Culture

PITTSBURGH, Sept. 3, 2020 - Especially in settings where personal protective equipment, or PPE, is in short supply, intubation -- inserting a breathing tube down a patient's throat -- poses a major risk of SARS-CoV-2 exposure for doctors and nurses as viral particles are released into the air.

Researchers from UPMC and the U.S. Army Combat Capabilities Development Command's Army Research Laboratory (CCDC-ARL) created an individual biocontainment unit, or IBU, to keep front line health care workers safe while they provide life-saving care. The device is described in a study published today in the Annals of Emergency Medicine.

Earlier attempts to minimize exposure to health care workers involved placing a plexiglass intubation box over a patient's head and shoulders. Clinicians slip their hands through two large holes in the box to intubate the patient inside. While such a device may contain the worst of the splatter, it can't keep aerosols from leaking out.

The IBU is designed to suck contaminated air out of the box with a vacuum and trap infectious particles in a filter before they seep into the room.

Simulating a COVID-19 patient, the researchers placed a mannequin inside the IBU as well as in a commercially available intubation box. Near its mouth, they piped in an oil-based aerosol which formed tiny droplets in the air, similar in size to the SARS-CoV-2 particles in breath that spread COVID-19.

The IBU trapped more than 99.99% of the simulated virus-sized aerosols and prevented them from escaping into the environment. In contrast, outside of the passive intubation box, maximum aerosol concentrations were observed to be more than three times higher than inside the box.

"Having a form of protection that doesn't work is more dangerous than not having anything, because it could create a false sense of security," said study co-lead author David Turer, M.D., M.S., a plastic surgeon who recently completed his residency at UPMC.

Because of concerns about the potential of airborne viruses to leak from the plexiglass boxes, the Food and Drug Administration (FDA) recently revoked their Emergency Use Authorization (EUA) for these enclosures.

Several months ago, Turer and colleagues submitted an EUA application for the IBU and are preparing to manufacture the devices for distribution.

"It intentionally incorporates parts from outside the medical world," said Turer, who now is at the University of Texas Southwestern Medical Center. "So, unlike other forms of PPE, demand is unlikely to outstrip supply during COVID-19 surge periods."

Besides protecting providers during intubation, the IBU also can provide negative pressure isolation of awake COVID-19 patients, supplying an alternative to scarce negative pressure hospital isolation rooms, as well as helping isolate patients on military vessels.

"The ability to isolate COVID-19 patients at the bedside is key to stopping viral spread in medical facilities and onboard military ships and aircraft," said study co-lead author Cameron Good, Ph.D., a research scientist at the CCDC-ARL.

Devices similar to IBUs were first used in practice by military personnel in the Javits Center field hospital in New York City when local hospitals were overrun with COVID-19 patients during the first wave of the pandemic.

Once the EUA is granted, hospitals and military units will be able to use the IBU to protect health care workers caring for COVID-19 patients.

Since the start of the COVID-19 pandemic, there has been empirical and anecdotal reports of declines in both emergency and ambulatory medical visits. However, little research has been conducted to identify why these declines have occurred. New research now shows a strong association between mental health symptoms and medical care avoidance.

Among a sample of over 73,000 U.S. adults from the Household Pulse Survey, a weekly survey conducted by the U.S. Census Bureau that aims to collect data on the social and economic impacts of COVID-19, researchers found that adults who experienced four common symptoms of anxiety and depression have upwards of two times greater risk of delaying medical care or not receiving needed non-coronavirus medical care amidst the pandemic.

"The results from our study are alarming given that delaying medical care can have significant adverse short- and long-term health outcomes, depending on the condition," said Kyle T. Ganson, PhD, MSW, assistant professor at the University of Toronto's Factor-Inwentash Faculty of Social Work and lead author on the study. "We need to increase access to telehealth, and in the U.S., health insurance policies must be expanded to cover telehealth services that address non-emergency medical concerns."

The study, published online in the Journal of General Internal Medicine,, found that in the four weeks prior to participating in the survey in June, 41% of the sample delayed medical care. In addition, nearly one third of the Americans surveyed did not receive necessary non-coronavirus medical care.

"Patients with chronic medical conditions or new symptoms that they are concerned about need to continue to seek medical advice," says senior author Jason M. Nagata, MD, MSc, assistant professor at the University of California, San Francisco's Department of Pediatrics. "As the pandemic continues, it remains vitally important that the public have accurate and updated information on the risks and benefits of seeking medical care."

The study also found that symptoms of anxiety and depression were overwhelmingly common among the sample. In the seven days prior to the survey, 65% reported being nervous, anxious or on edge, 56% reported not being able to stop or control worrying, 53% reported having little interest or pleasure in doing things, and 52% reported feeling down, depressed, or hopeless.

"More people are experiencing symptoms of anxiety and depression during the pandemic, which can often be addressed through telepsychiatry and telemental health services. As a clinical social worker, I have seen how effective and accessible teletherapy can be in addressing these symptoms," says Dr. Ganson.

The study's authors say that their findings also have important implications for clinical practice. "Medical professionals, social workers, and clinicians need to proactively take steps to help clients work through symptoms of anxiety and depression," Dr. Ganson says. "This will help to improve the likelihood that they will seek the medical care they need."

TORONTO (Sept. 3, 2020) -- The use of tear gas -- particularly CS gas -- as a riot control agent, cannot be reconciled with respect for fundamental human rights and should therefore be banned entirely in international law, the University of Toronto's International Human Rights Program (IHRP) says in a report released today. Lawmakers at all levels of government should act to put forward legislation that bans use of the chemical weapon, eliminates existing stockpiles and prohibits import, export and manufacture.

