Earth

After the Big Bang, there likely came a period of inflation where the universe rapidly expanded. As this rapid expansion ends, incredibly dense quantum matter--called a condensate--is expected to form. However, even if this condensate is long-lived, interactions between it and its own gravitational field ultimately cause it to fragment. Now, scientists have created the first simulation of the condensate during this process. Musoke et al. modeled the matter's fragmentation to provide the first quantitative examination of the gravitational disintegration of the condensate. They found that fragmentation can be described by the Schrodinger-Poisson equation, which describes how large numbers of quantum particles interact with their gravitational fields. Knowing how this quantum condensate might have behaved right after the Big Bang could also potentially help scientists understand the formation of dark matter and to make precise predictions for key cosmological observables.

Scientists at Caltech and JPL have tied a shift in winter weather patterns in Europe and northern Eurasia to a reduction in air pollution.

Over the past 50 years, the occurrence of extremely cold days has decreased throughout Europe and northern Eurasia, which includes Russia. Combining long-term observations with a state-of-the-art climate model revealed what researchers describe as an "unambiguous signature" of the reduction in the release of man-made aerosols over that time. This has caused changes in the wintertime Northern Hemisphere polar jet stream (a swiftly moving channel of air flowing from west to east) and surface-temperature variability during that time.

The work suggests that aerosols, which are solid particles polluting the atmosphere from activities like burning coal, can have a stronger impact on extreme winter weather than greenhouse gases at regional scale, although the relationship between aerosols and extreme weather is complicated to untangle.

"This discovery underscores the importance of understanding the effects of anthropogenic aerosols for accurate climate projection of extreme weather events, which is crucial to formulating climate mitigation and adaption strategies," says Yuan Wang, staff scientist at Caltech and at JPL, which Caltech manages for NASA, and the lead author of a study about the research that was published in Nature Climate Change on February 3.

Wang and his colleagues found that tighter air pollution regulations led to a reduction in atmospheric aerosols, and, as there were fewer particles in the atmosphere to reflect sunlight, this resulted in a local warming effect. Warmer temperatures in Europe led to a stronger temperature gradient between Europe and the North Pole, which in turn helped lock the jet stream into a stable, relatively straight position.

When the jet stream meanders, dipping south, it can carry cold arctic air to more southern latitudes. Some climate models have predicted that the steady increase in the arctic temperature, caused by greenhouse gas-driven global warming, could weaken the jet stream and cause it to meander, but Wang's team has found a more complicated underlying mechanism.

"This tells us that for winter extremes, aerosols have a greater impact than greenhouse gases," says Jonathan Jiang of JPL, co-corresponding author of the Nature Climate Change study, who managed research.

Because China is expected to enact air pollution regulations that will lead to aerosol reductions over the next two to three decades, the model predicts that a similar effect could also be seen over eastern Asia.

A year-round acoustic study of marine mammals in the northern Bering Sea is providing scientists with a valuable snapshot of an Arctic world already under drastic pressure from climate change, according to WCS (Wildlife Conservation Society), Columbia University, Southall Environmental Associates, and the University of Washington.

Authors of the new study in the journal Marine Mammal Science conducted a 4-year acoustic monitoring project to determine how seasons, sea surface temperature, and sea ice influence the presence, distribution, and movements of five species of endemic Arctic marine mammals. It is the first study to conduct year-round acoustic monitoring for marine mammals off St. Lawrence Island in the Bering Sea.

"The data gathered during the study will serve as an important baseline for future monitoring of the effects of climate change, subsequent sea ice changes, and expected increases in shipping on the distribution of the region's marine mammals," said Emily Chou, WCS scientist and lead author of the study.

The scientists conducted the study between 2012 and 2016 with a focus on five species of Arctic marine mammal: bowhead whales (Balaena mysticetus), beluga whales (Delphinapterus leucas), walrus (Odobenus rosmarus), bearded seals (Erignathus barbatus), and ribbon seals (Histriophoca fasciata).

With the support of local indigenous hunters and fishermen, the scientists deployed archival acoustic recorders in three locations in the northern Bering Sea. "Working with local residents to deploy and retrieve equipment was an important part of our effort to keep the work as locally-based as possible," said co-author Martin Robards.

Two of the recorders (attached to flotation devices and anchored to the seafloor with weights) were deployed off the northern shore of St. Lawrence Island, specifically near the Native villages of Savoonga and Gambell. The third recorder was placed in the Bering Strait, a 36-mile wide gap between the Russian Far East and Alaska that serves as the migratory pathway for thousands of marine mammals moving between the Bering Sea and the Arctic Ocean.

"Acoustic monitoring is the most effective means of determining the seasonal presence of these species in these challenging Arctic areas, given the unpredictable weather conditions and variable daylight and ice conditions," said Brandon Southall, a co-author on the study. "It can also be used to measure variability in ocean noise from both natural and human sources, such as shipping, and how they may affect the behavior and well-being of marine mammals."

The recorders logged more than 33,000 individual vocalizations from whales, walruses, and seals over the study period. Overall, the study supported previous scientific and traditional knowledge about the distribution of marine mammals in the northern Bering Sea with a finer-scale resolution than previously available. The data showed consistent seasonal distribution and movement patterns for most species, and analyses showed that time-of-year was the most statistically significant factor in the detection of marine mammal vocalization.

The study findings will help guide future monitoring efforts on the region's cetacean and pinniped species and will inform conservation management decisions for acoustically sensitive marine mammals in the context of disappearing ice and projected increases in maritime traffic. Specifically, this type of work and continued monitoring at strategic locations in this Arctic area will eventually help identify trends caused by long-term changes in environmental conditions and human-related activities.

