Culture

What The Study Did: Nationally representative survey data were used to examine changes over nearly two decades in daily use of high-dose biotin supplements, which are marketed as stimulating growth of hair and nails.

Authors: Danni Li, Ph.D., of the University of Minnesota in Minneapolis, is the corresponding author.

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

(doi:10.1001/jama.2020.8144)

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

WASHINGTON, August 11, 2020 -- In severe cases of COVID-19, damage can spread beyond the lungs and into other organs, such as the heart, liver, kidney and parts of the neurological system. Beyond these specific sets of organs, however, the virus seems to lack impact.

Ernesto Estrada, from the University of Zaragoza and Agencia Aragonesa para la Investigación Foundation in Spain, aimed to uncover an explanation as to how it is possible for these damages to propagate selectively rather than affecting the entire body. He discusses his findings in the journal Chaos, from AIP Publishing.

In order to enter human cells, the coronavirus relies on interactions with an abundant protein called angiotensin-converting enzyme 2.

"This receptor is ubiquitous in most human organs, such that if the virus is circulating in the body, it can also enter into other organs and affect them," Estrada said. "However, the virus affects some organs selectively and not all, as expected from these potential mechanisms."

Once inside a human cell, the virus's proteins interact with those in the body, allowing for its effects to cultivate. COVID-19 damages only a subset of organs, signaling to Estrada that there must be a different pathway for its transmission. To uncover a plausible route, he considered the displacements of proteins prevalent in the lungs and how they interact with proteins in other organs.

"For two proteins to find each other and form an interaction complex, they need to move inside the cell in a subdiffusive way," Estrada said.

He described this subdiffusive motion as resembling a drunkard walking on a crowded street. The crowd presents obstacles to the drunkard, stunting displacement and making it difficult to reach the destination.

Similarly, proteins in a cell face several crowded obstacles they must overcome in order to interact. Adding to the complexity of the process, some proteins exist within the same cell or organ, but others do not.

Taking these into account, Estrada developed a mathematical model that allowed him to find a group of 59 proteins within the lungs that act as the primary activators affecting other human organs. A chain of interactions, beginning with this set, triggers changes in proteins down the line, ultimately impacting their health.

"Targeting some of these proteins in the lungs with existing drugs will prevent the perturbation of the proteins expressed in organs other than the lungs, avoiding multiorgan failure, which, in many cases, conduces the death of the patient," Estrada said.

How the affected proteins travel between organs remains an open question that Estrada is dedicating for future studies.

Scientists have discovered that the larynx, or voice box, of primates is significantly larger relative to body size, has greater variation, and is under faster rates of evolution than in other mammals.

Published in the journal PLOS Biology and led by academics from Anglia Ruskin University (ARU), Stanford University, and the University of Vienna, the research is the first large-scale study into the evolution of the larynx.

The larynx has three main functions: protecting the airway during feeding, regulating the supply of air to the lungs, and vocal communication. Because of its important role in facilitating social behaviour, through vocalisation, it has long been believed that the larynx is a key area of evolution, particularly in species with highly developed vocal communication systems.

The researchers made CT-scans of specimens from 55 different species, and produced 3D computer models of their larynges. These were studied alongside detailed measurements, including body length and body mass.

The primates ranged in size from a pygmy marmoset (Cebuella pygmaea) weighing just 110g, to a Western gorilla (Gorilla gorilla) weighing approximately 120kg. The carnivorans spanned from a 280g common dwarf mongoose (Helogale parvula) to a 180kg tiger (Panthera tigris).

The study found that, for a given body length, primate larynges are on average 38% larger than those of carnivorans, and that the rate of larynx evolution is faster in these species.

There is also more variation in larynx size relative to body size among primates, indicating that primates have greater flexibility to evolve in different ways. Carnivorans follow more of a fixed larynx-size to body-size ratio.

Larynx size was also found to be a good predictor of the call frequency of a species, which demonstrates the relevance for vocal communication of the observed size variations.

Co-lead author Dr Jacob Dunn, Reader in Evolutionary Biology at Anglia Ruskin University (ARU), said: "This study demonstrates clear differences in the evolution of the larynx between groups of mammals.

"Specifically, we have shown for the first time that the primate larynx is larger, less closely linked to body size, and under faster rates of evolution than the carnivoran larynx, which is a well-matched comparison group, indicating fundamental differences in the evolution of the vocal organ across species."

