Culture

The project Electronic AXONs: wireless microstimulators based on electronic rectification of epidermically applied currents (eAXON, 2017-2022), funded by a European Research Council (ERC) Consolidator Grant awarded to Antoni Ivorra, head of the Biomedical Electronics Research Group (BERG) of the Department of Information and Communication Technologies (DTIC) at UPF principally aims to "develop very thin, flexible, injectable microstimulators to restore movement in paralysis", says Ivorra, principal investigator of the project.

A secondary goal of this project is to illustrate how volume conduction (also known as galvanic coupling) can be used to transfer power wirelessly to electronic implants. Volume conduction is considered an alternative to batteries or wireless power transfer based on inductive coupling since these two supply methods imply that implants must be relatively large to accommodate the components needed to obtain the energy required for operation.

One of the main parameters of interest to know if a technology has the potential to supply implants is to determine the maximum power implants can receive by using the proposed method. Thus, the main goal of the study published in the journal IEEE Access is to use equations to determine the maximum power an implant can receive by means of volume conduction when the currents applied are safe according to the electrical safety standards. Its authors are Marc Tudela, Laura Becerra-Fajardo, Aracelys García-Moreno, Jesus Minguillon and Antoni Ivorra.

"Today, the main element that hinders the development of minimally invasive implants is the way they get power. In this regard, we believe that volume conduction has the potential to solve this problem. Volume conduction allows us to develop thread-like devices that can be implanted by injection", Tudela explains.

Wireless Power Transfer (WPT)

The method of wireless energy transfer via volume conduction consists of using the body's own tissues as a channel for transferring electrical power. Using an external system, electrical currents are delivered through the human body and these currents flow through tissues and a small amount is drawn by the implants.

This is how the implants get the energy necessary for operating. The innovative aspect of the authors' approach is the thread-like form of the implants, which allows them to be injected without surgery, and the use of high frequency currents (> 5 MHz) applied in bursts, rendering them completely harmless and imperceptible.

To produce power to implants in the region of milliwatts, the authors propose applying currents with magnitudes of the order of a few amperes for which the external system must generate tensions of around a few hundred volts. These magnitudes would be most harmful if it they corresponded to alternating currents of a frequency like that of the grid (50 Hz). This completely avoids using higher frequencies. Specifically, the authors propose the use of alternating currents with a frequency of greater than 5 MHz.

The authors of the study published in IEEE Access obtained mathematical models that allowed them to determine the maximum local power that can be obtained by an implant using volume conduction according to the size of the implant, its electronic charge and the properties of the tissue where it will be placed. Finally, they validated these models in vitro using a saline solution that simulates the electrical properties of human tissue and obtained a good correlation between experimental and analytical results.

Devices that can be easily implanted by injection

Thus, the study results show that by applying high frequency electrical currents in a burst -harmless for the human body and that meet the main international safety standards- can yield powers of greater than 1 mW in very thin (section less than 1 mm), short (

"Another interesting result we have obtained is that the application of high frequency electrical currents in the form of bursts, rather than continuously, enables maximizing the power obtained in the implants", Tudela comments. And the researcher adds, "our results indicate that an implant with a section of only one millimetre and a length of about one centimetre could get 100 times the power currently required by a pacemaker".

CHICAGO (April 6, 2020): Researchers from Stanford University's department of surgery (Stanford, Calif.) have created an algorithm that aims to protect operating room team members who perform urgent and emergency operations from Coronavirus Disease 2019 (COVID-19) and rationally conserve the personal protective equipment (PPE) they wear. This best practice guideline is published as an "article in press" on the Journal of the American College of Surgeons website ahead of print. Stanford Health Care, verified as a Level 1 trauma center by the American College of Surgeons (ACS), serves Santa Clara and San Mateo Counties, which saw their first cases of COVID-19 infection in early March.

The Stanford algorithm is based on the urgency of the procedure, potential for aerosolization and release of virus droplets at the surgical site, and evidence that a patient has been infected. The algorithm aligns with the goals of the ACS Statement on PPE Shortages during the COVID-19 Pandemic, released April 1, 2020.

"We developed institutional guidelines based on how soon the surgical cases needed to be performed, the patient's condition, the risk that a surgeon would access an area of body where the amount of virus could be high, and the risk that a patient could be infected with COVID-19," said Joseph Forrester, MD, MSc, an assistant professor in general surgery and lead author of the algorithm article. Dr. Forrester was a field agent in Liberia during the 2014 Ebola outbreak where he conducted several investigations of the Ebola burden and preparedness as an Epidemic Intelligence Service officer with the Centers for Disease Control and Prevention.

At Stanford, a PPE task force of hospital and medical school leaders from interventional suites, including the operating room, interventional radiology, and endoscopy, as well as quality improvement and infectious disease experts, convened on March 19 to create institutional guidelines that could be implemented within 72 hours. At that time, Stanford Health Care had approximately 10 patients infected with COVID-19. Guidelines incorporated current data about COVID-19 transmission in hospital and non-hospital settings and operating room risk during outbreaks of severe acute respiratory syndrome (SARS) and Ebola.

Patients were triaged by severity of illness into urgent and emergency procedures. Urgent cases were stratified into high- and low-risk procedures depending on the expected viral burden at the surgical site. Procedures categorized as aerosol-generating (AGP) were classified as high-risk. These procedures include those that involve the aerodigestive tract, endoscopy, and open or laparoscopic surgery on the bowel with gross contamination.

The Stanford guideline assumes, above all, that any patient could be infected with COVID-19 unless proven otherwise by a negative RT-PCR test. When operating on COVID-19-postive patients or performing an AGP, the guideline requires operating room team members to be fitted with an N-95 respirator mask and wear a gown, gloves, and eye protection. Only when an RT-PCR test is negative for COVID-19 may surgical team members wear standard surgical clothing.

A surgeon may consider delaying an urgent or emergency procedure on a patient who exhibits viral symptoms (fever, cough, sore throat). If delay compromises the well-being of the patient, the surgeon orders in-house RT-PCR COVID-19 testing with a 24-hour turnaround. If the patient's status does not allow for a 24-hour wait, the case is considered to be an emergency and the patient is presumed to be COVID-19-positive.