"There is no doubt that the Arctic is currently undergoing rapid and significant changes that are alarming," said Dr. Howard Rosenbaum, Director of WCS's Ocean Giants Program. "Our work on Arctic marine mammal populations in this region is essential to assess any forthcoming resulting shifts or changes resulting from warming Arctic conditions, and ultimately working partners and authorities to find solution to protect these iconic species and their habitats"

Using results of a survey of more than 2,700 self-reported users of the herbal supplement kratom, sold online and in smoke shops around the U.S., Johns Hopkins Medicine researchers conclude that the psychoactive compound somewhat similar to opioids likely has a lower rate of harm than prescription opioids for treating pain, anxiety, depression and addiction.

In a report on the findings, published in the Feb. 3 issue of Drug and Alcohol Dependence, the researchers caution that while self-reporting surveys aren't always entirely reliable, they confirmed that kratom is not regulated or approved by the U.S. Food and Drug Administration (FDA), and that scientific studies have not been done to formally establish safety and benefits. They say that U.S. drug agencies should seek to study and regulate rather than ban kratom sales outright because of its seemingly safe therapeutic potential, and as a possible alternative to opioid use.

The American Kratom Association (AKA), a consumer advocacy group, estimates that 5 million people in the U.S. regularly use kratom by either eating its ground leaves in food or brewing them in tea. Kratom is a tropical plant related to coffee trees, and grown mainly in Southeast Asia. It contains a chemical called mitragynine, an alkaloid that acts on the brain opiate receptors and alters mood. In Asia, where use has long been widespread, people use it in small doses as an energy and mood booster, similar to coffee use in the West. They use larger amounts for pain, or recreationally like beer and wine.

Kratom products are unregulated and nonstandardized, and reports -- although sparse -- have linked its use to hallucinations, seizures and liver damage, when combined with alcohol or other drugs. In 2016, the U.S. Drug Enforcement Agency (DEA) proposed banning commercial sale and use, and the FDA has advised categorizing it as a Schedule I drug, meaning it has no proven medical application and has a high risk of abuse. These agencies were met with public and supplement industry pushback, and no action was taken. A salmonella contamination outbreak in 2018 among users increased concerns.

However, says Albert Garcia-Romeu, Ph.D., instructor of psychiatry and behavioral sciences at the Johns Hopkins University School of Medicine, the new survey findings "suggest that kratom doesn't belong in the category of a Schedule I drug, because there seems to be relatively low rate of abuse potential, and there may be medical applications to explore, including as a possible treatment for pain and opioid use disorder."

"There has been a bit of fearmongering," he adds, "because kratom is opioidlike, and because of the toll of our current opioid epidemic."

A 2015 study in Thailand that reported that people in Asia have been using kratom successfully to treat opioid addiction for decades renewed interest among researchers in the U.S.

For the current survey, Garcia-Romeu says, he and his team enrolled 2,798 people to complete an online survey on their use of kratom. They recruited participants online and through social media, as well as through the AKA. Overall, users were mostly white, educated and middle-aged. Some 61% of users were women, and 90% were white. About 6% reported being multiracial, 1.5% reported being Native American or Hawaiian, 0.5% reported being Asian and 0.4% said they were African American. Participants were an average age of 40. About 84% of participants reported having at least some college education.

Of these participants, 91% reported taking kratom to alleviate pain on average a couple times a day for back, shoulder and knee pain, 67% for anxiety and 65% for depression. About 41% of survey responders said they took kratom to treat opioid withdrawal, and of those people who took it for opioid withdrawal, 35% reported going more than a year without taking prescription opioids or heroin.

As part of the survey, participants completed a Substance Use Disorder Symptom checklist to assess whether their use qualified as a substance use disorder according to the American Psychiatric Association Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition guidelines. Fewer than 3% of responses met the criteria for moderate or severe substance use disorder for abusing kratom, but about 13% met some criteria for kratom-related substance use disorder. This is comparable to about 8%-12% of people prescribed opioid medications who became dependent, according to statistics from the U.S. National Institute for Drug Abuse (NIDA).

"Both prescription and illicit opioids carry the risk of lethal overdose as evidenced by the more than 47,000 opioid overdose deaths in the U.S. in 2017," says Garcia-Romeu. "Notably there's been fewer than 100 kratom-related deaths reported in a comparable period, and most of these involved mixing with other drugs or in combination with preexisting health conditions."

A third of the survey participants reported having mild unpleasant side effects from kratom, such as constipation, upset stomach or lethargy, which mostly resolved within a day. Only 1.9% reported that side effects were severe enough for them to seek medical treatment, such as feeling withdrawal symptoms such as anxiety, irritability, depression or insomnia when the kratom wore off. Fewer than 10% of participants reported notable kratom-related withdrawal symptoms.

"Although our findings show kratom to be relatively safe according to these self-reports, unregulated medicinal supplements raise concerns with respect to contamination or higher doses of the active chemicals, which could increase negative side effects and harmful responses," says Garcia-Romeu. "This is why we advocate for the FDA to regulate kratom, which would require testing for impurities and maintaining safe levels of the active chemicals. Otherwise, unregulated products run the risk of unsafe additives and dosing problems, which could be like getting a shot of grain alcohol when you were trying to order a beer."