Co-lead author Dr Daniel Bowling, Instructor in Psychiatry and Behavioral Sciences at Stanford University, added: "Our study also shows that differences in larynx size predict changes in voice pitch, highlighting the larynx's crucial role in vocal communication. This is demonstrated by the rich and varied calls produced by many primate species.

"The results imply fundamental differences between primates and carnivorans in the forces constraining larynx size, as well as highlighting an evolutionary flexibility in primates that may help explain why they have developed complex and diverse uses of the vocal organ for communication. This provides an exciting avenue for future studies examining variation among other mammalian groups."

What The Viewpoint Says: This Viewpoint advises parents on how to assess virtual schooling options for their children for the fall semester during the COVID-19 pandemic.

Authors: Lindsay A. Thompson, M.D., M.S., of the University of Florida in Gainesville, is the corresponding author.

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

(doi:10.1001/jamapediatrics.2020.3800)

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

Weary working parents aren't the only ones eager for their children to return to school in a few weeks. Many teachers, staff and administrators also want those classroom doors to reopen. Most importantly, kids are craving the clamor of school hallways and interaction with their friends.

The American Academy of Pediatrics recently highlighted the importance of students' returning to the classroom in its COVID-19 return-to-school guidance. Jason Wang, MD, PhD, of Stanford Health Policy also believes it's time for kids in the United States to get back to school. But he believes school districts could better protect their 55 million K-12 students by adhering to an additional set of strict measures.

"Prolonged school closures can exacerbate socioeconomic disparities, causing negative education and health outcomes, and amplifying existing educational inequalities," said Wang, a pediatrician and director of the Center for Policy, Outcomes and Prevention in the Stanford School of Medicine. "School closure may also aggravate food insecurity, domestic violence and mental health disorders. Many children from low-income households obtain food through the National School Lunch Program, and estimates suggest that 1 in 4 children may face hunger this year due to COVID-19."

But serious precautions must first be put into place, Wang said, starting with each school district establishing a COVID-19 task force composed of the superintendent, members of the school board, teachers, parents and health care professionals to develop policies and procedures.

"To implement and evaluate specific measures, the task force should create and oversee a command center for the school district, composed of data analysts and health experts who can liaise with the local health department," Wang writes in a JAMA Pediatrics article with co-author Henry Bair, a medical student at the Stanford School of Medicine who is also working on an MBA at the university's graduate school of business. The article will be published Aug. 11.

Three-pronged testing approach

The academy's guidance does not include ways schools can test for the virus, so the authors recommend that school districts collaborate with local hospitals to:

Test all students with symptoms.

Devise a schedule to randomly select a proportion of students and staffers for COVID-19 testing to identify asymptomatic individuals. The researchers note that a pooled testing strategy can significantly reduce costs.

Offer more frequent testing to students from high-risk households in ZIP codes with socioeconomic challenges.

In addition, the authors recommend that district task forces:

Work with its local health department to provide educational materials and training for students, parents and school staff on the basics of COVID-19 prevention.

Provide school staff with thermometers and train them to screen for COVID-19 symptoms.

Build temporary modular buildings if schools cannot maintain 6 feet of physical distance among students and teachers.

Expand the district's fleet of school buses or develop different pickup schedules.

Increase budgets to boost disinfection efforts of all teaching spaces, common areas and high-touch surfaces such as doorknobs, computers and desks.

Place transparent plastic shields in front of and along the sides of student desks.

Provide hand sanitizers and protective equipment, such as disposable surgical masks, reusable cloth masks or reusable face shields.

Wang concedes these are expensive measures. But as the Centers for Disease Control and Prevention noted in its July 24 telebriefing on new resources and tools to support opening schools: The 5.6 million parents who haven't been able to work due to school closures have collectively lost an estimated $232 billion in earnings.

Stricter measures mean bigger budgets

Some low-resource communities might find these guidelines difficult to adopt. Those transparent desk barriers, for example, range from $100 to $200 per desk; COVID-19 tests run between $50 and $200 per individual.

Wang said that's why additional federal funding and state subsidies are crucial for the low-income communities already hit by the double whammy of having more parents as essential workers and some of the highest hospitalization and fatality rates from the pandemic.

"Low-income communities are suffering most from shelter-in-place policies because parents who are essential workers are out of the home and not able to help with online learning," Wang said. "And many children in these communities also live in crowded conditions that are not conducive to learning at home."