Special considerations are made for the use of PPE during and after bag mask ventilation and endotracheal intubation, which both pose a high risk for viral transmission. All health care providers who are not directly involved with intubation are asked to leave the operating room beforehand. Anesthesiologists should be fitted with N-95 face masks and droplet-protective PPE because they are positioned at the head of the bed throughout the procedure. Cleaning staff should take droplet precautions when cleaning any operating room.

At the time the guideline was created at Stanford Health there was a nationwide shortage of N-95 face masks. To conserve the institution's supply, the algorithm requires a face shield to be placed over the mask. However, the federal government recently announced that millions of face masks, face shields, surgical masks, gloves, and gowns were entering the medical supply chain, which was encouraging, noted Dr. Forrester.

Dr. Forrester nevertheless recommends that surgical centers where urgent and emergency procedures are performed follow strategies that protect providers and conserve equipment. "You never know what's going to happen, and it's better to be prepared and use the right PPE at the right time and be careful not to waste PPE. Guidelines like ours show that health care providers on the frontline are trying to take care of every person with a serious surgical condition and make sure they have enough equipment to carry that mission through safely."

It's the outside that counts: Their charisma has an impact on the introduction and image of alien species and can even hinder their control. An international research team, led by the Biology Centre of the Czech Academy of Sciences and the Leibniz-Institute of Freshwater Ecology and Inland Fisheries (IGB), have investigated the influence of charisma on the management of invasive species.

More and more animals and plants are being taken from their habitat by humans - consciously and unconsciously. Many cannot adapt to the new living conditions, but some are becoming firmly established. "Some non-native species cause serious problems for native species - as predators, competitors for food and habitat, or vectors of diseases," explains Professor Jonathan Jeschke, researcher at IGB and Freie Universität Berlin, and head of the Invasion Dynamics Network which initiated the study.

As ornamental plants, aquarium inhabitants or exotic pets, charismatic species are probably more likely to be deliberately introduced than inconspicuous species. And "if a non-native species is introduced more frequently and in higher numbers, it is more likely to establish itself," says Jonathan Jeschke.

The social acceptance of attractive invasive species with charisma is higher than that of unattractive invasive species. This can hamper nature conservation measures designed to contain the spread of a species: "An appearance perceived as beautiful or cute can make the management of species invasions more difficult, because then public support is often lacking," regrets Ivan Jaric, lead author of the study and researcher at the Biology Centre of the Czech Academy of Sciences. For example, management actions in Italy to control the invasive grey squirrel - and to protect the native red squirrel - were prevented by protests from interest groups using cute cartoon characters of the animals.

Even research is taxonomically biased

The research priorities on invasive species are largely determined by their ecological and economic impacts. And yet there is a stronger focus on invasive vertebrates than on invertebrates and on large and charismatic species. "Public and also research interest is disproportionately concentrated on charismatic species. This can cause one-sided gaps in knowledge that lead to protective measures being wrongly prioritised," criticises IGB researcher Dr. Gregor Kalinkat, co-author of the study.

It is therefore important to be aware of the influence of charisma on the management of invasive species and to sensitise actors." This aspect is particularly important when planning and implementing management measures. Conflicts, especially when they affect charismatic species, can arise from the apparent incompatibility of two different ethical perspectives: between those who give priority to the protection of the ecosystem or the conservation of native species and those who are concerned about the welfare of the invasive species concerned," Ivan Jaric underlines the importance of the findings.

BOSTON - (March 17, 2020) - When we are exposed to sufficient cold or exercise, small clusters of brown fat cells in our bodies begin to burn up energy. Since 2009, when researchers at Joslin Diabetes Center and other institutions discovered that this helpful form of fat can be active in adults, scientists have sought to turn up the heat from these cells to treat obesity, diabetes and other metabolic conditions.

Researchers in the lab of Joslin's Yu-Hua Tseng, PhD, a Senior Investigator in the Section on Integrative Physiology and Metabolism, now have discovered an unexpected biological pathway by which brown fat cells can translate energy into heat.

Studies in mice showed that activating this pathway in precursors of brown or white fat cells boosts the heat-generating capacity of these cells without pushing the cells to accumulate fat, says Farnaz Shamsi, a postdoctoral associate in the Tseng lab and lead author on a paper describing the findings in Nature Communications.

Previously, researchers have found that certain biological signals that boost the production of brown fat cells are also likely to create unhelpful white fat cells, thus posing one of research challenges in enhancing brown fat activity. The finding, however, suggests that the pathway the Joslin team uncovered might offer a solution to that challenge.

The research began with a protein called UCP1 that is located on mitochondria, the cell's powerhouses. UCP1 is known to be a crucial component in activating brown fat cells, explains Tseng, who is also an Associate Professor of Medicine at Harvard Medical School.

Her team screened more than 5,000 mammalian proteins to identify factors that heightened UCP1 production in brown fat precursor cells. The screen identified two proteins called FGF6 and FGF9, members of the "fibroblast growth factor" family of proteins that can help to regulate diverse biological processes including cell development and growth.

Next, the investigators tried increasing the levels of the two proteins, and thus increasing UCP1 production, in immature mouse brown fat cells. The scientists expected that these cells would start to accumulate fats and other lipids, and to develop into mature brown fat cells--but surprisingly, that didn't happen.

Painstakingly uncovering the reasons for this unexpected outcome, "we found step-by-step the molecular events that happened downstream that eventually lead to UCP1 production in fat cells," says Shamsi. "This novel downstream pathway was completely different from what researchers in our field have understood as the mechanism to induce UCP1 in these cells."

Shamsi, Tseng and their colleagues saw that the two FGF proteins provide similar effects on production of UCP1 but are driven by different exposures in mice. FGF9 is stimulated by cold, while FGF6 is stimulated by exercise.

