Saturday, February 08, 2020

A possible explanation for the mysterious ice circles in Lake Baikal

by Bob Yirka , Phys.org

A team of researchers affiliated with several institutions in Russia and one in France has found a possible explanation for the creation of ice circles in Lake Baikal—the deepest lake in the world. In their paper published in the journal Limnology and Oceanography, the group describes their two-year study of the ice circles and what they learned about them.

Approximately twenty years ago, scientists became aware of ice circles forming in different locations in Lake Baikal in the spring and summer months. The mysterious circles were so large that they could only be seen from airplanes or satellites. The initial suspicion was that they formed due to methane bubbling up from below. But testing showed no methane deposits below the lake.

The lake is located in Siberia, where it gets so cold that its surface freezes over completely during the winter months. The ice circles that have been observed have appeared in different sizes and different locations—but they are all characterized by a bright center surrounded by a dark circle. Prior research had shown them to be on average 5 to 7 kilometers in diameter. They also last from just a few days to a few months. Additional research showed that the ice rings were not exclusive to Lake Baikal—some were seen in Mongolia, in Lake Hovsgol and another in Russia's Lake Teletskoye. Such sightings suggested they likely appear in most deep lakes that freeze over during the winter. But there was still no explanation for how they formed.

Determined to find the answer, the researchers with this new effort traveled to the lake several times over the winters of 2016 and 2017. On each expedition, the drilled holes in the ice and dropped sensors into the lake where the circles were forming. They also studied infrared satellite images that revealed temperature variations in the lake. In February of 2016, the team found a possible clue—an eddy had formed in the water beneath the ice circle. And the water in the eddy was a couple of degrees warmer than the water around it. The researchers suggest the ice circles are formed due to water movement and temperature differences from surrounding water due to eddy formation. The following year the team found another eddy, this one without a circle above it. They suggested that they had spotted the eddy before a circle formed above it. They were not able to explain why the eddies were forming, however.

Image: Lake Baikal, Siberia

More information: Alexei V. Kouraev et al. Giant ice rings on lakes and field observations of lens‐like eddies in the Middle Baikal (2016–2017), Limnology and Oceanography (2019). DOI: 10.1002/lno.11338

Arctic ice melt is changing ocean currents

by Rexana Vizza / Matthew Segal, NASA

A major ocean current in the Arctic is faster and more turbulent as a result of rapid sea ice melt, a new study from NASA shows. The current is part of a delicate Arctic environment that is now flooded with fresh water, an effect of human-caused climate change.

Using 12 years of satellite data, scientists have measured how this circular current, called the Beaufort Gyre, has precariously balanced an influx of unprecedented amounts of cold, fresh water—a change that could alter the currents in the Atlantic Ocean and cool the climate of Western Europe.

The Beaufort Gyre keeps the polar environment in equilibrium by storing fresh water near the surface of the ocean. Wind blows the gyre in a clockwise direction around the western Arctic Ocean, north of Canada and Alaska, where it naturally collects fresh water from glacial melt, river runoff and precipitation. This fresh water is important in the Arctic in part because it floats above the warmer, salty water and helps to protect the sea ice from melting, which in turn helps regulate Earth's climate. The gyre then slowly releases this fresh water into the Atlantic Ocean over a period of decades, allowing the Atlantic Ocean currents to carry it away in small amounts.

But since the 1990s, the gyre has accumulated a large amount of fresh water—1,920 cubic miles (8,000 cubic kilometers) - or almost twice the volume of Lake Michigan. The new study, published in Nature Communications, found that the cause of this gain in freshwater concentration is the loss of sea ice in summer and autumn. This decades-long decline of the Arctic's summertime sea ice coverhas left the Beaufort Gyre more exposed to the wind, which spins the gyre faster and traps the fresh water in its current.

Persistent westerly winds have also dragged the current in one direction for over 20 years, increasing the speed and size of the clockwise current and preventing the fresh water from leaving the Arctic Ocean. This decades-long western wind is unusual for the region, where previously, the winds changed direction every five to seven years.

Scientists have been keeping an eye on the Beaufort Gyre in case the wind changes direction again. If the direction were to change, the wind would reverse the current, pulling it counterclockwise and releasing the water it has accumulated all at once.

"If the Beaufort Gyre were to release the excess fresh water into the Atlantic Ocean, it could potentially slow down its circulation. And that would have hemisphere-wide implications for the climate, especially in Western Europe," said Tom Armitage, lead author of the study and polar scientist at NASA's Jet Propulsion Laboratory in Pasadena, California.

Fresh water released from the Arctic Ocean to the North Atlantic can change the density of surface waters. Normally, water from the Arctic loses heat and moisture to the atmosphere and sinks to the bottom of the ocean, where it drives water from the north Atlantic Ocean down to the tropics like a conveyor belt.

This important current is called the Atlantic Meridional Overturning Circulation and helps regulate the planet's climate by carrying heat from the tropically-warmed water to northern latitudes like Europe and North America. If slowed enough, it could negatively impact marine life and the communities that depend it.

"We don't expect a shutting down of the Gulf Stream, but we do expect impacts. That's why we're monitoring the Beaufort Gyre so closely," said Alek Petty, a co-author on the paper and polar scientist at NASA's Goddard Space Flight Center in Greenbelt, Maryland.