Wang and Bair note the academy's guidelines emphasize the importance of identifying symptoms and signs of COVID-19, but don't go far enough in recommending operational approaches.

"To address this, we recommend that schools implement multilevel screening for students and staff," they write. Each morning parents should report any fever or COVID-19 symptoms to an online or an automated telephone-based program maintained by the school or district. Any students with symptoms should stay home.

Even with all the precautions in place, COVID-19 outbreaks within schools are still likely, the authors said. Schools should prepare for temporary closures and be ready to transition back to full-time online education by investing in remote education platforms and training.

"Schools will need to ensure equitable implementation of online education among students, especially those with limited knowledge of or access to technological resources and consider subsidizing educational technologies for these students," the authors write.

CHAPEL HILL, NC - Aug. 11, 2020 - This spring, due to limited national supplies of N95 face masks, hospitals across the country asked the public and private companies to donate personal protective equipment (PPE), including many different types of masks, to be sure healthcare workers were protected while caring for patients.

With so many options, infection prevention experts at the UNC Medical Center set out to gather evidence on the fitted filtration efficiency of dozens of different types of masks and mask modifications, including masks sterilized for reuse, expired masks, novel masks sourced from domestic and overseas sources, and homemade masks.

Their data, published today in JAMA Internal Medicine, show that reused, sterilized N95 masks and very out-of-date N95 masks retain their effectiveness at protecting healthcare workers from COVID-19 infection.

To assess mask fitted filtration effectiveness, Emily Sickbert-Bennett, PhD, director of Infection Prevention at UNC Medical Center and colleagues turned to someone she knew she could trust: her dad, William Bennett, PhD, professor of medicine, who leads the Mucociliary Clearance and Aerosol Research Laboratory at the UNC Center for Environmental Medicine, Asthma, and Lung Biology (CEMALB).

"I told him we had two types of masks - used, sterilized and expired N95 masks - and we needed to know whether they would offer safe and effective protection, in case we needed our healthcare co-workers to use them." Sickbert-Bennett said. "And he said it would be possible for his lab to test them and give us data upon which to base our decision-making."

Thanks to a cooperative agreement with the EPA Human Studies Facility on the UNC-Chapel Hill campus, in which Bennett's labs reside, Bennett, assistant professor Phillip Clapp, PhD, and research associate Kirby Zeman, PhD, teamed with EPA research scientist, James Samet, PhD, to measure the fraction of submicron particles that penetrate into the breathing space of subjects wearing a mask while performing a series of tasks that simulate conditions such as speech and movement during a work shift. Such tests provided infection prevention leaders quantitative data they used to rank the best respiratory protection options for healthcare personnel during the COVID-19 outbreak.

The researchers found that certain N95 masks - as rated by the National Institute of Occupational Safety and Health (NIOSH) Administration - provide greater than 95 percent effectiveness at keeping the wearer from inhaling very small airborne particles that may carry SARS-CoV-2 - the virus that can cause COVID-19. Furthermore, these masks retain such effectiveness many years beyond the masks' expiration dates. In addition, these NIOSH-rated masks can be subjected to sterilization with hydrogen peroxide or ethylene oxide without compromising their efficiency. Finally, their fitted filtration procedures showed that surgical masks with ties were approximately 70 percent effective at filtering their inhaled particles, while surgical masks with ear loops were about 40 percent effective. Clapp, co-first author, emphasized that, "One of the keys to protection is how snug a mask fits. An N95 mask that forms a tight seal offers the optimal infection prevention. However, evidence from previous studies suggests that even the surgical masks with

"Our hierarchy of mask supplies essentially amounts to always using the safest option on the shelf, especially for those healthcare workers caring for COVID-19 patients," said Sickbert-Bennett, co-first author of the JAMA Internal Medicine paper. "We start with products of our usual make and model, then follow with CDC-FDA-NIOSH approved products.

"To date, UNC Health has maintained adequate supplies of NIOSH-approved PPE," Sickbert-Bennett said. "We feel confident we can maintain protection of the UNC Health workers with the variety of face masks and respirators tested as part of this JAMA-published study."

UNC Health infection prevention leaders are grateful for the partnership with the Center for Environmental Medicine, Asthma, and Lung Biology (CEMALB) and the EPA Human Studies Facility in Chapel Hill. Thanks to this collaboration, UNC Health can make evidence-based decisions on how to best protect our co-workers.