The use of tear gas has increased worldwide, quickly becoming a weapon of choice for policing assemblies from Iran to Hong Kong to the United States. The boom in its use by law enforcement for protests and crowd control has resulted in a corresponding expansion of the largely unregulated global market for its trade, demand for which is expected to continue growing.
Used as an area weapon, tear gas is inherently indiscriminate and is frequently abused when deployed against peaceful assemblies, in enclosed spaces, in excessive quantities and against vulnerable populations. It cannot distinguish between the young and the elderly, the healthy and the sick, the peaceful and the violent. Its deployment can also cause myriad health harms, including severe injuries and death.

"Tear gas is not a relatively benign method of crowd control. Its deployment effectively crushes the right to freedom of protest and assembly," said Vincent Wong, William C. Research Associate at the IHRP and co-author of the report. "Studies are showing that long-term exposure in the form that we are seeing with protest policing leave those affected at higher risk for a host of illnesses, including contracting respiratory illnesses such as COVID-19."

The report, "The Problematic Legality of Tear Gas Under International Human Rights Law," explores the deficient legal underpinnings and detrimental practical implications of the state of international human-rights law with respect to use and abuse of tear gas. Although tear gas is banned in warfare under the Chemical Weapons Convention, an exemption for the use of riot control agents for law enforcement purposes was negotiated during the drafting process in order to secure a greater number of ratifying state parties.

"While international guidance governing the use of tear gas exists, these soft law instruments have shown to be largely ineffective in constraining misuse of tear gas or in protecting fundamental rights," said Maija Fiorante, IHRP Summer Fellow and co-author. "Under international law, any use of force by law-enforcement authorities must abide by the principles of necessity and proportionality, but tear gas is hardly ever used in accordance with such principles."

In addition, there are no international agreements governing the trade and manufacture of tear gas. Consequently, the global market for tear gas is largely unregulated and outside the scope of accountability. There are no common standards for the composition of tear gas. Canisters come in different shapes and sizes and contain an array of toxic chemicals. In many cases, it is difficult to know what combination of chemicals is inside, its level of toxicity, and whether its safety has been tested prior to sale.

The report also tracks how international norms are starting to shift with respect to tear gas. Increased efforts are being made by international rights groups and the United Nations and European Union to restrict the use and trade of tear gas. Countries are passing legislation to ban exports to other jurisdictions where tear gas is being frequently abused to crack down on protests in a punitive fashion and efforts are being made to pass legislation and moratoriums to ban the use of tear gas by police forces domestically. Regional courts have also made rulings that use of riot-control agents in certain circumstances may violate prohibitions on torture and cruel and inhumane or degrading treatment.

In Canada, MP Matthew Green has sponsored a petition calling for a nationwide ban on the use of tear gas, the destruction of stocks of tear gas currently owned by the police and armed forces, prioritization on de-escalation tactics over dispersal and arrest tactics in crowd control, and an investigation into the May 31, 2020 use of tear gas by police in Montreal on an anti-Black racism demonstration.

"The assumption has always been that tear gas is necessary to avoid use of more lethal weapons," said Natasha Williams, IHRP Summer Fellow and co-author. "But this is a red herring. Banning tear gas under international law will force police to redouble their de-escalation efforts, as well as less harmful and less indiscriminate crowd control strategies."

(Vienna, 03 September 2020) Studies have indicated that people who dye their hair regularly may have a higher risk of cancer, especially bladder cancer and breast cancer. Hair dyes contain certain chemicals that have been held responsible for these relationships. In the largest study to date, which followed 117,200 women from the USA over 36 years, this could not be confirmed. A research team led by Eva Schernhammer, Head of the Department of Epidemiology at the Medical University of Vienna, showed in a specific analysis of the data from a cohort study of American nurses that regular hair colouring had no significant effect on most types of cancer - with a few exceptions. This study was published in the British Medical Journal.

The International Agency for Research on Cancer (IARC), part of the World Health Organization (WHO), has classified occupational exposure (e.g. hairdressers) to hair dyes as a probable human carcinogen, while personal use of hair dyes could not be classified. However, as current epidemiological evidence is far from conclusive, there is concern about the carcinogenic potential of personal use of permanent hair dye, especially those that are particularly aggressive and most commonly used.

Hardly an increased risk for most types of cancers - with exceptions

The current study - the largest prospective study on this topic to date - found no link between personal use of permanent hair dye and the risk of most cancers or cancer-related mortality.

However, it did find a positive association for the risk of basal cell carcinoma, hormone receptor-negative breast cancer (ER-, PR- and ER-/PR-), and ovarian cancer. Further, the study also found evidence for heterogeneity due to natural hair colour: an increased risk of Hodgkin's lymphoma was only observed in women with naturally dark hair, and a higher risk of basal cell carcinoma was especially observed in women with naturally light hair.

Eva Schernhammer: "The present prospective cohort study offers some reassurance against concerns that personal use of permanent hair dyes may be associated with an increased risk of cancer or mortality. Nevertheless, we also found a positive correlation for the risk of some cancers."

Current findings are limited to US white women and may not extend to other populations.

"Our results justify further prospective validation," explains Schernhammer. "This depends on different populations and countries, different susceptibility genotypes (e.g. NAT1 or NAT2), cancers if different genotypes and molecular genetic phenotypes, different exposure settings (personal use vs. occupational exposure), different time points and different colours of the permanent hair dyes used (dark dyed vs. light dyed), with refined exposure estimates and should be interpreted in the light of the totality of the evidence."