Garcia-Romeu adds that data is scant on whether one can overdose on kratom alone, or how it interacts with alcohol or other drugs. The researchers also say rigorous clinical research needs to be done to test kratom for its potential therapeutic benefits, for behavioral intoxication effects and adverse side effects to further help inform government policy and regulation. They also suggest that people err on the side of caution and not mix kratom with any other drugs or medications, and to always talk with their health care provider before taking any supplement.

Renewed investments in hydrogen fuel cell technologies and infrastructure by companies like Amazon; nations like China; and automakers like Toyota, Honda, and Hyundai, are sparking sales and fresh interest in the vast possibilities of polymer-electrolyte fuel cells. The fresh interest could revolutionize transportation and fill streets with vehicles whose only effluent is water vapor.

But that vision of clean, green cars and trucks is stymied by the need not only for massive infrastructure investment, but for more efficient processes in the cells themselves. Innovations that lower the cost of production -- meaning lower sticker price -- and that open the door to more vehicle segments, including performance cars, could drive greater adoption.

A team of researchers at the NYU Tandon School of Engineering, led by Miguel Modestino, professor of chemical and biomolecular engineering, and Lawrence Berkeley National Laboratory has created a novel polymeric material with the potential for solving both problems.

The research, "Highly Permeable Perfluorinated Sulfonic Acid Ionomers for Improved Electrochemical Devices: Insights into Structure - Property Relationships," published in the Journal of the American Chemical Society, focuses on a hybrid material that delivers copious amounts of oxygen from the atmosphere to the cell's electrode reaction sites -- generating more power -- while reducing the amount of expensive materials like platinum needed in fuel cells, potentially solving a major industry challenge.

Hydrogen fuel cells comprise an anode and a cathode, with an electrolyte membrane between them. Electricity is produced in a process whereby hydrogen reacts in the anode and atmospheric oxygen in the cathode. At the latter site, protons combine with oxygen to produce electricity and water. Ion-conducting polymers (ionomers) are used to bring the protons to the reaction sites where oxygen from air needs to permeate through them to drive the electricity-generating reaction.

Current, commercially available ionomers are typically perfluorinated sulfonic acid (PFSA) polymers that comprise a linear chainlike backbone composed of polytetrafluoroethylene (PTFE) matrix, and pendant sulfonic-acid groups attached to the PTFE backbone that impart ion conductivity. While this complex combination, molecularly similar to Teflon, confers high mechanical strength, research shows that it suffers from low oxygen permeability, leading to significant energy losses fuel cells.

The researchers -- including Yoshi Okamoto, a professor of chemical engineering and director of the Polymer Research Institute at NYU Tandon, and Ph.D. student Adlai Katzenberg, who did the research as part of a U.S. Department of Energy fellowship -- solved several problems at once by swapping the linear PTFE polymer chains with a bulky fluorinated chain, which added more free volume to the matrix, vastly enhancing its ability to transport oxygen in fuel cells.

Modestino explains that the hybrid material comprises an ion conducting polymer and a highly permeable matrix. "We've created a novel copolymer -- two components bound together. One part conducts ions, and the other is highly permeable to oxygen," he says. "Okamoto had been working on highly permeable polymers for gas separation processes. When I joined NYU Tandon, we realized that the polymers that he had developed could be adapted to improve fuel cells."

Young girls who are about to undergo treatment for cancer or other therapies that pose high risk of infertility can opt to have an ovary removed and preserved for future transplantation when they are ready to pursue pregnancy. However, the tiny ovary can be easily damaged during surgery and the quality of ovarian tissue for fertility preservation is affected by the surgical removal technique, according to a study from Ann & Robert H. Lurie Children's Hospital of Chicago published in the Journal of Pediatric Surgery. Using an experimental piglet model, researchers defined the safest laparoscopic technique for removing the ovary that also results in the best quality ovarian tissue for later use.

"We are already applying our findings for all ovary removals for fertility preservation," says lead author Erin Rowell, MD, Director of the Fertility & Hormone Preservation & Restoration Program at Lurie Children's and Associate Professor of Surgery at Northwestern University Feinberg School of Medicine. "The evidence from our study is the first step to defining standard of care surgical technique in prepubertal girls that will allow us to maximize ovarian tissue health and hopefully increase pregnancy rates after the tissue is transplanted back."

To preserve future fertility, the removed ovarian tissue is frozen - a process called cryopreservation. When a woman is ready to have a child, one of the current options is to transplant the preserved tissue onto the remaining ovary, where it starts to function normally and enables natural pregnancy. This technique is still considered experimental.

To date, two live births have been documented in women who had ovarian tissue cryopreservation as prepubertal girls, while over 130 live births occurred in women whose ovarian tissue was removed and cryopreserved after they reached puberty. Currently, less than a third of women who had their ovarian tissue transplanted back experienced a successful pregnancy.

To evaluate the quality of ovarian tissue after different surgical removal techniques, Dr. Rowell performed laparoscopic ovary removal in piglets. The goal was to simulate this surgery as precisely as possible, using the same type of instruments that are used in young girls, including an ultrasonic advanced energy device that provides heat to cut and cauterize tissue around the ovary. The piglet's ovarian tissue was then processed exactly the same way as human tissue would be handled for fertility preservation.

After examining ovarian tissue health and quality, researchers found that there was least damage when the heat source during surgery was farther away from the ovary. As a result, surgeons at Lurie Children's have adjusted their technique to maintain a 2 cm distance from the ovary when using the ultrasonic advanced energy device for ovary removal.