Dr. Clapp also led testing on other masks and homemade creations, using the same chamber and aerosol measurement equipment used for testing commercial masks. The UNC Office of Research Communications produced a Q and A with Dr. Clapp, along with a video about homemade masks based on his research.

What The Study Did: Researchers performed a series of FFE (fitted filtration efficiency) evaluations for a wide range of 29 respirators and face masks used by health care facilities, including expired N95 respirators, N95 respirators that have undergone sterilization, imported respirators approved by the U.S. Centers for Disease Control and Prevention, respirators not listed as approved, and surgical or procedure masks with ties and ear loops in this quality-improvement study.

Authors: Emily E. Sickbert-Bennett, Ph.D., M.S., of  UNC Health Care in Chapel Hill, North Carolina, is the corresponding author.

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

(doi:10.1001/jamainternmed.2020.4221)

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

Researchers at Fudan University in Shanghai, China have developed three different techniques that successfully replace almost all malfunctioning microglia - each technique with its own advantage in application.

The researchers published their findings on Aug 11, 2020 in Cell Reports.

Microglia are a specialized type of immune system cell that are found throughout the central nervous system (CNS), including brain, retina and spinal cord. Their main job is to protect the neurons of the central nervous system by gobbling up pathogens, cancer cells, foreign substances and cellular debris. They are sort of like a vacuum cleaner that the immune system uses to keep the central nervous system clean. Malfunctioning microglia are associated with many neurological diseases such as Alzheimer's, ALS and Parkinson's. Gene therapy to replace defective microglia-related genes with properly functioning ones offers tremendous potential to alleviate or perhaps one day even eliminate such diseases.

However, up till now, such efforts in the lab or testing on animals have largely failed long before any clinical trials on humans. Attempts at transplants of microglia or of bone marrow (because bone marrow is the main location in the body of production of new stem cells that can differentiate themselves into microglia) only end up replacing up to 5 percent of the faulty microglia. Other strategies that have been more successful when tested on mice require the animal to have a suppressed immune system and still be at the neonatal stage of life. This means that it is impossible for such a strategy to be used in any real-world clinical application for humans.

In an earlier study, the same team had noticed that when drugs had been used to almost completely eliminate all existing microglia, the few that remained had an astonishing ability to proliferate. This suggested to them that to get any microglia, native or transplanted, to substantially proliferate, you need the trigger of a completely empty microglial "niche" into which new microglia grow.

So the researchers replicated this effect by feeding normal adult mice for two weeks a diet that included a drug that inhibits the production of a molecule necessary for microglial survival. Only after all the microglia were wiped out, did the researchers attempt a bone marrow transplant. This time, some 93 percent of microglia were replaced in the brain, 99.5 percent in the retina, and 93 percent in the spinal cord.

They call this technique microglia replacement--because pretty much all the old microglia get replaced by new ones--by bone marrow transplant, or mrBMT.

"We pronounce the acronym for the technique 'Mister BMT'," said Bo Peng, the corresponding author and professor from the Institute for Translational Brain Research at Fudan University. "It's a cute name, but it makes it easy to say and to remember."

Despite the impressive replacement efficiency of mrBMT, bone marrow cells are rather scarce in clinical practice. So the researchers tried the same technique of eliminating existing microglia before transplant, but now with peripheral blood cells (PBC) instead of bone marrow cells. (Peripheral blood is the blood that circulates in much of the body, distinct from the blood cells that stay enclosed in the liver, spleen and other areas that have their own specialized type of blood). Such blood is abundant and easily acquired.

This second technique, called mrPB, (similarly pronounced "Mister PB"), replaced 80 percent of the microglia. So between the two techniques, there is trade-off: mrBMT offers close to full microglia replacement, but donor sources are hard to come by, while mrPB offers donor sources that are easy to come by, but the microglia replacement is slightly less efficient.

Sometimes though, a patient might need only the microglia in a specific part of the brain to be replaced without affecting the rest of the brain. So the researchers tweaked their concept still further. Using mrBMT first to replace resident cells with chemically sensitive microglia. After that, tamoxifen was applied to induce a fragment of a diphtheria toxin to kill off the replaced mrBMT cells. Meanwhile, they directly injected normally functioning microglia, which do not respond to tamoxifen, into a specific brain region with a syringe. While mrBMT and mrPB microglia still have some slight differences with regular microglia, the third technique, mrMT produces microglia almost indistinguishable from the normal kind.

