Culture

EAST LANSING, Mich. - For Michigan State University's Felicia Wu, the surprise isn't that people who work with livestock are at higher risk of picking up antibiotic-resistant bacteria, but instead how much higher their risk levels are.

"This is a bit of a wakeup call," said Wu, John. A Hannah Distinguished Professor in the Departments of Food Science and Human Nutrition and Agricultural, Food and Resource Economics. "I don't think there was much awareness that swine workers are at such high risk, for example. Or that large animal vets are also at extremely high risk."

Compared with individuals who don't work with animals, those working on swine farms are more than 15 times more likely to harbor a particular strain of a bacterium known as methicillin-resistant Staphylococcus aureus, or MRSA, acquired from livestock. For cattle workers, that number is nearly 12. For livestock veterinarians, it approaches eight.

Wu and Chen Chen, a research assistant professor in the Department of Food Science and Human Nutrition, published their findings, along with the risk factors for other related professions, in the journal Occupational & Environmental Medicine. Their paper highlights these elevated risks, what farmers can do to protect themselves and what we understand about the public health burden posed by livestock-associated MRSA.

"Livestock-associated MRSA is a strain of MRSA that is especially infectious among animals. Now it has evolved to infect humans as well," said Wu, who was recently named a fellow of the Society for Risk Analysis. "Bacteria have shown an amazing ability to jump across species to colonize and cause infections."

Livestock-associated MRSA is a zoonotic disease, a disease that can transmit between animals and humans. Such diseases can have devastating consequences for human health. The novel coronavirus pandemic, for example, was caused by a virus that likely originated in bats.

Although the novel coronavirus and livestock-associated MRSA work and spread in different ways, they both are a reminder that when people understand the risks posed by such diseases, they do have some power to minimize them. For example, good hygienic practices and policies supported by science can make meaningful differences, especially in the case of livestock-acquired MRSA, Wu said.

"The final message is that we need to protect our health and the health of our animals," she said. "We don't have control over bats, but we do have some level of control over how we raise and handle our poultry, cattle and swine."

Although it's possible to carry MRSA without it becoming a problem, the bacteria can cause serious infections when given the chance. Livestock-associated MRSA was first documented in the early 2000s and appears to be less dangerous to humans than MRSA that evolved in health care settings, where it built up defenses against a range of antibiotics.

The livestock-associated strain also appears to be less prevalent than community-associated MRSA, caused by bacteria lurking in gyms, schools and workplaces, which are typically more treatable than their counterparts found in hospitals and doctors' offices.

For these reasons, livestock-associated MRSA doesn't garner as much attention as other strains, but there's still much to learn about the bacteria from livestock and their impact on human health, Wu said. When she first came to MSU in 2013, she became interested in how the growing problem of antibiotic resistance was being influenced by bacteria that jumped to humans from livestock.

"We don't understand how much of that problem we have in human populations," said Wu. "This particular paper is trying understand one aspect of that."

To calculate the risk levels of acquiring livestock-associated MRSA, Wu and Chen combed through 15 years of published literature, extracting data about the likelihood of people acquiring the bacteria based on their livestock-related profession. The risk was elevated for every occupation they studied: vets, slaughterhouse employees and people who worked with swine, horses, cattle and poultry.

But there is also positive news to share along with the unsettling risk numbers. In 2017, the U.S. Food and Drug Administration introduced rules and monitoring programs to curb the use of antibiotics. Farmers can still use antibiotics to treat and prevent disease, but the agency forbid the use of antibiotics to spur animal growth. This has reduced the pressure on bacteria in agriculture settings to evolve resistance to antibiotics.

There are also a number of straightforward precautions individuals can take to help protect themselves and their animals. MRSA lives on soft tissue -- on people's skin and in their noses -- and can do so without causing harm when that tissue is intact. Reducing exposure of broken skin to the environment by keeping cuts and open wounds clean and covered can help reduce the risk of infection. Other simple steps, like regular hand-washing along with wearing gloves and protective clothing, can also stem the spread of livestock-acquired MRSA.

"Once the bacteria get a hold in an environment, they are really, really hard to get rid of," said Wu. "Reducing the risk of antibiotic-resistant infections is one of the main goals that farmers have"

The increased global use of antiviral and antiretroviral medication could have a detrimental impact on crops and potentially heighten resistance to their effects, new research has suggested.

Scientists from the UK and Kenya found that lettuce plants exposed to a higher concentration of four commonly-used drugs could be more than a third smaller in biomass than those grown in a drug-free environment.

They also examined how the chemicals transferred throughout the crop and found that, in some cases, concentrations were as strong in the leaves as they were in the roots.

The study - published in Science of the Total Environment - was conducted by environmental chemists from the University of Plymouth (UK), Kisii University (Kenya) and Jomo Kenyatta University of Agriculture and Technology (Kenya).

It is one of the first worldwide to examine the impact of pharmaceutical compounds on agriculture, and to consider the subsequent risks for consumers.

For it, scientists focused on the drugs nevirapine, lamivudine and efavirenz - which are used to treat and prevent HIV/AIDS - and oseltamivir, which stops the spread of the flu virus in the body.

However, they say it is also relevant in light of the current COVID-19 pandemic, with antiviral medications having been approved for use to treat those affected by the virus.

Such compounds get into soils when they are irrigated with contaminated surface water, treated or untreated waste water, sewage sludge and biosolids.

Through a series of analyses, they showed there were differing levels of uptake across the four drugs with lamivudine exhibiting the lowest bioaccumulation - a level similar to that shown previously with caffeine.

