Culture

As we age, the immune system gradually becomes impaired. One aspect of this impairment is chronic inflammation in the elderly, which means that the immune system is constantly active and sends out inflammatory substances. Such chronic inflammation is associated with multiple age-related diseases including arthritis and Alzheimer's disease, and impaired immune responses to infection. One of the questions in ageing research is whether chronic inflammation is a cause of ageing, or a consequence of the ageing process itself? Scientists in the laboratory of Director Adam Antebi at the Max Planck Institute for Biology of Ageing in Cologne, Germany have found evidence suggesting that increased inflammation causes the ageing process to speed up, and that there is a fine balance between maintaining immune system function and longevity.

From their work in the tiny roundworm, Caenorhabditis elegans, the scientists discovered a change in an evolutionarily conserved gene called PUF60, which made the worms long lived but at the same time dampened the immune response. Worms with this change lived about 20% longer than normal worms, but when they were infected with certain bacteria, they succumbed more quickly to the infection. This means that an overactive immune system also has a price: it shortens life span. Conversely, a less active immune system pays off as longer life span - as long as the animal does not die from an infection.

How does PUF60 regulate this fine balance between a maintained immune system and longevity? PUF60 works as a so-called "splicing factor", and is involved in the removal (or "splicing out") of segments in the ribonucleic acid, RNA. This process is essential to generate functional proteins.

The scientists found that the genetically changed PUF60 perturbs this process and alters the regulation of other genes that are involved in immune functions. "We're excited by this finding because it implicates a very fundamental process in the cell to immunity," says Adam Antebi. "These observations of course raise further questions. Notably pinpointing how PUF60 activity affects immunity and longevity, and how these two processes are balanced will be central to understanding the relationship between inflammation and ageing."

A new study shows that certain aerosol boxes of a similar type to those that have been manufactured and used in hospitals in the UK and around the world in order to protect healthcare workers from COVID-19 can actually increase exposure to airborne particles that carry the virus, and thus casts doubt on their usefulness.

The authors - who include Drs Peter Chan, Joanna Simpson and colleagues, Intensive Care and Anaesthesia Specialists at Eastern Health, Melbourne, VIC, Australia - say that "the consequences of promotion of such untested devices include either a false sense of security using these devices, or paradoxical increase in healthcare workers exposure to COVID-19". The study is published in Anaesthesia (a journal of the Association of Anaesthetists).

The danger posed to frontline health workers exposed to infectious COVID-19 is significant. The sickest COVID-19 patients often need to be placed onto a ventilator, which is also when the risk to the health worker of exposure to virus is potentially at its greatest. This has created a race to manufacture aerosol containment devices including improvised protection strategies and devices for use during tracheal intubation. This has taken on even greater urgency in the last week, with a global "second wave" becoming more likely, and a recent open letter to the World Health Organization from 239 global scientists in 32 countries warning that we have probably been severely underestimating the amount of COVID-19 spread through fine aerosol droplets over large distances. On Wednesday, July 8, WHO formally acknowledged this emerging evidence regarding potential spread of COVID-19 through these tiny droplets.

Aerosol boxes have been promoted by multiple worldwide news organisations in print, television, online and across social media (see examples below) as not only a quick and simple solution to protecting frontline workers but also an example of private industries stepping up production to support frontline healthcare workers. However, these devices were produced outside the normal regulatory framework, and thus were never clinically tested or validated for effectiveness and safety. They were subsequently heavily promoted in the media and on social media. Yet despite this heavy promotion, no international guideline on personal protective equipment (PPE) has ever endorsed their use.

In recent months there have been increasing concerns from the medical community that these devices might be either not helping, or potentially exposing frontline medical staff to unforeseen harm, but as this could not be proven, the devices continued to be used across the globe. In this new study, Drs Chan and Simpson and colleagues partnered with Ascent Vision Technologies, a Melbourne-based engineering company, to test the effectiveness of varying methods of aerosol containment, including the so-called aerosol box (see links to photos below), which various private companies have offered their services to manufacture.

The study was carried out in a self-contained intensive care unit room at Box Hill Hospital, Melbourne, using seven adult volunteers (four male, three female), who took turns in random order acting as the patient or the doctor (the person performing the intubation). The study simulated exposure of the doctor to airborne particles sized 0.3 - 5.0 microns using five aerosol containment methods (aerosol box; sealed box with and without suction; vertical drape; and horizontal drape) compared with no intervention. As each of the seven volunteers did all six trials (the five interventions plus no intervention), the study generated 42 sets of results.

To simulate aerosolisation, the patient volunteer held a bottle of fluid just under their mouth, and coughed every 30 seconds. Over five minutes particle detection devices were used to count different sized particles and assess particle spread.

Compared with no device use, the aerosol box surprisingly showed an increase in airborne particle exposure of all sizes over 5 minutes. Assuming that COVID-19 particles act in the same way as the fluid used in this simulation, the results of this study suggest that this aerosol box was increasing exposure to COVID-19 particles, in some cases by a factor of 5 times or more.

The authors say: "We were surprised to find airborne particle contamination of the doctor increased substantially using the aerosol box compared with all other devices and with no device use. Spikes of airborne particles were clearly seen, coinciding with patient coughing. We believe that these represent particles escaping from the arm access holes in the aerosol box."

They add: "The race to generate sustainable equipment to protect healthcare workers during intubation procedures in patients with suspected or proven COVID-19, particularly in settings where PPE supply is limited, has flooded the scientific community and social media with a variety of novel devices meant to contain potentially infectious aerosols produced by patients. Evidence for the safety and efficacy of these devices is lacking."

They conclude: "This study demonstrates that devices such as the aerosol box we tested - which is typical of designs used worldwide - confer minimal to no benefit in containing aerosols during an aerosol-generating procedure and may increase rather than decrease airborne particle exposure. The use of any aerosol containment device has been eliminated from our intubation protocols until their safety can be properly established."

Dr Chan adds: "If this box were a sold as a product, and therefore regulated, it would likely need to be immediately recalled due to a potential infection risk to the healthcare worker. Unfortunately, because these devices have been donated and are not regulated in any way, healthcare workers might be continuing to increase their exposure to COVID-19 while thinking they are protecting themselves."