"Each of the three approaches has its own merits and limits," said Peng, "but each is also more appropriate for different application scenarios. The hope is that all three of them open up a new era for treating microglia-associated CNS disorders."

Scientists have found that air pollution in the winter is associated with more hospitalisations for all strokes in Dublin.

The study, led by researchers from RCSI University of Medicine and Health Sciences, is published in the current edition of Cerebrovascular Diseases.

During winter months in Ireland, particularly in Dublin, higher levels of fine particles, coarse particles, sulphur dioxide and nitrogen dioxide are found in the air. The sources of these are solid fuel burning, such as coal, peat, and wood, as well as road traffic - especially diesel engines.

After accounting for other variables, such as temperature, humidity, day of the week and time, the researchers found that there was a statistically significant rise in the number of hospitalisations for strokes in Dublin zero to two days after a rise in air pollution.

For higher levels of nitrogen dioxide and sulphur dioxide, the researchers found both had an associated 3.5% higher risk of stroke. Higher levels of coarse particles correlated with a 3.2% higher risk, and finer particles correlated with a 2.4% higher risk.

The study marks the first time there has been a link demonstrated between short-term air pollution and stroke in Ireland.

"Every year, more than 10,000 people in Ireland have a stroke. Our research adds evidence that there needs to be a national ban on solid fuel burning to help in our efforts to reduce this number," said Dr Colm Byrne, the study's lead author and clinical lecturer in the RCSI Department of Geriatric and Stroke Medicine.

There was no significant association for all air pollutants found in the smaller urban area of Cork, but meta-analysis showed a significant association between hospitalisations for strokes and higher levels nitrogen dioxide and fine particles in the air.

"Because Ireland has relatively low air pollution when compared internationally, this highlights the need to introduce additional policy changes to reduce air pollution in all countries," said Professor David Williams, professor of stroke medicine at RCSI.

To protect humans against infection, a protein called MARCH8 tags the vesicular stomatitis virus (VSV) for destruction while it merely holds HIV hostage, a new study in eLife shows.

The findings reveal how a single protein can use multiple strategies to defend cells against viral infection. They could also improve our understanding of how HIV overcomes the human immune defence.

Previous studies have shown that MARCH8 stops HIV and VSV from entering human cells by targeting the viral proteins that are essential for these viruses to enter cells. But how the protein does this remained unclear. Researchers in Japan suspected that MARCH8 might flag an important VSV envelope protein for destruction by targeting a particular amino acid called lysine.

"The VSV G-glycoprotein (VSV-G) has a short tail containing five lysines, making it an ideal target," explains senior author Kenzo Tokunaga, Principal Investigator in the Department of Pathology, National Institute of Infectious Diseases, Tokyo, Japan. "The HIV envelope glycoprotein (Env), by contrast, has a very long tail with only two lysines, making it harder for MARCH8 to flag it for destruction."

To test their idea, Tokunaga and his team, including co-first authors and Postdoctoral Fellows Yanzhao Zhang and Takuya Tada, replaced the five lysines on the tail of VSV-G with five arginines - another type of amino acid. They also replaced the two lysines on the tail of HIV Env with two arginines. The change allowed VSV-G to escape MARCH8, but not HIV Env. This suggests that MARCH8 targets HIV Env and VSV-G using two different mechanisms.

Instead of marking HIV Env for destruction, the team found that MARCH8 holds it hostage, inhibiting its ability to make infectious copies of itself (replicate) and spread to other cells. When they created a mutant version of MARCH8 that lacks a specific pattern of the amino acid tyrosine, they found that HIV Env was able to escape, allowing the virus to replicate. This suggests that the tyrosine pattern in MARCH8 is essential to its HIV defence strategy.

"Our work may help explain why humans don't develop symptoms when infected with VSV, even though it can make some animals, mostly cows, horses and pigs, very ill," says Tokunaga. "The findings might also explain, at least in part, why HIV is able to hide from the human immune system, causing persistent infections that are difficult to treat."

On July 4, NASA's Transiting Exoplanet Survey Satellite (TESS) finished its primary mission, imaging about 75% of the starry sky as part of a two-year-long survey. In capturing this giant mosaic, TESS has found 66 new exoplanets, or worlds beyond our solar system, as well as nearly 2,100 candidates astronomers are working to confirm.

"TESS is producing a torrent of high-quality observations providing valuable data across a wide range of science topics," said Patricia Boyd, the project scientist for TESS at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "As it enters its extended mission, TESS is already a roaring success."