However, when exposed to a combination of the four drugs (as would be found in the wider environment) mean leaf and root mass was reduced by 34%.

Preston Akenga, PhD researcher and the study's lead author, said: "The occurrence of pharmaceutical compounds in the environment is well documented. While the environmental levels measured may not pose a direct threat to human health, evidence of ecological effects in both aquatic and terrestrial systems demonstrates an environmental impact that could be significant if left unchecked."

The research team has previously suggested that failure to ensure the environmental sustainability of growing patient access to medicines in developing economies could increase the risk of adverse environmental impacts.

They also published research highlighting that the increased use of antibiotics in people with COVID-19 could be placing an additional burden on waste water treatment works and resulting in increased resistance to the drugs' benefits among the wider population.

Mark Fitzsimons, Professor of Environment Chemistry and a co-author on the research, said: "The successful trialling of antiviral drugs in the treatment of COVID-19 is positive for human health outcomes, but may result in significant additional input of pharmaceutical compounds to the environment leading to unintended ecological consequences."

Sean Comber, Professor of Environment Chemistry and the senior author on the research, added: "We hope this is the start of taking the fate and behaviour of antibiotic and antiviral drugs in the environment seriously. We can therefore link the prescription and the consequences for the benefit of both the patient and the ecosystem as a whole."

An international team of researchers has characterized the effect and molecular mechanisms of an amino acid change in the SARS-CoV-2 Spike protein N439K. Viruses with this mutation are both common and rapidly spreading around the globe. The peer reviewed version of the study appears January 25 in the journal Cell.

Investigators found that viruses carrying this mutation are similar to the wild-type virus in their virulence and ability to spread but can bind to the human angiotensin converting enzyme 2 (ACE2) receptor more strongly. Importantly, researchers show that this mutation confers resistance to some individual's serum antibodies and against many neutralizing monoclonal antibodies, including one that is part of a treatment authorized for emergency use by the U.S. Food and Drug Administration.

"This means that the virus has many ways to alter the immunodominant domain to evade immunity while retaining the ability to infect and cause disease," says senior author Gyorgy Snell, Senior Director of Structural Biology at Vir Biotechnology. "A significant finding from this paper is the extent of variability found in the immunodominant receptor binding motif (RBM) on the spike protein."

Although the recently emerged UK variant, B.1.1.7, and the South African variant, B.1.351, have garnered more attention to date, the N439K mutation is the second most common in the receptor binding domain (RBD). The N439K mutation was first detected in Scotland in March 2020 and since then, a second lineage (B.1.258) has independently emerged in other European countries, which, by January 2021, was detected in more than 30 countries across the globe.

The Cell study also reports the X-ray crystal structure of the N439K RBD. "Our structural analysis demonstrates that this new mutation introduces an additional interaction between the virus and the ACE2 receptor," Snell says. "A single amino acid change (asparagine to lysine) enables the formation of a new point of contact with the ACE2 receptor, in line with the measured two-fold increase in binding affinity. Therefore, the mutation both improves interaction with the viral receptor ACE2 and evades antibody-mediated immunity."

Once researchers determined that the N439K mutation did not change virus replication, they studied whether it allowed evasion of antibody-mediated immunity by analyzing the binding of more than 440 polyclonal sera samples and more than 140 monoclonal antibodies from recovered patients. They found that binding of a proportion of both monoclonal antibodies and serum samples were significantly diminished by N439K. Importantly, the N439K mutation allowed pseudoviruses to resist neutralization by a monoclonal antibody that has been approved by the FDA for emergency use as part of a two-antibody cocktail. One way around this problem, researchers say, could be the use of antibodies that target highly conserved sites on the RBD. "The virus is evolving on multiple fronts to try to evade the antibody response," Snell says.

He notes that one of the challenges in studying SARS-CoV-2 variants is the limited amount of sequencing that's currently being done overall: more than 90 million cases of COVID-19 have been recorded and only about 350,000 virus variants have been sequenced. "That's only 0.4%--just the tip of the iceberg," he says. "This underscores the need for broad surveillance, a detailed understanding of the molecular mechanisms of the mutations, and for the development of therapies with a high barrier to resistance against variants circulating today and those that will emerge in the future."

A new position paper by an International Osteoporosis Foundation (IOF) Fracture Working Group reviews the clinical significance of vertebral fractures, and the rationale for performing vertebral fracture assessment (VFA) routinely within post-fracture care coordination programs such as fracture liaison services (FLS). [1]

VFA is a tool available on modern dual-energy X-ray absorptiometry (DXA) scanners which allows the detection of previous vertebral fractures by providing a lateral view of the spine during a regular DXA bone mineral density measurement of the hip and spine.

Professor Willem Lems, corresponding author of the position paper, stated:

"Vertebral fractures are independent risk factors for future vertebral and non-vertebral fractures. Yet the majority occur without the signs and symptoms of an acute fracture, and they often remain undetected. Routine use of VFA technology would allow fracture liaison services to detect more undiagnosed vertebral fractures and to identify, assess and monitor more high-risk patients in need of treatment."

With the availability of powerful anabolic therapies, which appear to act more rapidly than do anti-resorptives, IOF and ESCEO have set out recommendations for stratification of treatment according to baseline FRAX probability [2]. VFA detection of occult vertebral fractures in the FLS thus offers a valuable opportunity to further refine fracture risk assessment and to tailor treatment accordingly. Furthermore, awareness of baseline vertebral fractures facilitates definition of true new vertebral fracture events occurring during anti-osteoporosis treatment, and therefore enhances optimal monitoring and informs decisions to adjustment therapy if required.