When the Joslin scientists went on to analyze samples of human fat tissues, they also recognized this pathway at work. Among their results, levels of FGF9 and FGFR3 (the receptor protein that FGF9 and FGF6 both activate) were associated with higher levels of UCP1 in human brown and white fat. More strikingly, expression of FGFR3 in human white fat negatively correlated with the person's body mass index (a measure of obesity) and insulin resistance (a condition that can drive type 2 diabetes).

"This suggests that if we can activate this pathway, we potentially can benefit people with obesity, diabetes and related metabolic diseases," Tseng says.

Her team is working with collaborators to synthesize a version of the FGF protein that is optimized for greater efficacy and easier delivery, she says. Since her group has traced the mechanisms at work in this pathway, it also may eventually be possible to develop drugs that build up UCP1 production by targeting specific molecular steps in the pathway.

"As obesity becomes epidemic, we hope that our research in brown fat can help," Tseng says. "With a collective effort from many labs around the globe, we are getting closer to that goal."

UNIVERSITY PARK, Pa. -- The risk of transmitting the virus PPRV, which produces a highly infectious and often fatal disease in sheep and goats, does not appear to vary significantly by an animal's age, unlike its sibling virus measles, which is most prominent in children. Instead, animals in areas where livestock are the sole source of an owner's livelihood are more likely to become infected compared to herds whose owners rely on a mix of livestock and agriculture.

In a new study, an international team including Penn State researchers explored the rate of PPRV infection across ages and livestock management styles of sheep and goats, as well as in cattle, which do not express symptoms but can be infected by the virus. The study, which appears online in the journal Viruses, provides important insight into how we might target PPRV control efforts and builds on the team's previous research highlighting the importance of livestock management style in transmission.

"Infection risk varies by age for many well-known diseases, and knowing this can allow us to target high-risk age groups with control efforts, like vaccination," said Catherine Herzog, epidemiologist and graduate student in biology at the Center for Infectious Disease Dynamics at Penn State and lead author of the paper. "For example, while influenza can infect people of all ages, it often has greater impact among the youngest and the oldest members of a population. Similarly, Rinderpest - an animal disease closely related to PPRV - was a scourge on husbandry and a major killer of young and old cattle for centuries until it was finally eradicated through animal vaccination in the early 2000s. Our study was designed to determine if age is a key risk factor of PPRV transmission so that we can better target vaccination campaigns to control this virus."

The sheep and goat plague virus, more formally known as peste des petits ruminants virus, is currently present in Africa, the Middle East, and Asia, where livestock keepers rely heavily on sheep and goats for their livelihood. In 2015, the Food and Agricultural Organization (FAO) and the World Animal Health Organization (OIE) launched a global campaign to eradicate PPRV by 2030. While an affordable vaccine exists, it is not always available in rural areas, and research can help direct efforts to get the vaccine to high-risk populations.

The researchers studied the rate at which animals became infected--the force of infection--among different ages and livestock management styles in Tanzania. The research showed that while the force of infection was not significantly related to an animal's age, it was greater in animals from pastoral areas, where people rely almost solely on livestock, compared to agropastoral areas, where people rely on a mix of livestock and agriculture.

"Our results suggest that no particular age group bears the burden of infection," said Herzog. "Sheep and goats have some protection from the virus when they are first born if their mother was vaccinated or had recovered from previous infection with the virus. Therefore, it may be most reasonable to target animals for vaccination when that maternal immunity wears off, though additional studies are needed to determine the timing of this biological process so vaccines are given at the correct time."

"These findings align with our previous results that suggest that management style of livestock plays an important role in PPRV infection risk," said Ottar Bjørnstad, Distinguished Professor of Entomology and Biology and J. Lloyd and Dorothy Foehr Huck Chair of Epidemiology at Penn State, and a member of the research team. "We plan to investigate how specific husbandry practices--herd size, herd age structure, contact rates among livestock and wildlife, and access to veterinary service--affect risk of transmission so that we can better target control efforts of PPRV, which is currently a priority for world-wide elimination."

The researchers also found evidence of prior PPRV infection in cattle, which was much higher than previous reports. Co-author Brian Willett at the University of Glasglow determined that previous testing kits had a low sensitivity in cattle, and should thus be refined to improve future monitoring. In this study, when the researchers adjusted calculations for the sensitivity and specificity of tests, evidence of prior infection in cattle increased, doubling in the oldest age group.

"These results suggest that cattle may play a more important role in PPRV transmission than previously realized," said Bjørnstad. "Because the goal is to eradicate the virus, we need to better understand the role of PPRV transmission among cattle and other species that may carry the disease even though they are not the primary hosts."

PHILADELPHIA (April 6, 2020) - Data show that the number of people with clinically complex health and social needs is growing. Programs designed to support these adults have fallen short and the healthcare system is becoming overtaxed by these "super-utilizers".

In an article just published in JAMA Health Forum, nurse researchers from the University of Pennsylvania School of Nursing (Penn Nursing) underscore that while responses to the problem have resulted in well-motivated innovations, an effective and actionable path for immediate and long-term remediation should encompass micro- and macro-level solutions.

"Public and private investments in innovations designed to address the foundation of health inequities as well as healthcare models targeting those suffering the devastating consequences of a lifetime of health assaults should both be a priority," says lead-author Mary D. Naylor, PhD, RN, FAAN, the Marian S. Ware Professor in Gerontology, and Director of the NewCourtland Center for Transitions and Health. "These investments, however, should be informed by a systematic assessment of lessons learned from studies of existing innovations, including programs that did and did not meet desired objectives."

The researchers suggest that fostering the adoption or adaptation of rigorously proven solutions represents an immediate opportunity to improve outcomes for this complex population. Capitalizing on emerging policies that foster accountable health communities or promote better integration of health and social services as well as prioritizing payment for evidence will accelerate the spread of such innovations.

"People with complex healthcare needs deserve our best evidence-based care today," says Naylor. "Future generations deserve investments in both micro-level and macro-level solutions that will stem the tremendous human and economic consequences of living with complex care needs and give all members of society a better chance of living healthier, higher-quality lives."

