public awareness and vaccine uptake, particularly in areas where the official death counts suggested the pandemic had a limited impact," Stokes says.

Today, proteins that can be controlled with light are a widely used tool in research to specifically switch certain functions on and off in living organisms. Channelrhodopsins are often used for the technique known as optogenetics: When exposed to light, these proteins open a pore in the cell membrane through which ions can flow in; this is how nerve cells can be activated. A team from the Centre for Protein Diagnostics (PRODI) at Ruhr-Universität Bochum has now used spectroscopy to discover a universal functional mechanism of channelrhodopsins that determines their efficiency as a channel and thus as an optogenetic tool. The researchers led by Professor Klaus Gerwert describe the results in the journal Communications Biology of 14 May 2021. They expect that the findings will help tailor more efficient optogenetic tools in the future.

Properties of natural proteins not optimal for optogenetics

"The introduction of light-sensitive proteins into organisms for the targeted control of certain functions from the outside offers enormous potential for neuroscientific research and its therapeutic application," says Klaus Gerwert. "Unfortunately, the properties of these naturally occurring proteins, for example in green algae, are not always optimal for the relevant optogenetic application."

For this reason, the properties of the proteins have to be adapted by changing their gene sequences. Currently, this is done based on trial and error. "In order to specifically optimise the proteins for their potential applications, a deep understanding of molecular reactions and the resulting ion conduction is necessary," points out Klaus Gerwert. "We obtain the necessary structural dynamic understanding of protein mechanisms with high spatial and temporal resolution by combining time-resolved Fourier-transform infrared spectroscopy and biomolecular simulations," explains PRODI researcher Dr. Till Rudack.

Molecular mechanisms determine efficiency

Using these methods, Klaus Gerwert and his team recently discovered the mechanism that causes the channelrhodopsin 2 protein, which is widely used in optogenetics, to lose its efficiency over time. Previously, researchers had assumed that light excitation stimulated a specific structural change in the protein. However, the group found that light exposure induces two different structural changes: One is the desired channel opening, which is useful for optogenetics. The second provides only a weak ion current, but gains the upper hand with longer exposure and suppresses the channel opening - a drawback for optogenetics.

In the current study, the researchers used time-resolved Fourier-transform infrared spectroscopy and biomolecular simulations to explore a different channel rhodopsin, called anion-channelrhodopsin-1. "This channel hardly has any loss of efficiency following prolonged exposure and also doesn't have a second parallel pathway of structural change," explains Dr. Max-Aylmer Dreier, first author of the study.

"We have thus proven that splitting into two parallel pathways leads to inefficient channels. In efficient channels there doesn't seem to be a second parallel pathway," concludes Klaus Gerwert. "In the future, we will use the insights into the underlying molecular mechanisms of channel efficiency to block the inefficient second pathway by targeted protein design and thus design improved optogenetic tools," predicts Till Rudack.

Since our ancestors infected themselves with retroviruses millions of years ago, we have carried elements of these viruses in our genes - known as human endogenous retroviruses, or HERVs for short. These viral elements have lost their ability to replicate and infect during evolution, but are an integral part of our genetic makeup. In fact, humans possess five times more HERVs in non-coding parts than coding genes. So far, strong focus has been devoted to the correlation of HERVs and the onset or progression of diseases. This is why HERV expression has been studied in samples of pathological origin. Although important, these studies do not provide conclusions about whether HERVs are the cause or the consequence of such disease.

Today, new technologies enable scientists to receive a deeper insight into the mechanisms of HERVs and their function. Together with her colleagues, virologist Michelle Vincendeau* has now succeeded for the first time in demonstrating the negative effects of HERV activation on human brain development.

HERV activation impairs brain development

Using CRISPR technology, the researchers activated a specific group of human endogenous retroviruses** in human embryonic stem cells and generated nerve cells (neurons). These viral elements in turn activated specific genes, including classical developmental factors, involved in brain development. As a result, cortical neurons, meaning the nerve cells in our cerebral cortex, lost their function entirely. They developed very differently from healthy neurons in this brain region - with much a shorter axon (nerve cell extension) that were much less branched. Thus, activation of one specific HERV group impairs cortical neuron development and ultimately brain development.

Clinical relevance

Since neurodegenerative diseases are often associated with the activation of several HERV groups, the negative impact of HERV activation on cortical neuron development is an essential finding. It is already known that environmental factors such as viruses, bacteria, and UV light can activate distinct HERVs, thereby potentially contributing to disease onset. This knowledge, in turn, makes HERVs even more interesting for clinical application. Switching off distinct viral elements could open up a new field of research for the treatment of patients with neurodegenerative diseases. In a next step, the group at Helmholtz Zentrum München will study the impact of HERV deactivation in neurons in the context of disease.