FLS are important service models for delivering secondary fracture prevention for older adults presenting with a fragility fracture. The IOF Capture the Fracture® program's Best Practice Framework, the leading global initiative in support of secondary fracture prevention delivery through FLS, defines the essential and aspirational elements of service delivery for fracture care [3]. A questionnaire-based study of international FLSs based on the Best Practice Framework found that secondary fracture prevention is best delivered for hip fractures and remains suboptimal for vertebral fractures, where the care gap is clearly wider. [4].

Professor Nicholas Harvey, co-author and Chair of the IOF Committee of Scientific Advisors, noted:

"This position paper, the result of the close international collaboration between colleagues in the IOF Fracture Working Group and the MRC Lifecourse Epidemiology Unit, University of Southampton, documents the substantial potential for the improved detection of vertebral fractures within fracture liaison services. The findings are perfectly synergistic with recent guidelines from IOF and ESCEO which set out a personalised medicine approach to treatment based on level of fracture risk. VFA thus offers a useful tool in the FLS with which to further characterise risk and so select the most appropriate treatment for an individual patient."

CHAPEL HILL, NC - Many molecules in our bodies help our immune system keep us healthy without overreacting so much that our immune cells cause problems, such as autoimmune diseases. One molecule, called AIM2, is part of our innate immunity - a defense system established since birth - to fight pathogens and keep us healthy. But little was known about AIM2's contribution to T cell adaptive immunity - defenses developed in response to particular pathogens and health problems we develop over the course of our lives.

Now, UNC School of Medicine scientists led by Jenny Ting, PhD, the William Kenan Distinguished Professor of Genetics, and Yisong Wan, PhD, professor of microbiology and immunology, discovered that AIM2 is important for the proper function of regulatory T cells, or Treg cells, and plays a key role in mitigating autoimmune disease. Treg cells are a seminal population of adaptive immune cells that prevents an overzealous immune response, such as those that occurs in autoimmune diseases.

Published in Nature, the research shows that AIM2 is actually expressed at a much higher level in Treg cells of the adaptive immune system than in innate immune cells.

"Our study unveils an unexpected and previously unappreciated role for AIM2 in Treg cells in adaptive immunity, which is independent of AIM2's classic function in the innate immunity," said Ting, co-senior author of the study, member of the UNC Lineberger Comprehensive Cancer Center, and director of the Center for Translational Immunology.

Wan, co-senior author and member of the UNC Lineberger Comprehensive Cancer Center, added, "Because Treg cells are well-known players in a broad range of diseases including autoimmunity, inflammation, and cancers, our findings will help us identify new molecular targets and develop new therapeutic strategies to test against debilitating and fatal diseases."

Normal immune responses are carried out by both innate immunity and adaptive immunity to fight pathogens and maintain biological stability. But these responses need to be regulated so they do not escalate and cause a whole host of different health problems aside from what the pathogen originally caused. Distinct cell types and molecules play discrete roles in the down-regulation of innate immunity and adaptive immunity. This work shows that AIM2, in Treg cells, is one of them. Treg cells dampen over-exuberant immune responses, and so they are critical for the check-and-balance of the immunity system.

Impaired function of Treg cells often perturbs immune system stability and can trigger autoimmune and inflammatory diseases.

In lab experiments led by first author Wei-Chun Chou, PhD, research associate in the Ting Lab, the UNC scientists found that AIM2 was expressed at a much higher level in Treg cells than in innate immune cells, in both mice and humans.

"This suggests a big role for AIM2 in Treg cells," Chou said. "We found that AIM2 is important to maintain the normal function of Treg cells, which could not effectively protect mice from developing autoimmune encephalomyelitis and inflammatory colitis without AIM2."

Those two conditions are models of the human diseases multiple sclerosis and colitis.

"We conducted further molecular and biochemical analysis to reveal a new, cellular signaling pathway of protein molecules in Treg cells - called the AIM2-RACK1-PP2A-AKT pathway - which regulates the metabolism and function of Treg cells to mitigate autoimmune disease."

DURHAM, N.C. -- When their manhood is threatened, some men respond aggressively, but not all. New research from Duke University suggests who may be most triggered by such threats - younger men whose sense of masculinity depends heavily on other people's opinions.

"Our results suggest that the more social pressure a man feels to be masculine, the more aggressive he may be," said Adam Stanaland, a Ph.D. candidate in psychology and public policy at Duke and the study's lead author.

"When those men feel they are not living up to strict gender norms, they may feel the need to act aggressively to prove their manhood -- to 'be a man'."

The pair of studies considered 195 undergraduate students and a random pool of 391 men ages 18 to 56.

Study participants were asked a series of questions about "gender knowledge." For men, these included questions on such stereotypical topics such as sports, auto mechanics and home repair. After answering, participants were randomly told their score was either higher or lower than that of an average person of their gender.

To simulate real-world threats to manhood, men who received a low score were also told they were "less manly than the average man."

After receiving their quiz scores, study participants were asked to complete a series of word fragments by adding missing letters, in order to reveal their state of mind. The results were striking, revealing aggressive thoughts among certain men but not others.

Men whose sense of masculinity came from within seemed unruffled by receiving a low score. It was a different story for men with a more fragile sense of masculinity, whose feelings of masculinity relied on others. That group included men who said they behaved "like a man" due to social pressures such as the desire to fit in, be liked or get dates.

Men with a more fragile sense of masculinity responded to the word fragments by creating words with violent associations rather than neutral meanings. For instance, when provided with the letters "ki" and asked to complete the word, they wrote "kill" rather than, say, "kiss." When given the letters "blo," they typed "blood" instead of a word such as "blow" or "bloom."