Friday, 3rd of April, 2020, London, UK - The Biogerontology Research Foundation, a registered UK charity supporting and promoting aging and longevity research worldwide since 2008, today announced the publication of a paper titled "Geroprotective and senoremediative strategies to reduce the comorbidity, infection rates, severity, and lethality in gerophilic and gerolavic infections" in the leading journal Aging.

Vaccines and therapeutic solutions for COVID-19 are still far from the clinic and will not provide complete protection, and likely to be less effective in the elderly. Recent BBC article notes "It will, almost inevitably, be less successful in older people. This is not because of the vaccine itself, but aged immune systems do not respond as well to immunisation. We see this every year with the flu jab."

The author of the study, Alex Zhavoronkov, PhD, the chief scientist of the Biogerontology Research Foundation and the CEO of an artificial intelligence company Insilico Medicine proposed calling SARS-CoV-2 and other infections that are more infectious and harmful to the elderly as gerophilic and gerolavic infections.

He also proposed a strategy for repurposing known geroprotectors such as rapamycin, nicotinamide riboside, nicotinamide mononucleotide, metformin, and other drugs with the known safety profile for prevention of SARS-CoV-2 infection. The scientist analyzed the prior clinical studies of everolimus (RAD001) in healthy elderly, and previous evidence showing paradoxical immunopotentiation effects of rapamycin and proposed additional clinical trials for these molecules in the healthy elderly population.

Zhavoronkov also proposed the use of inexpensive and minimally-invasive deep aging clocks to track the efficacy of these preventative geroprotective interventions and to stratify the patients by predicted severity of COVID-19.

"We are pursuing several strategies for drug discovery and repurposing using the latest advances in artificial intelligence integrated into our battle-tested discovery platform. However, it is clear that COVID-19 is a gerophilic and gerolavic disease. It is more severe and lethal in the elderly. Aging research yields insights that may not only help with COVID-19 but may help prevent many other diseases and increase productive longevity and re-ignite the economy", said Alex Zhavoronkov, PhD.

Previous studies by the BGRF scientists including "Biomedical Progress Rates as New Parameters for Models of Economic Growth in Developed Countries", and books including "The Ageless Generation: How Advances in Biomedicine Will Transform the Global Economy" show that extending productive longevity in the developed countries will lead to unprecedented economic growth.

"Most of the companies and institutions are racing to create vaccines or drugs that target COVID directly. But these interventions will not offer complete protection. We see that children and very young people do not have severe symptoms. Geroprotectors may help improve the odds for the elderly. And once the epidemic subsides, we will need to find new ways to boost the economy and there are established models showing that the best way to grow the economy is by increasing healthy productive longevity", said Dmitry Kaminskiy, managing trustee of the Biogerontology Research Foundation.

"This is the first review highlighting geroprotective strategies that may decrease the disease burden of gerolavic infections such as COVID-19. It presents a case for further research and clinical studies to validate markers of biological age in the context of viral infections. Ageing Research at King's (ARK) is partnering with BGRF and Insilico Medicine to identify mechanisms by which geroprotectors enhance resilience against infections and reduce the severity of symptoms. The proposed research will acutely help physicians treat COVID-19, protect the elderly and benefit long term global health and longevity." said Dr. Richard Siow, Director of ARK and former Vice-Dean (International), Faculty of Life Sciences & Medicine, King's College London.

At the SuperKEKB Collider, scientists have performed the first searches of invisibly decaying low mass boson particles. The results come from the Belle II experiment--an experiment mainly dedicated to studying B mesons, which are rare, unstable particles composed by a beauty quark and other lighter quarks. Belle II creates B mesons by colliding electrons and positrons, but those same collisions can produce other particles. Now, researchers have searched for low mass Z' bosons, hypothetical new particles that could connect ordinary and dark matter. Investigating invisible decays might allow scientists to identify unexpected physical phenomena and potentially develop new physical principles to improve their understanding of the universe.

Search for an invisibly decaying Z? boson at Belle II in e+e-?μ+μ-(e±μ?) plus missing energy final states

De Pietro et al.

Washington, DC - Belief in all powerful supernatural entities that police moral behavior between people has been shown to promote prosocial behavior between co-religionists. But do these effects extend to members of different religious groups? In a new paper, which will appear in print in an upcoming special issue of Social Psychological and Personality Science, Michael Pasek, Jeremy Ginges, and colleagues find that, across religious groups in Fiji and Israel, religious believers see God as encouraging people to treat others in a more universal, or equal, manner.

The studies reported in this paper are part of a broader project, led by Ginges and funded by the Templeton Religious Trust and the U.S. National Science Foundation, that investigates the effect of religious belief on relations between different ethno-religious communities.

Whether exemplified through the crusades, the Holocaust, or modern persecution of Uyghur Muslims in China, religion is often implicated as a source of intergroup conflict. This leads many to believe that religious diversity makes societies less cohesive.

"Contrary to popular opinion, our findings suggest that, at least in some contexts, religious belief can attenuate, as opposed to promote, religious tension," says Pasek.

The team, led by researchers at The New School for Social Research and Artis International, conducted three preregistered studies, comprising two field studies with Christians, Hindus, and Muslims in Fiji (727 people total), and one online study with Jewish Israelis (539 people).

In every study, people were asked if a passerby should sacrifice his life to save five individuals trapped in a burning house. In one scenario, the trapped people were of the same religion as the passerby. In another scenario, the trapped people were from a different religion than the person passing by. For each scenario, study participants also indicated which action they thought God would prefer.

Across studies and religious groups, the researchers found that when participants did not uniformly think that out-group members should be saved, they thought that God would be more likely than them to want an in-group member to sacrifice his life to save out-group members. Moreover, when people showed a preference for saving in-group members more than out-group members, they thought that God would be less likely to endorse such in-group favoritism.

Findings replicate and extend a study by Ginges and colleagues from 2016, shedding new light on how people view God's moral preferences.

"In our previous research, we found similar beliefs among Muslim Palestinian youth, who thought that Allah would be more likely than them to want an in-group member to save Jewish Israelis. Our current work shows this belief is also held among Christian, Hindu, and Jewish populations," says Ginges.

