Category: Science

The pace and extent of ice destabilization along West Antarctica’s coast varies according to differences in regional climate, according to a new study.

The researchers combined satellite imagery and climate and ocean records to obtain the most detailed understanding yet of how the West Antarctic Ice Sheet—which contains enough ice to raise global sea level by 11 feet, or 3.3 meters—is responding to climate change.

The findings in Nature Communications show that while the West Antarctic Ice Sheet continues to retreat, the pace of retreat slowed in a key region between 2003 and 2015, driven by ocean temperatures, which were in turn caused by variations in offshore winds.

The marine-based West Antarctic Ice Sheet, home to the vast and unstable Pine Island and Thwaites glaciers, sits on an underwater landmass peaking 1.5 miles, or 2.5 kilometers, below the ocean’s surface.

Since the early 1990s, scientists have observed an abrupt acceleration in ice melt, retreat, and speed in this area, which is attributed in part to human-induced climate change over the past century.

Previous studies indicated that the observed changes could be the onset of an irreversible, ice-sheet-wide collapse, which would continue independently of any further climate-driven influence.

“The idea that once a marine-based ice sheet passes a certain tipping point it will cause a runaway response has been widely reported,” says lead author Frazer Christie at Cambridge University. “Despite this, questions remain about the extent to which ongoing changes in climate still regulate ice losses along the entire West Antarctic coastline.”

Using observations collected by an array of satellites, the new study found pronounced regional variations in how the West Antarctic Ice Sheet has changed since 2003 due to climate change, with the pace of retreat in the Amundsen Sea Sector, an area of West Antarctica facing the Pacific Ocean, having slowed significantly. That’s in contrast to the neighboring Bellingshausen Sea Sector, closer to the tip of the Antarctic Peninsula, where glacier retreat accelerated during that time.

By analyzing climate and ocean records, the researchers linked these regional differences to changes in the strength and direction of offshore surface winds. When the prevailing westerly winds are stronger, more of the deeper, warmer ocean water reaches the surface and increases the rate of ice melt.

Researchers found that winds near the Amundsen Sector slackened between 2003 and 2015, because of a deepening of the Amundsen Sea low pressure system. This system is the key atmospheric circulation pattern in the region, and its center—near which changes in offshore wind strength are greatest—typically sits offshore of its namesake coast for most of the year.

The researchers found that the accelerated response of the glaciers flowing from the Bellingshausen Sea Sector can be explained by more constant winds there, causing more persistent ocean-driven melt.

Ultimately, the study illustrates the complexity of the competing ice, ocean, and atmosphere interactions driving shorter-term changes across West Antarctica, and raises important questions about how quickly the icy continent will evolve in a warming world.

“Ocean and atmospheric forcing mechanisms still really, really matter in West Antarctica,” says coauthor Eric Steig, a professor of earth and space sciences at the University of Washington. “That means that ice-sheet collapse is not inevitable. It depends on how climate changes over the next few decades, which we could influence in a positive way by reducing greenhouse gas emissions.”

And while the strength of the low-pressure cell in the Amundsen Sea is not necessarily tied to levels of greenhouse gases—itself an active area of study—the system’s influence shows that even the West Antarctic ice sheet is sensitive to weather and climate shifts.

Results show that changes in ocean, driven by changes in the winds, can slow down and even reverse the loss of ice, Steig says. But he points out that the effect is local and unlikely to last for more than a few decades.

“Only the most aggressive reductions in greenhouse gas emissions can plausibly turn the situation around in the long term,” Steig says.

Additional coauthors are from the University of Edinburgh. Support for the study came from the Carnegie Trust for the Universities of Scotland; the Scottish Alliance for Geoscience, Environment and Society; the Prince Albert II of Monaco Foundation; the UK Natural Environment Research Council; the US National Science Foundation; the joint UK/US International Thwaites Glacier Collaboration project; and the European Space Agency.