TESS monitors 24-by-96-degree strips of the sky called sectors for about a month using its four cameras. The mission spent its first year observing 13 sectors comprising the southern sky and then spent another year imaging the northern sky.

Now in its extended mission, TESS has turned around to resume surveying the south. In addition, the TESS team has introduced improvements to the way the satellite collects and processes data. Its cameras now capture a full image every 10 minutes, three times faster than during the primary mission. A new fast mode allows the brightness of thousands of stars to be measured every 20 seconds, along with the previous method of collecting these observations from tens of thousands of stars every two minutes. The faster measurements will allow TESS to better resolve brightness changes caused by stellar oscillations and to capture explosive flares from active stars in greater detail.

These changes will remain in place for the duration of the extended mission, which will be completed in September 2022. After spending a year imaging the southern sky, TESS will take another 15 months to collect additional observations in the north and to survey areas along the ecliptic - the plane of Earth's orbit around the Sun - that the satellite has not yet imaged.

TESS looks for transits, the telltale dimming of a star caused when an orbiting planet passes in front of it from our point of view. Among the mission's newest planetary discoveries are its first Earth-size world, named TOI 700 d, which is located in the habitable zone of its star, the range of distances where conditions could be just right to allow liquid water on the surface. TESS revealed a newly minted planet around the young star AU Microscopii and found a Neptune-size world orbiting two suns.

In addition to its planetary discoveries, TESS has observed the outburst of a comet in our solar system, as well as numerous exploding stars. The satellite discovered surprise eclipses in a well-known binary star system, solved a mystery about a class of pulsating stars, and explored a world experiencing star-modulated seasons. Even more remarkable, TESS watched as a black hole in a distant galaxy shredded a Sun-like star.

Missions like TESS help contribute to the field of astrobiology, the interdisciplinary research on the variables and conditions of distant worlds that could harbor life as we know it, and what form that life could take.

PHILADELPHIA - Running is one of the most popular forms of exercise, enjoyed by a broad range of age groups and skill levels. More women are running recreationally compared to men; specifically 54% of runners are female as indicated by a 2018 National Runner Survey. Women, however, are at least twice as likely as men to develop stress fractures, an injury that impacts around 20% of runners. However, information is still lacking on how to best prevent and treat stress fractures in women. New pilot research from Jefferson suggests physiological factors that could be included in routine screening for stress fracture risk, as well as changes in training approach to aid in prevention.

The researchers examined physiological differences that might contribute to increased risk of stress fractures in a study published in Sports Health and also surveyed women's perception of risk and behaviors that contribute to stress fractures in a separate study published in Physical Therapy in Sport.

"Most of the literature focuses on elite runners or athletes," says Therese Johnston, PT, PhD, MBA, Professor in the Department of Physical Therapy and first author of both studies. "It was important for us to capture the regular or average female runner in these studies, and the main goal was to see how we can prevent a first or subsequent fracture."

Both studies surveyed the same group of 40 female recreational runners, age 18-65 years. 20 women had a history of running-related stress fractures, and they were matched according to age and running abilities with 20 women with no history of stress fractures. The two studies aimed to assess what contributed to risk of stress fractures, from the physiological, such as - bone structure and density, muscle mass, hormonal status, to ones influenced by training routine, such as training intensity, nutrition, insufficient strengthening, and ignoring pain.

"This mixed methods approach provides a richer context and a more detailed picture of the practices and risks that contribute to stress fractures in every-day women runners," says Jeremy Close, MD, Associate Professor in Family and Sports Medicine and one of the lead authors on the research. "It also tells us how perceived risk informs physiological risk."

For the study focused on physiological factors, the subjects underwent a comprehensive blood panel that examined levels of hormones like estradiol and testosterone, vitamins and minerals important for bone health such as vitamin D and calcium, and bone markers. They also underwent dual energy x-ray absorptiometry (DXA) to test for bone mineral density. The researchers found that while there was no difference in estradiol hormone levels between the two groups, women who had a stress fracture history reported menstrual changes or irregular periods as a result of their training, or during peak training times. The blood panel also examined markers for bone formation and resorption, and pointed to increased bone turnover in the group of women with stress fractures. They also found through the DXA testing that women with a history of stress fractures had lower hip bone mineral density compared to women with no history of stress fractures, indicating decreased bone strength that could increase risk of injury.