In the past century, neuroscientists have discovered various functional classes of neurons that are relevant to cognitive functions of the brain. These include orientation selective cells, place cells, grid cells and fear memory engram cells.

These specific functional classes of neurons have been regarded as cornerstones of the cognitive map of the brain. Recently, scientists from the Suzhou Institute of Biomedical Engineering and Technology of the Chinese Academy of Sciences, together with collaborators at home and abroad, presented the discovery of "holistic bursting" cells, a novel functional class of cortical neurons that represent learned complex objects as wholes rather than parts.

A consortium of interdisciplinary researchers performed a set of highly challenging experiments using cutting-edge technology, including the combination of two-photon Ca2+ imaging of neuronal populations and loose-patch recording of single neurons in behaving mice. The researchers found that in mice that had received an auditory association training, there existed a special subset of neurons in layer 2/3 of auditory cortex, each of which, reliably exhibited a unique mode of high-rate, prolonged burst firing response (instantaneous firing rate ~ 100 Hz, firing duration 100 - 250 ms) to the trained sound in each trial.

In contrast, neurons with such strong and reliable burst firing responses were almost absent in the auditory cortices of untrained animals, where the typical neuronal responses were unreliable singlet firings. A set of chronic imaging experiments revealed that the bursting response property emerged due to the associative training but occurred only in a sparse subset (~5%) of neurons in the auditory cortex.

Of particular interest, the researchers found that mice could be trained with different chords, each consisting of multiple pure-tones. The behavioral response showed a "holistic" character, i.e., the mice exhibited a reliable behavioral response exclusively to the trained chords but not to any of the constituent pure tones, even though all sounds were played at nearly the same volume.

In the animals trained with chords, a special class of neurons was found, referred to as holistic bursting (HB) cells, each of which reliably exhibited a bursting response exclusively to a trained chord, but not to other chords or to individual constituent tones. The experimental precision was sufficient to show that, for these HB cells, the response strength to the preferred chord was significantly larger than the sum of individual response strengths to the four tones that constituted the chord.

Dr. Israel Nelken, a renowned neuroscience expert in the auditory system and a key contributing author of this paper said, "the groundbreaking finding of this paper is the emergence of few neurons which respond, very powerfully, to a stimulus as a whole, rather than to its components, in contradistinction to most neurons surrounding them. These very few holistic bursting neurons could not be detected before the deployment of the combined technology of two-photon imaging and single-cell electrophysiology."

For patients who receive a heart transplant in the near future, the old adage, "Good things come in small packages," may become words to live by. In a recent study, researchers at Johns Hopkins Medicine and the National Cancer Institute (NCI) demonstrated in mice that they can easily deliver a promising anti-rejection drug directly to the area surrounding a grafted heart by packaging it within a tiny three-dimensional, protein gel cocoon known as a hydrogel. Best of all, the researchers say that the release of the drug is spread out over time, making it highly regulatable and eliminating the need for daily medication to keep rejection in check.

The findings are presented in the Aug. 18, 2020, issue of the journal Small.

Preventing the rejection of a transplanted heart has often been a Catch-22 situation. If you give an organ recipient large amounts of immune suppression drugs, there may be serious side effects, including kidney damage, hypertension, blood sugar imbalances and even lymphomas. Lowering the dose may be safer for general health but increases the risk that rejection will not be properly controlled and the grafted heart will be lost.

"What was needed was a drug delivery method that would get the anti-rejection medication only where needed; protect the drug from premature degradation; and maintain a high concentration for the period of time needed to retrain the immune system," says study co-author Giorgio Raimondi, M.Sc., Ph.D., assistant professor of plastic and reconstructive surgery at the Johns Hopkins University School of Medicine.

"Two earlier studies used the hydrogel method to successfully deliver conventional immunosuppressive drugs to other sites, and this prompted us to try it out for transplanted hearts," Raimondi explains. "Additionally, work by a team at the NCI Frederick National Laboratory for Cancer Research under Joel Schneider [Ph.D., a study co-author] showed that hydrogel-drug packages can be administered by syringe."

The drug these researchers wanted to supply to transplanted hearts is tofacitinib, an inhibitor of the process by which cells alert their receptiveness to binding with inflammation-inducing proteins called cytokines. In normal immune responses to foreign invaders within the body, cytokines play a critical role in alerting specialized white blood cells -- T lymphocytes -- to attack and remove the threatening bacteria or viruses. However, cytokines in the presence of a transplanted heart can direct the immune system to destroy the graft.

To see if a hydrogel courier could be used to deliver tofacitinib, the researchers first grafted mouse hearts into the necks of recipient mice to create an animal model of a human transplant. Next, they mixed tofacitinib with a solution of small protein fragments that assembled themselves around the drug during a 24-hour incubation process that Raimondi likens to the "make your own crystal" kits popular with children.

"We found that making tofacitinib into a crystal best controlled how the drug spreads out from the hydrogel," says study lead author Poulami Majumder, Ph.D., former NCI at Frederick postdoctoral fellow. "The resulting 'microcrystalline tofacitinib hydrogel,' or MTH, was extremely stable, preserved the encapsulated drug in pristine condition and could be injected at the transplantation site simply by using a syringe."

The researchers tested the MTH delivery system in their mouse model in tandem with a second immunosuppressant drug, CTLA4-Ig, which was injected separately. This was the first time that this specific combination therapy had been tried.