New ground-breaking research from the University of Surrey could change the way scientists understand and describe lasers - establishing a new relationship between classical and quantum physics.

In a comprehensive study published by the journal Progress in Quantum Electronics, a researcher from Surrey, in partnership with a colleague from Karlsruhe Institute of Technology and Fraunhofer IOSB in Germany, calls into question 60 years of orthodoxy surrounding the principles of lasers and the laser spectral linewidth - the foundation for controlling and measuring wavelengths of light.

In the new study, the researchers find that a fundamental principle of lasers, that the amplification of light compensates for the losses of the laser, is only an approximation. The team quantify and explain that a tiny excess loss, which is not balanced by the amplified light but by normal luminescence inside the laser, provides the answer to the spectral linewidth of the laser.

One of these loss mechanisms, the outcoupling of light from the laser, produces the laser beam used in vehicle manufacturing, telecommunications, laser surgery, GPS and so much more.

Markus Pollnau, Professor in Photonics at the University of Surrey, said: "Since the laser was invented in 1960, the laser spectral linewidth has been treated as the stepchild in the descriptions of lasers in textbooks and university teaching worldwide, because its quantum-physical explanation has placed extraordinary challenges even for the lecturers.

"As we have explained in this study, there is a simple, easy-to-understand derivation of the laser spectral linewidth, and the underlying classical physics proves the quantum-physics attempt of explaining the laser spectral linewidth hopelessly incorrect. This result has fundamental consequences for quantum physics."

DALLAS, July 10, 2020 -- Acute ischemic strokes (AIS) associated with COVID-19 are more severe, lead to worse functional outcomes and are associated with higher mortality , according to new research published yesterday in Stroke, a journal of the American Stroke Association, a division of the American Heart Association.

In "Characteristics and Outcomes in Patients with COVID-19 and Acute Ischemic Stroke: The Global COVID-19 Stroke Registry," researchers analyzed data on patients with COVID-19 and AIS treated at 28 health care centers in 16 countries this year and compared them to patients without COVID-19 from the Acute Stroke Registry and Analysis of Lausanne (ASTRAL) Registry, from 2003 to 2019. Researchers sought to determine the clinical characteristics and outcomes of patients with COVID-19 and AIS.

Between January 27, 2020 to May 19, 2020, there were 174 patients hospitalized with COVID-19 and AIS. Each COVID-19 patient with AIS was matched and compared to a non-COVID-19 AIS patient based on a set of pre-specified factors including age, gender and stroke risk factors (hypertension, diabetes, atrial fibrillation, coronary artery disease, heart failure, cancer, previous stroke, smoking, obesity and dyslipidemia). The final analysis included 330 patients total.

In both patient groups, stroke severity was estimated with the National Institute of Health Stroke Scale (NIHSS), and stroke outcome was assessed by the modified Rankin score (mRS). When AIS patients with COVID-19 were compared to non-COVID-19 patients:

COVID-19 patients had more severe strokes (median NIHSS score of 10 vs. 6, respectively);

COVID-19 patients had higher risk for severe disability following stroke (median mRS score 4 vs. 2, respectively); and

COVID-19 patients were more likely to die of AIS.

The researchers noted there are several potential explanations for the relationship between COVID-19-associated strokes and increased stroke severity: "The increased stroke severity at admission in COVID-19-associated stroke patients compared to the non-COVID-19 cohort may explain the worse outcomes. The broad, multi-system complications of COVID-19, including acute respiratory distress syndrome, cardiac arrhythmias, acute cardiac injury, shock, pulmonary embolism, cytokine release syndrome and secondary infection, probably contribute further to the worse outcomes including higher mortality in these patients. ... The association highlights the urgent need for studies aiming to uncover the underlying mechanisms and is relevant for prehospital stroke awareness and in-hospital acute stroke pathways during the current and future pandemics."

A team of scientists at the University of Vermont have invented a new tool--they call it a "nanocage"--that can catch and straighten out molecule-sized tangles of polymers.

Once a knotty polymer strand--whether made of protein or plastic--is pulled open "then we can activate just the polymers we want, while leaving the rest alone, " says UVM chemist Severin Schneebeli who led the new research. This tool--that works a bit like pulling a wad of thread through a needle hole--"opens a new way to create custom materials that have never been made before," he says. These might include nanoscale pill coatings that wrap around single molecules of medicine or new industrial products assembled from precisely arranged strands of plastic at the atomic scale.

The tool, composed of molecular edges with special "shape-directing" hydrogen bonds--and thousands of times smaller than a pinhead--can select out shorter strands of a polymer, leaving longer ones behind, demonstrating that the nanocage can be used to selectively find particular sizes of molecules in a soup of material. "It's selective and that's never been done before," Schneebeli says. This research is the first time that science has been able distinguish and activate different size polymer chains in a lab--opening the door to new possibilities for precision chemistry.

The new research was published in the June edition of the journal Chem.

NATURE KNOWS

The abilities of the nanocage are new to science--but not to nature. For billions of years, life has evolved ways to select just the bit of a protein or other biological knot that it wants to untie and turn on--what scientists call "functionalize." But people have had a hard time doing the same thing. "Despite plenty of examples in biology," the UVM scientists write, "efficient and selective modification of man-made polymers is still difficult."

Whether altering biological strands, like DNA, or industrial materials, like plastics, the new tetrahedron-shaped tool promises to let scientists do what nature already does well. "It took years of hard work in the lab to assemble this tetrahedron before we could test it," says Mona Sharafi, the lead author on the new study, and post-doctoral researcher at the Unversity of Vermont who came to the United States from Iran. "It's entirely man-made" she says, "but inspired by nature."