Source: University of Washington

Black and Hispanic hairdressers are exposed to a complex mixture of chemicals, many of them unknown, potentially hazardous, and undisclosed on product labels, researchers report.

The new study is the first to apply an advanced screening technique used to identify chemicals in food and wastewater to assess chemical exposures in hairdressers.

The results, published in the Journal of Exposure Science and Environmental Epidemiology, suggest more research is needed to better understand the risks for hairdressers, particularly those of color, and how best to mitigate them.

“We know women are more highly exposed to chemicals in personal care products and we also know women of color have elevated exposures compared to women of other demographics,” says coauthor and principal investigator Lesliam Quirós-Alcalá, an assistant professor of environmental health and engineering at Johns Hopkins University who studies chemical exposures’ health effects in underrepresented populations.

“We wondered, what about women who are doing this as a profession. How much more are they being exposed. There really wasn’t anything out there when we started this.”

Researchers tested urine samples from Black and Hispanic hairdressers in the United States and compared them to samples from women of color working in office jobs. Hairdressers of color are suspected to have more chemical exposures than stylists of other demographics because of the products used and services provided in salons serving primarily populations of color.

Unlike traditional studies, the team didn’t only measure for chemicals expected to be found in people working with hair products, they looked for other compounds that had not been previously investigated.

“The conventional methods just look for chemicals we might expect to be present, but these products contain a lot of different chemicals and not all of them are known,” says senior author Carsten Prasse, an assistant professor of environmental health and engineering who studies public and environmental health impacts of chemicals in the environment.

“We wanted to open up the lens and find potential other chemicals that hairdressers might be exposed to so that we could inform future regulations of these chemicals.”

Using the same technique, the Prasse Lab recently found vaping aerosols contain thousands of unknown chemicals and substances not disclosed by manufacturers.

Compared to the women working in offices, hairstylists had higher levels of chemicals in their bodies associated with salon treatments—hair relaxers, conditioners, dyes, and fragrances—but also many more substances the researchers couldn’t identify.

“There are more chemical exposures in this occupation group than we expect,” says lead author Matthew N. Newmeyer, a postdoctoral fellow at the Johns Hopkins Bloomberg School of Public Health.

“It’s definitely concerning. A lot of these chemicals we don’t even know what health risks they may pose,” says Quirós-Alcalá

There are more than 700,000 hairdressers in the United States, more than 90% of whom are estimated to be female, and 30% are Black or Hispanic/Latina. In this predominantly female workforce, with many women of reproductive age, exposures may not only pose a women’s health issue, but also a children’s health issue as exposures during the preconception and prenatal period could increase children’s health risks, Quirós-Alcalá says. About half the hairdressers in this study reported working in the salon while pregnant.

The findings show more studies are critical to better understand what hairdressers are exposed to on the job, and to determine how best to mitigate these risks and to try to reduce any health disparities, Prasse says.

“It’s clearly an under researched area,” he says, “and there is a racial dimension to it which must not be forgotten.”

Additional coauthors are from the University of Maryland and Johns Hopkins.

The NHLBI Career Development Award, NIEHS Training grant, the US Centers for Disease Control and Prevention, and the National Institute for Occupational Safety and Health funded the work.

Source: Johns Hopkins University

Alcohol may improve an in-person party, but the same doesn’t hold true for Zoom happy hour, research suggests.

Results from a study published in Clinical Psychological Science suggest combining alcohol and virtual social interaction had negative effects compared to in-person gatherings.

In the study, participants video called either a friend or a stranger seated in a separate room. Researchers gave some participants alcoholic drinks and others nonalcoholic drinks.

As the call took place, researchers tracked participants’ eye movements, or “gaze behavior.”

The study showed that participants who consumed alcohol before conducting the video chat spent more time watching themselves during the conversation instead of their partners. They also felt more negative after the virtual exchange than the people who didn’t drink.

Additionally, the mood-enhancing properties of alcohol seen in in-person interactions weren’t seen in the virtual interactions, says coauthor Michael Sayette, a professor of psychology at the University of Pittsburgh.