To determine if the location of MTH delivery was important, the researchers injected the packaged medicine locally, at the transplant site, and distantly, near the mouse's tail. As expected, only the group of mice with local injections showed a significant increase of graft survival time.

"The average survival of the grafted hearts in the locally injected group was approximately 125 days compared with just 35 days for mice injected with MTH far from the transplant," Raimondi says. "We also tested the plasma of the former group and found only minimally detectable traces of tofacitinib -- meaning that MTH delivery keeps the drug close to the transplant site and enables it act synergistically with CTLA4-Ig to provide enhanced and lasting protection of the organ."

Without the tofactinib/CTLA4 treatment, Raimondi says, the transplanted mouse hearts stopped beating within 10 days.

Raimondi says that among the advantages to using MTH as a drug-delivery system are that the hydrogel releases its content slowly, over a period of 5 to 20 days, and does not cause other complications because it is biocompatible, noninflammatory and biodegradable. He and his colleagues believe that using crystal engineering to further improve the hydrogel capsule, more control over the release rate can be obtained -- a critical goal to meet before human trials can be attempted -- or, the capsule can be made "tunable" to deliver drug only when the grafted heart is attacked by the immune system.

The researchers also feel that with additional research and testing, the MTH delivery system could be applied to fighting rejection of transplanted organs other than the heart and in the treatment of autoimmune diseases.

A new species of freshwater Crustacea has been discovered during an expedition of the desert Lut, known as the hottest place on Earth.

The newly identified species belongs to the genus Phallocryptus of which only four species were previously known from different arid and semiarid regions.

Dr Hossein Rajaei from the Stuttgart State Museum of Natural History and Dr Alexander V Rudov from Tehran University made the discovery during an expedition of Lut to better understand the desert's ecology, biodiversity, geomorphology and paleontology.

Further scientific examinations of the specimens by co-author Dr Martin Schwentner, Crustacea specialist from the Natural History Museum of Vienna, stated that they belong to a new species of freshwater Crustacea.

Publishing their findings in Zoology in the Middle East, the biologists name the new species Phallocryptus fahimii, in honor of the Iranian conservation biologist, Hadi Fahimi, who took part in the 2017 expedition and sadly died in an airplane crash in 2018.

Dr Rajaei, an entomologist from State Museum of Natural History Stuttgart, who actually found the species in a small seasonal lake in southern part of the desert says the discovery is "sensational".

"During an expedition to such an extreme place you are always on alert, in particular when finding water. Discovering crustaceans in this otherwise hot and dry environment was really sensational."

The team's study explains how Phallocryptus fahimii differs in its overall morphology and its genetics from all other known Phallocryptus species.

Dr Schwentner, who has worked with similar crustaceans from the Australian deserts in the past, adds: "These Crustaceans are able to survive for decades in the dried-out sediment and will hatch in an upcoming wet season, when the aquatic habitat refills. They are perfectly adapted to live in deserts environments. Their ability to survive even in the Lut desert highlights their resilience."

The Lut desert - also known as Dasht-e Lut - is the second largest desert in Iran.

Located between 33° and 28° parallels and with its 51,800 km2 larger than Switzerland, this desert holds the current record for the highest ever-recorded surface temperature. Based on 2006 satellite measurements, the NASA reported a record surface temperature of 70.7°C, which more recently has been increased to even 80.3°C. Dark pebbles that heat up are one of the causes of these record temperatures. Mean daily temperatures range from -2.6°C in winter to 50.4°C in summer with annual precipitation not exceeding 30 mm per year.

Almost deprived of vegetation, the Lut desert harbors a diverse animal life, but no permanent aquatic biotops (such as ponds).

After rain falls, non-permanent astatic water bodies are filled including the Rud-e-Shur river from north-western Lut.

Here a diverse community of Archaea has been described but aquatic life in the Lut remains highly limited, which makes this find particularly rare.

Taking the "One Million-Mu (666 km2)" Plain Afforestation (Phase I) Project as an example, the authors characterized the growth status and temporal trends of forest patches using time series NDVI. They selected forest patches with greater than 50 ha in size as the main objects for analysis. Using the maximum NDVI in the base year (2012), they calculated the change ratio of forest patches in different years. These ratios were further divided into three categories using the natural break approach. That is decreasing, relatively stable without notable changes and increasing. According to derived categories from the trend of greenness in forest patches, they analyzed the initial status of vegetation growing in the base year 2012 (Fig. 1). They found that the greenness of forest patches that were categorized as decreasing (in total 30) was relatively high in 2012 (i.e., ranging from 0.6 to 0.8). Meanwhile, these patches had a relatively low heterogeneity (Fig. 1a). This result suggests that the growing status of vegetation before afforestation is good. However, for those forest patches categorized as increasing (in total 33), their greenness is relatively low in 2012 and has a high heterogeneity (e.g., from 0.2 to 0.8) for pixels within the patch (Fig. 1b).

The authors found the growth status of some forest patches becomes worse in the Phase I afforestation project. For those farmland patches with relatively high greenness and low heterogeneity, their growth status is likely to become worse due to the interruption of afforestation. Also, the afforestation project occupies massive fertile farmland through decreasing their connectivity and compactness. These findings are helpful to urban greenspace planning in the future.

