Tech

New Rochelle, NY, March 10, 2020--A fascinating new study has shown that the duration of a text-based counseling session, the length of the counselor's messages, and quick response time by the counselor are important factors in determining the impact of counseling. The study of young people under the age of 23 who relied on a dialogue-based, human-handled child hotline is published in Cyberpsychology, Behavior, and Social Networking, a peer-reviewed journal from Mary Ann Liebert, Inc., publishers. Click here to read the full-text article free on the Cyberpsychology, Behavior, and Social Networking website through April 10, 2020.

The article entitled "Texting at a Child Helpline: How Text Volume, Session Length and Duration, Response Latency, and Waiting Time Are Associated with Counseling Impact" was coauthored by Trine Sindahl, University of Copenhagen and Willemijn van Dolen, University of Amsterdam Business School. The researchers concluded that even though there is no face-to-face interaction, the clients might benefit from the texting as long as the counselor responds promptly and in long, dense, expressive messages. The number of messages exchanged is not as important as the total length of the texting session.

The researchers found an overall positive effect of the counseling immediately after a session and two weeks later. Counseling impact was based on the client's experience of being heard, changes in well-being, and empowerment.

"The latest statistics indicate that 24 million children and young people reach out to helplines. By offering access through different modalities, including chat and text, individuals can now choose to discuss their emotions using the technology with which they feel most comfortable," says Editor-in-Chief Brenda K. Wiederhold, PhD, MBA, BCB, BCN, Interactive Media Institute, San Diego, California and Virtual Reality Medical Institute, Brussels, Belgium.

Concern about contamination caused by microplastics is growing; owing to their abundance, ubiquity and persistence over time, microplastics pose a potential risk for organisms and ecosystems. Yet studies into their distribution in freshwater systems, in both lakes and rivers, and their effects on the organisms in these waters are few and far between, and there is very little information about their potential effect on the functioning of these ecosystems.

In this context, in collaboration with the National Museum of Natural Sciences (CSIC-National Research Council) in Madrid, the UPV/EHU's Stream Ecology research group has studied "the effects of microplastics on freshwater ecosystems and on two of the most important groups of organisms that live in them: amphibians and invertebrates", explained Naiara López-Rojo, researcher in the UPV/EHU group. To do this they conducted lab experiments in which they replicated the conditions of the rivers and ponds where these animals live, and exposed them to different concentrations of fluorescent microplastics: "Replicas without microplastics (control), at a low, at an intermediate and at a high concentration, while the remaining characteristics were identical (light, temperature, etc.)."

That way the group studied firstly the effect of the microplastics on tadpole survival, food and growth as well as the ingestion and egestion of them. In addition "we analysed whether the microplastics attach themselves to periphyton (set of microscopic organisms that grow on the rocks at the bottom of the river or pond and main source of food for the tadpoles) and whether their productivity changes, because that would demonstrate an alteration in the way freshwater ecosystems function", said the researcher. Secondly, they examined the effects of the microplastics on the decomposition of the leaf litter (one of the most important processes in river ecosystems) and on the survival and growth of organisms that feed on it (detritivore invertebrates); they also studied the degree of attachment of the microplastics to the leaf litter and degree of ingestion and egestion of the detritivores, thus evaluating the trophic transfer mechanisms of the microplastics.

Combination with other stressors

The results demonstrate that "microplastics cause mortality in detritivores in all their concentrations (in the highest concentration mortality is nine times higher) but their growth is not affected. In the case of tadpoles, we saw that they die in the highest concentration of microplastics; in the other concentrations we did not see any lethality, but we did see a reduction in the growth of the amphibians", added López-Rojo.

The fluorescence studies conducted on the tadpoles indicate, according to the researcher, "a presence of microplastics in the organisms, in their faeces and in the periphyton. And that suggests that microplastics could be significant stressors for amphibians, like other contaminants, climate change, habitat loss, etc. Amphibians could also be a significant transmission channel of freshwater microplastics to terrestrial ecosystems". In the case of the invertebrates, the tests suggest that the microplastics were also ingested (very likely through the ingestion of particles attached to the leaf litter) and some of them were excreted. The more the concentration of microplastics increased, the less the leaf litter decomposed. "These results provide fresh evidence of the damaging effects of this contaminant on aquatic insects and on the functioning of river ecosystems, and highlight the need to standardise the methods to be used in future experiments on microplastics to be able to draw comparisons," concluded the researcher in the UPV/EHU's Department of Plant Biology and Ecology.

