Culture

As the novel coronavirus continues to spread around the world, so do the concerns of breastfeeding mothers. Although there have been no documented cases to date of an infant contracting COVID-19 as a result of consuming infected breast milk, the critical question of whether there is potential for this form of transmission remains. In a recent study, researchers from University of California San Diego School of Medicine and University of California Los Angeles collaborated to find the answer.

The study, published August 19, 2020 in the online edition of JAMA, examined 64 samples of breast milk collected by the Mommy's Milk Human Milk Research Biorepository from 18 women across the United States infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although one sample tested positive for viral RNA, subsequent tests found that the virus was unable to replicate, and thus unable to cause infection in the breastfed infant.

"Detection of viral RNA does not equate to infection. It has to grow and multiply in order to be infectious and we did not find that in any of our samples," said Christina Chambers, PhD, MPH, co-principal investigator of the study, professor of pediatrics at UC San Diego School of Medicine, director of Mommy's Milk Human Milk Research Biorepository and co-director of the UC San Diego Center for Better Beginnings. "Our findings suggest breast milk itself is not likely a source of infection for the infant."

The current recommendations to prevent transmission while breastfeeding are hand hygiene and sterilizing pumping equipment after each use.

"In the absence of data, some women infected with SARS-CoV-2 have chosen to just not breastfeed at all," said Grace Aldrovandi, MD, co-principal investigator of the study, chief of the Division of Infectious Diseases at UCLA Mattel Children's Hospital and a professor of pediatrics in the David Geffen School of Medicine at UC Los Angeles. "We hope our results and future studies will give women the reassurance needed for them to breastfeed. Human milk provides invaluable benefits to mom and baby."

Early breastfeeding is associated with a reduced risk of sudden infant death syndrome and obesity in children, as well as improved immune health and performance on intelligence tests. In mothers, breastfeeding has been associated with lower risks for breast and ovarian cancer, cardiovascular disease and type 2 diabetes.

The researchers also mimicked conditions of the Holder pasteurization process commonly used in human donor milk banks by adding SARS-CoV-2 to breast milk samples from two different donors who were not infected. The samples were heated to 62.5°C for 30 minutes and then cooled to 4°C. Following pasteurization, infectious virus was not detected in either sample.

"This is a very positive finding for donor milk, which so many infants, especially those born premature, rely on," said Chambers. "Our findings fill in some important gaps, but more studies are needed with larger sample sizes to confirm these findings."

Chambers said future work will not only look at whether breast milk is free of the virus, but also whether it contains active antiviral components. For example, antibodies to SARS-CoV-2 that women may produce after exposure to the virus and then transfer to their infants through breast milk, protecting them from COVID-19.

Plastic waste in the ocean is an increasing problem for wildlife, including seabirds who frequently mistake it for food. However, ingested plastic does not just pose physical risks for such birds. A new study in open-access journal Frontiers in Environmental Science is the first to show that plastic waste can release chemicals into the stomach oil of seabirds over time, potentially posing a threat to their health. The findings highlight the importance of reducing plastic pollution in our oceans and dealing with our waste responsibly.

With ever increasing levels of plastic polluting the ocean and beaches, this waste is a growing threat to marine wildlife. Many seabirds confuse plastic with food, and it can pose physical risks such as intestinal blockages. However, ingested plastic can stay in birds' intestines for long periods, and scientists are concerned that such plastic could release harmful chemicals.

"I've been working on northern fulmars for almost 10 years," said Susanne Kühn of Wageningen Marine Research in the Netherlands. "As these seabirds ingest plastics regularly, and 93% of the fulmars from the North Sea have some plastic in their stomachs, it is important to understand the potential harm this could cause."

Kühn and colleagues set out to investigate whether plastic waste could release chemicals after being eaten by fulmars. They aimed to replicate the conditions found in the fulmar stomach, and the plastic debris that fulmars ingest. The researchers obtained a nutrient-rich liquid found in the fulmar stomach, known as stomach oil, from hunters in the Faroe Islands who traditionally catch and eat these birds.

"Previous studies have typically used uniform plastic pellets, sometimes artificially contaminated, which is not representative of plastic found in the sea," explained Kühn. "Instead, we went beach combing and found a variety of plastic types and shapes to create a marine plastic sample that a fulmar might realistically ingest."

The researchers incubated the plastic samples in stomach oil and mimicked the conditions found in the fulmar stomach in terms of temperature and agitation. They performed chemical analysis on the oil at different time points to see whether chemicals had leached out of the plastic over time.

Concerningly, the study revealed that the plastic released a variety of chemicals in the stomach oil over time, in some cases for over three months. These were chemicals added by plastic manufacturers during the production process, including plasticizers, flame retardants and stabilizers.

Strikingly, the stomach oil, which came from fulmar chicks, already had some plastic-derived chemicals in it before the experiments, as the chicks' parents may have been feeding them plastic. The long-term health implications for the birds are unclear, but previous studies have reported that several of the leached chemicals can disrupt hormone release and reproduction and may have genetic effects in birds.