Those aggressive responses were strongest among the youngest study participants, men between 18 and 29 years old. The response was milder among middle-aged men between ages 30 and 37, and milder still among the oldest group of participants, men ages 38 years old and older.

"It's clear that younger men are more sensitive to threats against their masculinity," Stanaland said.

"In those years, as men attempt to find or prove their place in society, their masculine identity may be more fragile. In many places, this means that younger men are hit constantly with threats to their manhood. They have to prove their manhood every day of their lives."

Female students did not display a similar aggressive response when their gender was threatened.

Men's aggressive responses didn't end with the study questionnaire, the researchers noted. The study designers received violent threats from some men who received low scores - further evidence that the study hit a nerve.

Stanaland said he hopes to delve further into the forces that shape men's aggression.

"Men report aggressive behavior in all sorts of domains," Stanaland said. "Some of them are trying to prove their own manhood by being aggressive.

"Men's violence, terrorism, violence against women, political aggression - fragile masculinity may explain many of these behaviors. It's in everyone's interest to understand this phenomenon better."

Tiny molecular forces at the surface of water droplets can play a big role in laser output emissions. As the most fundamental matrix of life, water drives numerous essential biological activities, through interactions with biomolecules and organisms. Studying the mechanical effects of water-involved interactions contributes to the understanding of biochemical processes. According to Yu-Cheng Chen, professor of electronic engineering at Nanyang Technological University (NTU), "As water interacts with a surface, the hydrophobicity at the bio-interface mainly determines the mechanical equilibrium of the water. Molecular hydrophobicity at the interface can serve as the basis for monitoring subtle biomolecular interactions and dynamics."

Water droplets have been used to form biological microlasers that exploit water's intrinsic ability to confine light with minimal scattering. Droplet lasers benefit from laser oscillation in a microcavity, so any subtle changes induced by the gain medium or cavity can be amplified, leading to dramatic changes of laser emission characteristics. While droplet lasers have become cutting-edge platforms in biochemical/physical studies and biomedical applications, the optical interaction between droplet resonators and an interface has remained unknown.

As reported in Advanced Photonics, Chen's NTU team recently discovered that when a water droplet interacts with a surface to form a contact angle, the interfacial molecular forces determine the geometry of a droplet resonator. Dramatic mechanical changes at the interface play a significant role in the optical oscillation of droplet resonators.

Chen's group discovered an oscillation mechanism of droplet resonators, in which the laser resonates along the droplet-air interface in the vertical plane. Chen notes that this vertically oriented "rainbow-like" or "arc-like" lasing mode reflects back and forth between the two ends of the droplet interface, forming a unique and extremely strong laser emission. Chen's team noticed that, unlike the commonly seen whispering-gallery mode (WGM), this newly discovered lasing mechanism is much more sensitive to interfacial molecular forces. According to Chen, "The lasing emissions of this arc-like mode increase dramatically with the increment of interfacial hydrophobicity, as well as droplet contact angle."

Seeking to explain this modulating phenomenon, Chen's team also found that the quality- factor of new lasing modes increased significantly with an increasing droplet contact angle. And the number of oscillation paths of lasing modes in droplets increased dramatically. "Together, these two factors determine the enhancement of lasing emissions with the strength of interfacial molecular forces," says Chen.

Based on their discovery, Chen's team explored the possibility of employing droplet lasers to record mechanical changes at biointerfaces. As anticipated, they found that a tiny change of interfacial biomolecular forces, induced by a very low concentration of biomolecules, such as peptides or proteins, can be recorded by the lasing emissions of droplet lasers.

According to Chen, "This work demonstrates an important modulating mechanism in droplet resonators and shows the potential for exploiting optical resonators to amplify the changes of intermolecular forces." Lasing mechanism insights open new prospects for using microlasers to study biomechanical interactions and interface physics. As droplet lasers may provide a new platform for studying the intermolecular physical interactions at the interface, they could be particularly useful for examining hydrophobic interactions, which play a vital role in numerous physical dynamics and biological systems.

BOSTON-Boston Medical Center has released a study that shows post overdose outreach programs in Massachusetts have expanded across the state, as 44 percent of municipalities reported having such programs available - a majority established since 2015 - to reduce risks for those who survive an overdose. The results are published online in the February 2021 issue of Drug and Alcohol Dependence.

These post-overdose outreach programs leverage collaborations between public health overdose prevention practitioners and public safety organizations (police, fire, EMS) to engage overdose survivors and/or their social networks (family, friends, and acquaintances) at their home one to three days after an overdose. Individuals who survive an overdose are at higher risk for future overdose (Caudarella et al., 2016). The research team completed a statewide cross-sectional survey to identify and characterize these programs to develop strategies that should be further studied to determine best practice guidelines for these programs.

Municipalities that reported having a post-overdose outreach program were asked to complete a detailed survey characterizing their programs. The researchers found that the outreach teams relied on 911 call data to identify overdose survivors, and that outreach teams often comprised staff from community-based public health organizations and police departments. Outreach teams provide or refer individuals to a wide variety of services including inpatient addiction treatment, recovery support, outpatient medication, overdose prevention education, and naloxone.

"We know that post-overdose outreach programs will continue expanding, which means we need to conduct additional research in order to determine evidence-based best practices that will reduce subsequent overdose," said Alex Walley, MD, MSc, a physician and addiction medicine expert at Boston Medical Center who is the study's senior author. Walley is currently principal investigator on research to evaluate the effectiveness of these programs at reducing overdose rates. This project is funded by the Centers for Disease Control and Prevention (R01CE002052).