According to Pasek, "this suggests that the potential for religious beliefs to promote intergroup cooperation is not just limited to members of proselytizing religions, like Christianity and Islam."

This work also helps to confront an ongoing challenge in psychological research--the overreliance on samples from WEIRD (Western, educated, industrialized, and democratic cultures).

As Pasek explains, "A key contribution of our research is that it extends knowledge to understudied populations, like indigenous Christian iTaukei in Fiji, helping psychologists build theories that generalize beyond WEIRD contexts."

Hamilton, ON (April 6, 2020) - The N95 respirator masks should be preserved for health-care workers involved in inserting breathing tubes for patients with COVID-19. More common medical masks are fine for all other COVID-19 treatment, says preliminary research from McMaster University.

A systematic review of four randomized controlled trials on masks done between 1990 and last month shows the use of medical masks did not increase viral respiratory infection or clinical respiratory illness.

However, there is a consensus that the N95 respirators, designed to fit tight and prevent inhalation of small airborne particles, are best for procedures such as intubation or bronchoscopy when health-care professionals must insert a tube through a patient's throat.

"There is not convincing evidence that the loose-fitting medical masks are inferior to N95 respirators in protecting healthcare workers against viral respiratory infections during routine care during the pandemic," said Mark Loeb, a professor of pathology and molecular medicine at McMaster and an infectious disease physician in Hamilton.

"But the N95 respirators are unanimously recommended by national and international guidelines for aerosol generating procedures.

"This is an important distinction at a time when there is a serous concern about a shortage of N95 respirators because of COVID-19."

He pointed out that there have been conflicting recommendations on the use of the N95 masks. The U.S. Centers for Disease Control and Prevention and the European Centre for Disease and Prevention preferentially recommend the N95 respirator for routine care of patients with COVID-19, while the World Health Organization and Canadian Public Health Agency recommend medical masks.

"Although COVID-19 transmission is not fully understood, it's believed to be mainly through respiratory droplets, and the medical masks provide barrier protection for that, and prevent hand to face contact."

The study has been peer-reviewed and accepted for publication by the publication Influenza and Other Respiratory Viruses of the International Society for Infection and Other Respiratory Virus Diseases and is available online at https://onlinelibrary.wiley.com/doi/abs/10.1111/irv.12745?af=R

Jessica Bartoszko, first author of the paper, said: "This evidence to support the relative effectiveness of medical masks compared to N95 respirators in routine care, might help preserve stockpiles of N95 respirators for high-risk, aerosol generating procedures."

She is a PhD student with the Department of Health Research Methods, Evidence, and Impact.

However, the question needs further research and this month Loeb and his research team are beginning a new study on whether the N95 respirators or medical masks are the best option for health-care providers caring for COVID-19 patients.

In a multi-site randomized controlled trial, nurses will use either a medical mask or N95 respirator when providing care for patients with fever and respiratory illness.

"This study is critical to ensure we're using personal protective equipment correctly during this, and any future infectious disease outbreak," said Loeb.

Just as the sun has planets and the planets have moons, our galaxy has satellite galaxies, and some of those might have smaller satellite galaxies of their own. To wit, the Large Magellanic Cloud (LMC), a relatively large satellite galaxy visible from the Southern Hemisphere, is thought to have brought at least six of its own satellite galaxies with it when it first approached the Milky Way, based on recent measurements from the European Space Agency's Gaia mission.

Astrophysicists believe that dark matter is responsible for much of that structure, and now researchers at the Department of Energy's SLAC National Accelerator Laboratory and the Dark Energy Survey have drawn on observations of faint galaxies around the Milky Way to place tighter constraints on the connection between the size and structure of galaxies and the dark matter halos that surround them. At the same time, they have found more evidence for the existence of LMC satellite galaxies and made a new prediction: If the scientists' models are correct, the Milky Way should have an additional 150 or more very faint satellite galaxies awaiting discovery by next-generation projects such as the Vera C. Rubin Observatory's Legacy Survey of Space and Time.

The new study, forthcoming in the Astrophysical Journal and available as a preprint here, is part of a larger effort to understand how dark matter works on scales smaller than our galaxy, said Ethan Nadler, the study's first author and a graduate student at the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC) and Stanford University.

"We know some things about dark matter very well - how much dark matter is there, how does it cluster - but all of these statements are qualified by saying, yes, that is how it behaves on scales larger than the size of our local group of galaxies," Nadler said. "And then the question is, does that work on the smallest scales we can measure?"

Shining galaxies' light on dark matter

Astronomers have long known the Milky Way has satellite galaxies, including the Large Magellanic Cloud, which can be seen by the naked eye from the Southern Hemisphere, but the number was thought to be around just a dozen or so until around the year 2000. Since then, the number of observed satellite galaxies has risen dramatically. Thanks to the Sloan Digital Sky Survey and more recent discoveries by projects including the Dark Energy Survey (DES), the number of known satellite galaxies has climbed to about 60.

Such discoveries are always exciting, but what's perhaps most exciting is what the data could tell us about the cosmos. "For the first time, we can look for these satellite galaxies across about three-quarters of the sky, and that's really important to several different ways of learning about dark matter and galaxy formation," said Risa Wechsler, director of KIPAC. Last year, for example, Wechsler, Nadler and colleagues used data on satellite galaxies in conjunction with computer simulations to place much tighter limits on dark matter's interactions with ordinary matter.

Now, Wechsler, Nadler and the DES team are using data from a comprehensive search over most of the sky to ask different questions, including how much dark matter it takes to form a galaxy, how many satellite galaxies we should expect to find around the Milky Way and whether galaxies can bring their own satellites into orbit around our own - a key prediction of the most popular model of dark matter.

Hints of galactic hierarchy

The answer to that last question appears to be a resounding "yes."

The possibility of detecting a hierarchy of satellite galaxies first arose some years back when DES detected more satellite galaxies in the vicinity of the Large Magellanic Cloud than they would have expected if those satellites were randomly distributed throughout the sky. Those observations are particularly interesting, Nadler said, in light of the Gaia measurements, which indicated that six of these satellite galaxies fell into the Milky Way with the LMC.