POTENT POLYMERS

The word polymer comes from a pair of Greek words that mean "many parts." And polymers are just that: materials made from huge molecules comprised of many repeating parts. They're found in many everyday products. Some are natural, like rubber and shellac. Many are synthetic, and are used to produce much of the material in everyday life -- from shopping bags to diapers, clothing to water pipes. Polymers can be found in tidy long strings at the molecular level--or they can be tied up in godawful knots like a billion strands of micro-spaghetti

Nature has had eons to figure out how to both synthesize these huge molecules--biopolymers, like DNA--and how to edit and activate selected portions. People have gotten pretty good at making new synthetic polymers--but not so good at selecting and editing them. Many scientists and engineers--working on new applications for renewable energy (e.g., next-generation solar cells), precision medicine (like delivery of cancer drugs to targeted parts of the body) and advanced electronics (including flexible devices)--would like to have greater control and efficiency working with what the UVM team call "functional polymers with complex topologies." With support from the National Science Foundation and the National Institutes of Health (which supported the computational studies, directed by UVM chemist Jianing Li), the research on the nanocage provides a new tool to do so-- "to untie the knot, opening polymers that would have been inaccessible before," say UVM's Mona Sharafi. "We have opened something big."

Strains of a common subtype of influenza virus, H3N2, have almost universally acquired a mutation that effectively blocks antibodies from binding to a key viral protein, according to a study from researchers at Johns Hopkins Bloomberg School of Public Health.

The results have implications for flu vaccine design, according to the researchers. Current flu vaccines, which are "seasonal vaccines" designed to protect against recently circulating flu strains, induce antibody responses mostly against a different viral protein called hemagglutinin.

The new mutation, described in the study published online June 29 in PLOS Pathogens, was first detected in the 2014-2015 flu season in some H3N2 flu strains, and evidently is so good at boosting flu's ability to spread that it is now present in virtually all circulating H3N2 strains. Recent flu seasons, in which H3N2 strains have featured prominently, have been relatively severe compared to historical averages.

The mutation alters a viral protein called neuraminidase, and the researchers found in their study that this alteration paradoxically reduces the ability of flu virus to replicate in a type of human nasal cell that it normally infects. However, the researchers also found evidence that the mutation more than compensates for this deficit by setting up a physical barrier that hinders antibodies from binding to neuraminidase.

"These findings tell us that flu vaccines focusing on the hemagglutinin protein are leaving the virus openings to evolve and evade other types of immunity," says study senior author Andrew Pekosz, PhD, professor and vice chair of the Department of Molecular Microbiology and Immunology at the Bloomberg School.

Every year, influenza viruses sicken millions of people around the world, killing several hundred thousands. The diversity of flu strains and their ability to mutate rapidly--two strains infecting the same host can even swap genes--have made flu viruses an especially difficult target for vaccine designers. Although scientists are working towards a universal vaccine that will protect long-term against most flu variants, current flu vaccines are designed to protect against only a short list of recently circulating strains. Any mutation that occurs in these circulating strains and appears to improve their ability to spread is naturally of interest to flu virologists.

The goal of the study was to understand better the workings of the new H3N2 mutation. Scientists have known that it alters the flu virus's neuraminidase protein in a way that provides an attachment point, close to neuraminidase's active site, for a sugar-like molecule called a glycan. But how the presence of a glycan at that location on the neuraminidase protein improves the virus's ability to infect hosts and spread hasn't been clear.

Pekosz and first author Harrison Powell, PhD, a graduate student in his laboratory at the time of the study, compared the growth, in laboratory cells, of typical H3N2 strains that have the glycan-attachment mutation to the growth of the same flu strains without the mutation. They found that the mutant versions grew markedly more slowly in human cells from the lining of the nasal passages--a cell type that a flu virus would initially infect.

The researchers found the likely reason for this slower growth: the glycan-attracting mutation hinders the activity of neuraminidase. The protein is known to serve as a crucial flu enzyme whose functions include clearing a path for the virus through airway mucus, and enhancing the release of new virus particles from infected cells.

It wasn't entirely unexpected that the addition of a moderately bulky glycan molecule near the enzyme's active site would have this effect. But it left unexplained how that would benefit the virus.

The scientists solved the mystery by showing that the glycan blocks antibodies that would otherwise bind to or near the active site of the neuraminidase enzyme.

Neuraminidase, especially its active site, is considered one of the most important targets for the immune response to a flu infection. It is also the target of flu drugs such as Tamiflu (oseltamivir). Thus it makes sense that a mutation protecting that target confers a net benefit to the virus, even if it means that the neuraminidase enzyme itself works less efficiently.

The finding highlights the potential for flu viruses to evade therapies, seasonal vaccines, and the ordinary immune response, Pekosz says, and points to the need for targeting multiple sites on the virus to reduce the chance that single mutations can confer such resistance.

The researchers have been following up their findings with studies of how the new mutation affects the severity of flu, how it has spread so rapidly among H3N2 strains, and how these altered flu strains have adapted with further mutations.

"Neuraminidase antigenic drift of influenza A virus H3N2 clade 3c.2a viruses alters virus replication, enzymatic activity and inhibitory antibody binding" was written by Harrison Powell and Andrew Pekosz.

July 10, 2020 - A baby girl in Texas - born prematurely to a mother with COVID-19 - is the strongest evidence to date that intrauterine (in the womb) transmission of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) can occur, reports The Pediatric Infectious Disease Journal, the official journal of The European Society for Paediatric Infectious Diseases. The journal is published in the Lippincott portfolio by Wolters Kluwer.

The findings "suggest in utero transmission" of COVID-19 from an infected mother to her infant, according to the case report by Julide Sisman, MD, and colleagues of The University of Texas Southwestern Medical Center, Dallas.

"Numerous infants have now been delivered to pregnant women diagnosed with SARS-CoV-2, with the majority of these infants without respiratory illness or positive molecular evidence for SARS-CoV-2," comments Amanda S. Evans, MD, one of the lead authors of the new study. "Our study is the first to document intrauterine transmission of the infection during pregnancy, based on immunohistochemical and ultrastructural evidence of SARS-CoV-2 infection in the fetal cells of the placenta."

