Culture

In a new analysis of SARS-CoV-2, the virus that causes COVID-19, test results for nearly 38,000 people has found a positivity rate among Latinx populations about three times higher than for any other racial and ethnic group. The findings, published June 18 in the Journal of the American Medical Association (JAMA), add to evidence that there are much higher COVID-19 infection rates among U.S. minorities, particularly in Latinx communities.

Researchers from the Johns Hopkins Center for Data Science in Emergency Medicine and the Johns Hopkins University School of Medicine's Department of Emergency Medicine and Division of Infectious Diseases collaborated on the study.

"We suspected socially and economically marginalized groups were being heavily impacted by COVID-19," says Diego A. Martinez, Ph.D., assistant professor of emergency medicine at the Johns Hopkins University School of Medicine, and one of the study report's authors. "Our study is believed to be among the first in measuring such differences in a diverse region."

The researchers concluded that crowded living conditions and continuous working at jobs due to economic necessity and essential worker status contributed to the higher rate of positive tests in the Latinx community.

"It is clear that the systematic exclusion of this population from health care services has contributed to the disparities we see today," says Kathleen R. Page, M.D., associate professor of medicine at the Johns Hopkins University School of Medicine, and a study member, who also cared for many of the patients. "This pandemic has taught us that we are all interconnected. At the very least, we must engage with communities early and provide language and culturally appropriate information and services, removing as many barriers to care as possible."

The investigators analyzed results of diagnostic tests performed between March 11 and May 25 across five Johns Hopkins Health System hospitals, including emergency departments and 30 outpatient clinics in the Baltimore-Washington area.

Out of 37,727 adults and children tested, 6,162 tests came back positive. Of those tests, the positivity rate for Latinx was 42.6%, significantly higher than those who identified as Black (17.6%); Other (17.2%); or white (8.8%). Overall, about half of those Latinx who tested positive were women and half were men, and most (61.5%) were between the ages of 18 and 44.

The study also found that the number of positive cases in each group peaked at different times: Latinx patient cases peaked later in the study period, on May 10 at 53.4%, compared with Black patients, among whom cases peaked on April 19 (29.6%), and white patients, on April 16 (16.1%). Researchers say that as testing volume in Maryland increased for all racial and ethnic groups, positivity rates declined.

Among those who tested positive, 2,212 were admitted to a Johns Hopkins Health System hospital. The study data show that Latinx patients were less likely to be admitted to the hospital (29.1%) compared with Black (41.7%) and white (40.1%) patients. Of the patients who were hospitalized, Latinx patients were younger (18 to 44 years); more likely to be male (64.9%); and had much lower rates of comorbidities, such as hypertension (44.8%), congestive heart failure (41.1%), pulmonary disease (20.7%) and chronic obstructive pulmonary disease (COPD) (19.2%) than Black or white patients. Eighty-two percent of Black patients and 70.4% of white patients had hypertension; 56.1% of Black patients and 56.6% of white patients had congestive heart failure; 32.9% of Black patients and 33.9% of white patients had pulmonary disease; and 27.9% of Black patients and 30% of white patients had COPD. However, more Black patients had diabetes (52.8%), compared with Latinx (32.8%) and white (29.6%) patients.

Page calls the findings "staggering." She says that a majority of the Latinx patients are often immigrants with limited English proficiency who work in low-wage, essential jobs, such as construction and cleaning. "Many of these patients tell me they delayed coming to the hospital until absolutely necessary because they were worried about medical bills, and were not sure if they could receive care because of their immigration status," she says. "Most of the patients I've met are not eligible for benefits, have no health insurance, and rent rooms in crowded houses. The need to work, lack of occupational protections and crowded living conditions have led to high transmission in this community."

While the Baltimore-Washington area represents a small subsection of the Latinx community, researchers suspect similar health disparities will be found elsewhere around the nation, but their degree and causes might differ -- depending on the region. "Knowing what is driving these health disparities in each region is much-needed evidence to develop tailored policies and interventions to better serve all of our people," Martinez says.

The researchers say their data are already informing practices and planning across the Johns Hopkins Health System, and they hope their findings lead to changes elsewhere to mitigate the spread of COVID-19 in minority populations. "Protecting Latinx individuals, building trust and reducing barriers to engagement in public health initiatives, such as providing equal protection for workers; reducing the threat of deportation; and performing charity care for those unable to afford health care and, should be essential as our nation grapples with strategies to contain the impact of COVID-19," Martinez says. He adds that local health officials will likely see higher success by engaging community-based organizations, such as churches, which have experience addressing concerns of the vulnerable Latinx population.

Researchers have found that rocky exoplanets which formed early in the life of the galaxy seem to have had a greater chance of developing a magnetic field and plate tectonics than planets which formed later. As both these conditions are considered favourable to the development of life, this means that if life exists in the Galaxy, it may have developed earlier than later, and that planets formed more recently may have less chance of developing life.

As lead scientist, planetary researcher Craig O'Neill said,

"Plate tectonics is important for habitability, and it looks like the optimum conditions plate tectonics existed for planets forming early in the galaxy's lifespan, and may be unlikely to easily recur. For life, maybe that was as good as it gets".

Exoplanets - planets in orbit around distant stars - have been attracting great interest because of the possibility that some of them may harbour life. Presenting the results at the Goldschmidt geochemistry conference, Professor Craig O'Neill (Director of the Macquarie Planetary Research Centre, Macquarie University) continued:

"Because of the great distances involved, we have a limited amount of information on these exoplanets, but we can understand some factors, such as position, temperature, and some idea of the geochemistry of the exoplanets. This allows us to model how they develop".

Using huge simulations involving hundreds of processors on the Australian National Computing Infrastructure, the team ran the parameters through the ASPECT* geodynamics code, which simulates the development of the interior of planets. O'Neill's group was able to show that many early planets would have tended to develop plate tectonics, which is favourable to the development of life.