According to the results from Phase I afforestation and the impact of urbanization on green space, they constructed a series of spatial variables and generated a suitability map for the next "New Round of One Million-Mu (666km2) Afforestation project" (Phase II). The key of this evaluation is to maximize the suitability of vegetation growth based on the spatial distribution of patches, the initial growing status of vegetation (e.g., forest coverage, NDVI value, heterogeneity), and the temporal trend of greenspace over a given historical period. They modeled the distribution of forest patches in the Phase II afforestation project and assessed their suitability from an urban planning perspective (Fig. 2). Also, the basic farmland is not allowed for afforestation, while the abandoned built-up areas are preferentially considered for afforestation. Different from traditional approaches that operate at the pixel level, they used segments as our basic modeling unit in this study to represent the shape of forest patches appropriately. Their modeling results suggest most afforested areas are located in peripheral districts in the plain area of Beijing. Meanwhile, human intervention through occupying farmland around the existing forest patches is not recommended.

The authors derived the spatial map of reforestation areas at the segment scale in the Phase II afforestation project (Fig. 3). Comparing the results from the Phase I and Phase II, their overall patterns are similar, i.e., most of the forest patches are in Tongzhou, Daxing, Shunyi, and other districts with flat terrain. These regions are not only the focus of building greening and suitable urban society from the planning aspect but also the main area of the afforestation zones suggested in the Beijing Master Plan (2016-2035).

This study evaluated the implementation of urban green space planning using a multi-source dataset. Different from traditional approaches that focus on the current status of vegetation, they proposed a dynamic approach to evaluating the growth status of green space, taking into account the trend of greenness over the years. They developed a modeling approach to explore the spatial distribution of urban greenspace, in consideration of the patch distribution, the initial growing status of vegetation, temporal trends of growth, and particular planning constraints. The derived results can support decision making for urban greenspace planning. The proposed evaluation framework for the afforestation project can be extended to the national scale, by offering scientific insights to the monitoring and planning of regional afforestation project.

A new study led by Swansea University and the University of Bristol has revealed the size of the legendary giant shark Megalodon, including fins that are as large as an adult human.

There is a grim fascination in determining the size of the largest sharks, but this can be difficult for fossil forms where teeth are often all that remain.

Today, the most fearsome living shark is the Great White, at over six metres (20 feet) long, which bites with a force of two tonnes.

Its fossil relative, the big tooth shark Megalodon, star of Hollywood movies, lived from 23 to around three million years ago, was over twice the length of a Great White and had a bite force of more than ten tonnes.

The fossils of the Megalodon are mostly huge triangular cutting teeth bigger than a human hand.

Jack Cooper and colleagues from Swansea University and the University of Bristol used a number of mathematical methods to pin down the size and proportions of this monster, by making close comparisons to a diversity of living relatives with ecological and physiological similarities to Megalodon.

The project was supervised by shark expert Dr Catalina Pimiento from Swansea University and Professor Mike Benton, a palaeontologist at the University of Bristol. Dr Humberto Ferrón from Bristol also collaborated.

Jack Cooper, who will now start his PhD at Swansea University said: "I have always been mad about sharks. As an undergraduate, I have worked and dived with Great Whites in South Africa - protected by a steel cage of course. It's that sense of danger, but also that sharks are such beautiful and well-adapted animals, that makes them so attractive to study.

"Megalodon was actually the very animal that inspired me to pursue palaeontology in the first place at just six years old, so I was over the moon to get a chance to study it.

"This was my dream project. But to study the whole animal is difficult considering that all we really have are lots of isolated teeth."

Previously the fossil shark, known formally as Otodus megalodon, was only compared with the Great White. Jack and his colleagues, for the first time, expanded this analysis to include five modern sharks.

Dr Catalina Pimiento said: "Megalodon is not a direct ancestor of the Great White but is equally related to other macropredatory sharks such as the Makos, Salmon shark and Porbeagle shark, as well as the Great white. We pooled detailed measurements of all five to make predictions about Megalodon."

Professor Benton added: "Before we could do anything, we had to test whether these five modern sharks changed proportions as they grew up. If, for example, they had been like humans, where babies have big heads and short legs, we would have had some difficulties in projecting the adult proportions for such a huge extinct shark.

"But we were surprised, and relieved, to discover that in fact that the babies of all these modern predatory sharks start out as little adults, and they don't change in proportion as they get larger."

Jack Cooper added: "This means we could simply take the growth curves of the five modern forms and project the overall shape as they get larger and larger - right up to a body length of 16 metres."

The results suggest that a 16-metre-long Otodus megalodon likely had a head round 4.65 metres long, a dorsal fin approximately 1.62 metres tall and a tail around 3.85 metres high.

This means an adult human could stand on the back of this shark and would be about the same height as the dorsal fin.

The reconstruction of the size of Megalodon body parts represents a fundamental step towards a better understanding of the physiology of this giant, and the intrinsic factors that may have made it prone to extinction.

FRANKFURT. The Nebra sky disk is one of Germany's most significant archaeological finds and was included in the UNESCO Memory of the World Register in 2013. It was discovered in an illegal excavation in 1999 together with Bronze Age swords, axes and bracelets according to the finders. This discovery context was important for the scientific dating, as the disk itself could neither be scientifically nor archeologically dated by comparison with other objects. Many years of investigations by several research groups therefore attempted to verify both the attribution to the supposed discovery site as well as the common origins of the objects independent of the vague information given by the looters.