López-Rojo stresses the need to go on exploring the effect of this kind of contaminant on freshwater ecosystems: "We are seeing that the outcome depends on the type of organism you study, exposure time, etc. More prolonged exposure would need to be studied because in actual fact the plastics persist for much longer than 15 days. It would also be interesting to study the effect of this contaminant together with other types of stressors which both rivers and ponds are subjected to. The reason is that the interaction among various stressors could turn out to be even more harmful."

A change in chemical composition enabled scientists to boost the longevity and efficiency of a perovskite solar cell developed at the U.S. Department of Energy's (DOE's) National Renewable Energy Laboratory (NREL).

The new formula enabled the solar cell to resist a stability problem that has so far thwarted the commercialization of perovskites. The problem is known as light-induced phase-segregation, which occurs when the alloys that make up the solar cells break down under exposure to continuous light.

"Now that we have shown that we are immune to this short-term, reversible phase-segregation, the next step is to continue to develop stable contact layers and architectures to achieve long-term reliability goals, allowing modules to last in the field for 25 years or more," said Caleb Boyd, lead author of a newly published paper in Science titled "Triple-halide wide-bandgap perovskites with suppressed phase-segregation for efficient tandems." Boyd and co-author Jixian Xu are associated with University of Colorado-Boulder Professor Michael McGehee's research group, which investigates perovskites at NREL.

Additional NREL scientists who contributed to the paper are Axel Palmstrom, Daniel Witter, Bryon Larson, Ryan France, Jérémie Werner, Steven Harvey, Eli Wolf, Maikel van Hest, Joseph Berry, and Joseph Luther.

Perovskite solar cells are typically made using a combination of iodine and bromine, or bromine and chlorine, but the researchers improved upon the formula by including all three types of halides. The research proved the feasibility of alloying the three materials.

Adding chlorine to iodine and bromine created a triple-halide perovskite phase and suppressed the light-induced phase-segregation even at an illumination of 100 suns. What degradation occurred was slight, at less than 4% after 1,000 hours of operation at 60 degrees Celsius. At 85 degrees and after operating for 500 hours, the solar cell lost only about 3% of its initial efficiency.

"The next step is to further demonstrate accelerated stability testing to really prove what might happen in 10 or 20 years in the field," Boyd said.

The new formula created a solar cell with an efficiency of 20.3%.

Silicon remains the dominant material used in solar cells, but the technology is approaching its theoretical maximum efficiency of 29.1%, with a record 26.7% established to date. But putting perovskites atop a silicon solar cell to create a multijunction solar cell could boost efficiency and bring down the cost of solar electricity. NREL scientists were able to create a tandem perovskite/silicon solar cell with an efficiency of 27%. By itself, the silicon solar cell had an efficiency of about 21%.

DURHAM, N.C. -- Set against a piece of black construction paper, the wings of the male cattleheart butterfly look even blacker than black.

"Some animals have taken black to an extreme," said Alex Davis, a graduate student in the lab of Duke University biologist Sönke Johnsen.

The butterflies they study are 10 to 100 times darker than charcoal, fresh asphalt, black velvet and other everyday black objects. As little as 0.06% of the light that hits them is reflected back to the eye. That approaches the blackest black coatings made by humans to help solar panels absorb more energy from the sun, or that line telescopes to reduce stray light.

Yet they achieve this light-trapping effect using wing scales that are only a few microns deep, just a fraction as thick as the blackest synthetic coatings.

In a study in the March 10 issue of the journal Nature Communications, Duke researchers report that ultra-black butterflies from disparate regions of the globe appear to have converged on the same trick. The secret to making blacks this dark and lightweight, they say, isn't a surplus of melanin -- the pigment responsible for a crow's feathers or a black cat's fur. It's an optical illusion created by the 3-D structure of the butterflies' wing scales.

Light goes into their scales, but very little of it bounces back out.

In the study, Davis, Johnsen and Duke professor Fred Nijhout used high resolution scanning electron microscopy and computer simulations to examine the microscopic structures on the wings of 10 species of ultra-black butterflies and four regular black or dark brown butterflies from Central and South America and Asia.

Butterfly wings may look smooth to the naked eye. Up close it's a different story. Magnified thousands of times, butterfly wings are covered in scales with a mesh-like surface of ridges and holes that channel light into the scale's spongy interior. There, pillar-like beams of tissue scatter light until it is absorbed.

Until recently, the explanation for the incredible light-absorbing properties of some black butterflies was that it was due to a honeycomb-like pattern in the tiny holes on the scales' surface.

But the new study suggests "that doesn't matter," Johnsen said. Looking at butterflies from four subfamilies -- the widest range of ultra-black butterflies that have been examined to date -- the team found that other ultra-black butterflies suck up similar amounts of light using holes with a variety of shapes and sizes, from honeycombs and rectangles to a chevron pattern.