"The collaboration between surgeons and scientists in this study is a perfect example of translational research," says senior author Monica Laronda, PhD, Director of Basic and Translational Research, Fertility & Hormone Preservation & Restoration Program at Lurie Children's and Assistant Professor of Pediatrics at Northwestern University Feinberg School of Medicine. "Our findings in the lab had a direct impact on how our surgical team performs the ovary removal procedure for fertility preservation."

At Lurie Children's, the laparoscopic ovary removal procedure is performed on an outpatient basis, without delaying the patient's treatment for conditions that may threaten future fertility. Children with a variety of cancer, genetic, endocrine and rheumatologic conditions may be candidates for fertility preservation. The Fertility & Hormone Preservation & Restoration Program at Lurie Children's is the only one of its kind for pediatric patients in Illinois.

Research at Ann & Robert H. Lurie Children's Hospital of Chicago is conducted through the Stanley Manne Children's Research Institute. The Manne Research Institute is focused on improving child health, transforming pediatric medicine and ensuring healthier futures through the relentless pursuit of knowledge. Lurie Children's is ranked as one of the nation's top children's hospitals by U.S. News & World Report. It is the pediatric training ground for Northwestern University Feinberg School of Medicine. Last year, the hospital served more than 220,000 children from 48 states and 49 countries.

Every year, about 8 million metric tons of plastic are put into the world's oceans. Of particular concern are microplastics, materials found in the marine environment that occur in sizes below five millimeters and are the most abundant form of marine debris observed at the ocean surface.

Estuarine and coastal environments play a crucial role as a buffer between land, freshwater environments and the open ocean where plastic debris accumulates. Despite performing this critical function, estuarine and coastal environments have not been extensively studied for microplastic prevalence and impact.

To help better understand how these environments are affected by microplastics, University of Delaware researchers looked at microplastics in the Delaware Bay, which is a tide-, wind- and freshwater-driven estuarine environment.

They discovered a substantial concentration of microplastics in the Delaware Bay that accumulate in hotspots driven by buoyancy, winds and tides, all of which lead to high variability of microplastic distributions (across space and time) in the bay.

The results of their study were published in the Environmental Science and Technology academic journal.

The project was led by Jonathan Cohen and Tobias Kukulka, associate professors in the College of Earth, Ocean and Environment (CEOE), as well as CEOE master's students Anna Internicola and R. Alan Mason.

Cohen said that since this is an area of intense public interest, with possible government regulations of microplastics in the future, it's critical that there's science upon which to base politically and economically important decisions.

"If these decisions are going to be happening and the public is going to have to weigh in on them, there needs to be science that the decisions can be based on," said Cohen. "That's a pretty strong motivating factor for us."

Complementary expertise

The work started in 2016 with a mini-grant from Delaware Sea Grant to assess microplastics in the Delaware Bay, which led to a two-year grant to assess the impact microplastics are having on the ecology of the Delaware Bay.

Kukulka and Cohen have complementary expertise and research approaches, with Cohen focused on biology and field work and Kukulka focused on the physical aspects of oceanography and the modeling work.

Cohen and Internicola measured the distribution of microplastics from 16 sampling sites across the Delaware Bay, ranging from just above the Delaware Memorial Bridge in Wilmington to outside the bay mouth. The stations cover the area encompassing where the bay is fresh water to where the bay meets the Atlantic Ocean.

The researchers used a net to get surface samples, towing the net at the surface and using a flow meter inside the net to indicate how much water was sampled. They then rinsed the net, preserved the samples in a glass container and brought them back to the lab.

Chemical methods in the lab allowed the researchers to separate the plastics from the organics by dissolving the organic material and putting samples in a salty solution where the plastics would float and the organics would sink.

Kukulka and Mason then took the data from the samples and plugged it into their hydrological models.

By combining the observational data with tidal-, wind- and buoyancy-driven models to simulate the distribution of microplastics, they were able to extrapolate the results to a larger portion of the Delaware Bay and determine how particles move within the bay, exit the bay or accumulate in surface convergence regions.

Cohen said the sampling and modeling approach speaks to how marine science is conducted.

"It's not all about going on boats and collecting a bucket of water or dipping a net," Cohen said. "It's about combining what you can learn from that with what you can learn from these numerical approaches."

Kukulka agreed, saying that it is great to be able to combine the field sampling data with the modeling.

"It's challenging to do observations bay-wide, and sampling is time-limited and limited to a specific location," said Kukulka. "We didn't really get a broad snapshot bay-wide with sampling, but with the modeling, we can see the temporal variability and the whole spatial coverage of plastics."

Salinity fronts

In the area where the fresher water from the Delaware River meets the saltier water of the Atlantic Ocean, the researchers observed salinity fronts, with fresh water on top and saltier water on the bottom. Near such fronts, surface currents can converge.

Known as convergence zones, the researchers found microplastics in high concentrations in these areas.

UD graduate student Anna Internicola cleans a ring net used for collecting samples of microplastics from the Delaware Bay.

UD graduate student Anna Internicola cleans a ring net used for collecting samples of microplastics from the Delaware Bay.

"What we find in the simulation is that we have regions of very high concentrations, much higher than outside those convergence zones," said Kukulka.

Because the buoyant microplastics float on top of the water, they are also influenced and accumulate in areas due to the tides and the wind. Plastics move within the tidal cycle back and forth as tides move in and out of the bay, causing tremendous locational variability over a tidal cycle, especially if a researcher is measuring just inside or outside of those hotspots.

"You can stay at a given spot and sample a given location or station, but that patch of material isn't always going to be there," said Cohen. "It's going to move with the tides, and so you could be at a given station and based on the simulations, you could see a one-thousand times change in the concentrations."