Laser-induced breakdown spectroscopy (LIBS) is a rapid chemical analysis tool. A powerful laser pulse is focused on a sample to create a microplasma. The elemental or molecular emission spectra from that microplasma can be used to determine the elemental composition of the sample.

Compared with more traditional technology, like atomic absorption spectroscopy and inductively coupled plasma optical emission spectroscopy (ICP-OES), LIBS has some unique advantages: no sample pretreatment, simultaneous multi-element detection, and real-time noncontact measurements. These advantages make it suitable for practical analysis of solids, gases, and liquids.

Traditional LIBS and extensions

Traditional LIBS systems based on a nanosecond pulse laser (ns-LIBS) have some disadvantages due to laser power intensity, long pulse duration, and the plasma shielding effect. These issues adversely affect its reproducibility and signal-to-noise ratio. Femtosecond LIBS (fs-LIBS) can exclude the plasma shielding effect since the ultrashort pulse duration limits the laser-matter interaction time. The femtosecond pulse has a high power density so materials can be effectively ionized and dissociated, leading to a higher signal-to-background ratio and more precise spectral resolution.

Filament-induced breakdown spectroscopy (FIBS) combines the LIBS technique with a femtosecond laser filament. A single laser filament results from the interplay between the Kerr self-focusing and plasma defocusing mechanisms present in the propagation of an ultrashort, high-intensity beam in a transparent medium such as atmospheric air. The femtosecond laser filament produces a long and stable laser plasma channel, which guarantees the stability of the laser power density and can improve measurement stability. However, the power and electron densities saturate when the laser energy increases. This is known as laser intensity clamping effect, and it limits the detection sensitivity of FIBS.

Plasma grating

Fortunately, the laser intensity clamping effect can be overcome through a plasma grating induced by the nonlinear interaction of multiple femtosecond filaments. The electron density in the plasma grating has been proven to be an order of magnitude higher than that in a filament.

Based on that insight, researchers under the leadership of Heping Zeng at East China Normal University in Shanghai recently demonstrated a novel technique: plasma-grating-induced breakdown spectroscopy (GIBS). GIBS can effectively overcome the drawbacks of ns-LIBS, fs-LIBS, and FIBS. With GIBS, the signal intensity is enhanced more than three times and the lifetime of plasma induced by plasma grating is approximately double of that obtained by FIBS with the same initial pulse. Quantitative analysis is feasible because of the absence of plasma shielding effects, the high power, and the electron density of femtosecond plasma grating.

The study of warm dense matter helps us understand what is going on inside giant planets, brown dwarfs, and neutron stars. However, this state of matter, which exhibits properties of both solids and plasmas, does not occur naturally on Earth. It can be produced artificially in the lab using large X-ray experiments, albeit only at a small scale and for short periods of time. Theoretical and numerical models are essential to evaluate these experiments, which are impossible to interpret without formulas, algorithms, and simulations. Scientists at the Center for Advanced Systems Understanding (CASUS) at the Helmholtz-Zentrum Dresden-Rossendorf (HZDR) have now developed a method to evaluate such experiments more effectively and faster than before.

Describing the exotic state of warm dense matter poses an extraordinary challenge to researchers. For one, common models of plasma physics cannot handle the high densities that are prevalent in this state. And for another, even models for condensed matter are no longer effective under the immense energies it entails. A team around Dr. Tobias Dornheim, Dr. Attila Cangi, Kushal Ramakrishna, and Maximilian Böhme from CASUS in Görlitz are working on modeling such complex systems. Initial results were recently published in the journal Physical Review Letters. The team joined forces with Dr. Jan Vorberger from the Institute of Radiation Physics at HZDR and Prof. Shigenori Tanaka from Kobe University in Japan to develop a new method to calculate the properties of warm dense matter more efficiently and faster.

"With our algorithm, we can perform highly accurate calculations of the local field correction, which describes the interaction of electrons in warm dense matter and thus allows us to unlock its properties. We can use this calculation to model and interpret results in future X-ray scattering experiments, but also as a basis for other simulation methods. Our method helps determine the properties of warm dense matter, such as temperature and density, but also its conductivity for electric current or heat and many other characteristics," Dornheim explains.

Mainframe computers and neural networks

"The motivation behind our method is that we and many other researchers would like to know exactly how electrons behave under the influence of small perturbations, such as the effect of an X-ray beam. We can derive a formula for this, but it is too complex to be solved with pencil and paper. This is why we previously resorted to a certain simplification, which, however, failed to show some important physical effects. We have now introduced a correction that removes this very flaw," Dornheim continues.

To implement it, they conducted computationally intense simulations over millions of processor hours on mainframe computers. Based on this data and with the help of analytical statistical methods, the scientists trained a neural network to numerically predict the interaction of electrons. The efficiency gains provided by the new tool depend on the particular application. "In general, though, we can say that previous methods required thousands of processor hours to attain a high degree of accuracy, whereas our method takes mere seconds," says Attila Cangi, who joined CASUS from Sandia National Laboratories in the United States. "So now we can perform the simulation on a laptop whereas we used to need a supercomputer."

Outlook: A new standard code for experiment evaluation

For the time being, the new code can only be used for electrons in metals, for example in experiments on aluminum. However, the researchers are already working on a code that can be applied more generally and that should deliver results for a wide variety of materials under very different conditions in the future. "We want to incorporate our findings into a new code, which will be open source, unlike the current code, which is licensed and therefore difficult to adapt to new theoretical insights," explains Maximilian Böhme, a doctoral student with CASUS who is collaborating on this with British plasma physicist Dave Chapman.