It turns out the key differences between ultra-black and regular black scales lie elsewhere. When they looked at the butterflies' wings under an electron microscope, they found that both ultra-black and regular black scales have parallel ridges on their surface and pillars within. But the ridges and pillars are deeper and thicker in ultra-black scales compared to "normal" black scales.

When the team mimicked different wing scales in computer simulations, scales lacking either the ridged surface or interior pillars reflected up to 16 times more light. That would be like going from ultra-black to dark brown, Davis said.

This 3-D architecture is so good at swallowing light that the ultra-black scales still looked black even when coated with gold.

"You almost can't make them shiny," Davis said.

Similar deep blacks have popped up in other animals, such as peacock spiders and birds of paradise, which are known to reflect as little as 0.05% of visible light.

None of these natural beauties is quite as dark as the blackest synthetic blacks on record, which absorb more than 99.99% of incoming light using tightly packed "forests" of carbon nanotubes around 10 to 50 microns high. But what makes butterflies interesting, the researchers say, is they rival the best light-trapping nanotechnology, using structures that are only a fraction as thick.

Ultimately, the findings could help engineers design thinner ultra-black coatings that reduce stray light without weighing things down, for applications ranging from military camouflage -- for stealth aircraft that can't be seen at night or detected by radar -- to lining space telescopes aimed at faint, distant stars.

Why ultra-black coloration has popped up again and again across the butterfly family tree is still unclear, Johnsen said.

The blackness on the wings of many male butterflies is darker than it is on their female counterparts, so one theory is it helps them show off to potential mates. The black regions always border white, colored, or iridescent patches, so the idea is they might work like a dark picture frame to make the brighter blotches pop.

"Artists have known for a long time that the same color can look very different on different backgrounds," Johnsen said.

The next step, Davis said, is to figure out how many times butterflies have evolved ultra-black wings, and determine whether those species have anything in common that might help explain what favored the change.

"Why be so black?" Davis said. "We think it's likely some sort of signal to mates or maybe a predator. But there's a host of other possibilities, and we're hoping to clear that up."

Optimized surface structure innately reduces frost without heat or special coating

Approach even prevents frost formation on materials designed to attract water

Reducing frost increases energy efficiency in appliances and reduces drag on airplanes

Researchers were inspired by leaves, which do not form frost on their concave veins

EVANSTON, Ill. -- Northwestern University researchers discovered a new way to significantly reduce frost formation on any surface. The finding could help decrease the amount of energy needed for de-frosting and could potentially result in fewer canceled flights, which can be grounded by even the slightest layer of frost.

By tweaking the texture of any material's surface, the team was able to experimentally reduce frost formation by up to 60%. The millimeter-scale surface structure contains an optimized, jagged series of peaks and valleys, which the researchers observed in nature. With this structure, the team also showed theoretically that frost formation could be reduced by up to 80%.

"This idea came from looking at leaves," said Northwestern's Kyoo-Chul Park, who led the study. "There is more frost formation on the convex regions of a leaf. On the concave regions (the veins), we see much less frost. We found that it's the geometry -- not the material -- that controls this."

The study will be published today (March 10) in the Proceedings of the National Academy of Sciences. Park is an assistant professor of mechanical engineering in Northwestern's McCormick School of Engineering.

People who live in cold climates are all-too-familiar with frost. It forms when humid air vapor or condensation make contact with a surface that is below-freezing temperature.

Every winter, people scrape it off their cars or worry about it killing their plants. But frost is more than a nuisance. Frost on airplane wings can create drag, making flight dangerous or even impossible. And, when accumulating inside freezers and refrigerators, frost greatly reduces energy efficiency in appliances.

But frost doesn't form on everything. For objects, such as leaves, that have rippling geometry, frost forms on the peaks but rarely in the valleys.

"People have noticed this for several thousands of years," Park said. "Remarkably, there was no explanation for how these patterns form."

Through experimental work and computational simulations, Park and his collaborators found that condensation is enhanced on the peaks and suppressed in the valleys of wavy surfaces. The small amount of condensed water in the valleys then evaporates, resulting in a frost-free area. Even when Park used a surface material that attracts water, the water still evaporated from the valleys when below the freezing point.

Park used this new information to find the optimal surface texture to prevent frost formation. The winning surface contains millimeter tall peaks and valleys with small (40-60 degree) angles in between.

Although a thin line of frost still forms on the peaks of the surface topography, it can be defrosted with considerably less energy. It also bypasses the need for using liquids with lower frosting points or surface coatings, which can be easily scratched.

"The no-frosting region initiates the defrosting process," Park said. "So it would reduce the materials and energy used to solve frosting problems. All we have to do is provide others with the guidelines to design these serrated surfaces."