The distribution of the plastics also depends on the force of the winds, with a strong wind moving microplastics to various areas of the bay.

"If we know the forcing, we can make educated guesses on where we might expect plastics and where they're likely to accumulate," said Kukulka.

Next steps

As for the project's next steps, they would like to definitively determine how long microplastics stay in the bay and if they end up at the shores of New Jersey and Delaware or if they're trapped within the bay.

In the first national study of its size, researchers at University of California San Diego School of Medicine and UC San Diego Health, Department of Nursing, have found that male and female nurses are at higher risk of suicide than the general population. Results of the longitudinal study were published in the February 3, 2020 online edition of WORLDviews on Evidence Based-Nursing.

"Using the 2005-2016 National Violent Death Reporting System dataset from the Centers for Disease Control, we found that male and female nurses are at a higher risk for suicide, confirming our previous studies," said senior author Judy Davidson, DNP, RN, research scientist at UC San Diego. "Female nurses have been at greater risk since 2005 and males since 2011. Unexpectedly, the data does not reflect a rise in suicide, but rather that nurse suicide has been unaddressed for years."

The World Health Organization reports that one person dies every 40 seconds by suicide. It is the 10th leading cause of death in the United States, occurring at a rate of 13 per 100,000 persons. While overall mortality rates are decreasing in the US, the suicide rate is rising.

Davidson and colleagues found that female nurse suicide rates from 2005 to 2016 were significantly higher (10 per 100,000) than the general female population (7 per 100,000). Similarly, male nurses (33 per 100,000) were higher than the general male population (27 per 100,000) for the same period.

"Opioids and benzodiazepines were the most commonly used method of suicide in females, indicating a need to further support nurses with pain management and mental health issues," said co-author Sidney Zisook, MD, professor of psychiatry, UC San Diego School of Medicine. "The use of firearms was most common in male nurses, and rising in female nurses. Given these results, suicide prevention programs are needed."

UC San Diego has successfully tested a suicide prevention program called the Healer Education Assessment and Referral (HEAR) program. HEAR provides education about risk factors and proactive screening focused on identifying, supporting and referring clinicians for untreated depression and/or suicide risk. HEAR has been acclaimed as a best practice in suicide prevention by the American Medical Association.

Also published in the same issue of WORLDviews on Evidence Based-Nursing is a paper describing the sustainability of the HEAR program.

"To achieve success, suicide prevention programs for nurses should be anonymous and have a proactive screening process," said lead author Rachael Accardi, LMFT, HEAR therapist. "When a distressing event occurs in the hospital or clinic environment, an evaluation team should be deployed to access any psychologic needs. This is best achieved through tight organizational connections among the hospital's experience, risk management and HR teams, who can flag an event and then deploy confidential resources."

Since 2009, more than 500 HEAR referrals have been made for clinicians to mental health professionals. Approximately 40 nurses per year, many in crisis, have communicated with counselors, often anonymously through the website and always confidentially by email, phone or in person.

"It is time to take urgent action to protect our nursing workforce. The HEAR program is ready for replication at the national level to address this newly recognized risk among nurses," said Davidson, who co-chairs a task force for the American Nurses Association to address nurse suicide. "The HEAR program can be complemented with tested cognitive-based therapy resiliency skills building for maximum effect."

The Greenland Ice Sheet is melting faster today than it did only a few years ago. The reason: it's not just melting on the surface - but underwater, too. AWI researchers have now found an explanation for the intensive melting on the ice's underside, and published their findings in the journal Nature Geoscience.

The glaciers are melting rapidly: Greenland's ice is now melting seven times faster than in the 1990s - an alarming discovery, since climate change will likely intensify this melting in the future, causing the sea level to rise more rapidly. Accordingly, researchers are now working to better understand the underlying mechanisms of this melting. Ice melts on the surface because it is exposed to the sun and rising temperatures. But it has now also begun melting from below - including in northeast Greenland, which is home to several 'ice tongues'. Each tongue is a strip of ice that has slid down into the ocean and floats on the water - without breaking off from the land ice. The longest ice tongue, part of the '79° North Glacier', is an enormous 80 km long. Over the past 20 years, it has experienced a dramatic loss of mass and thickness, because it's been melting not just on the surface, but also and especially from below.

Too much heat from the ocean

A team led by oceanographer Dr Janin Schaffer from the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI) in Bremerhaven has now identified the source of this intense underwater melting. The conclusions of their study, which the experts have just released in the journal Nature Geoscience, are particularly unsettling because the melting phenomenon they discovered isn't unique to the 79° North Glacier, which means it could produce similar effects elsewhere. For the purposes of the study, the researchers conducted the first extensive ship-based survey of the ocean floor near the glacier, which revealed the presence of a two-kilometre-wide trough, from the bottom of which comparatively warm water from the Atlantic is channelled directly toward the glacier. But that's not all: in the course of a detailed analysis of the trough, Janin Schaffer spotted a bathymetric sill, a barrier that the water flowing over the seafloor has to overcome. Once over the hump, the water rushes down the back of the sill - and under the ice tongue. Thanks to this acceleration of the warm water mass, large amounts of heat from the ocean flow past the tongue every second, melting it from beneath. To make matters worse, the layer of warm water that flows toward the glacier has grown larger: measured from the seafloor, it now extends 15 metres higher than it did just a few years ago. "The reason for the intensified melting is now clear," Schaffer says. "Because the warm water current is larger, substantially more warmth now makes its way under the ice tongue, second for second."