Such X-ray experiments to study warm dense matter are only possible at a handful of large laboratories, including the European XFEL near Hamburg, Germany, but also the Linear Coherent Light Source (LCLS) at the Stanford Linear Accelerator Center (SLAC) at Stanford University, the National Ignition Facility (NIF) at Lawrence Livermore National Laboratory, the Z Machine at Sandia National Laboratories, and the SPring-8 Angstrom Compact free electron LAser (SACLA) in Japan. "We are in contact with these labs and expect to be able to be actively involved in the modeling of the experiments," Tobias Dornheim reveals. The first experiments at the Helmholtz International Beamline for Extreme Fields (HIBEF) at the European XFEL are already being prepared.

With a powerful enough light, you can see things that people once thought would be impossible. Large-scale light source facilities generate that powerful light, and scientists use it to create more durable materials, build more efficient batteries and computers, and learn more about the natural world.

When it comes to building these massive facilities, space is money. If you can get higher-energy beams of light out of smaller devices, you can save millions on construction costs. Add to that the chance to significantly improve the capabilities of existing light sources, and you have the motivation behind a project that has brought scientists at three U.S. Department of Energy national laboratories together.

This team has just achieved an important milestone that has been in the works for more than 15 years: They have designed, built and fully tested a new state-of-the-art half-meter-long prototype magnet that meets the requirements for use in existing and future light source facilities.

The next step, according to Efim Gluskin, a distinguished fellow at DOE's Argonne National Laboratory, is to scale this prototype up, build one that is more than a meter long, and install it at the Advanced Photon Source, a DOE Office of Science User Facility at Argonne. But while these magnets will be compatible with light sources like the APS, the real investment here, he said, is in the next generation of facilities that have not yet been built.

"The real scale of this technology is for future free-electron laser facilities," Gluskin said. "If you reduce the size of the device, you reduce the size of the tunnel, and if you can do that you can save tens of millions of dollars. That makes a huge difference."

That long-term goal brought Gluskin and his Argonne colleagues into collaboration with scientists from Lawrence Berkeley National Laboratory and Fermi National Accelerator Laboratory, both DOE labs. Each lab has been pursuing superconducting technology for decades and has in recent years focused research and development efforts on an alloy that combines niobium with tin.

This material remains in a superconducting state — meaning it offers no resistance to the current running through it — even as it generates high magnetic fields, which makes it perfect for building what are called undulator magnets. Light sources like the APS generate beams of photons (particles of light) by siphoning off the energy given off by electrons as they circulate inside a storage ring. The undulator magnets are the devices that convert that energy to light, and the higher a magnetic field you can generate with them, the more photons you can create from the same size device.

There are a few superconducting undulator magnets installed at the APS now, but they are made of a niobium-titanium alloy, which for decades has been the standard. According to Soren Prestemon, senior scientist at Berkeley Lab, niobium-titanium superconductors are good for lower magnetic fields — they stop being superconducting at around 10 teslas. (That's about 8,000 times stronger than your typical refrigerator magnet.)

"Niobium-3 tin is more complicated material," Prestemon said, "but it is capable of transporting current at a higher field. It is superconductive up to 23 tesla, and at lower fields it can carry three times the current as niobium-titanium. These magnets are kept cold at 4.2 Kelvin, which is about minus 450 degrees Fahrenheit, to keep them superconducting."

Prestemon has been at the forefront of Berkeley's niobium-3 tin research program, which began back in the 1980s. The new design, developed at Argonne, built on the previous work of Prestemon and his colleagues.

"This is the first niobium-3 tin undulator that has both met the design current specifications and been fully tested in terms of magnetic field quality for beam transport," he said.

Fermilab started working with this material in the 1990s, according to Sasha Zlobin, who initiated and led the niobium-3 tin magnet program there. Fermilab's niobium-3 tin program has centered on superconducting magnets for particle accelerators, like the Large Hadron Collider at CERN in Switzerland and the upcoming PIP-II linear accelerator, to be built on the Fermilab site.

"We've demonstrated success with our high-field niobium-3 tin magnets," Zlobin said. "We can apply that knowledge to superconducting undulators based on this superconductor."

Part of the process, according to the team, has been learning how to avoid premature quenches in the magnets as they approach the desired level of magnetic field. When the magnets lose their ability to conduct current without resistance, the resulting backlash is called a quench, and it eliminates the magnetic field and can damage the magnet itself.

The team will report in IEEE Transactions on Applied Superconductivity that their new device accommodates nearly twice the amount of current with a higher magnetic field than the niobium-titanium superconducting undulators currently in place at the APS.

The project drew on Argonne's experience building and operating superconducting undulators and Berkeley and Fermilab's knowledge of niobium-3 tin. Fermilab helped to guide the process, advising on the selection of superconducting wire and sharing recent developments in their technology. Berkeley designed a state-of-the-art system that uses advanced computing techniques to detect quenches and protect the magnet.

At Argonne, the prototype was designed, fabricated, assembled and tested by a group of engineers and technicians under the guidance of Project Manager Ibrahim Kesgin, with contributions in the design, construction and testing by members of the APS superconducting undulator team led by Yury Ivanyushenkov.

The research team plans to install their full-sized prototype, which should be finished next year, at Sector 1 of the APS, which makes use of higher-energy photon beams to peer through thicker samples of material. This will be a proving ground for the device, showing that it can operate at design specifications in a working light source. But the eye, Gluskin says, is on transferring both technologies, niobium titanium and niobium-3 tin, to industrial partners and manufacturing these devices for future high-energy light source facilities.