To study the LMC's satellites more thoroughly, Nadler and team analyzed computer simulations of millions of possible universes. Those simulations, originally run by Yao-Yuan Mao, a former graduate student of Wechsler's who is now at Rutgers University, model the formation of dark matter structure that permeates the Milky Way, including details such as smaller dark matter clumps within the Milky Way that are expected to host satellite galaxies. To connect dark matter to galaxy formation, the researchers used a flexible model that allows them to account for uncertainties in the current understanding of galaxy formation, including the relationship between galaxies' brightness and the mass of dark matter clumps within which they form.

An effort led by the others in the DES team, including former KIPAC students Alex Drlica-Wagner, a Wilson Fellow at Fermilab and an assistant professor of astronomy and astrophysics at the University of Chicago, and Keith Bechtol, an assistant professor of physics at the University of Wisconsin-Madison, and their collaborators produced the crucial final step: a model of which satellite galaxies are most likely to be seen by current surveys, given where they are in the sky as well as their brightness, size and distance.

Those components in hand, the team ran their model with a wide range of parameters and searched for simulations in which LMC-like objects fell into the gravitational pull of a Milky Way-like galaxy. By comparing those cases with galactic observations, they could infer a range of astrophysical parameters, including how many satellite galaxies should have tagged along with the LMC. The results, Nadler said, were consistent with Gaia observations: Six satellite galaxies should currently be detected in the vicinity of the LMC, moving with roughly the right velocities and in roughly the same places as astronomers had previously observed. The simulations also suggested that the LMC first approached the Milky Way about 2.2 billion years ago, consistent with high-precision measurements of the motion of the LMC from the Hubble Space Telescope.

Galaxies yet unseen

In addition to the LMC findings, the team also put limits on the connection between dark matter halos and galaxy structure. For example, in simulations that most closely matched the history of the Milky Way and the LMC, the smallest galaxies astronomers could currently observe should have stars with a combined mass of around a hundred suns, and about a million times as much dark matter. According to an extrapolation of the model, the faintest galaxies that could ever be observed could form in halos up to a hundred times less massive than that.

And there could be more discoveries to come: If the simulations are correct, Nadler said, there are around 100 more satellite galaxies - more than double the number already discovered - hovering around the Milky Way. The discovery of those galaxies would help confirm the researchers' model of the links between dark matter and galaxy formation, he said, and likely place tighter constraints on the nature of dark matter itself.

The research was a collaborative effort within the Dark Energy Survey, led by the Milky Way Working Group, with substantial contributions from junior members including Sidney Mau, an undergraduate at the University of Chicago, and Mitch McNanna, a graduate student at UW-Madison. The research was supported by a National Science Foundation Graduate Fellowship, by the Department of Energy's Office of Science through SLAC, and by Stanford University.

Citation: Ethan Nadler et al., accepted for publication in the Astrophysical Journal and available as an arXiv preprint (https://arxiv.org/abs/1912.03303)

A new therapy could combat persistent joint infections in horses, potentially saving them from years of pain. Morris Animal Foundation-funded researchers at North Carolina State University have developed a platelet-rich plasma (PRP) lysate that, when teamed with antibiotics, can eradicate bacterial biofilms common in joint infections. The therapy could also be applied to other species, including humans and dogs. The team presented their findings in the Journal of Orthopaedic Research.

"This could really provide a more effective way of clearing a joint infection quickly so that the horse does not suffer long-term consequences of joint damage," said Dr. Lauren Schnabel, Associate Professor of Equine Orthopedic Surgery at North Carolina State University, a primary investigator of the study. "For any horse's well-being, it's important to make them as comfortable as possible, as quickly as possible to avoid laminitis and other complications."

Horses are more prone to joint infections than other animals due to their predominantly outdoor, active lifestyles coupled with a lack of tissue protection over the joints of their lower limbs. Any wound near a joint, regardless of its size, requires immediate veterinary attention. Left untreated, they can be life-threatening.

Current joint infection treatment usually involves surgical flushing of the joint and giving antibiotics. Despite aggressive care, about 6% to 10% of horses die as a result of the infection or associated complications. For horses that survive, more than 50% will suffer from chronic arthritis for the rest of their lives.

A common complication that impedes successful treatment is the tendency for some bacteria to form biofilms in the joint. A biofilm is a sticky, slimy shield that forms around bacteria in synovial fluid. They become so large that immune cells can't attack them properly. Biofilms also render the bacteria metabolically inactive, which makes them more resistant to antibiotics.

To create their PRP lysate, the research team took blood from their small herd of horses and isolated the platelets, which are known to aid in healing. Then researchers packed 50 times the number of platelets that would be found in an equal amount of blood into their product. For comparison, typical PRP, for orthopedic and sports medicine purposes, is created by concentrating platelets usually up to three times what is found in a comparable amount of blood. The team felt that this super-concentrated product would be better at stopping infections than conventional PRP.

The team lysed the platelets to release antimicrobial peptides - proteins that attack bacteria. Researchers separated out the antimicrobial peptides then, after testing those against common bacteria, all the horses' peptides were pooled together for one lysate product. The team collected synovial fluid from the horses' knees with harmless taps. The fluid was seeded with bacteria in the laboratory and allowed to grow biofilms. Finally, researchers tested three methods to attack the biofilms; antibiotics alone, lysate alone and a combination of antibiotics and lysate.

They found that antibiotics alone were completely ineffective. The lysate alone significantly decreased the bacterial load. The antibiotic and lysate combination, however, completely eradicated the biofilms and bacteria.

Dr. Schnabel said her team has used this experimental therapy on horses with great results. Because the process to create the lysate is both complicated and expensive, her team is trying to find a way to produce it more efficiently. They also are trying to identify the exact peptides responsible for the antibacterial properties, so they can be synthesized and production scaled up to reach the greatest number of horses.

"This is really a critical piece of evidence to show this is a therapy with enormous potential to make traditional antimicrobials more effective," said Dr. Janet Patterson-Kane, Morris Animal Foundation Chief Scientific Officer. "Clearing bacteria more quickly and effectively from infected joints is a much-needed piece of the solution for this complex disease."