Unlike diamonds, solar panels are not forever. Ultraviolet rays, gusts of wind and heavy rain wear away at them over their lifetime.

Manufacturers typically guarantee that panels will endure the elements for at least 25 years before experiencing significant drop-offs in power generation, but recent reports highlight a trend of panels failing decades before expected. For some models, there has been a spike in the number of cracked backsheets -- layers of plastic that electrically insulate and physically shield the backsides of solar panels.

The premature cracking has largely been attributed to the widespread use of certain plastics, such as polyamide, but the reason for their rapid degradation has been unclear. By closely examining cracked polyamide-based backsheets, researchers at the National Institute of Standards and Technology (NIST) and colleagues have uncovered how interactions between these plastics, environmental factors and solar panel architecture may be speeding up the degradation process. These findings could aid researchers in the development of improved durability tests and longer-lived solar panels.

Cracks in backsheets often show up first near certain features -- such as the grid-shaped space in between the blue or black electricity-producing solar cells -- and can eventually propagate through the entire thickness of a sheet. These defects make way for oxygen and moisture to infiltrate and damage the interior where the cells lie and also allow electrical current to escape, increasing risks of electrocution.

If left outside for long enough, any plastic-based backsheet will start to fall apart, but not all backsheets are created equal. Some plastics deteriorate much more rapidly than others.

"In the 2010 to 2012 timeframe, many modules were deployed containing polyamide-based backsheets, which presented dramatic cracking failure in as little as four years despite meeting standard requirements," said Xiaohong Gu, NIST materials engineer and co-author of the study.

To get to the root of polyamide's degradation problem, Gu and her team acquired backsheet samples from solar panels deployed in regions around the globe, including sites in the U.S., China, Thailand and Italy. Most of the panels, which were in use from three to six years, showed clear signs of premature cracking.

With the weathered backsheets in hand, the researchers conducted a gamut of chemical and mechanical tests to examine the patterns and severity of degradation throughout the depth of the sheets. The results, described in the journal Progress in Photovoltaics: Research and Applications, showed that the areas of the sheets that had undergone the worst cracking were those that had become the most rigid. And curiously, the most brittle areas were on the inner side of the sheets, Gu said.

How could the quality of the walled-off interior diminish more quickly than the exposed outer layer? Gu and her team speculated that the sunlight-induced degradation of the top side of the encapsulant -- a film that surrounds the solar cells -- produced damaging chemicals that descended toward the backsheets, speeding up their decay. If true, the proposed mechanism would explain why cracks form in between solar cells, as chemicals could find passage to the back through these regions.

The researchers identified acetic acid as a prime suspect, as it is known to be harmful to polyamide and is produced during the degradation of a polymer commonly used as an encapsulant, called ethylene vinyl acetate (EVA). To test their hypothesis, the researchers stowed several polyamide strips away in vials of acetic acid and then, after five months, analyzed how they decayed compared with strips placed in either air or water.

Under the microscope, cracks mirroring those from the weathered backsheets appeared on the surface of the plastic strips exposed to acetic acid, which appeared much worse than on those that had been in air or water. Chemical analysis showed that degradation products of polyamide were higher in the acetic-acid-exposed strips, providing further evidence that the acid accelerates the deterioration of the backsheet material.

The study highlights the interplay between solar panel components (the EVA encapsulant and polyamide backsheet in this case) as a potentially critical factor to consider when designing solar panels that are built to last.

These new insights into premature failures could also become valuable to NIST researchers and others who seek to replicate the degradation process in the lab as a way to test and predict the longevity of solar panel components.

Researchers have found that injecting pellets of hydrogen ice rather than puffing hydrogen gas improves fusion performance at the DIII-D National Fusion Facility, which General Atomics operates for the U.S. Department of Energy (DOE). The studies by physicists based at DOE's Princeton Plasma Physics Laboratory (PPPL) and Oak Ridge National Laboratory (ORNL) compared the two methods, looking ahead to the fueling that will be used in ITER, the international fusion experiment under construction in France.

Improve the temperature

The researchers showed that icy pellets of hydrogen improve the temperature of the fusion plasma when compared with the gas fueling method now typically used in doughnut-shaped fusion facilities called tokamaks. Higher temperatures are beneficial for the fusion reactions. The results on DIII-D are encouraging for ITER, which plans to use pellet injection to fuel its hot inner core.

Fusion, the power that drives the sun and stars, combines light elements in the form of plasma - the state of matter that consists of positively charged atomic nuclei and negatively charged electrons - to create massive amounts of energy. Scientists seek to replicate fusion on Earth for a safe, clean and virtually inexhaustible supply of power to generate electricity.