"The key has been steady and persistent work, supported by the labs and DOE research and development funds," Gluskin said. "It has been incremental progress, step by step, to get to this point."

Attempts to identify the genetic causes of neuropsychiatric diseases such as post-traumatic stress disorder (PTSD) through large-scale genome-wide analyses have yielded thousands of potential links. The challenge is further complicated by the wide range of symptoms exhibited by those who have PTSD. For instance, does extreme arousal, anger, or irritation experienced by some have the same genetic basis as the tendency to re-experience traumatic events, another symptom of the disorder?

A new study led by researchers at Yale and the University of California-San Diego (UCSD) provides answers to some of these questions and uncovers intriguing genetic similarities between PTSD and other mental health disorders such as anxiety, bipolar disorder, and schizophrenia.

The findings also suggest that existing drugs commonly used for other disorders might be modified to help treat individual symptoms of multiple disorders.

"The complexity is still there, but this study helped us chip away at it," said co-senior author Joel Gelernter, the Foundations Fund Professor of Psychiatry and professor of genetics and neurobiology at Yale.

The study was published Jan. 28 in the journal Nature Genetics.

For the study, the researchers analyzed the complete genomes of more than 250,000 participants in the Million Veteran Program, a national research program of the U.S. Veterans Administration that studies how genes, lifestyle, and military experiences affect the health and illness of military veterans. Among those participants were approximately 36,000 diagnosed with PTSD.

But instead of looking just for gene variants shared by PTSD patients, they also searched for variants that have been linked to three kinds of clinical symptoms that are experienced, to varying degrees, by those diagnosed with the disorder. These symptom groups, or "subdomains," include the re-experience of a traumatic event, hyperarousal or acute anger and irritability, and the avoidance of people or subjects that might be related to past trauma.

While the researchers found underlying genetic commonalities among all three symptom groups, they also discovered specific variants linked to only one or two of the symptoms.

"We found a remarkably high degree of genetic relatedness between these three symptom subdomains. But we also wouldn't expect them to be genetically identical, and they are not," Gelernter said. "We found biological support for different clinical presentations of PTSD."

The research also showed that some these variants found in subgroups of patient symptoms are also linked to other disorders such as major depression. The results suggest drugs used to treat other disorders might also help treat of PTSD.

"Our research pointed to some medications that are currently marketed for other disease states and could be repurposed for PTSD," said co-senior author Murray Stein, Distinguished Professor of Psychiatry and Public Health at UC-San Diego.

Intriguingly, some of the variants linked to all PTSD symptoms have been associated with other neuropsychiatric disorders. For instance, PTSD-associated variants of the gene MAD1L1, which helps regulate cell cycling, have also been linked to schizophrenia and bipolar disorder.

"These observations, and the recent finding of GWS [genomewide-significant] association with anxiety suggest that MAD1L1 may be a general risk factor for psychopathology," the authors write.

Washington, DC - January 28, 2021 - Self swabs and caregiver swabs are effective at detecting multiple pathogens and are just as accurate as those taken by healthcare workers, according to a team of Australian researchers. The research appears in the Journal of Clinical Microbiology, a publication of the American Society for Microbiology.

"Across the range of pathogens and swab types, there was high agreement between results from self- or caregiver swabs and those performed by a healthcare worker, even when different sites were swabbed (e.g. nasopharyngeal vs. nasal)," said principal investigator Joshua Osowicki, BMedSci, MBBS, FRACP, a Pediatric Infectious Diseases physician in the Murdoch Children's Research Institute's Tropical Diseases research group, Melbourne, Australia.

"We found a pooled sensitivity of 91% and specificity of 98% for self- or caregiver-collected upper airway swabs compared to [healthcare worker] swabs," the investigators wrote. (Sensitivity refers to the proportion of those who test positive that are correctly identified, and specificity the proportion testing negative that are correctly identified.)

"Findings were similar when only SARS-CoV-2 data were considered," the researchers wrote. "This level of diagnostic performance should reassure clinicians, researchers, and public health officials that diagnostic performance is not necessarily compromised by self- or caregiver swabbing."

Pathogens swabbed in the study include SARS-CoV-2, influenza, group A Streptococcus, Staphylococcus aureus, pharyngeal Chlamydia trachomatis and Neisseria gonorrhoeae, and a panel of respiratory viruses.

The study was a systematic review and meta-analysis of 20 previous studies comprising swabs of more than 3,500 individuals, comparing self- or caregiver swabs with swabs collected by healthcare workers for diagnosis of a range of upper airway pathogens. "We searched for previous studies that included both kinds of swabs collected from the same individuals," said Dr. Osowicki. "For each study, we considered the sensitivity and specificity of self- or caregiver swabs compared to swabs by healthcare workers, and the agreement between the two kinds of swabs.

Self- and caregiver swabbing offer a number of advantages over swabbing by healthcare workers, including less likelihood of transmission, reduced expenses, conservation of personal protective equipment, and less discomfort to patients. An online survey of patients with SARS-CoV-2 symptoms found a much higher proportion willing to be tested via a self-collected saliva sample (92%) or a nasal swab (88%) than by a drive-through healthcare worker swab collection (71%)," according to the investigators.

When the plans of then medical student and first author Ciara Harrison to complete an immunology laboratory project were derailed by the pandemic, Dr. Harrison, now a first-year physician, pivoted to this systematic review and meta-analysis.

Although loggerhead sea turtles return to the same beach where they hatched to lay their eggs, a new study by a USF professor finds individual females lay numerous clutches of eggs in locations miles apart from each other to increase the chance that some of their offspring will survive.

