Culture

Leesburg, VA, October 9, 2020--According to an article in ARRS' American Journal of Roentgenology (AJR), the imaging findings of in situ pulmonary artery thrombosis (PAT) associated with radiation therapy (RT) are different from those of acute pulmonary emboli and do not appear to embolize. Due to the differences in clinical prognosis and subsequent management strategies, in situ PAT associated with RT--"which to our knowledge has not previously been described in the English literature," wrote the authors of this AJR article--must be distinguished from pulmonary embolism.

Searching the radiology database of a large teaching hospital to identify patients who had PAT develop after receiving RT, first author Jitesh Ahuja from the thoracic imaging department at the University of Texas' MD Anderson Cancer Center recorded the PAT's CT characteristics: number, location, appearance of filling defects, as well as the presence of associated lung fibrosis. The terminology (in situ thrombosis vs acute or chronic pulmonary embolism) used to describe PAT, the time between completion of RT and development of PAT, the size change of PAT, and any observation of new thrombi and emboli on follow-up imaging were also recorded.

With a study population consisting of 27 patients (19 men and eight women) at a mean age of 71 (range, 54-90 years), the primary malignancy was lung cancer in 22 patients (81%) and mesothelioma in five patients (19%). Whereas most PATs were solitary (93%) and nonocclusive (96%) and formed an obtuse angle to the vessel wall (89%), all PATs were eccentric within the involved pulmonary artery and located within the RT volume. The time from completion of RT to initial diagnosis of PAT on CT ranged from 53 to 2,522 days (mean, 675 days). In all patients, CT findings of radiation-induced lung fibrosis were present in the lung supplied by the affected pulmonary artery. "On follow-up imaging, none of the patients were observed to have filling defects develop in other parts of the PA, which would have suggested embolization," Ahuja et al. added.

Acknowledging that RT is a "key choice" in multimodality treatment of intrathoracic malignancies, the authors noted that RT-associated cardiovascular complications remain the leading non-cancer-related cause of morbidity and mortality among cancer survivors. "Radiologist awareness of PAT can facilitate accurate diagnosis and impact management," they concluded.

A team of chemists from RUDN University suggested a new reaction to produce organic compounds in one vessel. The end products turned out to be effective against the cells of carcinomas, including drug-resistant ones. The new reaction was described in the Bioorganic Chemistry journal.

For many organic substances synthesis is a multistage process of step-by-step molecule assembly. At each stage, only one chemical bond is formed. After each step, the product is purified and used in the next reaction. Domino reactions are a cascade of reactions that happen one after another in one vessel without any additional reagents. A team of chemists from RUDN University in collaboration with University of Bari, identified a number of substances that initiate a domino synthesis of chromenoisoquinolineamine derivatives. Similar compounds are used as anti-inflammatory and antitumor drugs, and some of them can potentially treat Alzheimer's disease.

The team suggested using salicylaldehyde (a derivative of salicylic acid) and homophthalonitrile and catalyzing the reaction with ammonium formate that is cheap and eco-friendly. The initial reagents were mixed with water and isopropyl alcohol and put into a microwave reactor where the mixture was heated up to 150°C for 20 minutes. The researchers used salicylaldehydes with different substituents and as a result, received 19 derivatives of chromenoisoquinolineamines with 43-85% yields of respective reaction products.

To analyze the medical potential of the new substances, the chemists tested their effect on human cancerous cells. Cisplatin that is used in chemotherapy and is known to kill tumor cells was taken as a benchmark for comparison. The team chose the cells of breast and colon cancers, as well as three strains of ovary cancer cells (two of which were cisplatin-resistant) for the test. All new substances turned out to be toxic for tumor cells, including the resistant strains. The researchers selected two compounds that proved to be efficient even in low concentrations and ran computer modeling. According to it, the reason for their efficiency was an additional amine group that forms a stable bond with the nucleotides of the cancer cells DNA.

"In our work, we searched for new compounds with promising therapeutic properties, as well as for ways to synthesize them. Our approach allows for the synthesis of tumor-combating substances in the course of one domino reaction that is extremely efficient: four new bonds are created within one synthetic operation. We worked together with our Italian partners, and the study was supported by the Russian Science Foundation. In the future, we plan to improve our methodology and develop three- and four-component reactions on its basis," said Alexey Festa, a Candidate of Chemical Sciences, and a senior lecturer at the Department of Organic Chemistry, RUDN University.

Banyan trees are fig trees that begin their life as an epiphyte. The most noticeable feature of banyan Ficus species is their extraordinary aerial roots, which enable them to live as hemi-epiphytes, as do the strangler figs often seen in tropical forests.

Being special for their enclosed urn-shaped inflorescence, fig plants rely on specific insect pollinators (fig wasps) for pollination and, in turn, provide nourishment and shelter for pollinators to reproduce. Morphological matching and signaling communication for host location between figs and their pollinators is required for successful pollination and oviposition.

This obligate mutualism is a fascinating case of extreme plant-insect codiversification.