“In a face-to-face conversation, we would expect alcohol to reduce your focus on yourself, which is one of the effects of alcohol that people seem to enjoy,” he says. “Yet in this online study, when your own face is staring back at you from the monitor, it seems that alcohol loses this effect. This may explain why some people don’t find alcohol to enhance socializing in a virtual format.”

Sayette also notes evidence that reducing one’s drinking or participating in Dry January or Sober October could provide longer-lasting health benefits.

“I would say that if you are not missing drinking, then there is no reason to return to it when February begins,” Sayette says. “It may turn out to improve your overall health, especially if you are a heavy drinker.”

Source: Donovan Harrell for University of Pittsburgh

A new study shows that levodopa, a drug that increases dopamine in the brain, has potential to reverse the effects of inflammation on brain reward circuitry, ultimately improving symptoms of depression.

Numerous labs across the world have shown that inflammation causes reduced motivation and anhedonia, a core symptom of depression, by affecting the brain’s reward pathways.

Past research from the department of psychiatry and behavioral sciences at Emory University School of Medicine has linked the effects of inflammation on the brain to decreased release of dopamine, a chemical neurotransmitter that regulates motivation and motor activity, in the ventral striatum.

In the study in the journal Molecular Psychiatry, researchers demonstrate that levodopa reversed the effects of inflammation on the brain’s functional connectivity in reward circuitry and anhedonia (inability to feel pleasure) in depressed individuals with higher C-reactive protein (CRP), a blood biomarker produced and released by the liver in response to inflammation.

Levels of inflammation can be easily measured by simple blood tests, like CRP, readily available in clinics and hospitals throughout the US.

The study included 40 depressed patients with a range of CRP levels from high to low who underwent functional brain scans on two visits after receiving in random order either placebo or levodopa, a drug often prescribed for disorders like Parkinson’s disease.

Levodopa improved functional connectivity in a classic ventral striatum to ventromedial prefrontal cortex reward circuit but only in patients with higher levels of CRP. This improvement in reward circuitry in depressed individuals with higher CRP also correlated with reduced symptoms of anhedonia after levodopa.

“This research demonstrates the translational potential for use of inflammation-related deficits in functional connectivity and could have important implications for the future investigations of precision therapies for psychiatric patients with high inflammation,” says principal investigator and senior author Jennifer C. Felger, associate professor of psychiatry and behavioral sciences at Emory School of Medicine.

Felger says the study findings are critical for two reasons. First, they suggest depressed patients with high inflammation may specifically respond to drugs that increase dopamine.

Second, Felger says these findings also provide additional evidence that functional connectivity in reward circuitry may serve as a reliable brain biomarker for the effects of inflammation on the brain.

“Moreover, as the effect of levodopa was specific to depressed patients with higher inflammation, this functional connectivity may be used to assess the responsiveness of the brain to novel treatments that might be targeted to this subtype of depressed patients in future studies and clinical trials,” says Felger.

Source: Emory University

When providers act to curtail water use because of a drought, water bills can rise for low-income families while dropping for high-income households, researchers report.

Access to safe, affordable water is a necessity for human health and well-being. But when droughts strike areas that are already water-stressed, water providers are forced to enact measures to curtail water usage or invest in supplies from more expensive sources, which can increase costs for consumers.

According to the new study, these measures can disproportionately affect water bills for low-income households, making water more costly for the most vulnerable people.

“A low-income household often has a different response to curtailment measures and surcharges because of how much water they used before the drought,” says Benjamin Rachunok, who conducted the work as a postdoctoral researcher at Stanford University and is now an assistant professor at North Carolina State University. “This can lead to different affordability outcomes for low- and high-income people, even if the same processes and policies are being applied to everyone.”

The researchers found that in some cases, low-income households end up seeing bills rise during droughts, while high-income households see their bills drop. The work illuminates the interconnected mechanisms that affect affordability and may be able to help water planners and policymakers better understand the potential impacts of long- and short-term drought responses.