A study published in the journal "Scientific Reports" found that some females lay as many as six clutches as far as six miles apart during the same breeding season.

"Nesting females don't lay all their eggs in one basket. Their reproductive strategy is like investing in a mutual fund. Females divide their resources among many stocks rather than investing everything in a single stock," said Deby Cassill, biology professor at USF's St. Petersburg campus and author of the study.

During their 50-year lifetime, a single female loggerhead will produce around 4,200 eggs and scatter them at 40 different sites on the barrier island. This strategy helps reduce the risk of complete reproductive failure by hurricanes and thunderstorms that could wash out or flood all clutches.

"Because females diversify reproduction in unpredictable patterns over time and space, nearly two-thirds of loggerhead sea turtle hatchlings made it into the Gulf of Mexico," said Cassill.

For the study, Cassill analyzed 17 years of data provided by the Conservancy of Southwest Florida on loggerhead females nesting on Keewaydin Island off the southwestern Gulf coast of Florida. For years, conservancy staff and community volunteers tagged turtles and patrolled the island to monitor and record detailed information on the nesting population.

Though the study shows most sea turtle hatchlings reach the Gulf of Mexico, future impacts due to human encroachment and climate change could affect the population. Increased frequency of extreme storms due to warmer waters and sea-level rise may flood or wash away larger portions of clutches, leading to population declines of the threatened species.

"It's important to follow individuals over time to really get a glimpse of how they mate, find food and ensure that some of their young survive to maturity. Without knowledge of the sea turtle's survival and reproductive biology, we cannot develop and implement effective conservation policies," said Cassill.

The study is one in a series of upcoming articles by Cassill pertaining to her "maternal risk management model," which looks at how natural selection pressures, such as predators, storms and resource scarcity, influence how mothers invest in offspring quantity and quality.

She argues turtles and fish invest in large numbers of offspring when the likelihood their offspring will be killed by predators is high. Mammal mothers like whales and elephants provide extensive care to one offspring at a time when the likelihood their young will starve during seasonal droughts is high.

The model, based on the number and size of offspring produced by a mother, extends Darwin's theory of natural selection by explaining the fusion of parents and offspring into family units and societies.

Maybe space is tight in your home and you share a remote office with your spouse.

Or your partner asks you to step away from work to watch the children because they have an important call to jump on. Then you may wonder, 'Well, what makes his/her job more important than mine!'

There have been no shortage of conflicts arising from the era of COVID-19, and that includes the challenges at home between married couples.

In fact, the more a person felt that their spouse disrupted their daily routine, the more they viewed their relationship as turbulent, according to West Virginia University research.

Kevin Knoster, a third-year doctoral student in the Department of Communication Studies, led a study examining 165 married individuals and how their partners interfered with their daily routines in April 2020, a month into the pandemic. Their findings are published in Communication Research Reports.

"When you are impeding your significant other from accomplishing their goals or are disrupting their daily routines, there will be emotional responses," Knoster said. "Based on our findings, more interference from your spouse leads to sadness and anger, and that's independent from one another. This can lead to perceptions of a turbulent relationship."

Knoster was joined by fellow communication studies doctoral student Heath Howard and faculty Alan Goodboy and Megan Dillow on the project. Knoster noted that he and Howard, who are both married and living with their spouses in Morgantown, decided to explore the issue as they studied relational turbulence theory for exams while the world was on lockdown.

Relational turbulence theory argues that transitions or periods of instability can create ripples within a relationship. Previous studies have focused on military spouses returning home and empty nesters, for instance. A shift in the makeup of a relationship, therefore, can influence a change in behaviors.

Couples working remotely due to the COVID-19 pandemic presented a novel approach to researching this theory, Knoster said.

"Like a lot of people, we, too, had to adapt on the fly all of a sudden to working from home," Knoster said. "Our routines were in a state of a flux."

The age of participants in the study ranged from 18 to 74. Of those with adult children, 64 of them moved back home during the pandemic.

The research team measured participants' level of agreement on statements such as "My spouse interferes with the plans that I make." Also, the survey questions prompted respondents with "During the past month of the COVID-19 pandemic, when I have interacted with my spouse, I have felt..."

Based on the results, researchers reported that husbands and wives who had everyday routines disrupted by spouses felt negative emotions toward them and perceived the marriage to be turbulent. The negative emotions reported - sadness and anger - were specifically directed toward interactions with their spouse.

The findings fit into a larger body of research connecting partner interference with feelings of instability and a turbulent relationship.

Knoster himself has recognized his own interferences into his wife's daily routine.

"I step on her toes every now and then," he said. "I teach classes from home (on the computer) and her office is through a closed door behind me. If she needs to go to the restroom, she has to walk behind me so she may be thinking, 'Do I need to coordinate with his schedule just to wash my hands?' It's interesting. It's changed our professional lives and personal lives in more ways than we think."

But, for couples who can strategize and remain cognizant of each other's schedules, any negative emotions can drift away.

"Maybe my wife has a meeting that overlaps with my workout time," Knoster said. "I could decide to go ahead and pick up weights and drop them or I can adapt my routine. In contrast, maybe my wife doesn't care about my fitness goals. If you're getting in their way or have a 'my way or the highway' attitude, well, that's going to facilitate more negative emotional responses.

"But when you and your partner support each other's goals and accommodate routines, that elicits positive emotional reactions. We need to remember to catch our breaths for a moment and work together. It's more important now that we're sort of sequestered inside at all hours of the day and starting to feel like rats in a cage."