He commented: "Plate tectonics act as a kind of thermostat for the Earth creating the conditions which allow life to evolve. The Earth has a lot of iron in its core, and we had assumed that this would be necessary for tectonic development. However we found that even planets with little iron may develop plate tectonics if the timing is right. This was completely unexpected".

The development of plate tectonics has a major knock-on effect. "Planets which formed later may not have developed plate tectonics, which means that they don't have this built in thermostat. This doesn't just affect the surface temperature, this means that the core stays hot, which inhibits the development of a magnetic field. If there's no magnetic field, the planet is not shielded from solar radiation, and will tend to lose its atmosphere. So life becomes difficult to sustain. A planet needs to be lucky to have the right position and the right geochemistry at the right time if it's going to sustain life", said Professor O'Neill.

Researchers know that the overall chemical balance of the Galaxy has changed over time for diverse reasons, such as material coalescing into stars and planetary bodies, or being expelled through supernova. This means that the interstellar material available to form planets is significantly different to that available in the early galaxy.

"So the planets which formed earlier did so in conditions favourable to allow the development of life" said Craig O'Neill, "These conditions are becoming increasingly rarer in our galaxy."

Commenting, Professor Sara Russell said:

"Over the last few years, amazing projects such as the NASA Kepler mission have located thousands of planets orbiting around other stars. However, these exoplanet observations alone provide very basic information. It is so important to combine observing campaigns with large simulation projects like this, that really tell us something about the geological evolution of planets formed at different stages of galactic evolution. This enables us to build a picture of what these strange worlds might look like, and how habitable they may be".

Sara Russell is a member of the Scientific Committee of the Geochemical Society. She is Professor of Planetary Sciences and leader of the Planetary Materials Group at the Natural History Museum, London. She was not involved in this work, this is an independent comment.

As of 5th June, NASA has confirmed the detection of 4158 exoplanets in our galaxy, see https://exoplanets.nasa.gov/ . The closest exoplanets yet found orbit the star Proxima Centuri, which is about 4 light years from Earth (latest data indicates either 2 or 3 exoplanets).

The Goldschmidt conference is the world's main geochemistry conference, hosted by the Geochemical Society and the European Association of Geochemistry. Held annually, it covers such material as climate change, astrobiology, planetary and stellar development and conditions, chemistry of Earth materials, pollution, the undersea environment, volcanoes, and many other subjects. For 2020 the scheduled Hawaii congress has been moved online, and takes place from 21-26 June, see https://goldschmidt.info/2020/index. Future congresses are in Lyon, France (2021) and the rescheduled Hawaii congress (2022).

*NOTE: See Advanced Solver for Problems in Earth's ConvecTion https://aspect.geodynamics.org/ ASPECT was developed by the University of California (Davis) with funding from the National Science Foundation.

ACADEMICS at the University of Huddersfield and University of Central Lancashire have revealed that the number of babies being taken into state care in their first week of life is almost 50% higher than previously believed.

Following Freedom of Information (FOI) requests issued to the Department for Education, which provided access to national data collected from local authorities in England, researchers found that in the decade to 2018, the proportion of children in England born into care rose from 26 to 48 per 10,000 live births - or from around one baby in 400 to one in 200.

The research, published in the Children and Youth Services Review, uncovered significant differences between regions. In the North East, born into care rates rose by 142% between 2008 and 2018, with one baby in 98 across the North East being removed at birth by 2018. By contrast, in Inner London rates fell slightly by 5%, to 26.5 per 10,000 or one baby in 378 in 2018.

This data also highlighted a strong correlation between deprivation of Local Authorities and the proportion of children born into care. For example, in Blackpool, one child in every 46 births was born into care in 2017, while in Richmond Upon Thames, this decreased to one child in 813 in the same year.

Of these children born into care between 2008 and 2018, 90% were never returned to their parents. Over 50% were adopted and another 33.5% were placed with special guardians long-term. This highlights that care in the first week of life is rarely to provide parents with temporary respite or opportunities to resolve problems.

Professor Paul Bywaters, Professor of Social Work at the University of Huddersfield, said: "Early separation can have a long-lasting impact on families, even when children are adopted by loving parents. Surely, we can find better ways to support families and to reduce the huge inequalities in children's life chances our research reveals."

Professor Andy Bilson, Emeritus Professor of Social Work at the University of Central Lancashire, said: "This pattern of children being immediately placed into care highlights a need for the government to closely examine its family policy, and the support that is currently provided to parents.

"Growing poverty and economic insecurity in work, the housing crisis and welfare reforms all undoubtedly play their part, and local authorities and central government must take steps to address this and, where appropriate, seek alternatives to young children being taken into care."

Oralia Loza, Ph.D., public health sciences associate professor at The University of Texas at El Paso, and the Borderland Rainbow Center (BRC) have collaborated on a survey that examines how the COVID-19 pandemic has disproportionately affected the LGBTQ+ population in Texas.

Led by Phillip W. Schnarrs, Ph.D., at The University of Texas at Austin's Dell Medical School, the survey involved a statewide coalition of community and research partners, including UTEP and El Paso's BRC, to better understand the needs, concerns and challenges of LGBTQ+ Texans and their allies during the coronavirus outbreak.

Preliminary results from this first-of-its-kind survey found that gender diverse people and queer people of color are experiencing a number of disparities. They include higher rates of COVID-19, more difficulty accessing a variety of services, and higher rates of anxiety and depression, as well as high unemployment compared with white participants.

The results, which are broken down by race, ethnicity and gender identity, are available here. Researchers plan to release the findings by individual Texas counties later this year.

"The purpose of the study is two-fold," said Loza, who collaborated with the BRC to include representation from El Paso in the survey data. She is currently translating the survey and preliminary findings of the study into Spanish. "One is to understand what are the needs of the LGBTQ population in our community because it has never been assessed before, especially statewide. But also, community organizations such as the BRC can use that data to show evidence of the need to advocate for those services. Other community organizations also can use the data to generate findings that are specific to the work they do. If their focus is mental health, they can look at the mental health data and report the needs for their city."