First Documented Intrauterine Transmission of COVID-19

The authors report on an infant delivered to a mother diagnosed with COVID-19, who also had type 2 diabetes. The infant was born at 34 weeks' gestation after the mother had premature rupture of the membranes. The baby was born "large for gestational age" (LGA) - an important complication in infants of diabetic mothers. She was treated in the neonatal ICU due to prematurity and possible SARS-CoV-2 exposure.

The infant appeared initially healthy, with normal breathing and other vital signs. On the second day of life, she developed fever and relatively mild breathing problems. "It is unlikely that the respiratory distress observed in this infant was due to prematurity since it did not start until the second day of life," the researchers write.

The baby tested positive for SARS-CoV-2 infection at 24 and 48 hours after birth. She was treated with supplemental oxygen for several days but did not need mechanical ventilation. COVID-19 tests remained positive for up to 14 days. At 21 days, the mother and infant were sent home in good condition.

The researchers examined the placenta, which showed signs of tissue inflammation. In addition, specialized tests documented the presence of coronavirus particles as well as a protein (SARS-CoV-2 nucleocapsid protein) specific for the COVID-19 virus in fetal cells of the placenta. Together, these findings confirmed that the infection was transmitted in the womb, rather than during or after birth.

Although data on COVID-19 remain very limited, "Intrauterine transmission of SARS-CoV-2 appears to be a rare event," Dr. Sisman and colleagues conclude. They highlight several urgent priorities for further research, including the mechanisms and risk factors of in utero SARS-CoV-2 transmission and the outcomes of congenital COVID-19 in infants.

"We wanted to be very careful of our interpretation of this data, but now is an even more important time for pregnant women to protect themselves from COVID-19," comments Dr. Evans. She adds, "The CDC has thoughtful guidance on ways to reduce risk of infection." (See https://www.cdc.gov/coronavirus/2019-ncov/need-extra-precautions/pregnancy-breastfeeding.html)

Two additional case reports in PIDJ also describe "vertical" transmission of SARS-Co-V2 from mother to infant occurring under different circumstances. Together, the three cases highlight the important but difficult distinction between virus transmission occurring before or during/after delivery (intrauterine versus intrapartum), according to a commentary led by George K. Siberry, MD, of the US Agency for International Development and Associate Chief Editor of PIDJ. Dr. Siberry and coauthors write: "As these cases illustrate, evaluation for vertical - and especially intrauterine - SARS-CoV-2 infection can be challenging, and assessment is often limited by lack of optimal testing of appropriate specimens obtained at specific timepoints."

CHICAGO (July 10, 2020): In the male-dominated field of surgery, female faculty of training programs tend to receive lower scores than male faculty on their teaching evaluations, which are important for career advancement, past research has found. Now a new study suggests progress in this apparent gender bias: Among 21 U.S. general surgery residency programs, female faculty scored slightly better overall than male faculty did on teaching evaluations performed by surgeons-in-training, even in programs with the fewest women, the authors report. The study is published as an "article in press" on the Journal of the American College of Surgeons website in advance of print.

These results were unexpected, according to the researchers, because a 2018 study found that female surgical faculty often received lower scores than male faculty did on teaching evaluations,1 and other study findings also show a negative bias against female faculty in academic medicine.2,3

"Hopefully, based on our results, we're seeing a shift in attitudes and perceptions of surgical residents about women in surgery and women as educators so that all surgeons are graded on an equal scale," said lead study author Adam Shellito, MD, a fourth-year surgical resident at Harbor-UCLA Medical Center in Torrance, Calif. "This shift will hopefully allow women to reach higher academic positions and leadership positions in surgery."

Nationwide, less than 21 percent of surgeons are women.4 Even fewer women hold leadership roles in surgery, with women representing only 18 percent of directors of general surgery residency programs.5

For residency program faculty, teaching evaluations are important because the results help determine promotions and tenure, said senior investigator Kristine Calhoun, MD, FACS, associate professor, University of Washington School of Medicine, Seattle.

Multi-institutional study

The study was conducted by members of the Surgery Educators Workgroup, a research collaboration of general surgery residency programs from across the United States. In their data analysis from 21 participating programs, the investigators included only full-time faculty who worked with general surgery residents. They also sent surveys to the program directors to gather information about each program, such as the sex-based composition of both residents and faculty.

Although all the programs require their residents to anonymously complete faculty teaching evaluations online after each surgical rotation, the evaluation tools varied greatly, Dr. Shellito noted. Therefore, the researchers created a composite score for each faculty member. They divided the total number of points a person received by the total possible points for that evaluation tool over the one-year study period from July 2018 to June 2019. For each faculty member and institution, the researchers calculated the percentage score from a maximum 100 percent.

The general surgery programs surveyed varied widely, from 14 to 77 residents and 14 to 155 teaching faculty per program, the researchers reported. Although nearly half (47 percent) of the residents were female, women made up only 28 percent of the faculty.

Evaluations ranged from one to 29 questions, for a total of 291 questions among all programs. In total, there were 20,187 evaluations of 1,177 faculty, according to the article.

Surprising results

Contrary to what the researchers anticipated, female faculty had significantly higher composite evaluation scores on average--90.6 percent versus 89.5 percent for male faculty. Because the difference was small, Dr. Shellito said they would classify the scores as an equalization between sexes.

The researchers also analyzed the results between quartiles of programs with the highest versus the lowest numbers of female faculty, female residents, and both. They found that residents at the programs with fewer women on the faculty and/or residency staff rated female faculty higher overall than male faculty.

This result also surprised the researchers, Dr. Calhoun said. They hypothesized multiple reasons for this finding, she said, including that in programs with few women on the faculty, residents may not have wanted to single them out with poor evaluations, that the female faculty were actually better educators, or that as more women become surgical residents, there is increased awareness of gender bias.

Among North American general surgery residents, 41 percent were women in 2018,6 a 5 percent increase from the previous year,7 according to the Association of American Medical Colleges.

Regardless of the educator's sex, this study's results showed a high satisfaction rate of surgical residents with their teaching faculty, which Dr. Calhoun called "a powerful finding."

Another finding confirms the importance of their research, Dr. Shellito stated. "More than 75 percent of program directors that we surveyed agree that faculty evaluations are important to the residency program or the institution," he said.