You may be familiar with distressing images of birds caught in plastic packaging or fishing line, but this study reveals that discarded plastic could also have long-term toxic effects on seabirds. "I hope that these results will increase awareness of the various negative effects of plastic debris in the oceans," said Kühn. "We urgently need to reduce the amount of plastic in the marine environment."

Shipwrecks act as artificial reefs and provide a substrate and nutrients for a great diversity of microorganisms, which can contribute to either the deterioration or preservation of the ship. Precisely how diverse such communities are, and how they are organized, is still unknown. Here, researchers from East Carolina University in Greenville, North Carolina, identify the bacteria associated with a shipwreck from the 1960s. They find a highly diverse community on the wreck, consisting of at least 4,800 OTUs (Operational Taxonomic Units, roughly corresponding to species) from 28 bacterial phyla, including nitrogen-, carbon-, sulfur-, and iron-cycling species. Microbial community composition strongly differed between locations within the site, suggesting niche partitioning, in the same way that fungal species specialize in particular microhabitats within a forest, based on the local abiotic and biotic environment. The results are published in the open-access journal Frontiers in Microbiology.

The 50-m-long wreck, called the Pappy Lane, represents the remains of the steel-hulled USS LCS(L)(3)-123, built in 1944 as a WWII warship and abandoned after running aground in the 1960s in the shallows of the Pamlico Sound lagoon, North Carolina, after a second career a barge. DNA sequencing of 14 samples from across the site - visibly corroded and visibly preserved shipwreck debris, drilled shipcores, nearby sediment, and surrounding seawater - revealed notable differences in composition and metabolic capacities of the local microbial communities living on and around the shipwreck, as well as the microbial communities living on different parts of the ship. The authors explain this diversity as evidence of niche partitioning, driven by small-scale variability in the abiotic environment, for example iron content, exposure to oxygen, and traces of hydrocarbons from a former fueltank.

Present across the shipwreck and abundant where corrosion was observed, were iron-oxidizing ("iron-eating") Proteobacteria, which may contribute to biocorrosion. These included a new strain of the marine iron-oxidizing Zetaproteobacteria, with the apt name Mariprofundus ferrooxydans O1. Genomic analysis showed that the metabolic capacities of this strain include iron oxidation, carbon fixation in both oxygen-rich and -poor environments, and nitrogen fixation, indicating that it contributes to the cycling of metals and nutrients in the shipwreck environment.

This research also has wider implications for future resource management and the development of conservation strategies for shallow water shipwrecks across all coastlines.

"We have learned that iron-oxidizing bacteria that produce rust are widespread on these shipwrecks, causing corrosion and deterioration of the wreck-site. These microbes are more abundant in areas where we see corrosion occurring, which makes them likely indicators of where further deterioration may occur. In order to prevent this damage, we can design strategies for early detection, stopping their growth and limit further biocorrosion by other microbes," says corresponding author Dr Erin Field, Assistant Professor in the Department of Biology at East Carolina University.

The results of this study point towards the need to adapt future conservation efforts to the unique situation of each shipwreck, taking into account original construction materials, environmental factors and time spent in water.

"Historically, shipwreck sites were treated as a single environment, but our research goes deeper, showing that there are different microbial communities within single wreck-sites and associated with the wreck itself. As such, we need to tailor conservation efforts to each shipwreck in order to more effectively mitigate biocorrosion and deterioration," explains Dr Field.

This study highlights the importance of increasing the understanding of the role of biocorrosion in the deterioration of shipwrecks and the need for more research into the microbial ecosystem of shipwrecks.

"While there is well-developed literature on the impact of galvanic corrosion on shipwrecks and historic ships, the role certain microbes play in corrosion is less well-understood. It is hoped that this article helps decipher the mechanisms of biocorrosion that could one day also lead to the development of protective measures and conservation strategies," concludes Dr Nathan Richards, Professor and Director of Maritime Studies in the Department of History at East Carolina University and co-author of the study.

August 19, 2020 - Sorghum, a common food item in regions of Africa and Asia, has one missing puzzle piece. The missing piece? Protein digestibility, which researchers in the Department of Agronomy at Kansas State University are trying to find.

"Sorghum is an important food crop grown in Africa," said Tesfaye Tesso. "It grows well in their climate because it requires less moisture and nutrients than other crops." Tesso is a researcher at Kansas State University.

The biggest flaw of sorghum is how difficult it is for people and animals to digest its protein. Once the problem is solved, sorghum will provide more nutrients to those who eat it. It will also increase the value of the crop for farmers.

With the goal of improving global hunger and food security, Tesso and his team began their research. While there are many aspects of the plant that may affect protein digestibility, the group narrowed their focus to the protein itself.

"Sorghum protein digestibility is affected by a lot of different pieces," said Tesso. "We focused on the characteristics of sorghum protein that may be associated with digestibility."

The research group selected 40 varieties of sorghum, including some with high digestibility and some with low digestibility. These varieties will help the team understand what genes are behind the difference in sorghum digestibility.

"Our goal was to look at the DNA that codes for all of the seed storage proteins, called kafirins," said Tesso. Then researchers identified differences in these codes, which could be a cause for digestibility differences.