If successful, this approach also has translational potential to help other species, including humans. For example, biofilm formation and infection are a significant problem for people with metal implants, such as those used in joint replacement surgeries. Dr. Jessica Gilbertie, first author on this publication and former Morris Animal Foundation Fellowship trainee under the mentorship of Dr. Schnabel, is working on making PRP lysate from other species, including dogs, because they also can suffer from biofilm formations related to surgical procedures.

Morris Animal Foundation, headquartered in Denver, is one of the largest nonprofit animal health research organizations in the world, funding more than $155 million in studies across a broad range of species.

Prions are a class of misfolded proteins that form aggregates called "amyloid fibrils." These aggregates are the main culprit behind severe mammalian neurodegenerative diseases like Alzheimer's. What makes them so deadly is that they are capable of transmitting their erroneous conformation to otherwise healthy proteins, causing an imbalance in cellular function. Currently, there are no effective treatments for fatal prion diseases, mainly because studying mammalian prions is challenging. Thus, scientists have turned to studying prions in less complex organisms like yeast, which could give us more insight about mammalian prions. Yeast prions, such as the protein Sup35NM, are also known to form amyloid fibrils. But, the process by which individual Sup35NM molecules, called monomers, combine to form amyloid fibrils is not yet understood. Moreover, Sup35NM monomers sometimes form smaller structures called oligomers--another process that remains unclear. To shed light on prion-related diseases, it is crucial to understand the exact details of how amyloid fibrils are formed from prions.

In a new study published in PNAS, researchers from Tokyo Institute of Technology and Kanazawa University, led by Prof Hideki Taguchi, set out to dig deeper into prion structures and their mechanisms. They used a modern microscopy technique, called high-speed atomic force microscopy (HS-AFM), developed by Dr. Toshio Ando at Kanazawa University, to visualize the formation of Sup35NM amyloid fibrils in real time. Prof Taguchi explains, "Previous studies used methods that do not allow for the simultaneous, high-resolution assessment of the structures and dynamics involved in Sup35NM oligomerization and fibrillation. To overcome this limitation, we used HS-AFM, which allows the direct visualization of protein molecules in dynamic action at a high resolution."

To begin with, the researchers analyzed Sup35NM monomers using HS-AFM. Their analysis revealed that Sup35NM molecules contained a globular structure with two highly flexible tail-like structures. Then, to observe the oligomeric forms of Sup35NM, monomers incubated in a denaturing solution in controlled conditions, which, in a few hours, led to the formation of oligomers. Further HS-AFM analyses revealed the exact size of these oligomers--a maximum of 3-4 nm, not growing any longer than this. Thus, the scientists inferred that this size could be an inherent property of oligomers under these conditions.

The researchers then moved on to study the fibril forms of Sup35NM. As opposed to oligomers, fibrils required much a longer incubation time to form, typically 2 to 3 days. In addition, the researchers observed that the fibril elongated smoothly without the attachment of the oligomers. These findings indicated that Sup35NM oligomers are not a prerequisite for the formation of amyloid fibrils, leading the scientists to conclude that oligomers might actually possess cellular functions that are different from those of Sup35NM.

Finally, the researchers studied an interesting phenomenon where oligomers and fibril structures seem to maintain an interspatial distance or "gap." They observed that the trunk of the fibrils has a rigid structure that repels oligomers coming from the sides. Meanwhile, the gap between the tip of the fibril and nearby oligomers is less pronounced because the tip does not have such rigid structures. This helped the scientists understand why Sup35NM amyloid fibrils always grow in a straight direction, without forming any branches.

In sum, these findings provide a detailed account into the structural and functional characteristics of yeast prions--in their monomeric, oligomeric, and fibril forms. "Our HS-AFM observations of Sup35NM unveiled features of Sup35NM dynamics, providing mechanistic insight into amyloid fibril formation," concludes Prof Taguchi.

Does this new insight into the structure and mechanism of prions bring hope for effective therapies against neurodegenerative diseases in humans? Only time will tell, but this study surely takes a huge step towards that direction.

Bird species that have the capacity to express novel foraging behaviours are less vulnerable to extinction than species that do not, according to a collaborative study involving McGill University and CREAF Barcelona and published today in Nature Ecology & Evolution.

The researchers found that birds that were able to incorporate new foods into their diet or develop new techniques to obtain food were better able to withstand the environmental changes affecting their habitat, which represent their main threat of extinction.

Throughout the years, scientists have noticed numerous examples of these behaviours. Green herons have been repeatedly observed using bread or insects as bait to catch fish. Opportunistic carrion crows have been seen using cars as nut- or seashell-crackers. Great cormorants in New Zealand have been observed coordinating their fishing periods with the movements of commercial ferries in order to take advantage of the strong currents generated by the propellers to catch confused fish.

Proving a long-held theory about species vulnerability

The ability to innovate, a measure of 'behavioural plasticity', has long been thought to render species less vulnerable to the risk of extinction, but it has been difficult to test this thoroughly on a global level.

Louis Lefebvre, the senior author of the new study, who teaches in McGill's Biology Department, he has spent the last 20 years combing through the literature, searching for evidence of foraging innovations in the wild. Thanks to the tireless dedication of bird watchers from around the world who have reported these novel behaviours, he has been able to compile a database of over 3,800 bird foraging innovations.

"The large database we now have has allowed us to test, on almost all bird species of the world, the idea that the more you can change your feeding behaviour, the better you might be able to cope with destruction of your normal habitat," said Lefebvre. "We feel our results are solid, as we have taken into account as many co-variables and possible biases that we could think of."

More innovations mean a greater probability of population stability or increase

The researchers gathered information about the feeding innovations described in articles published in 204 ornithological journals between 1960 and 2018.They then compared the number of observed innovations of each species with the level of their risk of extinction according to the Red List of the International Union for Conservation of Nature (IUCN). Their modelling showed that extinction risk was reduced in species that displayed innovative behaviours, and as the number of these behaviours increased, extinction risk was reduced further.