He cautioned, however, that their results suggesting a lack of overt gender bias may not apply to the entire country because more than half of the par

ITHACA, N.Y. - Climate change will leave some farmers with a difficult conundrum, according to a new study by researchers from Cornell University and Washington State University: Either risk more revenue volatility, or live with a more predictable decrease in crop yields.

As water shortages and higher temperatures drive down crop yields in regions that depend heavily on seasonal snow, the choice to use more drought-tolerant crop varieties comes at a cost, according to model projections detailed in the paper "Water Rights Shape Crop Yield and Revenue Volatility Tradeoff for Adaptation in Snow Dependent Systems," published June 10 in Nature Communications.

The study examined the Yakima River Basin in Washington, where a complex combination of snow, reservoirs and water rights controls the availability of irrigation water. That water dictates the success of some of the U.S.' largest producers of wheat, corn, potatoes, pears, cherries, grapes, apples and hops. With proper snowfall and melt, total agricultural productivity in the basin can reach more than $4 billion a year.

The research team sought to quantify climate change's direct and indirect effects on irrigated agriculture in the basin. Researchers also wanted to know if drought-resistant crop varieties could help recover productivity during times of drought.

Climate risk modeling is a specialty of Patrick Reed, the Joseph C. Ford Professor of Engineering at Cornell's School of Civil and Environmental Engineering. In this collaborative study, Reed's group built on prior research at Washington State University that developed a modeling platform connecting crop growth and development, land-surface hydrology and river-system processes. The model simulates dam operations and prioritizes the allocation of water among different sectors within the Yakima River Basin.

The team found that higher water stress and temperatures led to lower crop yield, as anticipated, said Keyvan Malek, a postdoctoral researcher in Reed's group and lead author of the study.

"However, the models show that year-to-year variability in expected crop yields goes down because the difference between the best and worst case yields is reduced," said Malek. "While this is not a positive result, year-to-year fluctuations in crop yield revenue are strongly important in how crop insurance programs balance revenue fluctuations."

The team then used its model to explore the potential of new drought-tolerant crop varieties, which are expected to improve annual yields under climate change. The results showed that although those varieties could significantly improve the average yield, farmers could also experience much higher revenue volatility from crop production.

"Typical and best-case annual yields are much higher," said Jennifer Adam, Berry Distinguished Professor of Engineering at Washington State University and co-author of the study. "But climate change still is likely to cause severe droughts where current water management institutions in the Yakima River Basin simply cannot provide enough water, and there are severe worst-case crop failures."

The researchers argue that the best outcomes for crop yield and revenue volatility must be through a simultaneous improvement in crop varieties - for example, by preserving agrobiodiversity - and in water systems, such as through improvements in water-governing institutions and infrastructure.

It is important to carefully capture a snow-dependent region's specific management constraints while being innovative with climate adaptation strategies, the researchers said.

"Otherwise, systems may unintentionally strike the wrong balance as they trade off improving average yields and farmers' revenue volatility," Reed said.

A commentary published in the journal Pediatrics, the official peer-reviewed journal of the American Academy of Pediatrics, concludes that children infrequently transmit Covid-19 to each other or to adults and that many schools, provided they follow appropriate social distancing guidelines and take into account rates of transmission in their community, can and should reopen in the fall.

The authors, Benjamin Lee, M.D. and William V. Raszka, Jr., M.D., are both pediatric infectious disease specialists on the faculty of the University of Vermont's Larner College of Medicine. Dr. Raszka is an associate editor of Pediatrics.

The authors of the commentary, titled "COVID-19 Transmission and Children: The Child Is Not to Blame," base their conclusions on a new study published in the current issue of Pediatrics, "COVID-19 in Children and the Dynamics of Infection in Families," and four other recent studies that examine Covid-19 transmission by and among children.

--In the new Pediatrics study, Klara M. Posfay-Barbe, M.D., a faculty member at University of Geneva's medical school, and her colleagues studied the households of 39 Swiss children infected with Covid-19. Contact tracing revealed that in only three (8%) was a child the suspected index case, with symptom onset preceding illness in adult household contacts.

--In a recent study in China, contact tracing demonstrated that, of the 68 children with Covid-19 admitted to Qingdao Women's and Children's Hospital from January 20 to February 27, 2020, 96% were household contacts of previously infected adults. In another study of Chinese children, nine of 10 children admitted to several provincial hospitals outside Wuhan contracted Covid-19 from an adult, with only one possible child-to-child transmission, based on the timing of disease onset.

--In a French study, a boy with Covid-19 exposed over 80 classmates at three schools to the disease. None contracted it. Transmission of other respiratory diseases, including influenza transmission, was common at the schools.

--In a study in New South Wales, nine infected students and nine staff across 15 schools exposed a total of 735 students and 128 staff to Covid-19. Only two secondary infections resulted, one transmitted by an adult to a child.

"The data are striking," said Dr. Raszka. "The key takeaway is that children are not driving the pandemic. After six months, we have a wealth of accumulating data showing that children are less likely to become infected and seem less infectious; it is congregating adults who aren't following safety protocols who are responsible for driving the upward curve."

Rising cases among adults and children in Texas childcare facilities, which have seen 894 Covid-19 cases among staff members and 441 among children in 883 child care facilities across the state, have the potential to be misinterpreted, Dr. Raszka said. He has not studied the details of the outbreak.

"There is widespread transmission of Covid-19 in Texas today, with many adults congregating without observing social distancing or wearing masks," he said. "While we don't yet know the dynamics of the outbreak, it is unlikely that infants and children in daycare are driving the surge. Based on the evidence, it's more plausible that adults are passing the infection to the children in the vast majority of cases."

Additional support for the notion that children are not significant vectors of the disease comes from mathematical modeling, the authors say. Models show that community-wide social distancing and widespread adoption of facial cloth coverings are far better strategies for curtailing disease spread, and that closing schools adds little. The fact that schools have reopened in many Western European countries and in Japan without seeing a rise in community transmissions bears out the accuracy of the modeling.