The study also found that, although the Beaufort Gyre is out of balance because of the added energy from the wind, the current expels that excess energy by forming small, circular eddies of water. While the increased turbulence has helped keep the system balanced, it has the potential to lead to further ice melt because it mixes layers of cold, fresh water with relatively warm, salt water below. The melting ice could, in turn, lead to changes in how nutrients and organic material in the ocean are mixed, significantly affecting the food chain and wildlife in the Arctic. The results reveal a delicate balance between wind and ocean as the sea ice pack recedes under climate change.

"What this study is showing is that the loss of sea ice has really important impacts on our climate system that we're only just discovering," said Petty.

Arctic ice sets speed limit for major ocean current

More information: Thomas W. K. Armitage et al. Enhanced eddy activity in the Beaufort Gyre in response to sea ice loss, Nature Communications (2020). DOI: 10.1038/s41467-020-14449-z

Scientists resurrected a Wrangel Island mammoth's mutated genes

by Charlotte Hsu, University at Buffalo

Scientists resurrect mammoth’s broken genes — Credit: Rebecca Farnham / University at Buffalo

Some 4,000 years ago, a tiny population of woolly mammoths died out on Wrangel Island, a remote Arctic refuge off the coast of Siberia.

They may have been the last of their kind anywhere on Earth.

To learn about the plight of these giant creatures and the forces that contributed to their extinction, scientists have resurrected a Wrangel Island mammoth's mutated genes. The goal of the project was to study whether the genes functioned normally. They did not.

The research builds on evidence suggesting that in their final days, the animals suffered from a medley of genetic defects that may have hindered their development, reproduction and their ability to smell.

The problems may have stemmed from rapid population decline, which can lead to interbreeding among distant relatives and low genetic diversity—trends that may damage a species' ability to purge or limit harmful genetic mutations.

"The key innovation of our paper is that we actually resurrect Wrangel Island mammoth genes to test whether their mutations actually were damaging (most mutations don't actually do anything)," says lead author Vincent Lynch, Ph.D., an evolutionary biologist at the University at Buffalo. "Beyond suggesting that the last mammoths were probably an unhealthy population, it's a cautionary tale for living species threatened with extinction: If their populations stay small, they too may accumulate deleterious mutations that can contribute to their extinction."

The study was published on Feb. 7 in the journal Genome Biology and Evolution.

Lynch, an assistant professor of biological sciences in the UB College of Arts and Sciences, joined UB in 2019 and led the project while he was at the University of Chicago. The research was a collaboration between Lynch and scientists at the University of Chicago, Northwestern University, University of Virginia, University of Vienna and Penn State. The first authors were Erin Fry from the University of Chicago and Sun K. Kim from Northwestern University.

To conduct the study, Lynch's team first compared the DNA of a Wrangel Island mammoth to that of three Asian elephants and two more ancient mammoths that lived when mammoth populations were much larger.

The researchers identified a number of genetic mutations unique to the Wrangel Island mammoth. Then, they synthesized the altered genes, inserted that DNA into cells in petri dishes, and tested whether proteins expressed by the genes interacted normally with other genes or molecules.

The scientists did this for genes that are thought or known to be involved in a range of important functions, including neurological development, male fertility, insulin signaling and sense of smell.

In the case of detecting odors, for example, "We know how the genes responsible for our ability to detect scents work," Lynch says. "So we can resurrect the mammoth version, make cells in culture produce the mammoth gene, and then test whether the protein functions normally in cells. If it doesn't—and it didn't—we can infer that it probably means that Wrangel Island mammoths were unable to smell the flowers that they ate."

The research builds on prior work by other scientists, such as a 2017 paper in which a different research team identified potentially detrimental genetic mutations in the Wrangel Island mammoth, estimated to be a part of a population containing only a few hundred members of the species.

"The results are very complementary," Lynch says. "The 2017 study predicts that Wrangel Island mammoths were accumulating damaging mutations. We found something similar and tested those predictions by resurrecting mutated genes in the lab. The take-home message is that the last mammoths may have been pretty sick and unable to smell flowers, so that's just sad.

The last mammoths died on a remote island

More information: Erin Fry et al. Functional architecture of deleterious genetic variants in the genome of a Wrangel Island mammoth, Genome Biology and Evolution (2019). DOI: 10.1093/gbe/evz279

New commuter concern: Cancerous chemical in car seats

by University of California - Riverside

The longer your commute, the more you're exposed to a chemical flame retardant that is a known carcinogen and was phased out of furniture use because it required a Proposition 65 warning label in California.

That is the conclusion of a new UC Riverside study published this month in the journal Environment International.

While much research on automobile pollution focuses on external air pollutants entering vehicle interiors, this study shows that chemicals emanating from inside your car could also be cause for concern.

Though there are other Proposition 65-list chemicals that are typically used in the manufacture of automobiles, this flame retardant is a new addition to the list. Known as the Safe Drinking Water and Toxic Enforcement Act, Proposition 65 requires the state to maintain and update a list of chemicals known to cause cancer or reproductive harm.