Other regions are also affected

In order to determine whether the phenomenon only manifests at the 79° North Glacier or also at other sites, the team investigated a neighbouring region on Greenland's eastern coast, where another glacier, the Zachariæ Isstrøm, juts out into the sea, and where a large ice tongue had recently broken off from the mainland. Working from the surface of an ice floe, the experts measured water temperatures near the ocean floor. According to Schaffer: "The readings indicate that here, too, a bathymetric sill near the seafloor accelerates warm water toward the glacier. Apparently, the intensive melting on the underside of the ice at several sites throughout Greenland is largely produced by the form of the seafloor." These findings will ultimately help her more accurately gauge the total amount of meltwater that the Greenland Ice Sheet loses every year.

Excess selenium from fertilizers and other natural sources can create air pollution that could lead to lung cancer, asthma, and Type 2 diabetes, according to new UC Riverside research.

The research team conducted previous UCR studies in the Salton Sea area, which contains selenium rich wetlands and soils toxic to birds and fish. These' studies also revealed that the area's concentration of aerosols, which are solid or liquid particles suspended in air, have increased in recent years.

However, the full chemical makeup of the aerosols, or whether they would have any effects on humans, remained unknown. This motivated the team to create similar aerosol particles in the laboratory and study them.

The team's new paper, published in the journal Environmental Science & Technology, details the composition of the selenium-rich aerosols and describes the multiple ways these particles can damage human lungs.

Though the Salton Sea-area aerosols are likely to be unhealthy, UCR Associate Professor of Atmospheric Science Roya Bahreini said people in nearby San Bernardino, Los Angeles, and Riverside counties are likely safe.

"Typically, the air masses from the Salton Sea area don't reach these cities," she said.

According to Bahreini, dangerous aerosols can occur anywhere there's excessive selenium in the soil, making agricultural workers and those living near contaminated soils more vulnerable to illnesses.

Along with naturally occurring selenium in the environment, the excess from manmade sources gets digested by soil microbes and processed by plants. Once excreted, the selenium-containing vapors, which include the compound dimethyl selenide, mix with other airborne chemicals and eventually become the toxic selenium-containing aerosol, which stays in the air for roughly a week.

Selenium in small amounts is important for regulating the immune system. Deficiency can cause thyroid issues, slowed growth, and impaired bone metabolism.

As with most substances, too much can be poisonous. An excess of selenium can lead to swollen lungs, garlic breath, gastrointestinal disorders, neurological damage, and hair loss.

Scientists once believed dimethyl selenide was less toxic than other forms of selenium. In fact, Bahreini said scientists once proposed planting specific grasses in wetlands and soils with excessive amounts of selenium to allow digestion and evaporation of selenium-containing vapors as a way to remediate these sites.

However, earlier mouse studies showed the aerosols can cause lung injury and inflammation in mice. According to Ying-Hsuan Lin, an assistant professor of environmental toxicology at UCR, this newest study also shows how dimethyl selenide can form aerosols and affect humans.

Lin's team tested the aerosols on human lung cells in her laboratory and found they damage the lung's protective barrier.

"If people are exposed to this long enough, or in high enough concentration, they have a greater risk of lung cancer," Lin said. "There is also evidence that the aerosols can cause allergic inflammation of the lungs, and disturb glucose metabolism, which are linked to asthma and Type 2 diabetes."

The team is planning further studies to understand asthma rates that may be linked to the allergic inflammation she observed.

In addition, Lin said it is important to identify other sources of selenium-containing aerosols, as this study only identifies one source.

"We need to control this to improve public health," she said.

The profound threat of future climate change to biodiversity demands that scientists seek ever more effective ways to identify the most vulnerable species, communities, and ecosystems.

In a new study, published in Nature Climate Change, an international team of scientists has shown that the most biodiverse regions on Earth are among the most vulnerable to future climate change.

By establishing global patterns of unusually extreme climate change events during Earth's history, and comparing these to 21st century patterns, the researchers were able to show that human-driven climate change will quickly erode important mechanisms that are likely to have sustained biodiversity across time.

"Our results show that the magnitude and accelerated rate of future climate change will disproportionately affect plants and animals in tropical regions and biodiversity hotspots. Worryingly, these are regions on Earth with the highest concentrations of biodiversity," says lead author Associate Professor Damien Fordham from the University Adelaide's Environment Institute.

Historically these regions have been safe havens from climate change during glacial-interglacial cycles. By providing refuge for species during periods of unfavourable global warming, these climate safe havens have shaped biodiversity by allowing older species to survive and new lineages to generate.

"Disturbingly, our research shows that more than 75% of the area of these climate safe havens will be lost in the near future due to 21st century warming," said Dr Stuart Brown from the University of Adelaide, who led the analysis.

"The future is most ominous for species in tropical oceans. Severe negative impacts on the richness of coral species and marine life they support are expected in regions such as the Indo-Pacific. This is likely to cause human hardship for communities that depend on these resources for food, employment and income."

For areas where climate safe havens are forecast to persist until the end of this century, the researchers show that temperatures are likely to exceed the acclimation capacity of many species, making them short-term hospices for biodiversity at best.

More generally the research shows that future climate change not only threaten species in polar environments, but also tropical regions, which contain particularly high biodiversity.

Immunotherapy, unlike chemotherapy and radiotherapy, arms the body's immune system to attack cancer cells. In recent years, it has proven to be remarkably successful at treating leukemia, lymphoma and other liquid cancers, or cancers present in body fluids.