Reopening schools in a safe manner this fall is important for the healthy development of children, the authors say. "By doing so, we could minimize the potentially profound adverse social, developmental, and health costs that our children will continue to suffer until an effective treatment or vaccine can be developed and distributed, or failing that, until we reach herd immunity," the paper concludes.

The ability to recognize faces is a complex neurocognitive skill with important social implications. The disorder, which, according to some estimates, affects more than 2 percent of the population, can lead to isolation and anxiety and impair personal and work relationships.

The traditional view of face blindness--prosopagnosia in scientific parlance--has held that the disorder arises from deficits in visual perception. Under that view, individuals with face blindness are unable to visually distinguish the features of faces presented side by side and unable to determine whether the faces are the same or not.

Now a new study led by researchers at Harvard Medical School and the VA Boston Healthcare System shows that face blindness may arise from deficits beyond visual perception and appears to involve glitches in retrieving various contextual cues from memory.

The results, published July 5 ahead of print in the journal Cortex, suggest that the traditional view of face blindness as a purely visual perceptual disorder may be reductive, the researchers said. Further, they reveal that successful facial recognition requires recollection, or the recall of relevant contextual details about a person, such as their name or profession.

The new findings can help explain a mystifying discrepancy in face blindness research: People with the condition often fail to visually identify familiar faces, but many also perform normally on visual-perception tests.

"This inconsistency has always hinted that there may be other factors at play that go beyond visual perception," said study senior author Joseph DeGutis, HMS assistant professor of psychiatry at VA Boston. "Our findings suggest that one important deficit beyond perception is face recollection."

The ability to recognize a face requires two forms of memory: Recollection and familiarity. Recollection is the retrieval of contextual information upon seeing a face--a fellow shopper greeting you in the store and you recognizing them as the person you met through work a few weeks back. Familiarity, on the other hand, is a fuzzier "feeling of knowing" without any contextual information, the researchers explained. Think of the fellow shopper looking vaguely familiar but without any of the relevant details that tell you how you know them.

The findings can help inform the design of techniques to boost face recognition in people with developmental prosopagnosia--a form of face blindness that is not caused by brain injury, poor vision or neurodevelopmental disorders like autism.

"Our results underscore that prosopagnosia is a far more complex disorder that is driven by more than deficits in visual perception," said study first author Anna Stumps, a researcher in the Boston Attention Learning Laboratory at VA Boston. "This finding can help inform the design of new training approaches for people with face blindness."

The research team is currently working to design one such experimental program in the VA Boston laboratory where the work was conducted.

The study involved 6o people, ages 18 to 65, half of whom had lifelong face blindness.

The participants were asked to perform a series of facial-recognition tasks by studying and then identifying sets of faces that the participants had not seen prior to the study.

Participants were asked to study 60 faces shown on a computer screen, one at a time. The participants were then shown a scramble of 120 faces--some of them already seen during the study session and some completely new.

To tease out the differences in recognition memory between participants with and without face blindness, DeGutis and colleagues measured their degree of confidence in classifying each face as "old" or "new" on a scale of 1 to 6. Correctly identifying a face as old with high confidence reflects the use of recollection, the researchers said, whereas correctly identifying a face as old with less confidence reflects the use of familiarity.

Compared with participants who had face blindness, people without it were significantly more confident that they had seen these faces before. However, those with face blindness were still able to correctly identify many of the faces they had seen before, although with less confidence. In other words, when trying to recognize a face, participants with face blindness relied on familiarity, the vague sense of knowing or having seen someone before without specific contextual information. In contrast, individuals without face blindness relied on recollection.

Taken together, these findings suggest that people with face blindness use different memory processes for face recognition.

The results, the researchers said, demonstrate that successful face recognition requires more than a vague familiarity with a face--a sense of having seen a face before but without recalling any other details to "place" the face. Memory researchers call this inability to identify a familiar face out of context "butcher-on-the-bus" phenomenon. Though everyone experiences this from time to time, for people with true face blindness this can happen frequently, as often as multiple times a day.

"Our findings suggest that people with developmental prosopagnosia use a different memory system when trying to learn and remember faces and that system is less optimally suited for the task of recognizing faces," DeGutis said.

A groundbreaking study using molecular genetic techniques and field studies brings together decades of research into the complex relationships among beluga whales (Delphinapterus leucas) that spans 10 locations across the Arctic from Alaska to Canada and Russia to Norway. The behavior of these highly gregarious whales, which include sophisticated vocal repertoires, suggest that this marine mammal lives in complex societies. Like killer whales (Orcinus orca) and African elephants (Loxodonta Africana), belugas were thought to form social bonds around females that primarily comprise closely related individuals from the same maternal lineage. However, this hypothesis had not been formally tested.

The study, led by Florida Atlantic University's Harbor Branch Oceanographic Institute, is the first to analyze the relationship between group behaviors, group type, group dynamics, and kinship in beluga whales. Findings, just published in Scientific Reports, reveal several unexpected results. Not only do beluga whales regularly interact with close kin, including close maternal kin, they also frequently associate with more distantly related and unrelated individuals.

Findings indicate that evolutionary explanations for group living and cooperation in beluga whales must expand beyond strict inclusive fitness arguments to include other evolutionary mechanisms. Belugas likely form multi-scale societies from mother-calf dyads to entire communities. From these perspectives, beluga communities have similarities to human societies where social networks, support structures, cooperation and cultures involve interactions between kin and non-kin. Given their long lifespan (approximately 70 years) and tendency to remain within their natal community, these findings reveal that beluga whales may form long-term affiliations with unrelated as well as related individuals.

"This research will improve our understanding of why some species are social, how individuals learn from group members and how animal cultures emerge," said Greg O'Corry-Crowe, Ph.D., lead author and a research professor at FAU's Harbor Branch. "It also has implications for traditional explanations based on matrilineal care for a very rare life-history trait in nature, menopause, which has only been documented in a handful of mammals, including beluga whales and humans."

Researchers found that belugas formed a limited number of group types, from mother-calf dyads to adult male groups, and from mixed-age groups to large herds. These same group types were consistently observed across population and habitats. Furthermore, certain behaviors were associated with group type, and group membership was found to often be dynamic.