The survey, which launched May 4, 2020, will continue to recruit participants until July 30, 2020. To date, researchers have gathered data from 1,000 LGBTQ+ individuals and their allies, including 111 respondents from El Paso. The survey is available here.

Researchers said the data collected will be given back to community partners to use for future planning, as well as the development and delivery of programs to support LGBTQ+ individuals and allies during the COVID-19 pandemic.

The short-term environmental benefits of the COVID-19 crisis, including declines in carbon emissions and local air pollution, have been documented since the early days of the crisis. This silver lining to the global crisis, however, could be far outweighed by the long-term impacts on clean energy innovation, a new Yale-led study finds.

The economic downturn triggered by the pandemic, researchers say, could have a devastating impact on long-term investment in clean energy.

Under a worst-case -- but realistic -- scenario, they predict an additional 2,500 million metric tons of carbon dioxide -- or the equivalent of nearly 3 trillion pounds of coal burned -- could be emitted, causing 40 more deaths per month, through 2035.

"This global crisis will certainly defer investments in clean energy," said Kenneth Gillingham, an associate professor of environmental and energy economics at the Yale School of Forestry & Environmental Studies (F&ES) and lead author of the paper. "Depending on how policymakers respond, the consequences for human health from this deferred investment could far exceed the short-term environmental benefits that we have seen so far."

Those short-term benefits have been substantial. Consumption for jet fuel and gasoline, for example, declined by 50 and 30 percent, respectively, from early March to June 7, while electricity demand fell by 10 percent. These impacts saved an estimated 200 lives per month since the lockdowns began.

However, there's also been another, subtler outcome: most investment in clean energy technologies has come to a halt.

"Overall clean energy jobs dropped by almost 600,000 by the end of April, as investments in energy efficiency and renewable generation have plummeted," said Marten Ovaere, a postdoctoral researcher at F&ES and co-author of the paper. "If that were to continue it could significantly set back the push toward a clean energy future."

The paper, published in the journal Joule, was coauthored by researchers at MIT Sloan School of Management and Northwestern University.

Drawing on evidence from previous economic shocks, the researchers examine two possible long-term scenarios in the U.S. In the best-case scenario -- in which the threat subsides relatively quickly, the worst projections of human fatalities are avoided, and the economy rebounds -- they say there should be few long-term implications. Most demands for products and services, they predict, "will be deferred rather than destroyed." While record declines in emissions would be temporary, investments in new energy solutions would likely reach pre-pandemic levels.

If there is a persistent, long-term recession, however, the impacts on energy innovation would be significant. While energy use related to travel might remain lower, home energy consumption would increase and commercial building use would stay largely unchanged, particularly if office spaces are used in a similar way (even if more American workers decide to work from home). Also, if the public becomes cautious about using public transportation, many commuters will simply decide to drive instead.

The greater impact, however, would be on the energy innovation sector, the study says. Investment in low-carbon technologies would dry up, the transition to cleaner vehicle fleets would be disrupted, and cash-strapped automakers would abandon new vehicle and energy efficiency technologies.

"For example, there has been a huge amount of investment going into electric vehicles," Gillingham says. "But if companies are just trying to survive, it's much less likely that they can make large investments towards new technologies for the next generation because they don't even know if they're going to make it to the next generation."

In addition, tighter state and local budgets over the next few years will likely deflate much of the investment in clean-energy options.

Even if green energy investments stall for just a single year, the authors calculate, it would outweigh any emissions reductions that occurred from March to June.

However, while the uncertainty of this crisis poses potentially enormous threats, it also presents an opportunity, Gillingham says. If federal governments produce large stimulus packages to strengthen the economy, even modest investments in clean energy technologies would pay long-term dividends.

"Including a green component in those stimulus packages would be an investment in the future, but it also has short-term benefits," he says. "We looked back at analyses of the clean energy investments that were part of the American Recovery and Reinvestment Act of 2009 -- which promoted new energy infrastructure, smart meters, and other new technologies -- and it made a big difference.

"So it really is very much in the hands of policymakers whether green energy is held back or accelerated by this crisis."

NEW YORK, NY (June 22, 2020)--A newly discovered Alzheimer's gene may drive the first appearance of amyloid plaques in the brain, according to a study led by researchers at Columbia University Irving Medical Center.

Some variants of the gene, RBFOX1, appear to increase the concentration of protein fragments that make up these plaques and may contribute to the breakdown of critical connections between neurons, another early sign of the disease.

The finding could lead to new therapies that prevent Alzheimer's and better ways of identifying people with the greatest risk of developing the disease.

Background

In recent years, amyloid PET brain imaging has helped to reveal that the earliest signs of Alzheimer's disease -- deposits of amyloid in the brain - appear as early as 10 or 15 years before any symptoms of the disease become apparent.

But aside from the few cases caused by rare, inherited genes, researchers have been searching for the cause of excessive accumulation of amyloid in the brain of Alzheimer's patients.

To find genes that drive EARLY amyloid accumulation, the new study examined the genomes of thousands of people whose PET images revealed amyloid deposits in the brain but who had not yet developed Alzheimer's symptoms.

"By studying people with the earliest signs of Alzheimer's, we can find genes that are unequivocally related to the start of disease. And these genes are more likely to lead to therapies that can prevent the disease from developing," says Richard Mayeux, MD, chair of neurology at Columbia University Vagelos College of Physicians and Surgeons, who led the study.

What's New

The study looked through the genomes of nearly 4,300 people who did not have Alzheimer's but whose brains already contained variable amounts of amyloid plaque, as measured by PET imaging using amyloid tracers.

A genetic analysis uncovered a link between the appearance of amyloid deposits and APOE, a known Alzheimer's gene, and a novel gene, RBFOX1.