Some scientists assumed that humans stopped being exposed to the chemical, called TDCIPP or chlorinated tris, after it was placed on California's Proposition 65 list in 2013. However, it is still widely used in automobile seat foam. The study shows that not only is your car a source of TDCIPP exposure, but that less than a week of commuting results in elevated exposure to it.

David Volz, associate professor of environmental toxicology at UCR, said the results were unexpected.

"I went into this rather skeptical because I didn't think we'd pick up a significant concentration in that short a time frame, let alone pick up an association with commute time," Volz said. "We did both, which was really surprising."

Over the past decade, Volz has studied how various chemicals affect the trajectory of early development. Using zebrafish and human cells as models, the Volz laboratory has been studying the toxicity of a newer class of flame retardants called organophosphate esters since 2011.

Little is known about the toxicity of these organophosphate esters—TDCIPP is one of them—but they've replaced older flame-retardant chemicals that lasted longer in the environment and took longer to metabolize.

Using zebrafish as a model, Volz found TDCIPP prevents an embryo from developing normally. Other studies have reported a strong association between TDCIPP and infertility among women undergoing fertility treatments.

Knowing its use is still widespread in cars, Volz wondered whether a person's exposure is elevated based on their commute. UC Riverside undergraduates made for excellent study subjects, as a majority of them have a daily commute.

The research team included collaborators at Duke University and was funded by the National Institutes of Health as well as the USDA National Institute of Food and Agriculture.

Participants included around 90 students, each of whom had commute times that varied from less than 15 minutes to more than two hours round trip. All of them were given silicone wristbands to wear continuously for five days.

The molecular structure of silicone makes it ideal for capturing airborne contaminants. Since TDCIPP isn't chemically bound to the foam, Aalekyha Reddam, a graduate student in the Volz laboratory, said it gets forced out over time and ends up in dust that gets inhaled.

Multiple organophosphate esters were tested, but TDCIPP was the only one that showed a strong positive association with commute time.

"Your exposure to TDCIPP is higher the longer you spend in your vehicle," Reddam said.

While Volz and his team did not collect urine samples to verify that the chemical migrated into the bodies of the participants, they believe that's what happened.

"We presume it did because of how difficult it is to avoid the ingestion and inhalation of dust," Volz said. Additionally, other studies have examined the accumulation of TDCIPP in urine, but not as a function of how long a person sits in a car.

Going forward, the research team would like to repeat the study with a larger group of people whose ages are more varied. They would also like to study ways to protect commuters from this and other toxic compounds.

Until more specific reduction methods can be identified, the team encourages frequently dusting the inside of vehicles, and following U.S. Environmental Protection Agency guidelines for reducing exposure to contaminants.

Until safer alternatives are identified, more research is needed to fully understand the effects of TDCIPP on commuters.

"If we picked up this relationship in five days, what does that mean for chronic, long-term exposure, for people who commute most weeks out of the year, year over year for decades?" Volz asked.

Pet tags link widely used flame retardant to hyperthyroidism in cats

More information: Aalekhya Reddam et al, Longer commutes are associated with increased human exposure to tris(1,3-dichloro-2-propyl) phosphate, Environment International (2020). DOI: 10.1016/j.envint.2020.105499

REVENGE
Pangolin identified as potential link for coronavirus spread

AFP

The endangered pangolin may be the link that facilitated the spread of the novel coronavirus across China, Chinese scientists said Friday.

© Sam YEH Researchers at the South China Agricultural University have identified the scaly pangolin as a 'potential intermediate host' for the virus

Researchers have long suspected that the virus, which has now killed more than 630 people and infected some 31,000, was passed from an animal to a human at a market in the central Chinese city of Wuhan late last year.

Researchers at the South China Agricultural University have identified the scaly mammal as a "potential intermediate host," the university said in a statement, without providing further details.

The new virus is believed to have originated in bats, but researchers have suggested there could have been an "intermediate host" in the transmission to humans.

After testing more than 1,000 samples from wild animals, scientists from the university found the genome sequences of viruses found on pangolins to be 99 percent identical to those on coronavirus patients, the official Xinhua news agency reported.

© AFP Graphic on pangolins, the world's most heavily trafficked mammals.

The pangolin is considered the most trafficked animal on the planet and more than one million have been snatched from Asian and African forests in the past decade, according to the International Union for Conservation of Nature (IUCN).

They are destined for markets in China and Vietnam, where their scales are used in traditional medicine -- despite having no medical benefits -- and their meat is bought on the black market.

- Shadowy wildlife trade -

Experts on Friday called for the Chinese scientists to release more data from their research.

Simply reporting the similarity between the genome sequences of viruses is "not sufficient," said James Wood, a veterinary medicine professor at the University of Cambridge.

Wood said the results could have been caused by "contamination from a highly infected environment."

"We would need to see all of the genetic data to get a feel for how related the human and pangolin viruses are," Jonathan Bell, a professor of molecular virology at the University of Nottingham, said.

China in January ordered a temporary ban on the trade in wild animals until the epidemic is under control.

The country has long been accused by conservationists of tolerating a shadowy trade in endangered animals for food or as ingredients in traditional medicines.