"Three out of the four kafirins we identified were linked to high protein digestibility, while the other one had lower digestibility," said Tesso. "Identifying these factors is one important piece of a very complex puzzle."

Moving forward, this research may lay foundation for enhancing protein digestibility through breeding. By understanding the genes associated with protein digestibility, scientists can watch for these genetic variations in sorghum plants, which will then have the desired traits.

Since protein digestibility is complex and affected by multiple factors, there is still more work to be done, according to Tesso. With their new ability to easily identify digestibility, researchers now have the power to select sorghum with other desired traits.

Not only will identifying this missing puzzle piece be beneficial to people in third-world countries, but it will also help United States livestock producers.

"Sorghum can be a feed ingredient for pigs," said Tesso. "The low protein digestibility affects what the animal gets from their diet. By improving the protein digestibility, livestock farmers can save costs on protein supplementation, which enhances the competitiveness of both the livestock and sorghum industries."

In the United States, sorghum farmers will have a higher valued product and livestock owners will have a better feed ingredient. Internationally, countries with developing agriculture will be able to aid in the fight against hunger and malnutrition.

A study of 181 patients at 16 sites across the country who test negative for two antibodies long known to cause muscle-weakening myasthenia gravis, found that about 15% test positive for one of two newly discovered antibodies that also attack the point of communication between nerves and muscle.

About 13% tested positive for antibodies to both LRP4 and agrin, proteins critical to healthy nerve-muscle communication, investigators report in the journal Muscle & Nerve about the largest group of patients examined for the new antibodies.

Those who tested positive for antibodies to LRP4, agrin or both, tended to be sicker when diagnosed and have a more severe disease course, investigators at Case Western Reserve University School of Medicine and the Medical College of Georgia at Augusta University report.

The investigators hope that learning more about antibodies that cause the disease will lead to treatments that target specific antibodies, which should reduce side effects and further improve efficacy.

Patients in the new study had no evidence of long-established antibodies for the receptor for acetylcholine, a chemical released by neurons, which activates muscle cell receptors, or MuSK, an enzyme that supports the clustering of these receptors on the surface of muscle cells and is essential to maintain the function of acetylcholine receptors.

Rather patients recruited for the study had been termed "double negative." Now the investigators say the roughly 85% of study participants who also tested negative for LRP4 and agrin are more accurately termed "quad negative."

Despite increased disease severity, better than 80% of patients with LRP4 and agrin antibodies had their disease moderated by standard therapy that includes a drug that increases acetylcholine levels by decreasing its breakdown as well as immunosuppressive drugs that reduce the body's overall production of antibodies.

All four now-established antibodies that cause myasthenia gravis fit together in a puzzle with the neuromuscular junction as their target, says Dr. Michael H. Rivner, MCG neurologist specializing in neuromuscular disease. "They are all functionally related to the neuromuscular junction even though they do different things," says Rivner, who directs the Electrodiagnostic Medicine Laboratory at MCG's adult teaching hospital AU Medical Center.

He and Dr. Lin Mei, chair of the Department of Neurosciences and Allen C. Holmes Professor of Neurological Diseases at Case Western Reserve University School of Medicine, are long-time collaborators and co-corresponding authors of the new study.

Mei's lab discovered the newer targets, reporting LRP4 antibodies as a new cause of myasthenia gravis in 2013 and agrin antibodies as associated with the disease the next year. Those findings filled important knowledge gaps in how the brain and muscle connect during development and continue to interact lifelong.

For our muscles to contract, they have to get a message from our nerves at the neuromuscular junction, which becomes the target of antibodies in myasthenia gravis. During development, agrin is released by motor neurons to direct construction of the synapse where nerves and muscles connect, then binds to the LRP4 receptor to activate MuSK, an enzyme on the muscle cell surface, which enables a clustering of receptors that are then activated by acetylcholine. While agrin and MuSK work together, they don't directly communicate, which is where LRP4 comes in. Mei's lab found that agrin communicates with LRP4 on the muscle cell surface, then recruits MuSK to join the conversation. LRP4 and MuSK become major components of the receptor needed for the muscle cell to receive the message agrin is sending.

LRP4 and agrin antibodies have been found in patients, and shown to produce myasthenia gravis in laboratory animals but there has been limited published data on their effect in humans.

Previously, about 10% of patients had no evidence of the two other antibodies already known to cause the disease. But they did have classic clinical symptoms such as general fatigue, blurred vision, drooping eyelids, generalized muscle weakness that gets worse with muscle use and, at its most aggressive, problems breathing, swallowing, even talking. When most patients first come to the doctor, it's because they are having problems with their droopy eyes and double vision, Rivner says, as the small muscle fibers and motor units that control them are ready targets for the antibodies.

In the newly published findings, about 70% of patients with the antibodies -- compared with nearly 43% without them -- had generalized symptoms of muscle weakness when they first sought medical care for those symptoms an average of 11 years ago.

Those with the antibodies also had a significantly higher severity of disease, including more eye problems, based on the Myasthenia Gravis Foundation of America's scale, with the state of disease classified as moderate to severe for 75% of the antibody positive patients compared with about 40% of the antibody negative individuals.