About 10% of people in the study (predominantly with European ancestry) had RBFOX1 variants that were linked with the emergence of amyloid deposition.

Lower amounts of RBFOX1 in the brain appeared to be associated with increased amyloid and global cognitive decline during life.

Why It Matters

Uncovering exactly how RBFOX1 regulates amyloid plaque could lead to ways to prevent plaque accumulation. Previous research has already suggested RBFOX1 is involved in the formation of amyloid precursors and the breakdown of synapses between neurons.

The connection between RBFOX1 and amyloid plaques may be relatively easy to untangle, unlike the well-known connection between APOE4 and amyloid, which is still not understood after decades of research.

"I think we're going to find that these markers of eventual disease are where real progress can be made against Alzheimer's," Mayeux says. "It will be virtually impossible to change the disease course at the time symptoms appear. By then, the disease has already flourished for 10 to 15 years."

"If we can target the genes that get amyloid started -- and correct those problems somehow -- we may be able to prevent the disease."

A fundamental question in biology is how individual cells within a multicellular organism interact to coordinate diverse processes.

A University of Wyoming researcher and his Ph.D. students studied myxobacteria -- common soil microbes that prey off other microbes for food -- and posed the question: "How do cells from a diverse environment recognize other cells as related or clonal to build social groups and a multicellular organism?"

"Myxobacteria assemble a multicellular organism by cobbling together cells from their environment. This is in contrast to plants and animals, where gametes fuse to create a unique cell, which, upon clonal expansion, creates a multicellular organism," says Dan Wall, a professor in the UW Department of Molecular Biology. "The ability of myxobacteria to create multicellular organisms is remarkable, given that soil is considered to be the most diverse environment on the planet, wherein a small sample can consist of tens of thousands of microbial species. Broadly speaking, our work helps to address this question."

Wall is corresponding author of a paper, titled "Rapid Diversification of Wild Social Groups Driven by Toxin-Immunity Loci on Mobile Genetic Elements," that was published in the June 22 (today) issue of the International Society for Microbial Ecology (ISME) Journal. Published by Springer Nature, the journal publishes leading research in microbial ecology, spanning the breadth of microbial life, including bacteria, archaea, microbial eukaryotes and viruses.

Christopher Vassallo and Vera Troselj, both Ph.D. candidates in Wall's lab at the time of the research, are co-authors of the paper. Vassallo and Troselj are now postdoctoral researchers at the Massachusetts Institute of Technology and the Lawrence Berkeley National Laboratory, respectively. Michael Weltzer, a UW graduate student in the Molecular and Cellular Life Sciences program from Idaho Springs, Colo., is another co-author.

This work is mostly fundamental and addresses how cells discriminate between the self and non-self, Wall says.

"Multicellularity is a difficult way of life to evolve and maintain, because cells are the smallest unit of life, and there is selective pressure for them to exploit their environment, including other cells, for their own benefit," he explains. "For example, cancer cells do this and are constantly arising in our own body. Fortunately, our immune system recognizes them as non-self and eliminates them. Our system works in an analogous manner."

Wall says his group's work builds on prior research on the subject that showed that a small patch of soil has another layer of remarkable diversity at the subspecies level. Among Myxococcus xanthus isolates, there are many different social groups that discriminate against one another. However, Wall says the prior research did not elucidate how it works at the molecular level.

"Our paper addresses the mechanism of how they (myxobacteria) discriminate and how highly related strains recently diverged, or evolved, into distinct social groups," Wall says.

This ISME paper also builds on Vassallo and Wall's previous paper, titled "Self-Identify Barcodes Encoded in Expansive Polymorphic Toxin Families Discriminate Kin in Myxobacteria," that was published in the Proceedings of the National Academy of Sciences (PNAS) Nov. 19, 2019.

The work in the PNAS paper showed that Myxococcus xanthus expresses a highly variable cell surface receptor called TraA. Cells use these receptors, which have many different sequences or alleles in populations, to recognize other cells as possible clonemates or as self. If the other cells bear identical TraA receptors, they interact. This results in the transient fusion of cells where they exchange cellular components, such as proteins and lipids, but no DNA. Included in this cargo are highly variable toxin proteins.

Thus, if the other cells are true clonemates, they have genetically encoded immunity to those toxins. But if they are divergent cells that happen to have compatible TraA receptors, but are not clonemates, they will be killed by toxin transfer. In the PNAS paper, Vassallo and Wall discovered six distinct families of toxins delivered by TraA recognition and exchange. Each of these families is diverse and abundant in myxobacterial genomes.

From the PNAS study, Wall says they sought to put their predictions to the test in the ISME paper.

"We analyzed the publicly available genomes of those 22 (myxobacteria) strains, identified their toxin genes and predicted how they would socially interact," Wall says. "We found a perfect correlation between our predictions and empirical findings by others. We then experimentally tested our predictions by creating mutants and showed we could engineer social harmony between otherwise antagonistic strains by inactivating toxin transfer."

Along with the TraA delivery/discrimination system, Wall says they also discovered two other systems -- type VI secretion system (T6SS) and rearrangement hotspot (RHS) -- were involved in kin discrimination. T6SS is a molecular injection apparatus that transfers toxins into adjacent cells. If the cells are clonal, they will encode immunity; if not, they will be intoxicated. T6SSs are widely distributed in many different types of bacteria. Although not well understood, the RHS system also serves as a nanoweapon.

Additionally, the group showed that the key discriminatory toxin genes resided on mobile genetic elements in the chromosome. That is, these highly related strains recently diverged by the horizontal transfer of genes in their environment, mediated by virus-like particles.

An international team of scientists and historians has found evidence connecting an unexplained period of extreme cold in ancient Rome with an unlikely source: a massive eruption of Alaska's Okmok volcano, located on the opposite side of the Earth.