"If we want to do everything in our power to prevent deadly disease outbreaks such as coronavirus, then a permanent ban on wildlife trade, in China, and around the world, is the only solution," said Neil D'Cruze, global head of wildlife research at World Animal Protection.

A price list that circulated on China's internet for a business at the Wuhan market showed a menagerie of animals or animal-based products including live foxes, crocodiles, wolf puppies, giant salamanders, snakes, rats, peacocks, porcupines, camel meat and other game -- 112 items in all.

The SARS (Severe Acute Respiratory Syndrome) virus that killed hundreds of people in China and Hong Kong in 2002-03 also has been traced to wild animals, with scientists saying it likely originated in bats, later reaching humans via civets.

"Working to end the trade in wildlife can help to resolve some of the longer-term risks associated with animal reservoirs of zoonoses," Wood said, referring to infectious diseases that can be passed between animals and humans.

---30---

Pangolin Suspect #1 as direct source of coronavirus outbreak

Researchers at the South China Agricultural University have identified the scaly pangolin as a 'potential intermediate host' for the virus

Chinese researchers investigating the animal origin of the deadly coronavirus outbreak in China said Friday the endangered pangolin may be the "missing link" between bats and humans, but other scientists said the search may not be over.

An earlier study—since discredited—pointed to snakes, and there remain numerous candidate species in the Wuhan wildlife market thought to be ground zero of the epidemic.

The SARS outbreak of 2002-3, involving a different strain of coronavirus, was transferred to humans by the civet, a small mammal prized in China for its flesh.

Missing link: A pangolin?

Many animals are capable of transmitting viruses to other species, and nearly all strains of the coronavirus contagious to humans originated in wildlife.

Bats are known carriers of the latest strain of the disease, which has infected at least 31,000 people and killed more than 630 worldwide, mostly in China where the outbreak originate.

A recent genetic analysis showed that the strain of the virus currently spreading among humans was 96 percent identical to that found in bats.

But according to Arnaud Fontanet, from France's Pasteur Institute, the disease likely didn't jump straight from bats to humans.

"We think there's another animal that's an intermediary," he told AFP.

Several studies have shown that the bat-bourne virus lacks the necessary hardware to latch on to human cell receptors. But it's still not clear which animal is the missing link.

Fontanet believes the intermediary was "probably a mammal," possible belonging to the badger family.

After testing more than 1,000 samples from wild animals, scientists at the South China Agricultural University found the genome sequences of viruses in pangolins to be 99 percent identical to those on coronavirus patients, the official Xinhua news agency reported.

But other experts urged caution.

"This is not scientific evidence," said James Wood, head of the department of veterinary medicine at the University of Cambridge. "Investigations into animal reservoirs are extremely important, but results must be then be published for international scrutiny."

"Simply reporting detection of viral RNA with sequence similarity of 99+ percent is not sufficient," he added.

Wild goose chase?

To conclusively identify the culprit, researchers would need to test each species that was on sale at the market—a near impossibility given that it's now permanently closed.

Martine Peeters, a virologist at France's Institute for Research and Development (IRD), worked on the team that identified the host animal of the Ebola virus during recent epidemics.

Endangered pangolins — Graphic on pangolins, the world's most heavily trafficked mammals.

They found that it was indeed a bat that passed the virus on to humans, and Peeters believes that's likely to be the case this time around.

During her Ebola research, "we collected thousands of bat dropping from several sites in Africa," Peeters told AFP.

Fontanet said that Chinese researchers were doing likewise now.

"They say they've analysed samples from a rubbish truck," he said. "They don't say which, but I think it's likely to have been excrement that was just lying around."

Why does it matter?

While it may be too late for this outbreak, identifying the carrier animal for the novel coronavirus could prove vital in preventing future flare ups.

China for example outlawed the sale of civet for food in the wake of the SARS epidemic.

Eric Leroy, a virologist and vet at the IRD said the search could well turn up a result quickly like in the case of SARS. Equally, it could take years.

"With Ebola, research started in 1976 and we didn't see the first results published until 2005," he told AFP.

One determining factor could be what percentage of the same species are infected.

"If that's low, less than one percent for example, that's obviously going to lower the chance you stumble upon an infected animal," said Leroy.

Prevent future outbreaks?

For Fontanet, coronavirus is just the latest example of the potentially disastrous consequence of humans consuming virus-carrying wild animals.

He said that China needed to "take pretty radical measures against the sale of wild animals in markets."

Beijing has prohibited the practice, but only moved to do so last month, when the outbreak was already out of control.

"Each time, we try to put out the fire, and once it's out we await the next one," said Francois Renaud, a researcher at the Paris-based National Centre for Scientific Research.

He recommended compiling a watch list of all animals that could potentially transmit viruses to humans.

"You need to see epidemics before they come, and therefore you need to be proactive," he said.

Studies suggest role of bats, snakes in outbreak of China virus

Study: To slow an epidemic, focus on handwashing

We learned this lesson during the H1N1 Pandemic
aparently the lesson needs to be repeated over and over

since this is also the way Norovirus spreads.
by David L. Chandler, Massachusetts Institute of Technology

Based on their study, the authors found that focusing efforts to increase handwashing rates at just 10 airports chosen based on the location of the outbreak could significantly reduce disease spread. In these maps, they show the airports that would be targeted for outbreaks originating near Honolulu, Hawaii, or Dubai, United Arab Emirates. Credit: Massachusetts Institute of Technology

A new study estimates that improving the rates of handwashing by travelers passing through just 10 of the world's leading airports could significantly reduce the spread of many infectious diseases. And the greater the improvement in people's handwashing habits at airports, the more dramatic the effect on slowing the disease, the researchers found.