At their sickest, about half the patients with the antibodies had a mix of symptoms including difficulty with swallowing and speech, moving their arms and legs and breathing in additon to eye problems. "They started out sicker and became sicker," Rivner says. Twice as many patients in the antibody positive group needed mechanical ventilation support at some point, 11% versus 5% in the antibody negative group.

Regardless of their antibody status, patients were treated with standard therapies for myasthenia gravis including the drug pyridostigmine to improve muscle strength by blocking the breakdown of acetylcholine, plasma exchange to help clear circulating antibodies, and immunosuppressive drugs like prednisone. And most responded well to therapy, the investigators say.

The fact that patients respond to immunosuppressive drugs indicates they are making antibodies, Rivner says, which likely includes the "quad negative" patients. Immunotherapy helps diminish the immune system's attack on the neuromuscular junction, which can enable recovery of this communication point between nerves and muscle and help restore function to patients.

Next steps include analyzing five-year data on an even larger number of patients. They would also like to compare disease severity to patients with the longer-established antibodies.

About 80% of patients with myasthenia gravis have antibodies to the acetylcholine receptor and about 10% have antibodies to MuSK. The investigators chose to look at patients categorized as "double negative" to ensure that those antibodies were not a factor in their disease, Rivner says. However, he suspects many patients with those longer-established antibodies also have one or both of the newer ones.

It's not a surprise to anyone that numerous vertebrate species are being sold at different wildlife markets, but at the moment there is still no comprehensive understanding of how much people are involved in those actions in Laos (Lao PDR), nor what the impact on local wildlife populations really is.

The majority of Laotians live in rural areas and their income largely depends on wildlife. Since wildlife products are used as one of the major food sources, numerous species of terrestrial vertebrates are currently being offered at local markets.

Across the tropical regions, mammals and birds have been vanishing, with recent models estimating up to 83% decline by 2050. Furthermore, wild-caught reptiles have been reported from Southeast Asian wildlife markets for over 20 years, with Laos occupying the position of a very popular source.

Due to the large number of native endemic species, Lao PDR should assume the responsibility to introduce conservation measures to keep control over the predicted population declines. At the moment, the regulations on wildlife use and trade in Laos are mostly based on the Lao Wildlife and Aquatic Law, which, however, largely disregards international statuses of the species and other biological factors.

Stricter and reinforced legislation is needed in the fields related to wildlife trade and consumption, since such practices are not only causing biodiversity loss, but also suggested to pose a great threat of wildlife-associated emergence of zoonotic parasites and pathogens to humans. As an immediate example, the outbreak of the Coronavirus (COVID-19) is primarily considered to be a consequence of human consumption of wild animals.

An international group of students and scientists, led by Professor Dr. Thomas Ziegler at the University of Cologne and the Cologne Zoo (Germany), has conducted a number of extensive surveys on wildlife markets (66 observational surveys at 15 trade hubs) and households (63 households at 14 sites) in the Khammouane Province of Laos. The key question of the survey was: "Which species are traded and to what extent?" The results of the study are published in the open-access journal Nature Conservation.

The surveys showed overlaps between the most traded species at wildlife markets and those of highest conservation importance.

As for the households, approximately 90% of the surveyed respondents confirmed the use of wildlife. For the majority of the population, wildlife harvesting was found to be important for their livelihood and trapping activities were mostly aimed at self-consumption / subsistence. The reason for this could be explained by the prices of domesticated meat, which can be three times as higher as those of wildlife products.

The demand for the species on the wildlife market remained the same over time, according to the opinions of 84,1% of respondents, while the availability of wild meats was reported to have decreased, due to increasing price.

"We recommend local authorities to assess the markets within the province capital Thakhek in particular, as they showed the highest quantity of wild meats. The markets at Namdik and Ban Kok turned out to be very active trade hubs for wildlife as well, regardless of the vertebrate group. The loss of certain species may cause a cascade of unforeseeable effects in the ecosystems. Therefore, the biodiversity of tropical Southeast Asian countries like Lao PDR must be protected.", shares Dr. Thomas Ziegler.

To help the local population to avoid the crisis related to the change of activity and growing unemployment, scientists propose to introduce new activities in the region.

"Eco-tourism presents a great opportunity to combine conservation efforts and an alternative source of income. Former hunters with excellent knowledge of the forest and wildlife habitats can serve as professional wildlife tour guides or their involvement in the Village Forest Protection Group could help to protect natural resources in Laos", suggests Dr. Thomas Ziegler.

Researchers have designed a new X-ray classification system for adult idiopathic scoliosis that can more precisely define which parts of the spine need correction, an achievement that could enhance treatment, communication, and analysis of spinal deformities affecting older patients, according to a study published in Spine Deformity in August.

The team of researchers, led by James D. Lin, MD, MS, a spine surgeon at The Mount Sinai Hospital and Assistant Professor of Orthopedic Surgery at the Icahn School of Medicine at Mount Sinai, said their modern approach to the X-ray classification system could provide a more universal and standard assessment of adult scoliosis.