One challenge for producing fusion energy is how to get cold hydrogen fuel into the hot plasma core. The sun has all the hydrogen that it needs for billions of years, but fusion reactors on Earth must constantly feed hydrogen into the plasma to sustain the fusion reactions. Puffing room-temperature gas is the most common way to inject hydrogen in current experiments.

Bigger and hotter

However, as fusion reactors get bigger and hotter it will become harder for the gas to penetrate into the core of the reactor where fusion reactions take place. New methods thus need to be developed to feed the fusion core without degrading the plasma performance.

The joint research effort on DIII-D compared the two fueling methods in high-performance plasmas planned for ITER. The experiments revealed a significantly higher pressure of plasma -- a key to fusion reactions -- using hydrogen ice compared to gas injection when the rate of fueling is roughly evenly matched between the two methods.

"The fueling plays a big role in the edge plasma performance," said Andrew "Oak" Nelson, a graduate student in the Program in Plasma Physics at Princeton University and first author of the Nuclear Fusion article describing these results. Nelson is part of a multi-institutional team that carefully designed and executed the experiments.

Scientists at ORNL

The technology for injecting the ice pellets was developed by scientists at ORNL. Interpretation of the experimental results requires sophisticated scientific instruments developed by multiple collaborating institutions on DIII-D. "It's great to see how our multi-institutional effort came together to tackle this important fueling question for ITER and future reactors," said Morgan Shafer, a lead research scientist at ORNL and a coauthor of the paper.

The research also demonstrates how graduate students can make important contributions to fusion energy by working on these large national research facilities. "For a graduate student to play an important role in this experimental study on DIII-D is impressive," said Egemen Kolemen, a PPPL and Princeton University physicist who was an advisor for the project. "Oak's success shows how large fusion experiments provide significant leadership opportunities for students and early career scientists."

New research by Texas A&M University biologist Dr. Charles Criscione and collaborators in Canada shows that family ties and traits such as manipulation, sacrifice and selflessness are just as key to survival in parasitic organisms as they are in cognitive species like humans.

In essence, when it comes to successful transmission, some parasites get by with a little help from their kin.

Specifically in the case of lancet liver flukes (Dicrocoelium dendriticum), a single larva travels to and takes over its ant host's brain, compelling the ant to cling to vegetation until it is eaten by the fluke's next host, a grazing mammal such as cattle and deer. In a textbook example of altruistic behavior, the brain fluke sacrifices itself to ensure the survival of its relatives, who co-infect the same ant's abdomen. Ant exposure via vegetation ensures transmission of the abdomen flukes, who live on by infecting the mammal's bile ducts, where they sexually reproduce and send the next generation of parasite progeny out into the world ensconced in host feces.

For more than 40 years, scientists have hypothesized kin selection -- the evolution of traits that favor survival of relatives -- to explain the brain fluke's noble self-sacrifice.

"It was presumed that genetically identical individuals, which we call clonemates, can end up in the same ant because in the snail first host, there is an asexual reproductive stage of the parasite," Criscione said. "Many larval parasites that are clonemates are released from the snail in a slime ball that ants like to eat. However, no one has tested the clonal relationships of the parasites co-infecting ants, especially between the brain fluke and abdomen flukes."

Criscione and colleagues Dr. John Gilleard (University of Calgary) and Dr. Cam Goater and Dr. Brad van Paridon (University of Lethbridge) did just that, and they now have the data to prove it.

In their study that measured genetic relatedness between brain and abdomen flukes within ants, the team was able to show not only that clonemates simultaneously occur in the same ant much more often than expected by chance, but also that the brain fluke commonly has clonemates within the same ant. Their research, currently published online and set to be included in next week's issue of the Proceedings of the National Academy of Sciences, provides rare genetic evidence to support a role for kin selection in the evolution of an altruistic, host-manipulating behavior that facilitates parasite transmission and as an evolutionary explanation for similar behaviors that improve the odds of survival and reproduction among genetically related family members.

"The lancet fluke is an extreme example of kin selection in that the asexual reproductive stage of the parasite in its snail host has enabled the highest degree of genetic relatedness; i.e., clonality," Criscione said. "While our data confirm the original hypothesis in that we find lots of clonemates and that these clonemates co-infect the same ant, our study also reflects the important need in science to collect hard data where possible to test our hypotheses regardless of how intuitive something may seem, especially in iconic systems such as the lancet fluke."

To explain kin selection, Criscione defers to one of the founding fathers of population genetics, J.B.S. Haldane -- specifically, a quote recalled by his graduate student and prominent evolutionary biologist John Maynard Smith, ascribed as follows: "I would lay down my life for eight cousins or two brothers." Essentially, a trait that reduces one's own survival and/or reproduction -- an altruistic trait -- can increase in frequency in the population because the trait benefits the survival and/or reproduction and therefore the individual fitness of one's relatives.