In a study published in the journal Cell, researchers from Fujian Agriculture and Forestry University (FAFU) and the Xishuangbanna Tropical Botanical Garden (XTBG) provided insights into fig-wasp coevolution through comparative analyses of two Ficus genomes - one with aerial roots and one without, one monecious and one dioecious, as well as the genome of a coevolving wasp pollinator. They also sequenced more samples of figs and pollinators.

The researchers sequenced genomes of the monecious Chinese banyan tree, F. microcarpa, and a dioecious species lacking aerial roots, F. hispida, and one wasp genome coevolving with F. microcarpa, Eupristina verticillata. Comparative analysis of the two Ficus genomes revealed dynamic karyotype variation associated with adaptive evolution.

"We quantified endogenous auxin in F. microcarpa and F. hispida, and proposed that an auxin-dependent pathway promoted by light is associated with aerial root initiation, growth, and pattern formation," said WANG Gang, associate professor at XTBG and co-first author of the study.

Furthermore, the researchers constructed an ultra-density F1 paternal genetic map and Hi-C chromosome for studying sex determination and sex evolution in Ficus plants. They found a nascent Y chromosome in F. hispida and a male-specific AGAMOUS paralog, the FhAG2 gene, as a candidate sex determination gene of this fig species.

"We also established a phylogeny of Ficus by using data from resequenced genomes of 112 Ficus accessions comprising 62 Ficus species. Our phylogenetic analysis revealed that monoecy represents the ancestral reproductive system across the genus," noted the study.

Lastly, the researchers investigated a potential molecular mechanism of coevolution between 14 fig species of the subgenus Sycomorus and their obligate pollinator wasps. They identified candidate genes that had undergone selection, and the species-specific signaling compounds that were essential for communication in three fig-wasp species pairs.

"Population genomic analysis of subgenus Sycomorus figs and their obligate pollinator wasps and electrophysiological testing of pollinators responding to floral scents emitted from three different Ficus species support the important roles of the mevalonate and shikimate pathways in attracting species-specific pollinators and reveal potential molecular mechanisms of codiversification in this obligate mutualism," said WANG.

"The work, integrating efforts from several universities and institutes from China and overseas, particularly the expertise on genomic analysis from FAFU and fig biology from XTBG, will enhance our understanding of the species-specific mutualism between figs and fig wasps," said CHEN Jin, one of the corresponding authors of the study.

As of October 2020, SARS-CoV-2 causes an ongoing pandemic, with more than 35 million reported cases and more than 1 million deaths worldwide. One prominent feature that distinguishes COVID-19 from SARS in terms of immune responses is the poor induction of a type I interferon (IFN) response by SARS-CoV-2 compared to SARS-CoV and influenza A virus. Notably, impaired IFN responses are associated with COVID-19 disease. However, the molecular mechanisms underlying the inefficient IFN responses in SARS-CoV-2 infection remain unclear.

A research team at The Institute of Medical Science, The University of Tokyo (IMSUT) aimed to characterize the viral factor(s) determining immune activation upon SARS-CoV-2 infection and found that ORF3b, a gene encoded by SARS-CoV-2, is a potent IFN antagonist.

"The poor IFN responses in COVID-19 patients may be explained by the action of this viral product, ORF3b", said the lead scientist, Kei Sato, Associate Professor (Principal Investigator) at Division of Systems Virology, Department of Infectious Disease Control, IMSUT.

The results of this research were published in "Cell Reports" on September 4, 2020.

ORF3b as a viral IFN antagonist

Although SARS-CoV infection causes acute and severe pneumonia, SARS-CoV-2 infection may be asymptomatic or result in flu-like symptoms such as fever, cough and fatigue. Also, compared to SARS-CoV and influenza A virus infections, a hallmark of SARS-CoV-2 infection, COVID-19, is the poor induction of a type I interferon (IFN). Notably, impaired IFN responses are associated with the severity of COVID-19. However, the molecular mechanisms underlying the inefficient IFN responses in SARS-CoV-2 infection remain unclear.

By comparing the sequences of SARS-CoV-2-encoding genes to those of SARS-CoV, the research group found that the gene length of SARS-CoV-2 ORF3b is markedly shorter than that of SARS-CoV ORF3b.

Because ORF3b of SARS-CoV is known as a viral antagonist against IFN production, they hypothesized that the difference on the length of ORF3b gene between SARS-CoV-2 and SARS-CoV may alter their anti-IFN activity and further may explain the difference in the symptoms of these two viral infections.

Surprisingly, SARS-CoV-2 ORF3b is a more potent IFN antagonist than SARS-CoV ORF3b. Phylogenetic analyses and functional assays revealed that SARS-CoV-2-related viruses from bats and pangolins also encode shorter ORF3b gene products with strong anti-IFN activity.

Characterization of a natural SARS-CoV-2 ORF3b variant with enhanced anti-IFN activity

Furthermore, analyses of approximately 17,000 SARS-CoV-2 sequences identified a natural variant, in which a longer ORF3b reading frame was reconstituted. This variant suppresses IFN even more efficiently than ORF3b of the parental SARS-CoV-2 strain.

In agreement with an association of IFN suppression with disease severity, the two patients in Ecuador harboring SARS-CoV-2 with the extended ORF3b variant were critically ill; one was treated in an intensive care unit and the other one died of COVID-19.