Water bill affordability

Drawing on public data from the 2011 to 2017 drought in California, the researchers built a model to examine how different combinations of drought length and severity, various resilience strategies, and household behavior can affect the affordability of water.

“The standard way of thinking about the connection between water scarcity and affordability has been to look at the cost of supplying water and how that cost is passed on to users through rate design,” says Sarah Fletcher, an assistant professor of civil and environmental engineering in Stanford Engineering and the Stanford Doerr School of Sustainability and senior author of the paper in Nature Water.

“But in order to fully understand the impacts of drought on water affordability, we have to include people’s behavioral responses to how the drought is unfolding and the restrictions that are put in place.”

When there is a water shortage, providers often ask consumers to cut back on their water usage, while applying a drought surcharge to bills to make up for lost revenue. Fletcher and Rachunok found that high-income households can cut back significantly, lowering their average water bill even with the addition of a surcharge.

Lower-income households, however, tend to have less flexibility in their water usage. Even when they are able to curtail their water use, the drop does not make up for the additional cost of the surcharge.

Water utilities may also invest in infrastructure, such as desalination or water-recycling plants, to increase their water supply. The model showed that in all drought scenarios, these projects increase costs and reduce affordability for low-income households.

“Affordability is a key part of water access,” Fletcher says. “If we think about water security as including affordability for low-income populations, then some of the expensive technological measures that we often consider might actually harm water security by making water unaffordable for a larger number of people.”

Long-term water planning

Water is typically considered affordable when it does not exceed between 2% and 4% of a household’s income. While the cost of supplying water is the primary driver of water bills, even a small bill increase during droughts could make it difficult for some households to afford the water they need.

By providing insight into the mechanisms that affect affordability, Fletcher and Rachunok hope to help cities evaluate different approaches for long-term water supply planning. They are continuing to investigate how rate structures and other drought management techniques affect people’s behavior and are working to develop a generalized approach to help regulators make the best decisions for an uncertain future.

“We have a changing climate and changing water needs,” Fletcher says. “We have to develop approaches that allow us to adapt in robust ways so that we can still have water systems that are reliable, cost effective, and provide all the services that we need. And we should really be centering the needs of vulnerable communities as we do that adaptation.”

The Stanford Impact Labs and the UPS Endowment Fund at Stanford University funded the work.

Source: Laura Castañón for Stanford University

The unique genetics of Australian black swans leaves them vulnerable to viral illnesses such as avian flu, according to a new study.

The first-ever genome of the black swan reveals the species lacks some immune genes which help other wild waterfowl combat infectious diseases.

The geographic isolation of Australia’s black swans has meant limited exposure to pathogens commonly found in other parts of the world, leading to reduced immune diversity, says Kirsty Short, associate professor in the School of Chemistry and Molecular Biosciences at the University of Queensland.

“Unlike mallard ducks for example, black swans are extremely sensitive to highly pathogenic avian influenza—HPAI which is often referred to as bird flu—and can die from it within three days,” Short says.

“Our data suggests that the immune system of the black swan is such that, should any avian viral infection become established in its native habitat, their survival would be in peril.

“We currently don’t have HPAI in Australia, but it has spread from Asia to North America, Europe, North Africa, and South America. “When it was introduced to new locations, such as Chile and Peru, thousands of wild seabirds perished.

“The risk to one of Australia’s most unique and beautiful birds is very real, and we need to be prepared if we hope to protect it.”

With the knowledge from the new study, Short says researchers and conservationists hope to be able to better protect not only the black swan, but also other susceptible species across the globe.

“We want to increase awareness about how vulnerable Australia’s bird species are to avian influenza and the highly precarious situation they are in,” Short says.

The study appears in Genome Biology. Coauthors are from the Vertebrate Genomes Project (VGP).

The Australian Department of Agriculture and Water Resources and an Australian Research Council Discovery Early Career Researcher Award funded the work.