"Full siblings and first cousins share on average 50% and 12.5%, respectively, of their genetic information," Criscione said. "By 'helping' two of one's full siblings or eight of one's cousins, the individual is in effect ensuring the survival and/or reproduction of itself, from a genetic information perspective.

"Theory indicates that a truly self-sacrificing behavior -- altruism -- cannot evolve by natural selection because the actor dies and cannot pass on the genetic variant(s) underlying the behavior. However, if the recipients of the actor's altruistic behavior are related to the actor, then the trait can evolve, or increase in frequency, because the actor shares its genes with its relatives. This is the premise of kin selection, or the evolution of traits that benefit one's relatives. We found the brain fluke has clonemates in the abdomen, so even though the brain fluke does not transmit to the next host, its clonemates, which are akin to twins because they share 100% of their genetic information, do."

Interestingly, Criscione notes that when the ant first eats the snail slime ball and ingests myriad parasite larvae, many migrate to the ant's head. But when one reaches the ant's brain, the rest change direction and migrate to the abdomen, where they form a protective cyst around themselves.

So what makes that one brain fluke turn hero, much less the others turn back and head for the comparative safety of the ant's abdomen?

"We do not know," Criscione said. "A hypothesis is that the genetic basis of this 'hero' trait is found in all individuals, but we need to know the gene or genes that control the trait to answer this. Thus, it remains an outstanding question. As for the change in direction, a hypothesis there is that either the brain fluke directly releases a chemical or the brain fluke indirectly causes the ant to release a chemical that informs the other larvae to go to the abdomen."

From a broader perspective, Criscione says the melding of kin and multilevel selection has rekindled interest in how genetic relatedness among individuals influences selection on traits, ranging from social behavior to how plants grow roots.

"Our study adds a unique trait to the list where the kin-selected trait is one that facilitates parasite transmission," Criscione said. "It is also interesting for trematodes, which are a diverse group of parasitic flatworms with more than 30,000 estimated species -- some of which are of major economic and health importance. All trematode species have asexual reproduction in their first host, which is usually a mollusk such as snails. Thus, clonality, the highest form of genetic relatedness, makes kin selection a possibility in the evolution of other trematode traits, including competition among clones and caste formation, or possibly even their hosts with regard to virulence."

Criscione says there is much to be learned about the transmission biology of clonemates within the lancet liver fluke system, from how many make it to the final mammal host to how dispersed they are among individual final hosts.

"If clonemates end up in the same host and mate, this is equal to self-mating," Criscione said. "Self-mating is an extreme form of inbreeding, which is one of the evolutionary mechanisms that shapes how genetic information is partitioned among individuals in a population. Moreover, it will be of interest to ask if any particular clone dominates, or do we see a mix of different clones surviving the transmission process to the final host?"

Because altered host phenotypes -- behavioral and morphological -- by parasites occur in other parasite groups beyond trematodes, Criscione says it will be important to merge the ecology, population genetics and phylogenetics of the parasites with these parasite manipulation traits to fully understand their origins, adaptive significance and ecological context.

"Parasites are extremely diverse in terms of their ecologies and the number of different species that have evolved a parasitic life cycle," Criscione added. "Therefore, it will be exciting to discover the possible ways by which altered host phenotypes have come about across the different parasites."

More than half of the world's population faces a looming threat to the quality and availability of their drinking water because climate change and urbanisation are expected to cause an increase in groundwater organic carbon, a new UNSW study has found.

The research, published in Nature Communications overnight, examined the largest global dataset of 9404 published and unpublished groundwater dissolved organic carbon (DOC) concentrations from aquifers in 32 countries across six continents.

DOC is a naturally occurring component of groundwater, but the higher its concentration, the more difficult and expensive it is to make groundwater drinkable. In Australia, groundwater is widely used as the main source of drinking water for many cities and towns.

Lead author Dr Liza McDonough, of the Connected Waters Initiative Research Centre at UNSW, said the study forecasted elevated DOC concentrations because of projected changes in temperature and rainfall due to climate change, as well as increased urbanisation.

"We identified groundwater DOC concentration increases of up to 45 per cent, largely because of increased temperatures in the wettest quarter of the year - for example, in a number of south-eastern states in the United States. We predict increases in DOC in these locations could increase water costs for a family of four by US$134 per year," Dr McDonough said.

"Other areas such as eastern China, India and parts of Africa already experience severe groundwater contamination issues. These may be further compounded, particularly in south-eastern China, by groundwater DOC increases associated with large predicted increases in temperature in the wettest quarter of the year by 2050.