The findings, which deal with infectious diseases in general including the flu, were published in late December, just before the recent coronavirus outbreak in Wuhan, China, but the study's authors say that its results would apply to any such disease and are relevant to the current outbreak.

The study, which is based on epidemiological modeling and data-based simulations, appears in the journal Risk Analysis. The authors are Professor Christos Nicolaides PhD '14 of the University of Cyprus, who is also a fellow at the MIT Sloan School of Management; Professor Ruben Juanes of MIT's Department of Civil and Environmental Engineering; and three others.

People can be surprisingly casual about washing their hands, even in crowded locations like airports where people from many different locations are touching surfaces such as chair armrests, check-in kiosks, security checkpoint trays, and restroom doorknobs and faucets. Based on data from previous research by groups including the American Society for Microbiology, the team estimates that on average, only about 20 percent of people in airports have clean hands—meaning that they have been washed with soap and water, for at least 15 seconds, within the last hour or so. The other 80 percent are potentially contaminating everything they touch with whatever germs they may be carrying, Nicolaides says.

"Seventy percent of the people who go to the toilet wash their hands afterwards," Nicolaides says, about findings from a previous ASM study. "The other 30 percent don't. And of those that do, only 50 percent do it right." Others just rinse briefly in some water, rather than using soap and water and spending the recommended 15 to 20 seconds washing, he says. That figure, combined with estimates of exposure to the many potentially contaminated surfaces that people come into contact with in an airport, leads to the team's estimate that about 20 percent of travelers in an airport have clean hands.

Improving handwashing at all of the world's airports to triple that rate, so that 60 percent of travelers to have clean hands at any given time, would have the greatest impact, potentially slowing global disease spread by almost 70 percent, the researchers found. Deploying such measures at so many airports and reaching such a high level of compliance may be impractical, but the new study suggests that a significant reduction in disease spread could still be achieved by just picking the 10 most significant airports based on the initial location of a viral outbreak. Focusing handwashing messaging in those 10 airports could potentially slow the disease spread by as much as 37 percent, the researchers estimate.

They arrived at these estimates using detailed epidemiological simulations that involved data on worldwide flights including duration, distance, and interconnections; estimates of wait times at airports; and studies on typical rates of interactions of people with various elements of their surroundings and with other people.

Even small improvements in hygiene could make a noticeable dent. Increasing the prevalence of clean hands in all airports worldwide by just 10 percent, which the researchers think could potentially be accomplished through education, posters, public announcements, and perhaps improved access to handwashing facilities, could slow the global rate of the spread of a disease by about 24 percent, they found. Numerous studies (such as this one) have shown that such measures can increase rates of proper handwashing, Nicolaides says.

"Eliciting an increase in hand-hygiene is a challenge," he says, "but new approaches in education, awareness, and social-media nudges have proven to be effective in hand-washing engagement."

The researchers used data from previous studies on the effectiveness of handwashing in controlling transmission of disease, so Juanes says these data would have to be calibrated in the field to obtain refined estimates of the slow-down in spreading of a specific outbreak.

The findings are consistent with recommendations made by both the U.S. Centers for Disease Control and the World Health Organization. Both have indicated that hand hygiene is the most efficient and cost-effective way to control disease propagation. While both organizations say that other measures can also play a useful role in limiting disease spread, such as use of surgical face masks, airport closures, and travel restrictions, hand hygiene is still the first line of defense—and an easy one for individuals to implement.

While the potential of better hand hygiene in controlling transmission of diseases between individuals has been extensively studied and proven, this study is one of the first to quantitatively assess the effectiveness of such measures as a way to mitigate the risk of a global epidemic or pandemic, the authors say.

The researchers identified 120 airports that are the most influential in spreading disease, and found that these are not necessarily the ones with the most overall traffic. For example, they cite the airports in Tokyo and Honolulu as having an outsized influence because of their locations. While they respectively rank 46th and 117th in terms of overall traffic, they can contribute significantly to the spread of disease because they have direct connections to some of the world's biggest airport hubs, they have long-range direct international flights, and they sit squarely between the global East and West.

For any given disease outbreak, identifying the 10 airports from this list that are the closest to the location of the outbreak, and focusing handwashing education at those 10 turned out to be the most effective way of limiting the disease spread, they found.

Nicolaides says that one important step that could be taken to improve handwashing rates and overall hygiene at airports would be to have handwashing sinks available at many more locations, especially outside of the restrooms where surfaces tend to be highly contaminated. In addition, more frequent cleaning of surfaces that are contacted by many people could be helpful.