Chimeric antigen receptor (CAR) T-cell therapy is a type of treatment in which a patient's T-cells - the body's most powerful immune cells - are extracted and engineered to recognize and kill cancerous cells. Yet when they target solid tumors, the modified T-cells can also attack healthy tissue, leading to toxicity, major organ damage and potentially even death.

A team of researchers from EPFL, the Ludwig Institute for Cancer Research at the University of Lausanne (UNIL), and Lausanne University Hospital (CHUV) have developed a new protein-based method to switch off the modified T cells on command - a sort of emergency safety net for patients who respond badly to treatment. The control system, known as STOP-CAR, has been tested and validated on mice infused with prostate cancer cells. Its discovery could speed the clinical development of new CAR therapies that were previously considered too risky. The team has published its research in the journal Nature Biotechnology.

Living drugs

At a basic level, the new control system works in much the same way as existing techniques. T-cells are taken from a patient's blood then genetically modified so that special receptors - known as chimeric antigen receptors, or CARs - grow on their surface. These receptors enable the modified cell to recognize and bind to cancer cells. A signal is then generated instructing the cell to attack.

It's at this point that the new method differs. Using computational protein design, the researchers re-engineered the receptor so that the signal generated when it binds to a tumor antigen can be switched off, effectively disabling the T-cell.

The control system involves administering a molecule to the patient as a separate drug. The T-cell contains naturally binding pairs of proteins that carry information between the receptor and the inner structure of the T-cell. The molecule breaks the interaction between these proteins, thereby disrupting the signal and effectively switching off the cell.

"The real advantage of this system is that we can switch the T-cell back on again if we stop administering the molecule," explains Bruno Correia, one of the paper's senior authors and a tenure-track assistant professor at the Institute of Bioengineering, part of EPFL's School of Engineering. "There's no need to destroy the T-cells if they pose a threat to a patient's health. The system lets us precisely control the effects of immunotherapy"

The benefits don't end there. Observations have shown that prolonged exposure to antigens can cause T-cell exhaustion. Switching the cells off temporarily gives them time to rest and recuperate.

"This work itself, and its potential, is really exciting," says George Coukos, director of the Branch of the Ludwig Institute for Cancer Research "but I think it is also illustrative of how well-orchestrated, multidisciplinary collaborations can yield significant scientific breakthroughs. Working with EPFL and our other partners in the region, we hope to bring STOP-CAR-T therapy as quickly as possible to cancer patients."

Experiences early in life have an impact on the brain's biological and functional development, shows a new study by a team of neuroscientists. Its findings, which centered on changes in mice and rats, reveal how learning and memory abilities may vary, depending on the nature of individual experiences in early life.

"The implications of this are many, including environmental influences on mental health, the role of education, the significance of poverty, and the impact of social settings," says Cristina Alberini, a professor in New York University's Center for Neural Science and the senior author of the paper, which appears in the journal Nature Communications.

"These results also offer promise for potential therapeutic interventions," add Alberini and Benjamin Bessieres, an NYU postdoctoral researcher and the paper's co-lead author. "By identifying critical time periods for brain development, they provide an indicator of when pharmaceutical, behavioral or other type of interventions may be most beneficial."

In general, very little is known about the mechanisms that underlie the development of learning and memory abilities. The Nature Communications study sought to shed new light on this process studying the biological elements linked to episodic memories--those of specific events or experiences--in infants by using rats and mice.

In their experiments, the scientists tested whether and how different types of experiences mature learning and memory abilities.

In one experience, infant mice and rats were placed in a small compartment--a procedure paired with a mild foot shock (a commonly used method to test memory for a context). Their memory was tested by placing them back in these compartments; if they revealed a hesitation, it indicated that they had formed a memory of previously being in the compartment.

In a different type of experience, the infant mice and rats were exposed to novel objects in a given spatial configuration. Here, rodents that have a memory for this experience show more exploration toward a novel object location when presented with a combination of new and old locations, simply because they have a natural tendency to explore more new object locations. This reveals a memory of object location. Both types of experiences, context and object location, are stored by the same memory system.

The authors then asked two questions.

The first was: Does learning mature memory abilities?

The results showed that it does as both context and object location experiences matured the brain at both biological and functional levels. Overall, in fact, researchers found that the episodic experiences of the young mice and rats led to unique biological changes, specifically indicating maturation in the hippocampus--a region critical for episodic memory formation. However, they did not find the same changes in older mice and rats.

Furthermore, they saw that with each type of learning, context or object location, the infant animal matured its performance and became capable of remembering long-term, more like an older animal does.

The team's second question was: Does the maturation produced by one type of experience develop the entire memory system and all its abilities? Or is the maturation selective for the type of experience that the animal had?

They found that the maturation produced by one type of experience (context) did not transfer to the other learning (object location) and vice versa, leading them to conclude that the maturation of learning and memory abilities is selective for the type of experiences encountered early in life.

"Because the biological maturation changes no longer occurred with episodic learning at later ages, it's clear that the infant brain employs distinct biological mechanisms to form and store episodic memories," write Alberini and Bessieres. "We found that this biological maturation is paralleled by and required for the functional maturation of memory--that is, the ability to express memory long-term."

"Our results indicate that specific experiences during the infantile developmental period make a major contribution to individual differences in learning and memory abilities," they add. "Although all individuals are exposed to general learning of facts, people, things, time, and spaces, and therefore must develop a wide range of abilities and competences processed by the hippocampal memory system, our data suggest that the individual history shapes the maturation of selective abilities."