"Generally, we expect urbanisation to increase groundwater DOC concentrations by up to 19 per cent, compared to agricultural or natural land use, likely as the result of contamination - for example, through leaking septic and sewer systems."

The research, a collaboration between UNSW, the Australian Nuclear Science and Technology Organisation (ANSTO), Southern Cross University, British Geological Survey, and the University of Bradford, found four major contributing factors to groundwater DOC levels: climate, land use, inorganic chemistry and aquifer age.

Health threat

Dr McDonough said increased groundwater DOC, whether naturally occurring or due to contamination, also posed a threat to human health.

"Groundwater is Earth's largest source of freshwater and provides essential drinking water for more than 50 per cent of the world's population," she said.

"But, because most health impacts caused by DOC are related to the formation of by-products of water treatment chlorination and depend on concentrations of other water chemical parameters, the World Health Organization and many countries - including Australia - do not regulate DOC concentrations in drinking water directly."

Dr McDonough said that while DOC is a naturally occurring, key element of groundwater it could combine with, and transport, potentially dangerous heavy metals otherwise bound to rocks and sediment where groundwater occurs.

"This is a concern when, for example, more than 100,000 lifetime cancer cases in the United States alone can be attributed to drinking water contaminants," she said.

Water treatment costs to rise

Dr McDonough said it was important to understand what caused high DOC concentrations in groundwater.

"An increase in groundwater DOC concentration impacts the ability and therefore cost to make groundwater drinkable," she said.

"For example, we projected a 16 per cent increase in annual household water costs in some parts of the United States because of rising water treatment costs - due to the need to implement additional water treatment measures to remove increased DOC concentrations.

"The decrease in groundwater quality and substantial increase in water treatment costs will also compound existing constraints on groundwater resources, including availability."

Wet vs arid climates

Dr McDonough said the impacts on groundwater DOC levels from climate change and urbanisation, while likely to occur globally, differed by geography and climate.

"Our research found that in arid climates, groundwater DOC concentrations increased with higher rainfall because microbes can better break down organic matter, such as leaves, under warm and increasingly wet conditions," she said.

"Increased temperatures in arid environments, however, reduced groundwater DOC concentrations because when conditions are too hot and dry, vegetation and organic matter sources are limited.

"By contrast, increased rain in warm and wet environments decreased groundwater DOC concentrations because heavy rainfall dilutes the DOC in groundwater."

Water treatment solutions

Dr McDonough said she looked forward to conducting further research to determine the best water treatment options for areas where groundwater DOC concentrations are anticipated to increase.

"Our next step is to investigate how the character of DOC changes when you have different aquifer minerals, because some types of organic matter can stick to certain mineral surfaces and ultimately reduce this type of organic matter remaining in the water," she said.

"This will help provide guidance on the most suitable water treatment options in areas where DOC concentrations are expected to increase."

Read the full research paper in Nature Communications: https://www.nature.com/articles/s41467-020-14946-1

Silicon is abundant in nature with high theoretical capacity (4200 mAh g-1), making it an ideal anode material for improving the energy density of dual-ion batteries (DIBs). However, its application in DIBs has been restricted by the large volume expansion problem (>300%).

Rigid contacts between silicon and current collectors, commonly made with metal foils, lead to significant interfacial stress. As a consequence, interface cracking and even exfoliation of active materials occur resulting in suboptima cycling performance.

A research group led by Prof. TANG Yongbing and his team members (Dr. JIANG Chunlei, XIANG Lei, MIAO Shijie etc.) from the Shenzhen Institutes of Advanced Technology (SIAT) of the Chinese Academy of Sciences, along with Prof. ZHENG Zijian from the Hong Kong Polytechnic University, have proposed a flexible interface design to reduce alloying stress on silicon anodes in silicon-graphite DIBs.

This flexible interface design modulates stress distribution via the construction of a silicon anode on a soft nylon fabric modified with a conductive Cu-Ni transition layer, thus endowing the silicon electrode with remarkable flexibility and stability over 50,000 bends.

Assembly of the flexible silicon anode with an expanded graphite cathode yielded a silicon-graphite DIB (SGDIB) having record-breaking rate performance (up to 150 C) and cycling stability over 2000 cycles at 10 C with capacity retention of 97%.

Moreover, the SGDIB showed high capacity retention of about 84% after 1500 bends and a low self-discharging voltage loss of 0.0015% per bend after 10,000 bends, indicating strong potential for high-performance, flexible energy-storage applications.

Faced with a gritty landscape of metal fences, concrete walls and asphalt pavement, city lizards in Puerto Rico rapidly and repeatedly evolved better tolerance for heat than their forest counterparts, according to new research from Washington University in St. Louis and the University of California, Los Angeles.