New paths for basic research

In addition, the research findings provide important indications that epigenetic mechanisms keep viral elements under control in healthy brain development. Michelle Vincendeau even suspects a functional role for the controlled HERVs in normal brain development. "We have carried these elements for about 40 to 70 million years. We assume that their presence is relevant to our natural processes, otherwise we would not have retained them for so long during evolution," Vincendeau says. Further basic research in this direction might reveal new functional roles for HERVs.

Passing down a healthy genome is a critical part of creating viable offspring. But what happens when you have harmful modifications in your genome that you don't want to pass down? Baby plants have evolved a method to wipe the slate clean and reinstall only the modifications that they need to grow and develop. Cold Spring Harbor Laboratory (CSHL) Professor & HHMI Investigator Rob Martienssen and his collaborators, Jean-Sébastien Parent and Institut de Recherche pour le Développement Université de Montpellier scientist Daniel Grimanelli, discovered one of the genes responsible for reinstalling modifications in a baby plant's genome.

A plant's genomic modifications--called epigenetic modifications--help turn off genes at the right times. Epigenetic changes accumulate with age. Martienssen explains:

"If you think about a tree, the flowers that arise a hundred years after it germinated, they're obviously a long way from the original acorn, and an awful lot of epigenetic changes could happen in that period. And so, these are important resets for development so that you don't inherit this epigenetic collateral damage."

Martienssen's team discovered that after baby plants remove the epigenetic modifications, the SUVH9 protein puts back the ones they need to survive. Without SUVH9, plants develop poorly because the wrong genes turn on at the wrong time. Parent, a research scientist at Agriculture and Agri-Food Canada, says:

"I remember this moment where we were like, 'Wow! This is not what we expected.' There was an opening for an actor that was not accounted for in the standard models, and that was the most innovative part of our story."

The SUVH9 protein uses small snippets of RNA to look for the right places to reinstall the beneficial modifications, which are on mobile genetic elements known as transposons. The SUVH9 protein adds the epigenetic modifications to them, and this ensures nearby genes are turned off at the right time. Reinstalling the beneficial modifications also stops the transposons from jumping around in the genome and disrupting other genes.

The scientists think SUVH9 protein contributed to today's plant diversity. By stopping harmful transposons from disrupting genes, the protein allowed different species to evolve. Parent says:

"One of the big mysteries about flowering plants is how they manage to become so diverse and to generate so many different species so quickly in evolutionary history. And, we believe that we are touching here a part of a molecular mechanism that can allow this sort of flexibility."

The study sought to describe and explain gender pay differences in the U.S. Department of Health and Human Services between 2010 and 2018. HHS comprises a quarter of the country's governmental public health workers, with over 80,000 employees.

Understanding what may be driving wage gaps at HHS provides opportunities for employers and legislators to take action to support women in the health care field, said lead author Zhuo "Adam" Chen, an associate professor of health policy and management at UGA's College of Public Health.

"A large percentage of the health care workforce are women," said Chen. "If you have underpaid women in the profession, I don't think it spells good things for the public health system."

Chen and his co-authors wanted to look at HHS in part for its size, but also because the agency is considered "gender neutral," meaning that it attracts male and female employees equally and promotes both genders equally.

"So, we would anticipate the gender pay gap should be minimal," said Chen.

Using a publicly available dataset of annual pay rates and job characteristics for federal employees, the team scraped information for HHS employees, classifying gender using first names.

Several factors could explain pay differences, including where employees lived and pay grade, a proxy of their levels of experience and education. In order to determine how much of a difference in pay could be attributed to these variables, the team systematically ran analyses controlling for job title, location and the employee's pay grade.

The results showed that overall, the gender pay gap narrowed from 13% to 9.2 % between 2008 and 2010. Job type, location and pay grade explained half of this gap, but 3.5% of the gap in 2018 was unexplained by these factors.

Chen says the key may be differences in promotion within the higher pay grades.

General schedule, the most common federal pay plan, has 15 levels, or pay grades. Higher pay grades often require advanced degrees, and the highest pay grades typically involve supervisory responsibilities. For each grade level, there are 10 "steps" through which employees can advance by serving a set length of time or by merit.

The analysis showed that women could be stuck in the last steps of level 13 and 14 pay grades.

"If you control pay grade, we get a 1% percent difference, which is getting close to parity. That is itself an indication of a gender promotion gap. Because of the rules of the pay grades in the federal government, differences in promotion are a major contributor of the pay difference," said Chen.

This is where some might point to gender discrimination, but Chen is not so certain.

"I know researchers like to say we need more data, but we do in order to say whether job segregation is self-selection or something else," he said.

Chen and his co-authors emphasize that increased data transparency and strengthening legislation action to ensure equal pay for equal work are needed to help close this gap.

A team of researchers at the University of Ottawa has found a way to use visible light to transform carbon dioxide gas, or CO2, into solid carbon forms that emit light. This development creates a new, low-energy CO2 reduction pathway to solid carbon that will have implications across many fields.