"Unlike killer and pilot whales, and like some human societies, beluga whales don't solely or even primarily interact and associate with close kin. Across a wide variety of habitats and among both migratory and resident populations, they form communities of individuals of all ages and both sexes that regularly number in the hundreds and possibly the thousands," said O'Corry-Crowe. "It may be that their highly developed vocal communication enables them to remain in regular acoustic contact with close relatives even when not associating together."

Beluga whale groupings (beyond mother-calf dyads) were not usually organized around close maternal relatives. The smaller social groups, as well as the larger herds, routinely comprised multiple matrilines. Even where group members shared the same mtDNA lineage, microsatellite analysis often revealed that they were not closely related, and many genealogical links among group members involved paternal rather than maternal relatives. These results differ from earlier predictions that belugas have a matrilineal social system of closely associating female relatives. They also differ from the association behavior of the larger toothed whales that informed those predictions. In 'resident' killer whales, for example, both males and females form groups with close maternal kin where they remain for their entire lives.

"Beluga whales exhibit a wide range of grouping patterns from small groups of two to 10 individuals to large herds of 2,000 or more, from apparently single sex and age-class pods to mixed-age and sex groupings, and from brief associations to multi-year affiliations," said O'Corry-Crowe. "This variation suggests a fission-fusion society where group composition and size are context-specific, but it may also reflect a more rigid multi-level society comprised of stable social units that regularly coalesce and separate. The role kinship plays in these groupings has been largely unknown."

For the study, researchers used field observations, mtDNA profiling, and multi-locus genotyping of beluga whales to address fundamental questions about beluga group structure, and patterns of kinship and behavior, which provide new insights into the evolution and ecology of social structure in this Arctic whale.

The study was conducted at 10 locations, in different habitats, across the species' range, spanning from small, resident groups (Yakutat Bay) and populations (Cook Inlet) in subarctic Alaska to larger, migratory populations in the Alaskan (Kasegaluk Lagoon, Kotzebue Sound, Norton Sound), Canadian (Cunningham Inlet, Mackenzie Delta, Husky Lakes) and Russian (Gulf of Anadyr) Arctic to a small, insular population in the Norwegian High Arctic (Svalbard).

"This new understanding of why individuals may form social groups, even with non-relatives, will hopefully promote new research on what constitutes species resilience and how species like the beluga whale can respond to emerging threats including climate change," said O'Corry-Crowe.

Medical University of South Carolina researchers report in Current Biology that the brain uses similar visual areas for mental imagery and vision, but it uses low-level visual areas less precisely with mental imagery than with vision.

These findings add knowledge to the field by refining methods to study mental imagery and vision. In the long-term, it could have applications for mental health disorders affecting mental imagery, such as post-traumatic stress disorder. One symptom of PTSD is intrusive visual reminders of a traumatic event. If the neural function behind these intrusive thoughts can be better understood, better treatments for PTSD could perhaps be developed.

The study was conducted by an MUSC research team led by Thomas P. Naselaris, Ph.D., associate professor in the Department of Neuroscience. The findings by the Naselaris team help answer an age-old question about the relationship between mental imagery and vision.

"We know mental imagery is in some ways very similar to vision, but it can't be exactly identical," explained Naselaris. "We wanted to know specifically in which ways it was different."

To explore this question, the researchers used a form of artificial intelligence known as machine learning and insights from machine vision, which uses computers to view and process images.

"There's this brain-like artificial system, a neural network, that synthesizes images," Naselaris explained. "It's like a biological network that synthesizes images."

The Naselaris team trained this network to see images and then took the next step of having the computer imagine images. Each part of the network is like a group of neurons in the brain. Each level of the network or neuron has a different function in vision and then mental imagery.

To test the idea that these networks are similar to the function of the brain, the researchers performed an MRI study to see which brain areas are activated with mental imagery or vision.

While inside the MRI, participants viewed images on a screen and were also asked to imagine images at different points on the screen. MRI imaging enabled researchers to define which parts of the brain were active or quiet while participants viewed a combination of animate and inanimate objects.

Once these brain areas were mapped, the researchers compared the results from the computer model to human brain function.

They discovered that both the computer and human brains functioned similarly. Areas of the brain from the retina of the eye to the primary visual cortex and beyond are both activated with vision and mental imagery. However, in mental imagery, the activation of the brain from the eye to the visual cortex is less precise, and in a sense, diffuse. This is similar to the neural network. With computer vision, low-level areas that represent the retina and visual cortex have precise activation. With mental imagery, this precise activation become diffuse. In brain areas beyond the visual cortex, the activation of the brain or the neural network is similar for both vision and mental imagery. The difference lies in what's happening in the brain from the retina to the visual cortex.

"When you're imagining, brain activity is less precise," said Naselaris. "It's less tuned to the details, which means that the kind of fuzziness and blurriness that you experience in your mental imagery has some basis in brain activity."

Naselaris hopes these findings and developments in computational neuroscience will lead to a better understanding of mental health issues.

The fuzzy dream-like state of imagery helps us to distinguish between our waking and dreaming moments. In people with PTSD, invasive images of traumatic events can become debilitating and feel like reality in the moment. By understanding how mental imagery works, scientists may better understand mental illnesses characterized by disruptions in mental imagery.

"When people have really invasive images of traumatic events, such as with PTSD, one way to think of it is mental imagery dysregulation," explained Naselaris. "There's some system in your brain that keeps you from generating really vivid images of traumatic things."

A better understanding of how this works in PTSD could provide insight into other mental health problems characterized by mental imagery disruptions, such as schizophrenia.

"That's very long term," Naselaris clarified.

For now, Naselaris is focusing on how mental imagery works, and more research needs to be done to address the connection to mental health.

A limitation of the study is the ability to recreate fully the mental images conjured by participants during the experiment. The development of methods for translating brain activity into viewable pictures of mental images is ongoing.

This study not only explored the neurological basis of seen and imagined imagery but also set the stage for research into improving artificial intelligence.