Explore furtherUS beefs up screening of travelers for new virus from China
More information: Christos Nicolaides et al. Hand‐Hygiene Mitigation Strategies Against Global Disease Spreading through the Air Transportation Network, Risk Analysis (2019). DOI: 10.1111/risa.13438
Journal information: Risk Analysis

Provided by Massachusetts Institute of Technology

This story is republished courtesy of MIT News (web.mit.edu/newsoffice/), a popular site that covers news about MIT research, innovation and teaching.
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Research voyage brings Zealandia secrets to the surface

by Victoria University of Wellington

Fresh evidence of how the continent of Zealandia was created has been published by an international team of scientists co-led by Te Herenga Waka—Victoria University of Wellington's Professor Rupert Sutherland.

The research both upends the previous theory and establishes a new geological concept.

Professor Sutherland from the University's School of Geography, Environment and Earth Sciences was part of the team of predominantly GNS Science researchers that made global headlines in 2017 when they announced Zealandia should count as a new fully-fledged continent, Earth's seventh and smallest.

New Zealand to the south and New Caledonia to the north are the only major land masses of the otherwise mostly underwater Zealandia, which, at 4.9 million square kilometers, is about two-thirds the size of Australia.

Its continental crust is mostly between 10 and 30 kilometers thick, which is thinner than the 30 to 45 kilometers of the six other continents, yet thicker than oceanic crust, which is about seven kilometers thick.

The first scientific drilling expedition to Zealandia in 1972 hypothesized it was underwater after its crust was stretched, thinned and ripped away from the ancient supercontinent of Gondwana (which included Australia and Antarctica) about 85 million years ago.

Although evidence remains compelling that this was at least part of the case, new samples collected and tested by Professor Sutherland and his colleagues during a nine-week Tasman Sea voyage under the auspices of the International Ocean Discovery Program indicate a key additional factor: Zealandia's subsequent modification during the formation of the Pacific Ring of Fire about 50 million years ago.

The Pacific Ring of Fire is a zone of volcanoes and earthquakes that result from the geological process of subduction, where a tectonic plate sinks back deep into the Earth. The process by which the zone formed has always been a mystery.

"We propose that a 'subduction rupture event' propagated around the whole of the western Pacific at that time," says Professor Sutherland. "We suggest the process was similar to a massive super-slow earthquake that resurrected ancient subduction faults that had lain dormant for many millions of years. This concept of 'subduction resurrection' is a new idea and may help explain a range of different geological observations."

As a result of the Pacific Ring of Fire, "things that were in 1,000 meters of water came up to sea level and then subsided down to be more than 1,000 meters deep again," he says. "The permanent effects included the New Caledonia Trough that comes all the way to Taranaki."

Professor Sutherland's team included more than 30 scientists from New Zealand, the United States, Italy, Spain, New Caledonia, China, the Netherlands, Germany, Brazil, Japan, the United Kingdom and South Korea. He co-led it with Professor Gerald Dickens from Rice University in Texas in the United States.

They used a 300-tonne drill to make six boreholes up to 900 meters below the sea floor, from which rock and sediment cores were collected and analyzed for clues about the timing and length of Zealandia's uplift.

"We used fossils from three of the sites to show that northern Zealandia became much shallower and likely even had land areas between 50 and 35 million years ago. At about the same time, two other sites subsided into deeper water, and then the whole region subsided by at least a kilometer to its present depth," says Professor Sutherland.

The team's evidence shows that events such as the creation of the Pacific Ring of Fire "can dramatically alter the geography of continents, and the sedimentary record preserved on Zealandia will help us figure out in more detail how and why it happened, and what the consequences were for plants, animals, and regional climate."

Lost continent of Zealandia: Scientists return from expedition to sunken land

More information: R. Sutherland et al. Continental-scale geographic change across Zealandia during Paleogene subduction initiation, Geology (2020). DOI: 10.1130/G47008.1

New research to help identify safe sites for nuclear waste storage

by University of Sheffield

New insights into rates of bedrock erosion by glaciers around the world will help to identify better sites for the safe storage of nuclear waste, according to researchers.

A new analysis of global glacier erosion rates and flow speeds by scientists at the University of Sheffield, University of Dundee and Keele University has overturned previous findings about the link between glacial flow and erosion rates.

Published in Nature Communications today, the findings confirm the importance of glacier flow speed in determining the rate of glacial erosion. But in an unexpected result, the scientists show that the increase in erosion rate with glacier flow speed occurs much more slowly than previously thought.

Dr. Darrel Swift, a member of the Energy Institute at the University of Sheffield, said: "As glaciers flow downhill, they slide over the bedrock beneath, causing the bedrock to be eroded. This analysis shows that a glacier that flows twice as fast as its neighbor does not necessarily produce twice the rate of bedrock erosion.

"This may be because, as glacier flow speed increases, spaces between the ice and the bed are formed in the lee of bedrock bumps. This means that the base of the glacier begins to separate from, or lose contact with, the bed.

"This effect has been suggested by some to enhance the rate of erosion, because it increases the stress placed by sliding ice on the few lumps of bedrock that remain in contact with the glacier's base. However, it is perfectly possible that this effect is negated by the fact that less and less of the bed is in contact with sliding ice."

For the first time, the analysis also shows the clear importance of local temperature and precipitation in determining glacial erosion rates at the global scale.

Dr. Swift explained: "The speed of glacier flow is important because this dictates how fast ice at the base of the glacier slides over the bedrock beneath.