"DXA for bone density and blood testing for bone markers are not routinely performed in this population - they are usually reserved for post-menopausal women --so we may be missing important clinical indicators for stress fractures in these women," says Dr. Johnston. "While the link between menstrual changes and bone strength is unclear, our findings also indicate that asking female runners about any menstrual irregularities during heavier training times is important during routine screening."

For the study investigating women's self-perception of risk, interviews were conducted with the goals of finding out which factors women thought were associated with stress fractures or maintaining bone health while running. Several themes emerged from these interviews, specifically, compared to women without stress fractures, women with histories of stress fractures had increased their training load more quickly. Also, while they knew of the importance of nutrition and strengthening exercises, women with a history of stress fracture more often reported not having or making the time for a balanced diet and proper cross-training to complement their running regimen.

Finally, women in this group reported pushing through the pain and running despite an injury more often than those without stress fracture. "In the interviews, it sounded like these women had trouble knowing which pain was normal, and which pain was abnormal. They also reported not always receiving appropriate guidance from healthcare providers on how to progress running safely," says Dr. Johnston.

"It is clear that there needs to be more guidance from healthcare providers for woman runners on how to prevent stress fractures" says Dr. Close. "It can be very frustrating for these women who are on a path to wellness, but are impeded by an injury that can take several months to heal. If they don't have the proper guidance on how to return to running safely, they risk a second injury."

"We hope that our findings will encourage more thorough and routine screening in women runners for bone density and strength," says Dr. Johnston, "as well as a comprehensive education plan on how to balance running with cross-training, and how to interpret pain cues from the body, to help women differentiate between normal aches and pains and indicators of a serious injury."

Dr. Johnston plans to continue this research by studying women with acute stress fractures as they start running again, in order to identify factors related to successful or unsuccessful return to running following a stress fracture. The study will include Dr. Close as well as Marc Harwood, MD, Service Chief in the Department of Non-Operative Sports Medicine at Rothman Orthopaedic Institute.

CATONSVILLE, MD, August 11, 2020 - The Transportation Security Administration (TSA) has reported that it found 4,432 firearms in carry-on baggage at airport security checkpoints in 2019, and more than 20,000 firearms since 2014. New research published in the INFORMS Journal on Applied Analytics suggests that they could have found even more.

The initial reaction to these numbers is shock and concern. It's easy to jump to conclusions about airline security, but Sheldon H. Jacobson of the University of Illinois at Urbana-Champaign is encouraging air travelers to look closer.

Jacobson was funded in 2001 by the National Science Foundation (NSF) to conduct research on risk-based security and its impact on improving airport security following 9/11. This research provided the technical foundations for PreCheck, a prescreening program for airline passengers that conducts background checks and fingerprinting prior to travel to ensure a speedy travel experience. The amount of passengers prescreened through PreCheck rose from 2014 through 2017, leveling off since then.

While this new study, "Using Risk-based Security to Quantify the Number of Firearms Missed at Airport Security Checkpoints," reveals an uptick in firearms found at airport security checkpoints from 2014 through 2019, and estimates thousands more missed, the results aren't bad, they're good.

"This 2018 and 2019 data trend suggests that increases in firearms detected since 2017 are largely due to more passengers being screened using PreCheck," said Jacobson, a founder professor of computer science at the University of Illinois. "Moving forward, the most effective way for the TSA to miss fewer firearms in carry-on baggage at airport security checkpoints is to increase the number of PreCheck qualified screenings."

What we are seeing is an enhanced focus from TSA agents because they can slow down, as lines are being reduced due to prescreened passengers, and pay closer attention to higher risk passengers who have not been prescreened.

Jacobson used publicly available data on firearm detection, number of passengers screened, and the fraction of passenger screenings in PreCheck lanes to estimate the number of firearms missed at airport security checkpoints in the United States. Under the assumption that firearms are only being detected in standard screening lanes he estimates as many as 4,600 firearms may have been missed by TSA officers in carry-on baggage at airport security checkpoints during the above time frame.

Another point to note, amid the current COVID-19 pandemic, with 94% fewer travelers from March 22, 2020 through April 22, 2020 and 75% fewer passengers in July 2020, officers working standard lanes are more focused, so miss less, creating a PreCheck-like environment in standard checkpoint lanes. Ironically, the 65% miss rate, cited in a recent editorial written by Jacobson about the impact of this reduced number of passengers, is consistent with the numbers in the new paper.