Importantly, however, there is no direct evidence indicating that the viruses detected in these two COVID-19 patients in Ecuador are more pathogenic than the reference strain. Although they cannot tell whether this variant is associated with a different outcome in disease, it is plausible that naturally occurring length variants of ORF3b can potentially contribute to the emergence of more pathogenic SARS-CoV-2 variants.

Thus, it will be important to continue monitoring viral sequences to see whether novel ORF3b variants emerge during the current pandemic.

Associate Professor Kei Sato said that "To our knowledge, this study is the first investigation revealing the role of a SARS-CoV-2-encoded protein that can be associated with the progression of COVID-19".

Being a man, having a lower income, having a lower level of education, not being married, and being born abroad in low- or middle-income countries - these are factors that, independent of one another, are related to an elevated risk of dying from COVID-19 in Sweden. These are the findings of a new study in the journal Nature Communications from Stockholm University.

"We can show that there are independent effects of various separate risk factors that have been brought up in debates and news about COVID-19. All of these factors are accordingly individually associated with a strongly elevated risk of dying from COVID-19," said Sven Drefahl, Associate Professor of Demography at Stockholm University Demography Unit in the Department of Sociology, and main-author of the study.

When it comes to the elevated risk for people from low- and middle-income countries in, for example, the Middle East and North Africa of dying from COVID-19, it does not agree with the general patterns of mortality for that group. Sven Drefahl explains that those born abroad generally have a lower mortality than people born in Sweden. This also applies when the research took income and level of education into account. The elevated risk of dying from COVID-19 for this group remains after the researchers controlled for circumstances, such as income and level of education. The study also shows that the risk of dying from COVID-19 was much higher in the Stockholm area than outside, both for those born in Sweden and those born abroad, which can be explained by the spread of disease being greater in that area.

The study shows that being a man, having a lower income and lower level of education also result in a strongly elevated risk of dying from COVID-19. As to these aspects, this also agrees with the patterns for mortality from other diseases.

"Men generally have a higher mortality at comparable ages, which is considered to be due to a combination of biology and lifestyle. The fact that people with little education or a low income have a higher mortality may largely be due to lifestyle factors including finances -how much one can afford to prioritise one's health. Similarly, we can explain the elevated mortality from COVID-19 for these groups," said Gunnar Andersson.

A number of earlier studies have also shown that single and unmarried people have a higher mortality from various diseases. This is usually to some part explained by selection, meaning that people who have worse health from the beginning are less attractive on the partner market and therefore get married to a lesser degree.
"The explanation is also considered to be in singles having a less protected environment than those who live in a couple relationship. Accordingly, marriage can lead to a healthier life with a lower risk of disease than for the unmarried. This can also explain the elevated risk of dying from COVID-19 for unmarried individuals shown by our study," said Sven Drefahl.

Facts: How the study was done

The study is based on data from the Swedish National Board of Health and Welfare on all registered deaths from COVID-19 in Sweden for adults aged 20 and older, until 7 May 2020. This was combined with register data from Statistics Sweden on city of residence, marital status, country of birth, income, level of education and age. The research is being funded by Forte, the Swedish Research Council for Health, Working Life and Welfare.

Facts: Mortality from COVID-19

Men had more than twice as high a risk of dying from COVID-19 than women.

Unmarried men and women (including those never married, widows/widowers and the divorced) had a 1.5-2 times as high a risk of dying from COVID-19 as those who were married.

Living in the Stockholm area was linked to a 4.5 times as high risk of dying from COVID-19 (for both men and women) compared with the rest of the country.

Those born abroad from low- and middle-income countries in the Middle East and North Africa had twice as high a mortality from COVID-19 for women and 3 times as high for men compared with people born in Sweden.

Those born abroad from low- and middle-income countries outside the Middle East and North Africa had a more than 1.5 times as high mortality from COVID-19.

Men with a compulsory-school and upper-secondary education ran an approximately 25 per-cent higher risk of dying from COVID-19 compared with men with post-upper-secondary education.

Women with a compulsory-school and upper-secondary education ran a 40-50 per-cent higher risk of dying from COVID-19 compared with women with post-upper-secondary education.

FAYETTEVILLE, Ark. -University of Arkansas researchers have established a link between climate patterns in the Amazon and large parts of North and South America using their newly developed tree-ring chronology from the Amazon River basin.

The discovery helps researchers better understand large-scale climate extremes and the impact of the El Niño phenomenon.

Tree growth is a well-established climate proxy. By comparing growth rings in Cedrela odorata trees found in the Rio Paru watershed of the eastern Amazon River with hundreds of similar chronologies in North and South America, scientists have shown an inverse relationship in tree growth, and therefore precipitation patterns, between the areas. Drought in the Amazon is correlated with wetness in the southwestern United States, Mexico and Patagonia, and vice versa.

The process is driven by the El Niño phenomenon, which influences surface-level winds along the equator, researchers said. El Niño is the name given to a large-scale irregularly occurring climate pattern associated with unusually warm water in the Pacific Ocean.