"This classification system provides a new language for clinicians and researchers, helping us reliably categorize and communicate the radiographic features of adult idiopathic scoliosis, in order to more effectively facilitate treatment and further analysis," said Dr. Lin. "This will help researchers and surgeons scrutinize past results from prior surgeries and refine future treatment."

Scoliosis is a sideways curvature of the spine, a condition that affects an estimated six million people in the United States. Many develop it in adolescence, but only a small percentage of adolescent cases require surgery. While adult scoliosis can be the natural progression of adolescent scoliosis, adults can also develop it for the first time; those cases are called adult degenerative scoliosis. The symptoms and surgical treatment can differ significantly for older patients; for example, adults often experience more pain from the condition.

The new method builds on the Lenke classification system for adolescent idiopathic scoliosis, which is widely used to define six curve types but is not applicable to adults. The new three-component method maintains the curve types from the Lenke classification and introduces assessments of the global alignment and lumbosacral curve, two features that more commonly deteriorate in older patients.

In the study, 12 spine surgeons used the new classification system to grade 30 cases twice, which resulted in near-perfect agreement in the assessment of the patients. This latest method to classify adult scoliosis could improve treatment options because it helps define the different areas of the spine that need to be corrected and fused, and there is currently no widely accepted X-ray classification system for the complex condition.

"The development of a new classification system, led by Dr. Lin, strengthens our efforts at the Spine Center at The Mount Sinai Hospital to provide innovative and customized treatment for patients with spinal disorders and injuries," said Andrew Hecht, MD, Chief of Spine Surgery for the Mount Sinai Health System and The Mount Sinai Hospital, and Director of the Spine Center at Mount Sinai. "The new method ensures that we have a more exhaustive, thorough, and rigorous benchmark in how we analyze and treat adults with spinal conditions throughout the Mount Sinai Health System, but also for our colleagues throughout the entire orthopedic community, helping us all to provide exceptional care."

Leading coma experts have created an ambitious plan to help doctors better care for comatose patients and answer that most awful question: "Will my loved one wake up?"

The three-part plan outlines key steps physicians and researchers should take in the coming years to improve patient care and deepen our understanding of coma and other conditions that reduce consciousness. The plan was developed by a blue-ribbon scientific advisory council as part of the Neurocritical Care Society's Curing Coma Campaign, a major effort launched in 2019.

"We now have the tools to understand comatose patients in a way we haven't in the past. This opens the door to ask the question, 'Can we improve consciousness in patients in a coma?'" said advisory council member and lead author J. Javier Provencio, MD, director of UVA Health's Nerancy Neuroscience Intensive Care Unit. "This research endeavor aims to help patients and families dealing with the consequences of brain damage gain clarity about the current chances for improvement and maintain hope that, in the future, there will be treatments to help recover consciousness."

The Coma Plan's Three Pillars

The plan's first recommendation is to better classify and understand different types of coma and their causes. Current treatments are limited in part because it is difficult for physicians to distinguish between different underlying mechanisms of impaired consciousness, the researchers say. This makes it challenging to predict whether patients will recover.

To improve this, they suggest several different classifications. For example, coma without underlying physical damage, such as those caused by drug overdoses or seizures, are often reversible using available treatments. Those must be treated differently than coma with causes such as brain injuries. Another category is particularly tricky - coma with hidden physical causes. Better categorization of common coma "endotypes" will help physicians with their diagnoses and treatment decisions, the council says.

The council also urges the development of better indicators of patient prognosis. These indicators, known as biomarkers, already play important roles in guiding treatment. But more sophisticated ones are needed to understand the complex interactions occurring inside the brain. This will help doctors guide patients to better outcomes and advise families on how well their loved one will recover.

Finally, the council urges clinical trials of new therapies to promote recovery of consciousness for intensive-care patients who are in comas or suffering from other forms of reduced consciousness.

"We envision that a principled, mechanistic approach to predicting and measuring responses to new therapies in the ICU could allow clinicians to provide targeted treatments that are personalized to each patient, ensuring that each patient is given the best possible chance to recover consciousness in the ICU and beyond," the council members write in a new paper outlining their recommendations.

"Coma is the most severe manifestation of brain injury," Provencio said. "With this initiative, we hope to be able to treat patients in a coma the way we treat patients with strokes and heart attacks. In the future, having impaired consciousness from brain injury won't be the lifelong medical condition it is now."

Unconventional monetary policy does not lead to greater risk-taking by banks, according to new research. This will be welcome news for central banks and policymakers as they ramp up efforts to limit the economic fallout of the pandemic.

"Slashing interest rates is the usual response to a recession, but with rates now at 0.25% the Reserve Bank of Australia (RBA) can't cut any further, so it has now resorted to "unconventional" means to free up funds," says University of Technology Sydney finance researcher Dr Thomas Matthys.

"This means they are buying bonds to add cash to the balance sheets of Australian banks. The idea is that banks then channel this forward to the rest of the economy, providing loans at cheaper rates to individuals and firms, and allowing for extended mortgage holidays," he says.

While these unconventional policies should help to lift the economy, grow asset prices and stem panic on markets, there can also be negative impacts.