Around the time of Julius Caesar's death in 44 BCE, written sources describe a period of unusually cold climate, crop failures, famine, disease, and unrest in the Mediterranean Region -impacts that ultimately contributed to the downfall of the Roman Republic and Ptolemaic Kingdom of Egypt. Historians have long suspected a volcano to be the cause, but have been unable to pinpoint where or when such an eruption had occurred, or how severe it was.

In a new study published this week in Proceedings of the National Academy of Sciences (PNAS), a research team led by Joe McConnell, Ph.D. of the Desert Research Institute in Reno, Nev. uses an analysis of tephra (volcanic ash) found in Arctic ice cores to link the period of unexplained extreme climate in the Mediterranean with the caldera-forming eruption of Alaska's Okmok volcano in 43 BCE.

"To find evidence that a volcano on other side of the earth erupted and effectively contributed to the demise of the Romans and the Egyptians and the rise of the Roman Empire is fascinating," McConnell said. "It certainly shows how interconnected the world was even 2,000 years ago."

The discovery was initially made last year in DRI's Ice Core Laboratory, when McConnell and Swiss researcher Michael Sigl, Ph.D. from the Oeschger Centre for Climate Change Research at the University of Bern happened upon an unusually well preserved layer of tephra in an ice core sample and decided to investigate.

New measurements were made on ice cores from Greenland and Russia, some of which were drilled in the 1990s and archived in the U.S., Denmark, and Germany. Using these and earlier measurements, they were able to clearly delineate two distinct eruptions - a powerful but short-lived, relatively localized event in early 45 BCE, and a much larger and more widespread event in early 43 BCE with volcanic fallout that lasted more than two years in all the ice core records.

The researchers then conducted a geochemical analysis of the tephra samples from the second eruption found in the ice, matching the tiny shards with those of the Okmok II eruption in Alaska - one of the largest eruptions of the past 2,500 years.

"The tephra match doesn't get any better," said tephra specialist Gill Plunkett, Ph.D. from Queen's University Belfast. "We compared the chemical fingerprint of the tephra found in the ice with tephra from volcanoes thought to have erupted about that time and it was very clear that the source of the 43 BCE fallout in the ice was the Okmok II eruption."

Working with colleagues from the U.K., Switzerland, Ireland, Germany, Denmark, Alaska, and Yale University in Connecticut, the team of historians and scientists gathered supporting evidence from around the globe, including tree-ring-based climate records from Scandinavia, Austria and California's White Mountains, and climate records from a speleothem (cave formations) from Shihua Cave in northeast China. They then used Earth system modeling to develop a more complete understanding of the timing and magnitude of volcanism during this period and its effects on climate and history.

According to their findings, the two years following the Okmok II eruption were some of the coldest in the Northern Hemisphere in the past 2,500 years, and the decade that followed was the fourth coldest. Climate models suggest that seasonally averaged temperatures may have been as much as 7oC (13oF) below normal during the summer and autumn that followed the 43 BCE eruption of Okmok, with summer precipitation of 50 to 120 percent above normal throughout Southern Europe, and autumn precipitation reaching as high as 400 percent of normal.

"In the Mediterranean region, these wet and extremely cold conditions during the agriculturally important spring through autumn seasons probably reduced crop yields and compounded supply problems during the ongoing political upheavals of the period," said classical archaeologist Andrew Wilson, D.Phil. of the University of Oxford. "These findings lend credibility to reports of cold, famine, food shortage and disease described by ancient sources."

"Particularly striking was the severity of the Nile flood failure at the time of the Okmok eruption, and the famine and disease that was reported in Egyptian sources," added Yale University historian Joe Manning, Ph.D. "The climate effects were a severe shock to an already stressed society at a pivotal moment in history."

Volcanic activity also helps to explain certain unusual atmospheric phenomena that were described by ancient Mediterranean sources around the time of Caesar's assassination and interpreted as signs or omens - things like solar halos, the sun darkening in the sky, or three suns appearing in the sky (a phenomenon now known as a parahelia, or 'sun dog'). However, many of these observations took place prior to the eruption of Okmok II in 43 BCE, and are likely related to a smaller eruption of Mt. Etna in 44 BCE.

Although the study authors acknowledge that many different factors contributed to the fall of the Roman Republic and Ptolemaic Kingdom, they believe that the climate effects of the Okmok II eruption played an undeniably large role - and that their discovery helps to fill a knowledge gap about this period of history that has long puzzled archaeologists and ancient historians.

"People have been speculating about this for many years, so it's exciting to be able to provide some answers," McConnell said.

PRINCETON, N.J.--The avalanche of online content available to people around the world has outpaced humans' ability to separate fact from what can be highly toxic and even dangerous fiction.

But helping people identify nefarious information online might be possible through inexpensive digital-media literacy outreach, according to a Princeton University-led study published in the Proceedings of the National Academy of Sciences (PNAS).

A team of researchers studied Facebook's efforts to educate users on how to spot misinformation. After being exposed to tips on how to spot misinformation, people in the United States and India were less likely to say a false headline was true.

The researchers also found, however, that people's ability to spot erroneous information weakened over time, leading the authors to conclude that digital literacy needs to be taught with regularity.

"Most people struggle to reliably evaluate the quality of information they encounter online, even under the most ideal conditions," said Andy Guess, assistant professor of politics and public affairs. "This is because they lack the skills and knowledge required to distinguish between high and low-quality news content. We find that effort to promote digital literacy can improve people's ability to evaluate the accuracy of online content."

Guess's collaborators were Michael Lerner of the University of Michigan, Benjamin Lyons of the University of Utah, Jacob M. Montgomery of Washington University in St. Louis, Brendan Nyhan of Dartmouth College, Jason Reifler of the University of Exeter, and Neelanjan Sircar of Ashoka University.

This study is among the first to systematically explore the role of digital media literacy shortfalls.

The team originally set out to explore why people fall victim to misinformation, selecting the United States and India as both countries have struggled with misinformation campaigns (especially during national elections).