"But a glacier also has to keep its bed clean. This is because sediment produced by erosion can accumulate at the glacier bed, and the accumulation of a thick sediment layer would eventually slow the rate of erosion. Warmer and wetter environments may help glaciers to wash their beds because glacial melt will likely be more abundant, and this means sliding ice will maintain closer contact with bedrock."

The findings help to explain patterns of glacial erosion produced by glaciers and larger ice caps or ice sheets, which are responsible for creating spectacular Alpine landscapes—and also have implications for the safe long-term storage of hazardous nuclear waste.

Dr. Swift, who has advised organizations responsible for the siting and development of deep geological nuclear waste disposal facilities, said: "For many countries, underground storage of hazardous nuclear waste in a deep geological facility is the accepted safest solution. Organisations responsible for finding suitable sites for these facilities, and for designing the necessary underground infrastructure, must ensure that future glacial erosion will not adversely affect the facility's integrity.

"Advancing ice during future glacial periods could, over many hundreds of thousands of years, remove many hundreds of meters of bedrock. This would likely affect the environment of the disposal facility beneath, where nuclear waste can remain dangerous for over 100,000 years.

"In many countries, otherwise ideal sites for the development of deep geological disposal facilities are in areas that have previously been covered by ice. This means that those sites will likely experience glaciation, and glacial erosion, in the future."

How some of Earth's most breathtaking landscapes are created by glaciers

More information: Simon J. Cook et al. The empirical basis for modelling glacial erosion rates, Nature Communications (2020). DOI: 10.1038/s41467-020-14583-8

Meet the 71-year-old staging a one-man protest in his Trump-loving retirement community

For most of his life, Ed McGinty kept his political beliefs to himself.

Ed McGinty is a rare protester in the Trump stronghold of The Villages. “When Trump won, it changed the whole ballgame for me,” McGinty says. “I thought to myself, ‘This was supposed to be a joke. What’s wrong with these people?’ ” (Chris Stanley)

Raised Irish Catholic in Philadelphia, the 71-year-old retired real estate broker has always been a Democrat, just like his parents before him. But the last time he remembers being especially politically motivated was when Hubert Humphrey ran against Richard Nixon in 1968. After that, he’d wake up the morning after Election Day, find out George W. Bush or another Republican had won and say, “Okay, well, back to work.”

Then Donald Trump was elected.

“When Trump won, it changed the whole ballgame for me,” McGinty told The Washington Post. “I thought to myself, ‘This was supposed to be a joke. What’s wrong with these people?’ ”

In the three years since then, the once-quiet political observer has transformed into the best-known Trump protester in The Villages, a sprawling, meticulously planned and maintained retirement community that lies about 45 miles northwest of Orlando. McGinty’s daily vigil with signs blasting the president as a “SEXUAL PREDATOR” (among other things) has drawn ire in the Trump-loving Florida town he has called home since 2016. It has also brought viral fame.

For his one-man protest against the president, McGinty has been berated as a baby killer and a “dumb a--,” decried in letters to the editor of a local news site and hit with an anonymous, handwritten threat — a sign that even a town that is described as Disney World for retirees and markets itself as “Florida’s Friendliest Hometown” is not immune to the divisiveness of this political era.

“There was always a divide, but we coexisted,” said Chris Stanley, president of The Villages Democratic Club. “There would be some good-natured back and forth, but your neighbors were your friends. You’d have dinner with the Republicans because it wasn’t a big deal. … These days, the division in the country shows up best in The Villages because now the Republicans, they won’t golf with you anymore, or you don’t want to golf with them.”

The 120,000-person enclave is a Trump stronghold in a county the president carried by nearly 70 percent, where Republicans outnumber Democrats two to one and golf carts — the main mode of transportation — are adorned with Trump bumper stickers. A regular stop for GOP politicians and hopefuls, it is Republican to its roots, created by billionaire conservative developer H. Gary Morse, who donated millions of dollars to the party’s candidates and committees before his death in 2014.

Even employees of The Villages have been pressured to support the Republican cause, according to Politico Magazine, which noted in a 2018 feature on the community that the development firm encouraged them to donate to Mitt Romney’s 2012 presidential campaign to show that “The Villages family is ‘all in.’ ”

Jerry Prince, president of The Villages Republican Club, disputed the notion that the town has become highly politicized as a result of Trump’s rise, saying that most political disagreements are benign and short-lived. He supports the president but has maintained friendships with people who do not.

“There’s radicals on both sides, okay,” he said. “And I’ve heard of people wearing a Trump hat and somebody berates them, and I’ve seen the Republican side berate people to the left down here. They would have done that if they were in New York, or wherever the hell they came from.”

In McGinty’s telling, however, merely wearing an Elizabeth Warren hat cost him the friendly relationship he shared with a neighbor who used to give treats to his dogs. The man demanded he stop wearing the Warren hat — “and that was what really began my quest,” McGinty said. He called it “the defining day of my life as far as protesting.”

Soon after that encounter, he added the first of many anti-Trump signs to his golf cart, which previously was decorated only with stickers bearing the Penn State logo and his and his wife’s names. He rode around undeterred and even amused by the response: People shouting obscenities and giving him the finger, along with the occasional thumbs-up.