"The extent to which the brain differs from what the machine is doing gives you some important clues about how brains and machines differ," said Naselaris. "Ideally, they can point in a direction that could help make machine learning more brainlike."

RIVERSIDE, Calif. -- Whether you decided to engage in social distancing in the early stages of COVID-19 depended on how much information your working memory could hold.

This is the crucial finding of a research paper published in the Proceedings of the National Academy of Sciences coauthored by Weiwei Zhang, an associate professor of psychology at the University of California, Riverside. The study offers potential strategies to mitigate social distancing noncompliance in a public health crisis.

The researchers found individuals with higher working memory capacity have an increased awareness of benefits over costs of social distancing and, subsequently, show more compliance with recommended social distancing guidelines during the early stage of the COVID-19 outbreak.

Working memory is the psychological process of holding information in the mind for a brief period of time - typically, just seconds. The amount of information working memory can hold briefly -- its capacity -- is predictive of many mental abilities such as intelligence, comprehension, and learning.

"The higher the working memory capacity, the more likely that social distancing behaviors will follow," said Zhang, the paper's senior author. "Interestingly, this relationship holds even after we statistically control for relevant psychological and socioeconomic factors such as depressed and anxious moods, personality traits, education, intelligence, and income."

In the United States, where social distancing is mostly voluntary, widespread noncompliance persists, and was especially high during the early stages of the COVID-19 pandemic. According to Zhang, one reason for this is concerns about the inherent socioeconomic costs associated with social distancing. But what constitutes an individual's cognitive ability to come to a decision regarding compliance with social distancing guidelines remains largely unclear.

"Our findings reveal a novel cognitive root of social distancing compliance during the early stage of the COVID-19 pandemic," Zhang said. "We found social distancing compliance may rely on an effortful decision process of evaluating the costs versus benefits of these behaviors in working memory -- instead of, say, mere habit. This decisional process can be less effortful for people with larger working memory capacity, potentially leading to more social distancing behaviors."

The study included the participation of 850 U.S. residents from March 13 to March 25, 2020 -- the first two weeks following the U.S. presidential declaration of a national emergency about the COVID-19 pandemic.

Participants first filled out a demographic survey. Then they completed a set of questionnaires that captured individual differences in social distancing compliance, depressed mood, and anxious feelings. Personality variables, intelligence, and participants' understanding about the costs and benefits of social distancing practice were measured also.

"Individual differences in working memory capacity can predict social distancing compliance just as well as some social factors such as personality traits," Zhang said. "This suggests policy makers will need to consider individuals' general cognitive abilities when promoting compliance behaviors such as wearing a mask or engaging in physical distancing."

Zhang and his colleagues recommend media materials for promoting norm compliance behaviors to avoid information overload.

"The message in such materials should be succinct, concise, and brief," Zhang said. "Make the decision process easy for people."

The study's findings also suggest learning social distancing as a new norm requires an effortful decision process that relies on working memory.

"The bottom line is we should not rely on habitual behaviors since social distancing is not yet adequately established in U.S. society," Zhang said. "Before social distancing becomes a habit and a well-adopted social norm, the decision to follow social distancing and wearing masks would be mentally effortful. Consequently, we will have to deliberately make the effort to overcome our tendency to avoid effortful decisions, such as to not practice social distancing."

Zhang expects the contribution of working memory will decline as new social norms, such as wearing a mask or socially distancing, are acquired by society over time.

"Eventually social distancing and wearing face masks will become a habitual behavior and their relationship with working memory will diminish," he said.

Next, the team will analyze data it collected across the United States, China, and South Korea to identify protective social and mental factors that help people cope with the pandemic.

The researchers have also been collecting data assessing how working memory is related to racial discrimination during the pandemic.

Rape and sexual trauma may have long-lasting consequences for physical health as well as mental health, University of Otago researchers have found.

The team of researchers, led by respiratory specialist Professor Bob Hancox and sexual health specialist Dr Jane Morgan from Waikato DHB, found a history of rape is associated with "dysfunctional breathing" in both women and men, and with late-onset asthma diagnosis in women.

"Dysfunctional breathing", which is also known as Hyperventilation Syndrome, involves breathing too deeply or too rapidly. People can present with chest pain and a tingling sensation in the fingertips and around the mouth and it may accompany a panic attack.

While previous studies have found that a history of adverse events and psychological trauma, including sexual trauma, are associated with self-reported asthma, links with other respiratory problems have not been examined. Professor Hancox explains the team set out to assess whether the experience of being raped - an extreme form of psychological trauma - was associated with dysfunctional breathing among participants in the Dunedin Multidisciplinary Health and Development Study.

This world-renowned study is a longitudinal investigation of health and behaviour in a group of 1037 people born in Dunedin in 1972 or 1973 and followed regularly throughout their lives.

Nearly 20 per cent of women and 4 per cent of men in the study reported being raped at some stage throughout their life. Both men and women who had reported being raped were more likely to have dysfunctional breathing at 38 years of age.

Rape was also associated with self-reported diagnoses of asthma and symptoms of wheeze among women, but not men.

"If this is a true cause-and-effect association, these analyses indicate that 23 per cent of all asthma among women at 38 years of age, or nearly a third of adult-onset asthma could be attributed to rape."

While both rape and the outcome of dysfunctional breathing were less common among men, the association between rape and hyperventilation syndrome was equally strong - or even stronger - among men who reported rape.

The Otago researchers believe this is the first epidemiological study to investigate the possible origins of hyperventilation syndrome.

"The findings indicate that dysfunctional breathing may be a consequence of severe psychological trauma and are consistent with case reports of sexual abuse in patients with other patterns of breathing difficulty," Professor Hancox explains.

"Health professionals should recognise the possibility of prior traumatic experiences triggering either dysfunctional breathing or late-onset asthma and consider whether psychological counselling or other forms of therapy would help their patients," he says.

The researchers focused on rape because it is a particularly traumatic experience that can be clearly defined, but Professor Hancox says it is likely that other forms of sexual and non-sexual abuse may have similar effects.

"We need to investigate whether other forms of sexual, physical and psychological trauma are also associated with breathing pattern disorders."