Source: University of Queensland

Current medical standards for accessing stroke risk perform worse for Black Americans than for white Americans, research finds.

The study, published in the Journal of the American Medical Association, evaluated various existing algorithms and two methods of artificial intelligence assessment that are aimed at predicting a person’s risk of stroke within the next 10 years.

The study found that all algorithms were worse at stratifying the risk for Black people than white people, regardless of the person’s gender. The implications are at the individual and population levels: people at high risk of stroke might not receive treatment, and those at low or no risk are unnecessarily treated.

“We need to improve data collection procedures and expand the pool of risk factors for stroke to close the performance gap of algorithms between Black and white adults,” says Michael Pencina, corresponding author of the study, professor in the department of biostatistics and bioinformatics at Duke Health and director of AI Health at Duke University School of Medicine.

“For example, the algorithms tested here mostly do not account for social determinants of health and some other factors suggested by the Stroke Prevention Guideline,” Pencina says. “Data collection needs to be closer to the patient and the community.”

“Disparities can potentially become propagated by these algorithms, and things could get worse for some people, which may lead to inequity in treatment decisions for Black versus white adults,” he adds.

The study specifically looks at something called risk ordering, which provides perspective on how likely someone is to experience stroke compared to others—an important concept used to allocate limited medical resources.

The study also finds that a simple method using answers to patient questions was the most accurate on a population level and that sophisticated machine learning methodologies failed to improve performance.

“While advanced AI techniques have been touted as the most promising path for better algorithms, our results indicate that for simpler types of data like the ones used in our study, complex math does not help,” Pencina says.

“The better accuracy of simpler algorithms, based on self-reported risk factors, suggest a promising and potentially cost-effective avenue for preventative efforts,” he says.

The study had funding from the National Institute of Neurological Disorders and Stroke of the National Institutes of Health and from a cooperative agreement co-funded by the National Institute of Neurological Disorders and Stroke and National Institute of Aging.

Source: Duke University

A new blood test that can identify progression of osteoarthritis in the knee is more accurate than current methods, researchers report.

It could provide an important tool to advance research and speed discovery of new therapies.

The test relies on a biomarker and fills an important void in medical research for a common disease that currently lacks effective treatments. Without a good way to identify and accurately predict the risk of osteoarthritis progression, researchers have been largely unable to include the right patients into clinical trials to test whether a therapy is beneficial.

“Therapies are lacking, but it’s difficult to develop and test new therapies because we don’t have a good way to determine the right patients for the therapy,” says Virginia Byers Kraus, a professor in the medicine, pathology, and orthopedic surgery departments at Duke University School of Medicine and senior author of the study in the journal Science Advances.

“It’s a chicken-and-the-egg predicament,” Kraus says. “In the immediate future, this new test will help identify people with high risk of progressive disease—those likely to have both pain and worsening damage identified on X-rays—who should be enrolled in clinical trials. Then we can learn if a therapy is beneficial.”

Kraus and colleagues isolated more than a dozen molecules in blood associated with progression of osteoarthritis, which is the most common joint disorder in the United States. It afflicts 10% of men and 13% of women over the age of 60 and is a major cause of disability.

With further honing, the researchers narrowed the blood test to a set of 15 markers that correspond to 13 total proteins. These markers accurately predicted 73% of progressors from non-progressors among 596 people with knee osteoarthritis.

That prediction rate for the new blood biomarker was far better than current approaches. Assessing baseline structural osteoarthritis and pain severity is 59% accurate, while the current biomarker testing molecules from urine is 58% accurate.

The new, blood-based marker set also successfully identified the group of patients whose joints show progression in X-ray scans, regardless of pain symptoms.

“In addition to being more accurate, this new biomarker has an additional advantage of being a blood-based test,” Kraus says. “Blood is a readily accessible biospecimen, making it an important way to identify people for clinical trial enrollment and those most in need of treatment.”

The National Institutes of Health funded the work.

Source: Duke University