"The new Cedrela chronologies from the Amazon, when compared with the hundreds of tree-ring chronologies in temperate North and South America, document this Pan American resonance of climate and ecosystem extremes in the centuries before widespread deforestation or human-caused climate change," said Dave Stahle, Distinguished Professor of geosciences and first author of a study documenting the findings in the journal Environmental Research Letters.

The connection was not documented until researchers at the University of Arkansas Tree Ring Laboratory, along with colleagues from Brazil and Argentina, developed rainfall reconstructions from growth rings in Cedrela trees. Most rainfall records in the Amazon only date back about 70 years, but Cedrelas live for 200 to 300 years, providing valuable rainfall proxies that pre-date human-influenced climate change. Their work in the Amazon is documented in a short video, and also on a dedicated web site.

In the past 40 years, drought and flood extremes have increased in the Amazon basin, the researchers noted, raising the question of whether human-induced climate change and deforestation are affecting Amazon climate. While that remains an open question, the longer Cedrela-based precipitation record indicates that periods of rainfall extremes occurred in the past and the current extremes might be partly due to natural climate rhythms.

The study will help researchers better understand an area of unequaled biodiversity. The Amazon is home to an estimated 16,000 species of trees and one-tenth of all known species found on the planet, Stahle noted. "The long climate history written in the growth rings of old Cedrela trees in Amazonia will surely be important to the sustainability of the biome."

Meltwater lakes that form at glacier margins cause ice to recede much further and faster compared to glaciers that terminate on land, according to a new study. But the effects of these glacial lakes are not represented in current ice loss models, warn the study authors.

Therefore, estimates of recession rates and ice mass loss from lake-terminating glaciers in the coming decades are likely to be under-estimated.

Many mountain glaciers now terminate in such lakes, formed as meltwater becomes trapped behind ridges of glacier debris. They are known as proglacial lakes. Climate change has increased glacier melt worldwide and this in turn has led to a dramatic increase in the size and number of proglacial lakes. But the effects of proglacial lakes on the rates of deglaciation and on glacier behaviour have previously been poorly understood.

Now, an international team of researchers, led by the University of Leeds, has quantified for the first time the influence of proglacial lakes on mountain glaciers using computer simulations. They found that the presence of a proglacial lake causes a glacier to recede more than four times further and accelerate ice flow by up to eight times when compared to the same glacier terminating on land under the same climate.

The findings, published today in the journal Geophysical Research Letters, show that a land-terminating glacier took 1000 years to succumb to the same amount of recession as a lake-terminating glacier experienced in 100 years.

Study lead author Dr Jenna Sutherland undertook this research while a PhD candidate in the School of Geography at Leeds. She said: "An ice cube in a bowl of water is going to melt much more quickly than an ice cube sitting on a table, and the effect proglacial lakes have on glacier ice is roughly the same.

"The simulations show that the influence of a proglacial lake on a glacier predominantly takes place over decades to centuries rather than over millennia, meaning the glacier recedes much faster than it ever could from climatic changes alone."

Study co-author Dr Jonathan Carrivick, a senior lecturer in geomorphology at Leeds, said: "Our findings suggest that simulations of past, contemporary or future glaciers ignore the effects of ice-contact lakes and will likely mis-represent the timing and rate of recession, especially the changes to the timing and rate that will occur once a proglacial lake forms.

"This effects need to be included in all future models and simulations if we are to have an accurate global picture of glacial ice loss."

The team used the BISICLES ice-flow model, to analyse the effects of a proglacial on the Pukaki Glacier, New Zealand, during recession from the end of the last ice age.

Study co-author James Shulmeister from the University of Canterbury, New Zealand said: "While this study focussed on New Zealand, proglacial lakes are prevalent during glacial retreat worldwide and this paper should therefore be of global interest and importance."

In addition, he noted: "This study is also critical because the timing of ice retreat is often used to determine the synchrony or lack thereof of in climate events globally. Major inferences have been made about the roles of phenomena like oceanic circulation in affecting the global climate system from glacial retreat timings. If the timings are wrong, the relationship between these processes may need to be re-examined."

Providing adequate personal protective equipment (PPE) for all health care workers around the world requires an initial investment of billions of dollars, but the returns on that investment could be close to 8000% in productivity gains, according to a new study published this week in the open-access journal PLOS ONE by Nicholas Risko of the Johns Hopkins University School of Medicine and colleagues.

As COVID-19 spread around the world in early 2020, even resource-rich health systems experienced supply shortages of PPE to protect frontline health care workers. Over 80% of the world's population lives in low- and middle-income countries (LMICs) where fragile health systems with few resources make health care workers particularly vulnerable to PPE shortages and COVID-19 infection.

In the new study, researchers calculated the cost of providing PPE to all LMIC health systems and used a model to compare the costs and effects of two PPE use scenarios for all LMICs. Data from the World Health Organization COVID-19 Essential Supplies Forecasting Tool was used, as well as estimates of national mortality and hospitalizations that had been previously calculated and published.