Savers will receive a lower deposit rate on their savings accounts, so self-funded retirees will find it harder to get by, and it will become more difficult for banks to get a return on their investments.

Previous research has suggested that when a central bank's policy interest rate goes lower (conventional monetary policy), banks start reaching for yield by investing in riskier loans. This can lead to bank failures and imperil the economy.

So researchers decided to examine whether unconventional monetary policy measures also lead to increased risk taking by the banking sector.

They looked at the syndicated loan market, which is the market for large corporate loans, and the impact of unconventional monetary policy in the US after the global financial crisis in 2008.

With a syndicated loan, two or more banks get together to grant a loan to one corporation - typically larger companies such as miners or retail chains.

What they found was that although, on average, loan interest rates go down following looser monetary policy, this was only the case for firms with sound financial performance.

The researchers found no additional interest rate reduction for riskier firms, which would have pointed to bank risk-taking behaviour.

These results, published in the Journal of International Money and Finance, confirm that, at least in the syndicated loan market, unconventional monetary policy doesn't necessarily lead to increased risk-taking, which is good news for the Reserve Bank and policy-makers.

"While unconventional monetary policy supports the financial system in a crisis, it needs to be complemented by other prudential policies that ensure bank asset quality.

"The Australian Prudential Regulation Authority (APRA) will strike the balance between supporting the economy and ensuring bank risk-taking is kept in check using such instruments as loan to value ratios and capital and liquidity ratios," says Dr Matthys.

Dr Matthys also notes that there are other lessons to be learned from the US and European responses to the 2008 global financial crisis.

"In Europe, unconventional monetary policy did not seem to help businesses as much as it did in the US. This may be because the US was very quick to clean up toxic assets on banks' balance sheets in the midst of the crisis through TARP - the Troubled Asset Relief Program," says Dr Matthys.

"Europe for a long time after the crisis had a legacy of high non-performing loans on bank balance sheets, which contributed to the ineffectiveness of unconventional monetary policy and very low rates. It leaves them with reduced firepower in the face of market instability," he says.

Many countries have a high debt burden, which means that if unemployment rises substantially, it will lead to home loan defaults, which negatively feed back to the stability of the financial system through lower bank income and additional write-offs.

"While the 2008 global financial crisis was a crisis of household debt burdens, companies today also on average have higher debt. This is where unconventional monetary policy may provide relief, as central banks supply liquidity," says Dr Matthys.

With the global COVID-19 pandemic shifting more and more of our work and school online, virtual communities are more important than ever -- but how do we know, without bias, that our online groups are actually successful in helping us with our goals? A team of researchers based in Italy think has proposed the first objective metric to assess the effectiveness of virtual groups. They published their results on IEEE/CAA Journal of Automatica Sinica.

"Group formation is a key issue in social communities due to the importance of establishing an effective organization in which users perform actions that could benefit from collaboration and mutual social interactions," said the author Giancarlo Fortino, professor of computer engineering in the DIMES Department of the University of Calabria. "Is it possible to form effective groups in virtual communities by exploiting trust information without significant overhead, similarly to real user communities?"

Facebook, for example, reached 2.4 billion active users in 2019, and, in the last five years, more than one billion groups have formed on the platform. In each group, individuals must trust that the group will provide some value to them, whether it is in the form of humor or parenting tips or product reviews. The group, in turn, must determine the value the individual will add to their group, as well as how important that value is, when admitting members.

"In general, the ability of the members of the same groups to have positive interactions will improve the social capital -- or, simply, the effectiveness -- of the community which represents the group itself," Fortino said. In the team's previous research, they proposed that individual members who trust each other and their contributions to a group enforces the cohesiveness of a group even as more members who are not directly connected join, such as friends of friends. "In this work, we address the general problem of forming effective groups."

The researchers examined interaction data from 34,541 individuals on two Italian-based social networks, EPINIONS and CIAO.

"EPINIONS and CIAO users review items and assign them numeric ratings," Fortino said. "Users can also build their own trust network by adding the people whose reviews they think are valuable."

Fortino and the researchers analyzed three classes of users, from most valued to least valued in their reviews. They found that when one user had limited or inadequate interactions with another user, they would turn to their network of friends to determine trustworthiness.

"It's similar to real communities," Fortino said. "We have implemented this strategy in our algorithm to form groups in virtual communities based on a weighted voting mechanism, whereby each vote is represented by a trust value obtained by a suitable combination of reliability and local reputation."

The strategy, when applied to the social network data, significantly improved the overall trust value of groups. The researchers are now studying the trust value metric in more complex configurations of the groups.

The female reproductive tract has the final say in human mate choice, according to new research from the University of Eastern Finland.

Achieving pregnancy has been shown to be more likely between partners who carry dissimilar human leucocyte antigen (HLA) immune genes. Accordingly, humans are expected to choose HLA dissimilar reproductive partners. Earlier studies have demonstrated that HLA dissimilarity preferences are mediated either by body odours or facial preferences. However, it has been unclear whether HLA-based mating preferences could occur after sexual intercourse in the female reproductive tract. Researchers at the University of Eastern Finland have now shown that the women's reproductive tract is capable of mediating post-mating sexual selection (known as the "cryptic female choice") towards the sperm of HLA dissimilar men. This indicates that the ultimate mating bias towards genetically compatible partners occurs only after mating, at the gamete level.