The team looked at the effects of Facebook's "Tips to Spot False News," which appeared at the top of users' news feeds in 14 countries in April 2017. The list was also printed as a full-page ad in many U.S. newspapers, and a version appeared in India as well.

These tips have likely been the most widely distributed digital-media literacy intervention. They also are not overly complex, allowing for quick decision-making. For example, one tip cautions readers to be skeptical of headlines, warning that if claims sound unbelievable, they probably are.

The researchers then employed a "two-wave panel design," studying the same group of people immediately after exposure to the tips, and then again several weeks later, allowing them to see whether the digital media literacy efforts took root over time.

Participants were exposed to the tips and then presented with the same series of mock headlines, which they rated for accuracy. The headlines were balanced in terms of partisan slant, well-known and lesser-known media outlets, as well as low-quality and mainstream content. While the tips were offered to respondents, they couldn't be forced to read them, so the researchers took this into account in their modeling.

This two-wave design was conducted online in both the U.S. and India, though in-person interviews were also conducted in areas of rural India where there is greater religious polarization and potentially higher risk of misinformation spread.

The team found that the intervention improved people's ability to discern between mainstream and false news headlines by 26.5% in the U.S. and 17.5% in India. In the U.S., this lessened but remained measurable several weeks later. One-third of participants also were more likely to point out a less accurate headline. Their ratings of false headlines as "very accurate" or "somewhat accurate" went from 32% to 24%.

While the online results between the two countries were similar, India's face-to-face interviews yielded different results. There was no evidence that exposure to the tips increased the perceived accuracy of mainstream news articles. That said, this group had much less experience with evaluating news headlines online, the researchers said.

The researchers listed a few caveats with their work. First, the effects were modest, and the intervention did not completely eliminate belief in false news headlines. The effects also decayed over time, suggesting the need for regular reinforcement of these lessons. Lastly, it's not clear whether everyone actually read the tips.

Still, the study provides opportunities for future research. Rather than using an intervention done by a tech company, academics could take this into their own hands by sampling people in other countries and electoral contexts. Likewise, more intensive training models could be used to see if the effects are more durable.

"We see no reason why this wouldn't work for any type of misinformation. Currently there are sources spreading misleading or even dangerous information about Covid-19 regarding protective measures, vaccines, miracle cures. We think this intervention could work in the public health domain, as well," Guess said.

What The Study Did: Measures implemented in a community in China to restrict the spread of COVID-19 are examined in this case series.

Authors: Wen-Wu Zhang, B.Med., and Qing-Li Dou, Ph.D., of The People's Hospital of Baoan Shenzhen in China, are the corresponding authors.

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

(doi:10.1001/jamanetworkopen.2020.12934)

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

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MADISON, Wis. -- University of Wisconsin-Madison scientists have found that a constantly fluctuating environment can enable some species to invade new areas by helping them maintain the genetic diversity they need to settle into their new homes.

And once those invasive species arrive, adaptation can take surprisingly similar paths. Evolution can act on exactly the same genomic regions, even during independent invasions across widely separated populations and on opposite sides of a continent.

The findings could make future encroachments easier to predict, a huge priority since invasive species cause hundreds of billions of dollars in damage each year. And as climate change forces more species to move or perish, the ability to predict adaptability could help us understand which organisms will survive.

Writing in Nature Ecology and Evolution on June 22, UW-Madison Professor of Integrative Biology Carol Eunmi Lee and postdoctoral researcher David Stern describe how a small crustacean from salty waters, the copepod Eurytemora affinis, was able to invade the Great Lakes and other freshwater lakes.

In the estuaries that Eurytemora call home, fluctuations in the water's salinity drive a high level of genetic diversity among the copepod population, allowing them to survive changing conditions. When the invaders reach fresh water, that genetic diversity helped them undergo natural selection, flourish and take over.

"Fluctuating conditions in the native range probably provide a major evolutionary force enabling species to invade a new habitat," says Lee. "This is not a principle just for this one copepod, but it probably also explains why a large portion of invasive species in the Great Lakes are coming from brackish water habitats with fluctuating conditions."

Lee and Stern studied Eurytemora populations from two widely separated locations: the St. Lawrence Estuary in Quebec and the Gulf of Mexico near Texas and Louisiana. Each has gone on to invade freshwater lakes, either the Great Lakes or inland lakes upstream of the Gulf. The researchers sequenced the genomes of hundreds of copepods to investigate how they made the jump from salt water to fresh water.

"We looked for those genetic changes that were the same across these different independent invasion events," says Stern.

Where these two different populations in different locations experienced the same genetic changes, it was evidence of what's known as parallel evolution. In the case of the copepods, the two populations experience 29 times more parallel evolution than expected if it were up to chance alone, at least in places of the genome related to salinity tolerance. That trend also held across broader regions of the genome.

"That was surprising, because the Gulf and Atlantic populations are very different," says Lee. "But they have the same mutations in their native ranges, and then the same mutations independently rose in frequency in the invading populations."

The researchers then investigated how populations of Eurytemora separated by thousands of miles could retain enough genetic similarity to promote this degree of parallel evolution. Lee and Stern found that the genes that underwent parallel evolution had experienced balancing selection at home. Balancing selection promotes the maintenance of diverse alleles -- variants of genes -- to handle different conditions.

For Eurytemora, seasonal changes in salinity have selected for variation in genetic traits that help the crustacean survive a wide range of conditions. When the copepod made it to fresh water, it could rely on that genetic diversity to adapt to its new home.

Most of the genomic regions that changed to adapt to fresh water have unknown functions. But the researchers spotted a string of genes molded by parallel evolution with clear ties to changing salinity. One region with seven copies of an ion transporter, which can control how much sodium is pumped into a cell, had the highest density of parallel evolution in the copepod genomes.

"We expected that ion transporters would play a big role," says Lee. "It's going to be the number one thing that you have to do when you get to fresh water, is start pumping more ions into the cell."