The model predicted that an initial global investment of $9.6 billion U.S. could save the lives of roughly 2.2 million health care workers by providing adequate PPE. This comes out to $59 dollars per case averted and $4,309 per life saved. The benefit to society yields $755.3 billion dollars, or about an 8,000% return. The largest net economic gains would be seen in the East Asia & Pacific region, South Asia, and Sub-Saharan Africa. In addition, the study shows that scaling up the provision of PPE is a required component of national strategy if the health care workforce is to be protected.

The authors add: "This study predicts the impact of supplying front-line health care workers in low and middle-income countries with protective equipment during the COVID-19 pandemic. Our central finding is that a small upfront investment will save many lives and provide a substantial economic return, whereas neglecting to protect health care workers risks heavy losses due to illness and death."

Should I or shouldn't I? The activity of individual nerve cells in the brain tells us how confident we are in our decisions. This is shown by a recent study by researchers at the University of Bonn. The result is unexpected - the researchers were actually on the trail of a completely different evaluation mechanism. The results are published in the journal Current Biology.

You are sitting in a café and want to enjoy a piece of cake with your cappuccino. The Black Forest gateau is just too rich for you and is therefore quickly eliminated. Choosing between the carrot cake and the rhubarb crumble is much trickier: The warm weather favors the refreshingly fruity cake. Carrot cake, however, is one of your all-time favorites. So what to do?

Every day we have to make decisions, and we are much more confident about some of them than others. Researchers at the University Hospital Bonn have now identified nerve cells in the brain whose activity indicates the confidence in decisions. A total of twelve men and women took part in their experiment. "We showed them photos of two different snacks, for example a chocolate bar and a bag of chips," explains Prof. Dr. Dr. Florian Mormann from the Department of Epileptology. "They were then asked to use a slider to indicate which of these alternatives they would rather eat." The more they moved the slider from its center position towards the left or right photo, the more confident they were in their decision.

Fire rate and confidence are related

Participants had to judge a total of 190 different snack pairs in this way. At the same time, the scientists recorded the activity of 830 nerve cells each in the so-called temporal lobe. "We discovered that the frequency of the electrical pulses in some neurons, in other words their 'firing rate', changed with increasing decision confidence," explains Mormann's colleague Alexander Unruh-Pinheiro. "For instance, some fired more frequently, the more confident the respective test person was in their decision."

It is the first time that such a correlation between activity and decision confidence has been identified. The affected neurons are located in a brain region that plays a role in memory processes. "It is possible that we not only store what decision we made, but also how confident we were in it," speculates Mormann. "Perhaps such a learning process saves us from future wrong decisions."

Ethical reasons usually prohibit the study of the state of individual neurons in living humans. However, the participants in the study suffered from a severe form of epilepsy. In this form of the disease, the characteristic seizures always start in the same area of the brain. One possible treatment is therefore to remove this epileptic focus surgically. To pinpoint the exact location of the defective site, the doctors at the Clinic for Epileptology implant several electrodes in the patient. These are distributed over the entire potentially affected area. At the same time, they also allow an insight into the functioning of individual nerve cells in the brain.

Researchers at the University of Bonn were originally looking for a completely different phenomenon: When we make a decision, we assign a subjective value to each of the alternatives. "There is evidence that this subjective value is also reflected in the activity of individual neurons," says Mormann. "The fact that we instead came across this connection between fire behavior and decision confidence surprised even us."

NASA's extensive fleet of spacecraft allows scientists to study the Sun extremely close-up - one of the agency's spacecraft is even on its way to fly through the Sun's outer atmosphere. But sometimes taking a step back can provide new insight.

In a new study, scientists looked at sunspots - darkened patches on the Sun caused by its magnetic field - at low resolution as if they were trillions of miles away. What resulted was a simulated view of distant stars, which can help us understand stellar activity and the conditions for life on planets orbiting other stars.

"We wanted to know what a sunspot region would look like if we couldn't resolve it in an image," said Shin Toriumi, lead author on the new study and scientist at ?the Institute of Space and Astronautical Science at JAXA. "So, we used the solar data as if it came from a distant star to have a better connection between solar physics and stellar physics."

Sunspots are often precursors to solar flares - intense outbursts of energy from the surface of the Sun - so monitoring sunspots is important to understanding why and how flares occur. Additionally, understanding the frequency of flares on other stars is one of the keys to understanding their chance of harboring life. Having a few flares may help build up complex molecules like RNA and DNA from simpler building blocks. But too many strong flares can strip entire atmospheres, rendering a planet uninhabitable.

To see what a sunspot and its effect on the solar atmosphere would look like on a distant star, the scientists started with high-resolution data of the Sun from NASA's Solar Dynamics Observatory and JAXA/NASA's Hinode mission. By adding up all the light in each image, the scientists converted the high-resolution images into single datapoints. Stringing subsequent datapoints together, the scientists created plots of how the light changed as the sunspot passed across the Sun's rotating face. These plots, which scientists call light curves, showed what a passing sunspot on the Sun would look like if it were many light-years away.

https://www.youtube.com/watch?v=QJc1G8Zuqo8

"The Sun is our closest star. Using solar observing satellites, we can resolve signatures on the surface 100 miles wide," said Vladimir Airapetian, co-author on the new study and astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "On other stars you might only get one pixel showing the entire surface, so we wanted to create a template to decode activity on other stars."