The researchers conducted two experiments, where they activated sperm from multiple men with follicular fluid (the oocyte surrounding bioactive liquid) or cervical mucus from several different women. Then they examined sperm motility and other functionally important physiological changes of sperm in all possible male-female combinations. All the participants were also genotyped for their Human Leucocyte Antigen (HLA) class I and II alleles.

In both studies, the results showed that the fertilisation capability and viability of sperm are strongly dependent on the male-female combination. In other words, women's reproductive secretions had a stronger effect on the sperm performance of some males than others. Both datasets also showed that the sperm performance was better in HLA dissimilar male-female combinations than in HLA similar males and females.

Together, the results indicate that the fertilisation capability of sperm is dependent on the immunogenetic compatibility of the reproductive partners and that the fusion of the gametes may be a highly selective process.

"These findings can have important implications for a deeper understanding of sexual selection and the fertilisation process in humans and other mammals," Associate Professor Jukka Kekäläinen from the University of Eastern Finland says.

"Since the gametes of some partners may be immunologically more compatible than others, our results may also open up novel possibilities for the development of more accurate infertility diagnostics," Annalaura Jokiniemi, MSc, adds.

WASHINGTON, August 18, 2020 -- Trace vapor detection technologies are crucial for ensuring reliable and safe detection of explosives and illegal drugs. Researchers from the U.S. Naval Research Laboratory have developed a compact testing device called the Trace Vapor Generator for Explosives and Narcotics (TV-Gen), which is portable and can be used for non-contact sampling of these vapors.

In the journal Review of Scientific Instruments, published by AIP Publishing, the team reports the TV-Gen can accurately generate trace vapors of low vapor pressure compounds, such as explosives or narcotics, and can produce vapors in complex backgrounds.

"We can use the TV-Gen in the early stages of sensor development, where the developer is just determining if their proposed sensing material responds to a target analyte, all the way to determining instrument and assay limits of detection for hand-held trace detectors and hyphenated instrumentation," said author Braden Giordano.

This device is the next generation of the Test Explosive Sensor (TESTbed) developed for the Department of Homeland Security, with advanced vapor mixing and a smaller footprint, making transport to other laboratories or into the field possible.

"The TV-Gen is significantly smaller than the TESTbed, and while providing only a single sample port for device evaluation, it maintains or improves upon the older systems' performance metrics," said Giordano. "It can fit on a small cart, so you can bring the vapor source to your technology, not the technology to the vapor source."

The device can provide a stable vapor for several hours and can rapidly switch between a clean vapor stream and an analyte vapor stream while matching humidity.

"An interesting application that will be taking place this year is testing detector canines to get quantitative measurements of olfactory detection threshold and, potentially in the future, be able to compare canines directly to instrument for the first time," said Giordano.

The researchers hope to continue meeting the needs of the vapor detection community by expanding the library of vapors and exploring methods to maximize vapor generation efficacy at lower operating temperatures.

An enzyme that usually stops bacterial growth in the large intestine stimulates inflammation in some people, resulting in ulcerative colitis - a chronic digestive disease that affects more than 750,000 Americans, according to scientists at Rutgers University-Newark.

In a new study published in Immunity, lead author Nan Gao, Associate Professor of Cell Biology in the Department of Biological Sciences, School of Arts and Sciences-Newark, reports that in people with ulcerative colitis, the gut enzyme lysozyme which normally functions to restrain bacterial growth, instead stimulates inflammation.

This results in the formation of ulcers and sores in the large intestine and rectum, hallmarks of the inflammatory bowel disease. Detecting these cells in the inner lining of the colon and rectum is a standard diagnostic feature of chronic intestinal inflammation.

"This study demonstrated the existence of a delicate balance between inflammatory and anti-inflammatory factors in our intestines," said Gao, who conducted it with postdoctoral researcher Richard Yu and doctoral student Iyshwarya Balasubramanian. "Insights about how to gain such beneficial immune balance may be useful for future intervention of inflammatory bowel disease."

In biochemical and genetic mouse laboratory studies, Gao and his team focused on Paneth cells, the main producers of lysozyme, which are typically found in the small intestine and rarely observed in the large intestine or healthy colon. In cases of patients with inflammatory bowel disease, which affects 1.6 million people in the US, Paneth cells are often seen in the colon and rectum.

"The frequent appearance of Paneth cells in the inflamed tissues of patients colons is highly unusual and poorly understood," Gao said.

In the Rutgers-Newark study, scientists discovered that lysozyme secreted by Paneth cells located in colon results in suppressing the growth of certain bacterial species and results in an imbalance in the gut microbiome which leads to intestinal inflammation.

In healthy individuals that have normal production of gut lysozyme, these bacteria flourish enabling an individual immune response that prevents colitis.

"This delicate balance is achieved and maintained by a constant interaction between our body and the commensal microorganisms that play a significant role in digestion, metabolism, and the immune system," Gao said.