"Although the TSA has missed thousands of firearms at airport security checkpoints, none of these missed items have resulted in any malicious activity," adds Jacobson. "Given that risk-based security is more about people rather than items, partitioning passengers according to their risk is the most effective means to ensure a secure air system for all."

The study comments that making PreCheck available to anyone (at a cost below the current $85 for five years) wishing to enroll and undergo the background check, would enhance overall air system security and improve passenger service, a win-win for all. This would allow TSA agents to search for needles in a smaller haystack, if you will. Less hay means that it is easier to identify needles.

EVANSTON, Ill. -- Northwestern University researchers have uncovered a new vulnerability in the novel coronavirus' infamous spike protein -- illuminating a relatively simple, potential treatment pathway.

The spike protein contains the virus' binding site, which adheres to host cells and enables the virus to enter and infect the body. Using nanometer-level simulations, the researchers discovered a positively charged site (known as the polybasic cleavage site) located 10 nanometers from the actual binding site on the spike protein. The positively charged site allows strong bonding between the virus protein and the negatively charged human-cell receptors.

Leveraging this discovery, the researchers designed a negatively charged molecule to bind to the positively charged cleavage site. Blocking this site inhibits the virus from bonding to the host cell.

"Our work indicates that blocking this cleavage site may act as a viable prophylactic treatment that decreases the virus' ability to infect humans," said Northwestern's Monica Olvera de la Cruz, who led the work. "Our results explain experimental studies showing that mutations of the SARS-CoV-2 spike protein affected the virus transmissibility."

The research was published online last week in the journal ACS Nano.

Olvera de la Cruz is the Lawyer Taylor Professor of Materials Science and Engineering in Northwestern's McCormick School of Engineering. Baofu Qiao, a research assistant professor in Olvera de la Cruz's research group, is the paper's first author.

Made up of amino acids, SARS-CoV-2's polybasic cleavage sites have remained elusive since the COVID-19 outbreak began. But previous research indicates that these mysterious sites are essential for virulence and transmission. Olvera de la Cruz and Qiao discovered that polybasic cleavage site is located 10 nanometers from human cell receptors -- a finding that provided unexpected insight.

"We didn't expect to see electrostatic interactions at 10 nanometers," Qiao said. "In physiological conditions, all electrostatic interactions no longer occur at distances longer than 1 nanometer."

"The function of the polybasic cleavage site has remained elusive," Olvera de la Cruz said. "However, it appears to be cleaved by an enzyme (furin) that is abundant in lungs, which suggests the cleavage site is crucial for virus entry into human cells."

With this new information, Olvera de la Cruz and Qiao next plan to work with Northwestern chemists and pharmacologists to design a new drug that could bind to the spike protein.

A first-of-its-kind study by researchers from the Boston University School of Public Health (BUSPH) shows a decline in deaths related to atrial fibrillation (irregular heartbeat) over the last 45 years.

But the study, published in the journal BMJ, finds that the increasingly common condition still takes an average of two years off of a person's life, compared to three years back in the 1970s and early 1980s.

"The prognosis of individuals with atrial fibrillation has improved over time, but atrial fibrillation is still associated with a major gap in life expectancy as compared to individuals without atrial fibrillation," says study senior author Dr. Ludovic Trinquart, associate professor of biostatistics at BUSPH.

Trinquart and colleagues at BU and in Denmark used data from the BU-based, multigenerational Framingham Heart Study, the longest-running cardiovascular health study in the United States.

"The Framingham Heart Study is one of the only studies in the world that allow studying such temporal trends," says study lead author Dr. Nicklas Vinter, a physician at Silkeborg Regional Hospital and doctoral student at Aarhus University in Denmark.

The researchers analyzed health data from three generations of Framingham Heart Study participants from 1972 to 2015, tracking the likelihood of a participant dying 10 years after an atrial fibrillation diagnosis, compared with someone of the same age, sex, and with otherwise similar health.

In the first period (1972-1985), a participant with atrial fibrillation lived an average of 2.9 fewer years 10 or more years after diagnosis than a comparison participant without atrial fibrillation.

In the second period (1986-2000) the gap narrowed to 2.1 years, and in the third period (2001-2015) it was 2.0 years.

"Improvement in the excess mortality associated with atrial fibrillation may be explained by continued improvements in early detection, management, and treatment," Trinquart says. "But the findings of this new study highlight that atrial fibrillation remains a very serious condition. Advances in prevention will be essential to stem the epidemic of atrial fibrillation and reduce its associated mortality."