Rupert Gebhard, Director of the Munich Archäologischen Staatssammlung, and Rüdiger Krause Professor for Prehistory and Early European History at Goethe University Frankfurt have now extensively analysed the discovery circumstances and research results on the Nebra sky disk. Their conclusion: The site that was considered the discovery site until today and which was investigated in subsequent excavations is with high probability not the discovery site of the looters. Furthermore, there is no convincing evidence that the Bronze Age swords, axes and bracelets form an ensemble of common origins. For this reason, it must be assumed that this is not a typical Bronze Age deposit and that the disk was not found together with the other objects in an original state at the excavation site.

According to the archaeologists, this means that the disk must be investigated and evaluated as an individual find. Culturally and stylistically, the sky disk cannot be fitted into the Early Bronze Age motif world of the beginning of the second millennium B.C. On the contrary, clearer references can be made to the motif world of the Iron Age of the first millennium B.C. According to Gebhard and Krause, on the basis of a divergent data situation and on the basis of this new assessment, all previous, sometimes far-reaching cultural-historical conclusions must be discussed anew and with an open mind, and the disk must be interpreted and evaluated in different contexts than before. The basis for this must be the submission of all previously unpublished data and facts.

RESEARCH TRIANGLE PARK, N.C. - New Army-funded study looks at effects of sleep deprivation, which can greatly affect Soldiers on the battlefield.

Research conducted at the University of Rochester Medical Center and funded by the Army Research Office, an element of the U.S. Army Combat Capabilities Development Command's Army Research Laboratory, suggests that people who rely on sleeping during daytime hours are at greater risk for developing neurological disorders.

The study, published in Nature Communications, details how the complex set of molecular and fluid dynamics that comprise the glymphatic system - the brain's unique process of waste removal - are synchronized with the master internal clock that regulates the sleep-wake cycle.

"Establishing a role for communication between astrocytes and the significant impacts of circadian timing on glymphatic clearance dynamics represent a major step in understanding the fundamental process of waste clearance regulation in the brain," said Dr. Frederick Gregory, a program manager for ARO's neurophysiology of cognition initiative. "This knowledge is crucial to developing future countermeasures that offset the deleterious effects of sleep deprivation and addresses future multi-domain military operation requirements for Soldiers to sustain performance over longer periods without the ability to rest."

The glymphatic system, first discovered by the URMC Nedergaard lab in 2012, consists of a network that piggybacks on the brain's blood circulation system and is comprised of layers of plumbing, with the inner blood vessel encased by a 'tube' that transports cerebrospinal fluid. The system pumps the fluid through brain tissue primarily during sleep, washing away toxic proteins and other waste.

"These findings show that glymphatic system function is not solely based on sleep or wakefulness, but by the daily rhythms dictated by our biological clock," said neuroscientist Maiken Nedergaard, M.D., D.M.Sc., co-director of the Center for Translational Neuromedicine at URMC and senior author of the study.

The research team and others have shown the role that blood pressure, heart rate, circadian timing, and depth of sleep play in the glymphatic system's function and the chemical signaling that occurs in the brain to turn the system on and off. They have also shown how disrupted sleep or trauma can cause the system to break down and allow toxic proteins to accumulate in the brain, potentially giving rise to a number of neurodegenerative diseases, such as Alzheimer's.

Circadian rhythms, 24-hour body clocks, are maintained in a small area of the brain called the suprachiasmatic nucleus. This clock regulates several important biological functions, including the sleep-wake cycle.

The new study, conducted in mice, showed that when the animals were anesthetized all day long, their glymphatic system still only functioned during their typical rest period - mice are nocturnal, so their sleep-wake cycle is the opposite of humans.

"Circadian rhythms in humans are tuned to a day-wake, night-sleep cycle," said Dr. Lauren Hablitz, first author of the new study and a research assistant professor in the Center for Translational Neuromedicine at URMC. "Because this timing also influences the glymphatic system, these findings suggest that people who rely on cat naps during the day to catch up on sleep or work the night shift may be at risk for developing neurological disorders. In fact, clinical research shows that individuals who rely on sleeping during daytime hours are at much greater risk for Alzheimer's and dementia along with other health problems."

The study singles out cells called astrocytes that play multiple functions in the brain. Scientists believe that astrocytes in the suprachiasmatic nucleus help regulate circadian rhythms. Astrocytes also serve as gatekeepers that control the flow of cerebrospinal fluid throughout the central nervous system. The results of the study suggest that communication between astrocytes in different parts of the brain may share the common goal of optimizing the glymphatic system's function during sleep.

The researchers also found that during wakefulness, the glymphatic system diverts cerebrospinal fluid to lymph nodes in the neck. Because the lymph nodes are key waystations in the regulation of the immune system, the research suggests that cerebrospinal fluid may represent a fluid clock that helps wake up the body's infection fighting capabilities during the day.

A Rochester Institute of Technology researcher developed a mathematical method that shows climate change likely caused the rise and fall of an ancient civilization. In an article recently featured in the journal Chaos: An Interdisciplinary Journal of Nonlinear Science, Nishant Malik, assistant professor in RIT's School of Mathematical Sciences, outlined the new technique he developed and showed how shifting monsoon patterns led to the demise of the Indus Valley Civilization, a Bronze Age civilization contemporary to Mesopotamia and ancient Egypt.

Malik developed a method to study paleoclimate time series, sets of data that tell us about past climates using indirect observations. For example, by measuring the presence of a particular isotope in stalagmites from a cave in South Asia, scientists were able to develop a record of monsoon rainfall in the region for the past 5,700 years. But as Malik notes, studying paleoclimate time series poses several problems that make it challenging to analyze them with mathematical tools typically used to understand climate.