The new study, published in the Astrophysical Journal, looked at simple cases where there is just one group of sunspots visible across the entire face of the Sun. Even though NASA and JAXA missions have continually gathered observations of the Sun for over a decade, these cases are quite rare. Usually there are either several sunspots - such as during the solar maximum, which we are now moving toward - or none at all. In all the years of data, the scientists only found a handful of instances of just one isolated sunspot group.

Studying these events, the scientists found the light curves differed when they measured different wavelengths. In visible light, when a singular sunspot appears at the center of the Sun, the Sun is dimmer. However, when the sunspot group is near the edge of the Sun, it's actually brighter due to faculae - bright magnetic features around sunspots - because, near the edge, the hot walls of their nearly vertical magnetic fields become increasingly visible.

The scientists also looked at the light curves in x-ray and ultraviolet light, which show the atmosphere above the sunspots. As the atmospheres above sunspots are magnetically heated, the scientists found brightening there at some wavelengths. However, the scientists also unexpectedly discovered that the heating could also cause a dimming in the light coming from the lower temperature atmosphere. These findings may provide a tool to diagnose the environments of spots on the stars.

"So far we've done the best-case scenarios, where there's only one sunspot visible," Toriumi said. "Next we are planning on doing some numerical modeling to understand what happens if we have multiple sunspots."

By studying stellar activity on young stars in particular, scientists can glean a view of what our young Sun may have been like. This will help scientists understand how the young Sun - which was overall more dim but active - impacted Venus, Earth and Mars in their early days. It could also help explain why life on Earth started four billion years ago, which some scientists speculate is linked to intense solar activity.

Studying young stars can also contribute to scientists' understanding of what triggers superflares - those that are 10 to 1000 times stronger than the biggest seen on the Sun in recent decades. Young stars are typically more active, with superflares happening almost daily. Whereas, on our more mature Sun, they may only occur once in a thousand years or so.

Spotting young suns that that are conducive to supporting habitable planets, helps scientists who focus on astrobiology, the study of the origin evolution, and distribution of life in the universe. Several next generation telescopes in production, which will be able to observe other stars in x-ray and ultraviolet wavelengths, could use the new results to decode observations of distant stars. In turn, this will help identify those stars with appropriate levels of stellar activity for life - and that can then be followed up by observations from other upcoming high-resolution missions, such as NASA's James Webb Space Telescope.

In Salt Lake City schools, absences rise when the air quality worsens, and it's not just in times of high pollution or "red" air quality days--even days following lower levels of pollutions saw increased absences.

Research is still ongoing, and the evidence isn't yet conclusive enough to draw a cause-and-effect relationship between air quality and children's absences from school but the correlation, according to Daniel Mendoza, a research assistant professor in the Department of Atmospheric Sciences and visiting assistant professor in the Department of City & Metropolitan Planning, merits further exploration. Mendoza and his colleagues published their results in Environmental Research Letters.

Air pollution is harmful for not only the health, but also the education and well-being of children in our community," says study co-author Cheryl Pirozzi, assistant professor in the Division of Respiratory, Critical Care, and Occupational Pulmonary Medicine. "Even at relatively low levels that many people would not think to be harmful air pollution is associated with increased school absences."

"Any pollution is bad," Mendoza says. "And these lower levels of pollution, which are still harmful to our health, have been understudied."

The correlation

Mendoza, who also holds appointments as adjunct assistant professor in the Pulmonary Division at the School of Medicine and as senior scientist at the NEXUS Institute, and his interdisciplinary colleagues looked at absence data from 36 schools in the Salt Lake City School District and compared them with ozone and air particulate matter levels in those neighborhoods from 2015 to 2018.

This kind of neighborhood-level air quality modeling requires a network of research-quality air sensors, and such a network has been building in the Salt Lake Valley over the last several years, operated by the U and by the state Division of Air Quality. That network includes mobile sensors on light rail trains as well as stationary research and regulatory grade sensors.

"These are critical because now we can see small nuances, small differences across neighborhoods," Mendoza says. "Now we can see how one school, for example, had slightly higher or slightly lower values of ozone and particulate matter. And now, instead of looking at the difference between green and yellow days, we can actually see small amounts of variability because of the density of our networks."

To understand the findings, it's important to first review how air quality conditions are reported. Particulate matter is most often reported as PM2.5, or the amount of particulate matter with a diameter less than 2.5 microns. These particles can reach the deepest parts of our lungs and may actually pass into our bloodstream. The unit of measurement is micrograms per cubic meter (μg/m3). Ozone is a molecule made from three oxygen atoms and is highly reactive, damaging the respiratory and circulatory systems. It's reported in parts per billion (ppb).

Although the study looked at elementary, middle and high schools, the authors write that elementary students may be most vulnerable to health effects from air pollution.

"Children are particularly susceptible to the health effects of air pollution," Pirozzi says, "and it is possible that health effects, such as respiratory tract infections or asthma exacerbations, may lead to them missing more school, which can have long-term consequences for them."