"Memory formation is important for thinking, future learning, planning, decision-making, problem-solving, reflecting, imagining, and the overall capacity to form a sense of self," the authors note. "This means that what infants learn and experience is crucial for their later development."

Tokyo, Japan - Researchers at The University of Tokyo have used computational methods and analysis of recent experimental data to demonstrate that water molecules take two distinct structures in the liquid state. The team investigated the scattering of X-ray photons through water samples and showed a bimodal distribution hidden under the first diffraction peak that resulted from tetrahedral and non-tetrahedral arrangements of water molecules. This work may have important implications throughout science, but especially with regard to living systems, like proteins and cell structures, which are strongly affected by their surrounding water molecules.

Given the ubiquity of water on our planet and the central role it plays in all known life, it may be hard to believe that there is anything left to learn about this most familiar fluid. A simple molecule made up of just two hydrogen atoms and one oxygen; water still hides fundamental mysteries that remain to be unraveled. For example, water has unusually high melting and boiling points, and even expands when it freezes (unlike most liquids, which contract). These and other unusual properties make it very different from almost all other liquids, but also allow life as we know it to exist.

The weirdness of water can be best understood by thinking about the very unique interactions between H2O molecules--the hydrogen bond. Water tends to form four hydrogen bonds with its four neighbors, which leads to tetrahedral arrangements of the neighbors. Such arrangements can be largely distorted under thermal fluctuations. However, whether the distortion leads to the coexistence of distinct tetrahedral and non-tetrahedral arrangements has remained controversial.

Now, scientists at The University of Tokyo have combined computer simulations and the analysis of scattering experimental data to find the "structure factor" of water - the mathematical function that represents the paths of dispersed X-rays when they scatter off the hydrogen and oxygen atoms. The analysis showed two overlapping peaks hiding in the first diffraction peak of the structure factor. One of these peaks corresponded to the distance between oxygen atoms as in ordinary liquids, while the other indicated a longer distance, as in a tetrahedral arrangement. "The combination of new computational methods and analysis of recent X-ray scattering data allowed us to see what was not visible in previous work," first author of the study Rui Shi explains.

This discovery may have huge implications across many scientific fields. Knowing the exact structural ordering of water is critical for a complete understanding of molecular biology, chemistry, and even many industrial applications. "It is very satisfying to be able to unravel the liquid structure of such a fundamental substance," senior author Hajime Tanaka says.

An Australian study examining the relationship between flexibility and parent health has revealed formal family-friendly workplace provisions alone are not meeting the demands of working mothers and fathers.

The La Trobe University survey of more than 4,000 parents from different occupations found 86 per cent relied on additional informal 'catch-up' strategies to manage work-family responsibilities on a daily-to-weekly basis.

Lead researcher Dr Stacey Hokke - from La Trobe's Judith Lumley Centre - said the study offers an Australian-first analysis into informal work practices amongst parents.

"We found these ad hoc self-directed strategies, such as performing family-related tasks at work or leaving early and catching up on work after hours, were common and often utilised alongside formal employer-provided flexible work arrangements," Dr Hokke said.

"This may be a sign that parents feel comfortable enough in their workplace to accommodate some quick family-related jobs to keep the family running during their workday, or it may indicate that despite best intentions, flexible work arrangements aren't being provided enough, or aren't meeting the actual needs of working parents."

Of the 12 informal strategies studied, the researchers found:

62 per cent of parents received or sent family-related phone calls or emails at work

59 per cent of parents worked through breaks to leave work on time

47 per cent of parents used their break time to attend to family matters or errands

42 per cent of parents performed household-related tasks while at work

While both mothers and fathers used informal strategies, there were some differing patterns by gender.

"We know that mothers often work part-time and fathers are more likely to work long hours. Our research suggests that mothers accommodate family by compressing their workday, missing breaks and working after hours to fit everything in; while fathers have to accommodate family within long workdays by performing family-related tasks at work," Dr Hokke said.

The researchers also looked at the relationship between work arrangements and parents' mental health. They found formal flexible work arrangements were associated with less occupational fatigue and burnout for both genders, and of particular benefit to fathers.

By comparison, informal 'ad-hoc' strategies were associated with worse mental health outcomes for parents including higher rates of occupational fatigue, psychological distress and burnout, even when combined with some formal workplace flexibility.

"This tells us two things: either parents need access to more formal flexible work arrangements or they're not utilising the arrangements they're entitled to," Dr Hokke said.

"Our study found one in four parents had not accessed formal flexible work arrangements in the past 12 months. Just under half (44 per cent) had used only 1-2 types of flexible work to manage work and family demands; the remaining third (31 per cent) had used 3 or more arrangements. Mothers accessed more of these formal arrangements than fathers."

The researchers recommend parents review their employee agreements and Fair Work Australia guidelines to gain a better understanding of their entitlements.

"While family-friendly workplaces are becoming more commonplace in Australia, in the past decade, we haven't seen a significant rise in requests for flexible work or awareness of flexible work rights," Dr Hokke said.

"Working parents make up around two-fifths of the Australian workforce. They are integral to our working culture.

"Workplaces have a vital role in providing transparent information to parents about their entitlements, but also ensuring flexibility is a real option for employees. We must encourage employers to maintain open conversations with their employees and celebrate those who value staff wellbeing and encourage work-life balance."

Dr Hokke said ensuring equitable access to family-friendly workplace arrangements for fathers, along with mothers, will support gender equity by improving women's access to paid work and men's access to caring for their children.