The researchers believe that balancing selection likely explains a number of other invasions, especially in the Great Lakes. Other invaders, like zebra and quagga mussels, also hail from areas that experience fluctuations in salinity. As long as the environment regularly changes on a time scale longer than reproductive cycles and across generations, balancing selection -- and subsequent invasion -- is possible.

"Balancing selection might be a widespread evolutionary force that predisposes certain populations to evolve when they encounter evolutionary environmental change," says Lee.

Campaigns to plant huge numbers of trees could backfire, according to a new study that is the first to rigorously analyze the potential effects of subsidies in such schemes.

The analysis, published on June 22 in Nature Sustainability, reveals how efforts such as the global Trillion Trees campaign and a related initiative (H. R. 5859) under consideration by the U.S. Congress could lead to more biodiversity loss and little, if any, climate change upside. The researchers emphasize, however, that these efforts could have significant benefits if they include strong subsidy restrictions, such as prohibitions against replacing native forests with tree plantations.

"If policies to incentivize tree plantations are poorly designed or poorly enforced, there is a high risk of not only wasting public money but also releasing more carbon and losing biodiversity," said study co-author Eric Lambin, the George and Setsuko Ishiyama Provostial Professor in Stanford's School of Earth, Energy & Environmental Sciences. "That's the exact opposite of what these policies are aiming for."

There is no question that forests have an outsized role to play in efforts to slow global biodiversity loss and combat climate change by sequestering carbon as biomass. So it makes sense that tree-planting as a solution has gained traction in recent years with ambitious commitments, such as the Bonn Challenge, which seeks to restore an area of forest more than eight times the size of California by 2030, and Trillion Trees, which seeks to plant as many trees as its name implies.

A closer look reveals faults in the optimistic plans. For example, nearly 80 percent of commitments to the Bonn Challenge involve planting monoculture tree plantations or a limited mix of trees that produce products such as fruit and rubber rather than restoring natural forests. Plantations typically have significantly less potential for carbon sequestration, habitat creation and erosion control than natural forests. The potential benefit dwindles further if planted trees replace natural forests, grasslands or savannahs - ecosystems that have evolved to support unique, local biodiversity.

In the new study, the researchers critically examined another aspect of some mass-tree planting efforts: subsidies designed to encourage private landowners to plant trees. Such payments are widely proposed as a promising solution to a variety of environmental challenges. So, the scientists looked at one of the world's longest running and most influential afforestation subsidy policies, Chile's Decree Law 701. The law, in effect from 1974 to 2012 and currently being considered for reintroduction, has served as the model for similar policies in a number of South American countries and international development projects.

"In light of global enthusiasm to plant a trillion trees, it's important to reflect on the impact of past policies," said lead author Robert Heilmayr, an assistant professor at UCSB, who worked on the study while a PhD student in the Emmett Interdisciplinary Program in Environment and Resources at Stanford's School of Earth, Energy & Environmental Sciences. "Chile's experience can help us understand the climate, ecological and economic impacts that might occur when governments pay landowners to establish massive tree plantations."

Chile's Decree Law 701 subsidized 75 percent of afforestation costs and provided support for ongoing plantation management. Lax enforcement and budgetary limitations hobbled prohibitions on the use of subsidies on already-forested lands, leading to situations in which the government subsidized the replacement of native forests with profitable tree plantations. Anecdotal evidence indicated the law's subsidies further reduced native forest cover by encouraging the establishment of plantations on shrublands or marginal agricultural lands where forests might have naturally regenerated.

The researchers set out to quantify the full impact of the afforestation subsidies and calculate their effects on net carbon and biodiversity changes across the entire country. They compared the area of Chilean forests under three scenarios: actual observed subsidy patterns, no subsidies and subsidies combined with fully enforced restrictions on the conversion of native forests to plantations. They found that, relative to a scenario of no subsidies, afforestation payments expanded the area covered by trees, but decreased the area of native forests. Since Chile's native forests are more carbon dense and biodiverse than plantations, the subsidies failed to increase carbon storage, and accelerated biodiversity losses.

"Nations should design and enforce their forest subsidy policies to avoid the undesirable ecological impacts that resulted from Chile's program," said study coauthor Cristian Echeverría, a professor at the University of Concepción in Chile. "Future subsidies should seek to promote the recovery of the many carbon- and biodiversity-rich natural ecosystems that have been lost."

The resistance of bacteria to antibiotics is a major health problem. The problem? Bacteria acquire new defense mechanisms to counteract the action of drugs. For several years, the team of Jean-François Collet, professor at the de Duve Institute at UCLouvain, has been interested in this question, and in particular in bacteria surrounded by two membranes (or two surrounding walls).
For a bacterium to survive, it must succeed in building its two surrounding walls and, once assembled, it must protect them from attacks by toxic molecules, including certain antibiotics. Indeed, if one of the walls is damaged, the bacterium dies.

In the outer perimeter wall, there is a particularly important type of guard tower. These towers, called BAM, are essential places for the surveillance, maintenance and protection of fortifications. Several discoveries, including by UCLouvain, have made BAM a prime target for the development of new antibiotics. However, despite the intense work of many university laboratories and pharmaceutical companies, the mode of operation of BAM remains poorly understood, which hinders the development of new antibacterial strategies.

UCLouvain scientists have caught BAM red-handed. The BAM guard towers are compulsory crossing points for all protein soldiers who stand guard on the ramparts as well as for certain protein soldiers who leave the bacterial fortification to patrol the surroundings. The UCLouvain scientists have achieved the feat of obtaining an instantaneous photograph (or three-dimensional structure), which makes it possible to observe BAM in the process of exporting one of the protein soldiers (RcsF) through the outer surrounding wall.

This UCLouvain discovery, published in the prestigious scientific journal Nature Chemical Biology, offers an unprecedented perspective: it provides precious information on the mechanism of bacteria and offers a new angle of attack to take over the BAM watchtowers during antibiotic treatment. In this sense, the discovery of the UCLouvain researchers contributes to the global effort to respond to this growing problem.