Across the school district, they found, school absences increased by 1.04 per μg/m3 of particulate matter and by 1.01 per ppb of ozone, even at levels of air pollution that aren't considered harmful. The worst increase in absences happened the day after high pollution exposure - possibly because reactions to high pollution might reduce exposure and prevent further absences. But on days after low, yet still elevated, pollution, absences continued to rise on the third, fourth and fifth days of exposure--suggesting a cumulative exposure effect, Mendoza says.

"So what that really leads us to think is that even low levels of poor air quality can, in a cumulative manner lead to negative health outcomes--in this case increased school absences. Even on green air quality days, when the pollution was just slightly elevated, if we had several of those days, then kids would still be absent."

Additionally, the researchers write that there may be a disparity between eastside and westside schools. Schools on the west side, with a higher proportion of residents from minority groups, already have a higher rate of absences than the comparatively more affluent east side and are slightly more affected by the same level of pollution. The disparity isn't yet statistically significant, and Mendoza hopes that an interdisciplinary team can further study these socioeconomic factors.

Mendoza acknowledges that there may be more factors at play that could account for some of the absences. Poor air quality days in the winter tend to be colder days, for example, and some children might stay home to stay out of the cold.

"So we're not saying that this is all due to poor air quality," he says. "We do know that there are more social and demographic variables at play here, but we already know the best way to estimate the pollution is in your zip code is by quantifying the percent of minority residents."

The costs

Absences come at a cost to schools, families and the larger economy. As part of the study, the researchers tried to estimate those costs.

First, the cost to schools. Using average per-pupil spending, the authors found that the state spends $41.30 per student per day--funding that doesn't benefit a student who's absent.

Next, the cost to families. Often a child staying home from school means a parent staying home from work. At an average hourly wage of $23.74, an absence can cost an hourly worker close to $200 a day. For families who receive free or reduced lunch, the cost of food then reverts to the family on days home.

And there are costs to the larger economy as well. Factoring in lost wages, lost taxes and lost productivity due to absences, reducing air pollution by 50 percent could save Utah's economy around $426,000 per year just from reducing absences in the Salt Lake School District. This result, the authors say, shows how reducing school absenteeism can and should be considered a benefit of improving air quality in the Salt Lake Valley.

"This is definitely not negligible," Mendoza says. "This is a real definite number, very close to half a million dollars in terms of income that does not need to be lost."

Find the full study here.

In June, two studies in Science reported an antibody cocktail against SARS-CoV-2 developed from studies in humanized mice and recovering patients. The two antibody cocktail was designed to bind the virus to reduce the risk of a drug-resistant form emerging. Now, expanding upon this work, researchers show this antibody cocktail offers benefits in animal models that mimic the diverse pathology of SARS-CoV-2 infection, both when administered prophylactically and therapeutically. "These findings highlight the therapeutic potential of [this approach] to both protect from and treat SARS-CoV-2 disease," the authors say. While multiple studies have described discovery and characterization of potent neutralizing monoclonal antibodies against SARS-CoV-2, evaluation of the efficacy of these antibodies in vivo is limited, and it's largely focused on the prophylactic setting. As well, no single animal model has emerged as being more relevant for human disease, which has led some to say multiple animal models may be required to mimic various settings of human infection. Building on studies Johanna Hansen et al. and Alina Baum et al. published in Science in June that identified and characterized a double antibody therapy, Baum and colleagues tested this cocktail, REGN-COV2, in rhesus macaques, which manifest mild COVID-19 symptoms, and in golden hamsters, which show symptoms that are much more severe, including rapid weight loss. When administered three days before viral challenge, treatment almost completely blocked establishment of viral infection in macaques, the authors say. This ability, they note, "matches or exceeds the effects recently shown in vaccine efficacy studies using the same animal models." In macaques treated with the drug one day after infection, the authors report faster viral clearance than in controls who'd not been treated. Next, the authors used the hamster model to evaluate the drug's ability to alter the disease course in more severe cases. Hamsters treated with the drug two days before infection exhibited a "dramatic protection from weight loss" and decreased viral load in the lungs, the authors report. They also report benefits for hamsters treated one day after infection, as compared to controls. "In conclusion," say the authors, "our data provide evidence that REGN-COV2 based therapy may offer clinical benefit in both prevention and treatment settings of COVID-19 disease, where it is currently being evaluated."