These days, McGinty devotes about two hours a day to protesting, crashing rallies planned by the Villagers for Trump group and parking his golf cart in well-trafficked areas where people are most likely to see his signs: “TRUMP BIGOT AND RACIST,” “TRUMP IS A SEXUAL PREDATOR” and “TRUMP COMPULSIVE LIAR.” He said he rotates between about 30 posters carrying various anti-Trump sentiments. He sits in his cart reading while he puts them on display, enjoying the confrontations that follow.

His critics call it deranged. Stanley calls it “something that’s coming from his soul.”

McGinty said he watched Trump’s career in New York and was appalled by his tabloid-fodder infidelity. During the 2016 election, he was angered anew by the then-candidate’s mocking of a disabled reporter, which was personal, McGinty said, because he has a sister with a disability.

He thinks Trump is immoral and unqualified, and he is frustrated by his community’s vehement support for him.

“These people down here are emboldened because there’s so many of them,” McGinty said. “And they really try to intimidate any Democrat that even sticks his head above water.”

His chief adversary — Villagers for Trump, which hosts frequent sign wavings and turns out for visits from MAGA stars including George Papadopoulos and Roger Stone, both convicted in the special counsel investigation into Russian election interference — did not respond to The Post’s request for comment.

But Stanley, the Democratic club president, agreed that opposition to Democrats has become more forceful. She said her 800-member group has always had to rent office space outside of The Villages, unable to get a lease in town. But now the partisan divide has gotten “ugly,” she said, pointing to video of a man pulling down an anti-Trump protester who had climbed onto a bench during a rally for the president’s October visit to the town

She’s started new golf and dinner clubs for Democrats whose previous social circles were casualties of the 2016 election.

“If the rest of the country is as ugly as it is here,” Stanley said, “that’s terrifying.”

Tension over McGinty’s protest hit new heights last week, when he found a threatening letter on his front door. “BE VERY CAREFUL IF THE WELL BEING OF YOUR FAMILY IS OF IMPORTANCE,” it read. The Sumter County Sheriff’s Office took a report on the “vague threat,” noting that “Mr. McGinty advised he had no idea who had composed the note, but thought it was due to his political views.”

Days later, video of an exchange between McGinty and a woman who said she would “defend Trump until the day I die” went viral on Twitter, earning him notice outside of the Villages bubble.

The argument started when the woman, identified by Villages-News.com as Marsha Hill, approached McGinty with a camera rolling and asked him why he thought Trump was a sexual predator. An incredulous McGinty said the president had “admitted it,” citing the infamous hot-microphone conversation in which he bragged about groping women.

“Do you live in a cave, lady?” he asked, closing the book he’d been reading: “A Very Stable Genius,” by Post reporters Philip Rucker and Carol Leonnig.

There were honks and name-calling. Hill announced that she was going to send the video to Trump and his son, Donald Trump Jr. McGinty responded, “Good. And tell Donald Trump to come down here. I want to punch him right in the nose.”

“This guy should be arrested,” Hill told Villages-News.com, accusing McGinty of defamation. “You can’t say that about the president with no proof.”

But when she posted footage of the confrontation on Twitter, tagging conservative radio commentator and failed Florida congressional candidate Dan Bongino, people ridiculed her and rallied around McGinty.

“THIS GUY IS AN AMERICAN HERO!!” said one representative tweet. McGinty’s own sparsely used Twitter account (pinned tweet: “I can’t wait for the presidential election #GoodbyeTrump”) picked up nearly 20,000 followers. Hill briefly locked hers (bio: “Trumpateer. MAGA2020”), writing in a tweet that “Twitter liberals are the meanest” and that she had been harassed.

In letters to the editor of the local news site, one of McGinty’s neighbors suggested that he was “suffering from a devastating case of Trump Derangement Syndrome” and called his new Twitter fans “lemming Trump haters.” Another noted that his speech is protected by the Constitution, “besides the fact that I whole heartedly agree with him.” A third said the “rabid fans of Trump have made living in The Villages intolerable,” while a fourth brought up Hillary Clinton, imagining a “disastrous future” if she had been elected and brought “her rapist husband back into the White House.”

Prince, of the Republican club, told The Post he wasn’t familiar with McGinty, and doesn’t get agitated by protesters anyway.

“The thing I say is, ‘This is America and you can think what you want,’ ” he said.

For his part, McGinty was back in his golf cart this week with his “TRUMP COMPULSIVE LIAR” sign. During an hour-long phone interview with a Post reporter on Wednesday, he was approached by a man who hurled an insult not fit for print (McGinty responded in kind) and by a woman who called him “my hero.” He handed her the phone.

“I had to come over and shake his hand,” she said, declining to give her name. “I just admire him for being so courageous.”

It was just another day in the lonesome stand against Trump: Angry opposition, quiet praise and McGinty in the middle, reveling in it all. His wife worries, his neighbors think he’s crazy and some of his friendships have suffered.

But he said he has no intention of stopping: His newfound activism is one of the things he’s most proud of in his life.

“I’m proud that I’m standing up for what’s right,” he said. “There’s never been a doubt in my mind that what I’m doing is right.”