Nearly three-quarters of older adults with dementia have filled prescriptions for medicines that act on their brain and nervous system, but aren't designed for dementia, a new study shows.

That's despite the special risks that such drugs carry for older adults -- and the lack of evidence that they actually ease the dementia-related behavior problems that often prompt a doctor's prescription in patients with Alzheimer's disease and related disorders. In fact, some of the drugs have been linked to worse cognitive symptoms in old adults.

The study looks at several classes of psychoactive drugs, including ones that the federal government has actively encouraged nursing homes to limit using in residents with dementia. The new study suggests a need to reduce prescribing to people living at home with dementia, too.

In all, 73.5% of the study's community-based population filled at least one prescription for an antidepressant, opioid painkiller, epilepsy drug, anxiety medication or antipsychotic drug in a one-year period, according to Medicare prescription records.

The percentages generally were even higher among women, non-Hispanic white patients, people in their late 60s and early 70s, and people with low incomes.

The study is published in the journal JAMA and based on data from 737,839 people with dementia, and is the first large-scale study of prescription-filling patterns for psychoactive medications outside of nursing homes and other long-term care facilities.

Nearly half of those in the study received an antidepressant, which might be prescribed to try to counteract the withdrawal and apathy often seen in dementia, says lead author Donovan Maust, M.D., M.S., a geriatric psychiatrist at the University of Michigan and VA Ann Arbor Healthcare System. Unfortunately, antidepressants don't treat this aspect of dementia, he says.

Even so, the study shows antidepressant prescribing at nearly triple the rate for older adults overall.

Meanwhile, for each of the other drug types studied, nearly a quarter of the adults with dementia filled at least one prescription.

"As a nation we have a goal of keeping dementia patients living in the community as much as possible. But the use of these medications appears to be as high for them as it is for those who are in nursing homes," says Maust, who specializes in helping patients with dementia-related behavioral issues at Michigan Medicine, U-M's academic medical center. "Clinicians and caregivers may need more support to provide non-drug based approaches to prevent or address the symptoms that these medications are probably being prescribed for."

Known risks

None of the drug classes studied has received U.S. Food and Drug Administration approval for use in dementia, and Maust says that evidence for their off-label use is slim.

But all of the drugs are associated with special risks to people in their 60s and older, including falls or dependence that could lead to withdrawal. Most are included on the list known as the Beers criteria, which identifies medications with extra risks for all older adults, not just those with dementia.

While there is limited evidence that antidepressants help people with dementia, Maust notes that someone who had depression before they developed dementia might benefit from staying on a drug that worked for them in the past.

And while there is little evidence of benefit, all these medications have side effects. For example, some people starting a new antidepressant can experience nausea or feel a little "jittery." Unfortunately, a person with dementia might have difficulty articulating such side effects to the loved one who takes care of them. Instead, they may appear more agitated - leading to another prescription medication to calm them.

While the current study doesn't look at polypharmacy - the use of multiple psychoactive drugs by the same patient - Maust is exploring this issue further in the Medicare data.

The long haul

Maust notes that, of the 29% who received opioids, they most often filled just one or two short-term prescriptions, which may indicate treatment of an injury or acute pain.

But those receiving other drugs tended to fill multiple prescriptions in the year that Maust and his colleagues studied. This included epilepsy drugs that are sometimes prescribed as substitutes for antipsychotic drugs, or to treat chronic pain.

Taking these drugs for months on end is especially risky, says Maust. "A brain that has dementia is doing its best to function as well as it can," he explains. "If we add a psychotropic medication into the mix it may not be a helpful thing - and it comes with risks."

One bright spot in the data, Maust says, is that only one in five of the dementia patients studied had filled a prescription for an antipsychotic medicine such as Abilify, Seroquel or Risperdal. Because of the safety risks associated with antipsychotics, they have received a lot of regulatory attention and professional guidelines such as the "Choosing Wisely" for physicians urge caution.

On the other hand, this class of drugs has more evidence than the others that it actually helps some patients with behavioral problems such as aggression. "So it is worrisome that all the other classes -- which have less evidence of benefit -- are all prescribed more widely," says Maust.

Better education needed

In addition to helping caregivers and clinicians understand both the lack of evidence and the elevated risks that come with psychoactive medications, and to learn the non-drug caregiving strategies they can use to reduce behavioral issues in the person they're caring for, Maust notes they may just need better education about the disease itself.

Accessing support services through local, state and federal agencies, including Area Agency on Aging programs, and nonprofits such as the Alzheimer's Association and AARP, could help caregivers too, he says.

"Apathy and withdrawal, and a tendency to get agitated, are common symptoms of dementia," he says. "And as much as health care providers want to help these patients and their family caregivers, these medications are just not helpful enough to justify this amount of prescribing."

What The Study Did: Researchers looked at the association between race and death among patients hospitalized with COVID-19 at 92 hospitals in 12 states.

Authors: Baligh R. Yehia, M.D., M.P.P., of Ascension Health in St. Louis, is the corresponding author.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jamanetworkopen.2020.18039)

Editor's Note: The article includes conflict of interest disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.