Antibodies in serum samples collected from patients infected with SARS-CoV during the 2003 outbreak effectively neutralized SARS-CoV-2 infection in cultured cells, according to a new study. The authors also report that, surprisingly, mice and rabbits immunized with a receptor binding domain (RBD) from a strain of SARS-CoV that infects the Himalayan palm civet elicited stronger antibody responses against SARS-CoV-2 than animals immunized with an RBD from a human SARS-CoV strain. The authors suggest that their findings may inform strategies to develop universal vaccines against emerging and future coronaviruses. Yuanmei Zhu and colleagues analyzed 20 convalescent serum samples from patients infected with SARS-CoV, determining cross-reactivity for protein antigens derived from four regions of the SARS-CoV-2 spike protein, including the S ectodomain (S), S1 subunit, RBD, and S2 subunit. While all serum samples reacted strongly with the S and S2 proteins, they reacted more weakly with the S1 and RBD proteins. A separate test using a single-cycle infection assay determined that the convalescent SARS-CoV sera efficiently prevented both SARS-CoV and SARS-CoV-2 pseudoviruses (which cannot produce viral surface proteins on their own) from infecting cells, although they inhibited SARS-CoV-2 activity less efficiently. The researchers verified their findings in animals and specifically characterized the RBD's ability to mediate cross-reactivity in mice, since the RBD is the least conserved of the spike protein sites between the two viruses. They found that anti-RBD serum from SARS-CoV cross-reacted well with SARS-CoV-2, suggesting a key antigen component is genetically conserved in the RBD sites of the two viruses. Zhu et al. note that although antibody-dependent enhancement (when binding a virus to certain antibodies actually eases its entry into host cells) was not observed in this study, the effect should be addressed during vaccine development.

What The Study Did: This Viewpoint from the U.S. Food and Drug Administration puts into context recent guidance on clinical trials during COVID-19 for oncology and shares insight regarding regulatory challenges and lessons learned.

Authors: Anand Shah, M.D., of the FDA in Silver Spring, Maryland, is the corresponding author.

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

(doi:10.1001/jamaoncol.2020.4975)

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

Viewer preference for right-wing US TV media is linked to significantly fewer preventive measures against COVID-19 and behaviours likely to increase the risk of infection, finds research published in the online journal BMJ Global Health.

The media has a key role in disseminating health information. And to better understand the relationship between political bias in the media and health behaviours, the researchers wanted to find out if behaviours related to COVID-19 differed according to viewer trust in left-or right-wing TV media and whether these behaviours changed over time.

They drew on data from the Understanding America Study (UAS) COVID-19 Survey National Sample. This is an ongoing longitudinal national online survey of approximately 9000 US adults living independently.

UAS started tracking the impact of the pandemic on 10 March 2020. Follow-up surveys were issued every fortnight beginning 1 April 2020 (wave 2) to June 9 (wave 6).

Participants were asked about preventive behaviours over the past 7 days, such as hand-washing and use of face coverings, and about risky behaviours, including going out to a bar or club, attending gatherings of more than 10 people, and visiting other people's homes.

They were also asked how much they trusted 18 media sources for information on COVID-19, focusing primarily on the left wing CNN and the right wing Fox News, the two largest news outlets in the US.

And they were asked, which of 20 other sources of information they used, including professional bodies, social and traditional media, friends, family, colleagues, and the White House.

Some 4863 respondents who completed all five waves of the survey were included in the final analysis. Their responses were scored on a scale of 0-5 and added together.

Around 29% of the sample said they trusted CNN more than Fox; about half (52%) expressed no preference, and one in five (20%) said they trusted Fox more than CNN.

On average, respondents said they had used around 3 professional sources and around 6 other diverse sources to learn about the coronavirus in the preceding 7 days.

Analysis of the responses showed that people who trusted CNN were more likely to engage in preventive behaviours and less likely to report risky behaviours than those who trusted Fox News, at most time points.

Those who trusted Fox News more than CNN practised an average of 3.41 preventive behaviours, while people who trusted CNN more than Fox News practised 3.85. Fox News devotees also practised an average of 1.25 risky behaviours, while CNN fans engaged in 0.94 risky behaviours.

Health behaviours changed significantly over time, becoming more cautious, before relaxing as the pandemic unfolded. But once again, these changes varied by media preference, with the speed of change much faster among those who preferred Fox News.

People who trusted Fox News more than CNN consistently practised fewer preventive and more risky behaviours during waves 1 to 5, compared with those who trusted CNN more.

Those who expressed no media preferences practised significantly more preventive and fewer risky behaviours than those who trusted Fox News more during the last two survey waves. And they consistently exhibited significantly fewer preventive and more risky behaviours than those who trusted CNN more for all survey waves.

People aged 65 and above, women, those of non-Hispanic Asian ethnic backgrounds, and the most educated were all more likely to practise preventive behaviours, while those with a job but unable to work from home were least likely to do so.

Diversity of information was linked to more risky behaviours, while having more sources of professional information was linked to fewer risky behaviours.

This is an observational study, and as such, can't establish cause. But the findings echo those of other studies, say the researchers.

They propose two possible explanations, the first of which is that behaviours are influenced by politically "biased health messaging." Compared with CNN, Fox News "consistently downplayed the danger of the virus for the sake of political interest."

Alternatively, behaviours may be influenced by personal political beliefs, so media preference becomes a proxy for political preference instead of a source of information.

"Specifically, republican ideology has long been centred around the idea of individualism and an emphasis on personal freedom... Therefore, it is possible that people who trust Fox naturally prefer a more 'hands-off' approach and are more likely to refuse strict health policies such as self-quarantining and social distancing," the researchers suggest.

They conclude: "This study has many policy implications for the future progression of COVID-19 and health messaging in general. In a highly partisan environment, false information can be easily disseminated.

"Health messaging, despite being one of the few effective ways to slow down the spread of the virus in the absence of a vaccine, is doomed to fail if the media prioritise political interests over population health."