"Usually the data we get when analyzing paleoclimate is a short time series with noise and uncertainty in it," said Malik. "As far as mathematics and climate is concerned, the tool we use very often in understanding climate and weather is dynamical systems. But dynamical systems theory is harder to apply to paleoclimate data. This new method can find transitions in the most challenging time series, including paleoclimate, which are short, have some amount of uncertainty and have noise in them."

There are several theories about why the Indus Valley Civilization declined--including invasion by nomadic Indo-Aryans and earthquakes--but climate change appears to be the most likely scenario. But until Malik applied his hybrid approach-- rooted in dynamical systems but also draws on methods from the fields of machine learning and information theory--there was no mathematical proof. His analysis showed there was a major shift in monsoon patterns just before the dawn of this civilization and that the pattern reversed course right before it declined, indicating it was in fact climate change that caused the fall.

Malik said he hopes the method will allow scientists to develop more automated methods of finding transitions in paleoclimate data and leads to additional important historical discoveries. The full text of the study is published in Chaos: An Interdisciplinary Journal of Nonlinear Science.

The U.S. Army partnered with the University of Pittsburg Medical Center to create a biocontainment unit that could help healthcare workers caring for COVID-19 patients.

Researchers from the U.S. Army Combat Capabilities Development Command's Army Research Laboratory and UPMC created an individual biocontainment unit that uses negative pressure to suction the air from around a patient and filter out viral particles. This prevents environmental contamination and limits exposure to SARS-CoV-2.

"Outside of the current pandemic, the IBU could be rapidly deployed to isolate patients with any respiratory illness." said study co-author Dr. David Turer, a plastic surgeon who recently completed his residency at UPMC. "It's easy to see this technology used to contain influenza, MERS, or tuberculosis, particularly in places lacking advanced hospital infrastructure."

The device and the results of safety testing are described in a study published today in the Annals of Emergency Medicine. This research was first reported by the Army in April during an effort to identify solutions to help combat the spread of COVID-19.

At that time, initial approaches to minimize viral spread involved the use of plexiglass barriers, such as intubation boxes, to limit healthcare worker exposure when inserting a breathing tube down a patient's throat. While these barriers may mitigate exposure to larger droplets, the research team hypothesized that they do little to stop the spread of smaller aerosolized viral particles.

Army researcher and study co-author, Dr. Cameron Good and Turer, along with a team of colleagues, developed prototype IBUs and tested them by performing simulated medical procedures. Using validated techniques adopted from the medical research laboratory community, they tested the IBU and a plexiglass intubation box for their ability to contain virus-sized particles from a simulated COVID-19 patient.

"Greater than 99.99% of the virus-sized aerosols were trapped by the IBU and prevented from escaping into the room," Good said. "When we tested the passive intubation box, we observed more than three times the aerosol concentration outside the box--where the healthcare provider is located--than inside the box. It is not safe to use these intubation boxes without actively filtering the air."

The Food and Drug Administration recently revoked an emergency use authorization for passive plexiglass intubation barriers and mandated the use of negative pressure systems, such as the IBU, to prevent viral spread.

The team is actively developing a portable vacuum and filter system that can run on a battery pack for use in austere environments where energy resources are limited, which is of particular interest for military and humanitarian applications.

"The ability to isolate COVID-19 patients at the bedside is key to stopping viral spread in medical facilities and onboard military ships and aircraft, particularly to limit transmission through close quarters or shared ventilation systems," Good said.

The FDA is considering a recently submitted emergency use authorization. Once granted, hospitals and military units will be able to use IBUs immediately to protect healthcare workers caring for COVID-19 patients and to prepare for future surges.

"None of this would have been possible without the extremely dedicated clinicians and engineers who rapidly designed, built, tested and validated the equipment," Good said. "I want to thank Dr. Robert Turer [David Turer's brother] from Vanderbilt University Medical Center, Nick Karlowsky from Filtech, Inc., Drs. Lucas Dvoracek, J. Peter Rubin and Jason Chang from UPMC, and Ben Schilling and Dr. Heng Ban from the University of Pittsburg. It truly takes a team."

In one of the first comprehensive assessments of the fuel economy standards in the United States, Princeton University researchers found that, over their 40-year history, the standards helped reduce reliance on foreign oil producers, cut greenhouse gas emissions, and saved consumers money.

Using data including household spending data, oil use, and greenhouse gas emissions, the researchers found that the standards (known as the CAFE standards), which were first enacted in 1975 as a way to reduce dependence on foreign oil after the oil crisis, set well-defined societal objectives and were cost-effective, fair, durable and adaptive. The standards required automakers to produce more efficient vehicles over time, increasing the number of miles per gallon required of their vehicle fleets. The researchers cite that the standards saved $5 trillion in fuel costs and prevented 14 billion metric tons of carbon from being released into the atmosphere, the equivalent of the United States eliminating all emissions from all sectors for nearly three years.

"It has been one of the most effective policies to date," said Judi Greenwald, a co-author of the study, former top U.S. Department of Energy official and non-resident fellow at the Princeton University's Andlinger Center for Energy and the Environment.

The paper, coauthored by Greenwald, Rebecca Ciez and David Greene, was published on August 23 in the journal Energy Policy. Ciez was a Distinguished Postdoctoral Fellow at the Andlinger Center and Greene is a research professor in the Department of Civil and Environmental Engineering at the University of Tennessee, Knoxville. Ciez has accepted a position as assistant professor in mechanical engineering and environmental and ecological engineering at Purdue University.