We talked to lead author Dr. Jaspreet Walia, Post-Doctoral Fellow in the School of Electrical Engineering and Computer Science at the University of Ottawa, and research lead Dr. Pierre Berini, uOttawa Distinguished Professor and University Research Chair in Surface Plasmon Photonics, to learn more.

Please tell us about your team's discovery.

Pierre Berini: "We have reduced carbon dioxide, a greenhouse gas, to solid carbon on a nanostructured silver surface illuminated with green light, without the need for any other reagents. Energetic electrons excited on the silver surface by green light transfer to carbon dioxide molecules, initiating dissociation. The carbon deposits were also found to emit intense yellow light in a process known as photoluminescence."

How did you come to these conclusions?

Jaspreet Walia: "We used a technique known as Raman Scattering to probe the reaction in real time to determine which products, if any, were forming. To our surprise, we consistently observed signatures of carbon forming on the surface, as well as bright and visible yellow light emanating from the sample."

Why is it important?

Pierre Berini: "Recently, there has been considerable global research effort devoted to developing technologies that can transform CO2 using visible light. Our work not only demonstrates that this is possible, but also that light emitting solid carbon can be formed."

What are the applications of this discovery in our lives?

Jaspreet Walia: "This fixed pathway for reagent-less CO2 reduction to light emitting solid carbon, driven by visible light, will be of interest to researchers involved in the development of solar driven chemical transformations, industrial scale catalytic processes, and light-emitting metasurfaces."

"More specifically, with respect to the creation of carbon directly from CO2 gas, our findings will have an impact on research involving plasmon assisted reactions and I would expect the emergence of applications in the oil and gas industries, where catalytic transformations involving carbon-based compounds is a key focus area."

"Next-generation reactions involving CO2 and light could also lead to other useful outcomes, such as the potential for artificial photosynthesis. Our findings could be used for light control and manipulation at the nanoscale, or to possibility realize flat light sources due to the light-emitting aspect of our discovery. The nanostructured carbon itself could also be used in catalysis."

"Finally, the wavelength (color) of the light emitted from carbon dots on a silver surface could be very sensitive to the local environment, making it an attractive sensing platform for pollutants, for example."

Is there anything you would like to add?

Pierre Berini: "We have learned how to form solid carbon deposits that emit light "out of thick air", in a breakthrough enabled by light-assisted transformation of CO2 gas driven by energetic electrons. The project was entirely driven by curiosity, with no set expectations on outcomes, and benefitted from close collaboration with graduate students Sabaa Rashid and Graham Killaire, as well as Professors Fabio Variola and Arnaud Weck."

May 20, 2021 - Comets that circle the Sun in very elongated orbits spread their debris so thin along their orbit or eject it out of the solar system altogether that their meteor showers are hard to detect. From a new meteor shower survey published in the journal Icarus, researchers now report that they can detect showers from the debris in the path of comets that pass close to Earth orbit and are known to return as infrequent as once every 4,000 years.

"This creates a situational awareness for potentially hazardous comets that were last near-Earth orbit as far back as 2,000 BC," said meteor astronomer and lead author Peter Jenniskens of the SETI Institute.

Jenniskens is the lead of the Cameras for Allsky Meteor Surveillance (CAMS) project, which observes and triangulates the visible meteors in the night sky using low- light video security cameras to measure their trajectory and orbit. There are CAMS networks now in nine countries, led by co-authors on the paper.

In recent years, new networks in Australia, Chile and Namibia significantly increased the number of triangulated meteors. The addition of these networks resulted in a better and more complete picture of the meteor showers in the night sky.

"Until recently, we only knew five long-period comets to be parent bodies to one of our meteor showers," said Jenniskens, "but now we identified nine more, and perhaps as many as 15."

Comets comprise only a small fraction of all impactors on Earth, but researchers believe they caused some of the biggest impact events over Earth's history because they can be big and the fact that their orbits are such that they can impact at high speed.

"In the future, with more observations, we may be able to detect fainter showers and trace the orbit of parent comets on even longer orbits," said Jenniskens.

Every night, the CAMS network determines the direction from which comet debris is entering Earth's atmosphere. Maps are created on an interactive celestial sphere (posted at http://cams.seti.org/FDL/) that shows the meteor showers as colored blobs. Clicking on those blobs shows the measured orbits in the solar system.

"These are the shooting stars you see with the naked eye," said Jenniskens. "By tracing their approach direction, these maps show the sky and the universe around us in a very different light."

An analysis of the data found that long-period comet meteor showers can last for many days.

"This was a surprise to me," says Jenniskens. "It probably means that these comets returned to the solar system many times in the past, while their orbits gradually changed over time."

Data also revealed that the most dispersed meteor showers show the highest fraction of small meteoroids.

"The most dispersed showers are probably the oldest ones," says Jenniskens. "So, this could mean that the larger meteoroids fall apart into smaller meteoroids over time."