"We long suspected that this relationship between innovation and survival must exist, but now we have been able to verify it quantitatively," says the study's first author, Simon Ducatez, a post-doctoral researcher at McGill University and at CREAF in Barcelona. "We have also been able to verify that the greater the number of innovations described for a species, the greater the probability that its populations are stable or increasing. The result is clear: the greater the innovative capacity, the lower the risk of extinction of the species."

Ability to find new food sources no guarantee of survival

The authors caution that behavioural plasticity only reduces birds' risk of extinction from habitat alteration, and that it does not affect sensitivity to invasive species or overexploitation. The study reveals that the ability to invent new behaviours represents a clear evolutionary advantage for birds coping with the destruction of their habitats, although it is not always a guarantee of survival.

Indeed, the type of problem-solving skills that allow birds to face drastic changes in habitat does not seem to work against other types of threats such as over hunting. "It must be taken into account that the species with the greatest capacity for innovation have longer generation times, which makes them more vulnerable to hunting," explains Daniel Sol, researcher at CREAF and the CSIC in Barcelona. "This implies that, unlike what is usually assumed, the ability to innovate protects animals from some but not all of the rapid changes in the environment."

In satellite photos of the Earth, clouds of bright green bloom across the surface of lakes and oceans as algae populations explode in nutrient-rich water. From the air, the algae appear to be the primary players in the ecological drama unfolding below.

But those single-celled organisms we credit for influencing the aquatic environment at the base of the food chain may be under the influence of something else: viruses whose genes can reconfigure their hosts' metabolism.

In a new study published in Nature Communications, a research team from Virginia Tech reported that they had found a substantial collection of genes for metabolic cycles -- a defining characteristic of cellular life -- in a wide range of "giant viruses."

Giant viruses disrupt the familiar narrative about viruses: That they're the tiniest denizens of the microbiome, little more than a stripped-down husk of an organism -- just a few genes' worth of DNA or RNA folded into a shell so small you need an electron microscope to see it. In fact, the giant viruses, ten times the size of their more compact cousins and with hundreds or even thousands of genes, are so unlike the rest of the family that when the first species was discovered in 1992, researchers dismissed it as bacteria.

They were eventually correctly classified, but even then considered an isolated curiosity. Frank Aylward, an assistant professor of biological sciences in the College of Science, who led the research, explained that routine surveys of viral diversity often missed them for a prosaic reason: They're so big that they get caught in the filters researchers use to separate viruses from bacteria and other larger organisms.

But gradually, it became clear that these oversized viruses were everywhere -- and especially plentiful in aquatic environments, where they infect single-celled organisms like algae and protozoans. That's important, because the metabolism of those comparatively complex organisms -- what nutrients they consume, what waste they produce -- heavily influences the health of the oceans and lakes they live in, and ultimately the planet's carbon cycle.

"They're all over the biosphere. It's just we haven't really paid attention to them," Aylward said.

Aylward started paying attention after postdoctoral researcher Monir Moniruzzaman, the lead author of the new study, joined the lab in 2018.

"Monir is the giant virus expert," Aylward laughed. "He just wouldn't stop talking about giant viruses, so finally I said, okay, we'll start working on them."

Working from publicly available metagenome databases, which house jumbles of genetic data from the vast array of organisms in a variety of environments, Moniruzzaman began to tease out genomes that belonged to giant viruses. Using known giant-virus genes as markers and patterns in the data as clues, he pieced together genomes for 501 giant viruses, mostly from marine and freshwater environments. Those genomes contained the standard features you'd expect -- genes that direct the construction of the virus' protective shell, and that allow it to infect and kill its host.

They didn't expect to see so many metabolic genes. Metabolism, the collection of processes cells use to extract energy from nutrients, is a hallmark of cellular life, absent from viruses almost by definition. Nevertheless, these giant viruses seemed to have genes linked to several key metabolic pathways in living cells.

These weren't the first metabolic genes that had turned up in viral genomes, but they included many functions that had never been seen in viruses. Other examples had been isolated viral genes that were virtually identical to their cellular counterparts, suggesting they had been acquired from the host by chance during an infection and pasted into the virus' genome relatively recently: vestigial artifacts of invasions past rather than functional tools.

The genes Moniruzzaman and Aylward found, on the other hand, comprised large portions of familiar metabolic pathways but had their own unique signature.

"It implies that the viruses have had these genes for millions of years, even billions of years, and they're virus-specific metabolic genes," Aylward explained.

That suggests that these genes aren't just genetic flotsam, but working components the virus deploys as it commandeers its host. In this case, the researchers say, the implication is that the virus is altering the cell's metabolism.

"Once viruses infect a cell, we can't think of the cell as being its own autonomous entity anymore," Aylward says. "The fundamental aspects of cellular physiology are being rewired by these viruses upon infection."

Changes in the host's metabolism can shift the balance of nutrients being consumed and released into the environment, giving viruses sway over aquatic biogeochemistry. Even though viruses aren't alive, Aylward explains, "they are significantly altering the course of life every day in the environment."

The next step is figuring out how by using experimental studies that can help uncover how these genes function and interact with the host's native metabolism. The team will also probe the evolution of these genes to determine how they slipped into the viral genome, and when.

Discovering these genes, which stretch our ideas about how giant viruses influence their environment, has broader implications for virology. Finding the building blocks for metabolism in something that's not alive blurs the distinction between what's alive and what isn't.

"I think of these Venn diagrams, where it used to be that there was very little overlap, and the more we learn, the more they continue to overlap," Aylward said. "Now it's gotten to the point where there are actually very few genes that are only found in cells, and very few genes that are only found in viruses. In terms of the genomic repertoires, they have much more in common than we would actually expect."

Moniruzzaman suspects that there are more surprises lurking in these genomes, which are stuffed with what he describes as "viral dark matter" -- genes that keep surfacing in studies of giant viruses but whose functions are still unknown.

"Don't you think they're fascinating? I just think they're fascinating," Moniruzzaman marvels. "They're just a bag of mystery. They're like a big forest and you are standing in front of the forest and you don't know what's in it. And I think this is the right time to understand it. I think they're mysterious, that's what I think."