"There really hasn't been any comprehensive lookback to day one of the standards to consider what their impacts have been, how they changed over time, whether the potential threats to their effectiveness materialized or not, and their overall impact," said Greene.

The researchers noted that the policies helped, in part, to keep the rate of yearly growth in U.S. gasoline consumption to 0.2% since 1975. The policy, in addition to fluctuations in gas prices, reduced oil imports and saved 2 trillion gallons of gasoline, enough to fuel all the light-duty vehicles in the United States for fifteen years.

"These standards have been remarkably effective from both an environmental perspective and an energy security perspective, and most people don't realize it," said Greenwald.

The authors said these types of regulations are more effective at improving fuel economy than other policy tools, like a gasoline tax, because they don't rely on the consumer to make the long-term fuel-efficient choice and, therefore, gain cost benefits at the pump. The fuel economy standards move the calculation to regulators and require that manufacturers improve fuel economy across their product lines using technologies that may cost a little more but save consumers much more on fuel in the long run.

A prior study by Greene found that over the lifetime of the policy, the technology for efficiency upgrades increased the cost of cars by an average of $4,800, but yielded $16,000 in savings for consumers at the pump.

Dan Sperling, founding director of the Institute of Transportation Studies at the University of California, Davis, who is unaffiliated with the study, called it an "important and authoritative history and analysis." "There is nothing like this in the literature," said Sperling, who is also the Distinguished Blue Planet Prize Professor of Civil Engineering and Environmental Science and Policy at UC, Davis and a member of the California Air Resources Board.

Greenwald said the standards have evolved in ways that continue to benefit and serve the public and have endured various administrations and political tides. It is a testament to their initial design, as well as regulators' adaptive responses to changing circumstances over time. In 2010, two sets of vehicle standards affecting automakers, one for greenhouse gas emissions and one for fuel efficiency, were harmonized so that manufacturers could meet one set of standards when designing new vehicles.

The analysis concludes with a recommendation to continue to increase the stringency of the standards based on the best available data and analysis, as regulators have done historically. The most recent rules promulgated by the Trump administration aim to loosen the fuel efficiency requirements by dropping the annual efficiency increase from five percent to one and a half percent through 2026. Given that transportation is the largest source of U.S. greenhouse gas emissions (GHG) and that people keep their cars for approximately 10 years, this would severely stymie environmental progress, the researchers said. The Rhodium Group, an independent research organization unaffiliated with the study, estimates that the policy change would achieve only one fifth of greenhouse gas reductions that the Obama-era policy would achieve.

Ciez pointed to the 1990s as an example of what can happen when fuel targets are effectively frozen. She said it led automakers to produce bigger, faster, and more polluting cars. Gas prices were cheap and gas-guzzling vehicles hit the road in mass numbers. Car companies made SUVs and vehicles with quicker acceleration times, which became very popular among American drivers. Ciez said without the standards, there is little incentive for automakers to focus on fuel economy as opposed to horsepower or vehicle comfort. The standards have spurred technological innovation, allowing cars to provide all three attributes - power, comfort, and efficiency - at a reasonable cost.

Regardless of the what happens over the next four years, Sperling said, the authors have provided "a model for assessing other policies."

In the closing statement the authors contextualized this moment in history.

"It is likely that the United States is in the middle, not the end, of the story of the adaptive response of the vehicle CAFE and GHG standards."

With many questions remaining around how children spread COVID-19, Children's National Hospital researchers set out to improve the understanding of how long it takes pediatric patients with the virus to clear it from their systems, and at what point they start to make antibodies that work against the coronavirus. The study, published Sept. 3 in the Journal of Pediatrics, finds that the virus and antibodies can coexist in young patients.

"With most viruses, when you start to detect antibodies, you won't detect the virus anymore. But with COVID-19, we're seeing both," says Burak Bahar, M.D., lead author of the study and director of Laboratory Informatics at Children's National. "This means children still have the potential to transmit the virus even if antibodies are detected."

She adds that the next phase of research will be to test if the virus that is present alongside the antibodies can be transmitted to other people. It also remains unknown if antibodies correlate with immunity, and how long antibodies and potential protection from reinfection last.

The study also assessed the timing of viral clearance and immunologic response. It found the median time from viral positivity to negativity, when the virus can no longer be detected, was 25 days. The median time to seropositivity, or the presence of antibodies in the blood, was 18 days, while the median time to reach adequate levels of neutralizing antibodies was 36 days. Neutralizing antibodies are important in potentially protecting a person from re-infection of the same virus.

This study used a retrospective analysis of 6,369 children tested for SARS-CoV-2, the virus that causes COVID-19, and 215 patients who underwent antibody testing at Children's National between March 13, 2020, and June 21, 2020. Out of the 215 patients, 33 had co-testing for both the virus and antibodies during their disease course. Nine of the 33 showed presence of antibodies in their blood while also later testing positive for the virus.

Also of note, researchers found patients 6 through 15 years old took a longer time to clear the virus (median of 32 days) compared to patients 16 through 22 years old (median of 18 days). Females in the 6-15 age group also took longer to clear the virus than males (median of 44 days for females compared to median of 25.5 days for males).

Although there is emerging data regarding this timing in adults with COVID-19, there is far less data when it comes to the pediatric population. The findings being gathered by Children's National researchers and scientists around the world are critical to helping understand the unique impact on children and their role in viral transmission.

"The takeaway here is that we can't let our guard down just because a child has antibodies or is no longer showing symptoms," says Dr. Bahar. "The continued role of good hygiene and social distancing remains critical."