This research was conducted by an international team from the de Duve Institute of UCLouvain, in collaboration with researchers from the VUB, VIB, CNRS and the University of Leeds. The research was funded by the EOS program and WELBIO. The co-first author of the publication, Raquel Rodriguez Alonso, is supported by the European ITN network Train2Target which aims to train a new generation of scientists specializing in the research of new antibiotics.

The large-scale planting of new forests in previously tree-free areas, a practice known as afforestation, is hailed as an efficient way to remove excess carbon dioxide from the atmosphere - a so-called natural climate solution.

But a new study led by a Colorado State University biology researcher finds that the carbon-capture potential of afforestation may be overestimated. The study, published online June 22 in Nature Sustainability, contends that ratios of soil organic carbon underneath afforested areas vary greatly across different ecosystems and climates, and these variations depend on factors like tree species, land-use history and soil type.

These results, based on over 11,000 soil samples taken across control and afforested plots in northern China, indicate that natural climate solutions alone are not enough to meet global climate mitigation goals.

"We hope that people can understand that afforestation practices are not one single thing," said Anping Chen, a research scientist in the CSU Department of Biology and a lead author on the study. "Afforestation involves many technical details and balances of different parts, and it cannot solve all our climate problems." Chen helped launch the ambitious study while a graduate student at Princeton University about a decade ago.

Inspired to find better data

The research was inspired by a 2010 workshop at Princeton, which led to a high-profile publication on the global forest carbon sink in Science by U.S. Forest Service scientist Yude Pan. In the absence of better data sources, the scientists had used a fixed ratio between tree biomass and soil carbon to estimate total soil organic carbon stocks - a measure that Chen and and Peking University collaborator Shilong Piao suspected was not accurate. This method can be even more problematic, Chen said, for estimating afforestation carbon sequestration potential because land-use changes are often associated with soil disturbances.

As Chen and Piao sat in the workshop, they decided to try and find a new way to estimate below-ground soil carbon changes, and designed a field study to investigate their hypotheses.

In 2012-13, researchers from the U.S. and China led by Chen and Piao collected comparative soil samples at various depths from 619 pairs of afforested plots and control plots across northern China. The Chinese government has run extensive afforestation campaigns as both climate mitigation strategies as well as an attempt to reduce dust from the Gobi desert.

The researchers found that in carbon-poor soils, afforestation did increase soil organic carbon density. But in soils already rich in carbon, they found that carbon density decreased. Their findings concluded that fixed biomass-to-soil organic carbon ratios assumed in previous studies might be overestimating the overall soil organic carbon enhancement features of afforestation practices in general.

The results have implications for forest managers and policymakers. For example, a site that's already above a certain threshold of soil organic carbon underground may be best left alone for natural forest regeneration rather than planted with trees, Chen said.

"Our results strongly suggest that estimated afforestation carbon sink potentials that do not account for background soil carbon stocks or the potentially negative effects of afforestation is overly optimistic," the authors wrote. "These findings also indicate that the assumption of a fixed ratio between soil and biomass carbon, which has been widely used in previous studies for estimating soil carbon stocks, is unreliable."

A new technique that synchronises the clocks of computers in under a billionth of a second can eliminate one of the hurdles for the deployment of all-optical networks, potentially leading to more efficient data centres, according to a new study led by UCL and Microsoft.

Data centres, comprising tens or hundreds of thousands connected servers, are the underlying technology empowering everything we do online, from storing films and photos to serving up webpages and online services. However, they face rapidly rising demand, with server-to-server traffic increasing by 70% each year, which is increasingly hard to meet with existing technologies. All-optical networks that use light to both transmit and route data represent a promising alternative. However, their viability has been limited due to the need for each server to continuously adjust its clock time according to incoming data, which resulted in lower overall performance.

The study, published in Nature Electronics, shows that by synchronising clocks of all connected servers via optical fibre, and programming hardware to memorise clock phase values so clock time does not have to be re-checked, the time to "recover" the clock could be practically eliminated.

PhD candidate Kari Clark (Optical Networks Group, UCL Electronic & Electrical Engineering, winner of the EPSRC Connected Nation Pioneers competition), lead author of the study, said: "Our research makes optical switching viable for the data centre for the first time by providing a solution to the clock synchronisation problem. It has the potential to transform communication between computers in the cloud, making key future technologies like the internet of things and artificial intelligence cheaper, faster and consume less power."

Until now, cloud providers have been able to accommodate rapid growth in demand by relying on Moore's Law for networking, whereby, about every two years, electronic switch integrated circuits double their data transmission speed at the same cost and power. However, the sustainability of this trend is increasingly being questioned due to the difficulty of continuing to be able to make silicon transistors smaller and faster.

Dr Hitesh Ballani and Dr Paolo Costa, researchers with Microsoft Research Cambridge and co-authors of the study, added: "With the expected slowdown of Moore's Law and ever-increasing cloud traffic, all-optical networks represent an attractive technology that has remained elusive so far. We are very excited by this collaboration with the UCL Optical Networks Group, which started from Kari's internship in our lab back in 2016 and evolved into a multi-year journey as part of the Optics for the Cloud Research Alliance. While there is still a long way to go, this technique brings us a step closer to the vision of an all-optical data centre."

Dr Zhixin Liu (Optical Networks Group, UCL Electronic & Electrical Engineering), senior author of the study, said: "We started this work by investigating how to support future cloud services beyond the end of Moore's law. By bringing the top minds from cloud operators and optical communication research, we propose a future-proof alternative using optics, helping data centres to cope with demand in the long term."

The team, working with researchers at Microsoft Research Cambridge, developed a prototype and found that their technique, called "clock phase caching," could synchronise the clocks of thousands of computers in under a billionth of a second, or the time it takes for light to travel 30 cm in air.