Studies that delve into how animals adapt in urban environments are still relatively rare. But anoles are becoming a model system for urban evolutionary research.

"Urban lizards are exposed to higher temperatures, consistent with the urban heat island effect," said biologist Kristin Winchell, postdoctoral research associate in the Losos laboratory in Arts & Sciences. "We found that they are able to maintain their function at temperatures of about 0.82 degrees C (or 1.47 F) higher on average across all populations."

In one population in this study, urban lizards were able to go about their business in temperatures above 40 C (104 F). That's a lot of heat for a tiny animal -- one that measures about 5 centimeters long, not including its tail.

"Better heat tolerance can make all the difference in an urban habitat," Winchell said. "Whether it's being able to stay active during longer parts of the day or being able to occupy perches that reach higher temperatures, it expands their niche space."

This adaptive thermal response is even more interesting because only those lizards that grow up in the city seem to be able to tap into it -- an example of natural selection favoring trait 'plasticity,' researchers said. The study is published March 9 in the journal Nature Ecology & Evolution.

A hidden superpower

In previous work, Winchell showed that city lizards have evolved longer limbs and larger toepads with specialized scales. Both of these traits allow them to more effectively and quickly traverse urban habitats, allowing them to climb up smooth, painted walls.

Compared with these adaptations, thermal tolerance is a relatively complex trait. It affects multiple body systems and involves potentially hundreds of genes. And cold-blooded animals like these lizards also have the option to behaviorally regulate temperature -- for example, by shuttling in and out of sun, or by changing the time of day when they hunt or look for mates.

Winchell's partner for this effort, Shane Campbell-Staton, assistant professor at UCLA, is an expert at sussing out genomic aspects of thermal adaptation.

"A big part of this story is that the target of selection in urban heat islands is plasticity, the ability of an individual to respond adaptively to its environment," Campbell-Staton said. "Individuals that are high responders -- that is, those that can become more heat tolerant when raised in cities -- are favored by natural selection. The major difference is that the adaptation only appears when an individual is born and raised in a city environment.

For example, when Winchell's previous work showed that lizards with long limbs do better in cities, those individuals would have longer limbs no matter where they are raised.

"In contrast, differences in heat tolerance are hidden in a forest habitat and only show themselves when the proper genes are exposed to warm temperatures," Campbell-Staton said. "It's kind of like a hidden superpower that only presents itself in the right environment. We are only just beginning to understand how natural selection works on this type of trait to influence the process of evolution."

Comparing city lizards to forest lizards

The ability to withstand more heat anytime, anyplace, is potentially a game changer for Anolis cristatellus, the most abundant and visible species in urban environments of the 10 kinds of lizards that are found across Puerto Rico.

Winchell and her team studied 150 lizards from four municipalities across the island, including the capital San Juan. Each of these locations was part of a paired site: with one lizard collection area in the city, and the other in a nearby forest. The researchers also brought back some of the lizards to a laboratory setting at the University of Massachusetts Boston, where Winchell was a graduate student at the time.

The scientists relied on an established lizard research protocol that tests thermal tolerance as a measure of a lizard's ability to right itself after being placed gently on its back. The researchers raised the temperature by small increments, and the trial ended when a lizard took too long to right itself. After the tests, a cool water bath helped bring the lizards comfortably back down to normal temperatures.

Separately, the researchers also took tissue samples from lizards exposed to cold, ambient and warm temperatures. Genetic tests revealed different patterns of gene expression in the tissues from city and forest lizards exposed to different temperatures.

Even more interesting, the researchers discovered a single gene variant that differed consistently between the city and forest populations -- one that was associated with differences in thermal tolerance. The researchers believe that this indicates natural selection is selecting for the ability to respond to higher temperatures when needed, what they refer to as a 'high-plasticity genotype.'

Rapid and repeated changes

"One of the unique and exciting things for me about this study is that we're able to simultaneously address this question about the repeatability of evolution at several different levels of biological organization," Campbell-Staton said.

"Starting at the whole organism level, we clearly see that urban lizards are able to maintain functioning at significantly higher temperatures than their forest counterparts.

"Then, when we look at all the genes that are being differentially expressed, we see pretty high repeatability in how those large suites of genes are changing as well," he said. "But if you zoom in even further, we found not only a single gene, but what seems to be a single polymorphism that is repeatedly under selection in these urban heat islands as well, which is fascinating."

By studying how animals adapt to different habitats, like life in the city, researchers have a unique opportunity to investigate traits that are environmentally dependent but influenced by an animal's genetic makeup.

That dynamic is part of why Winchell says she is partial to A. cristatellus, which is abundant in urban areas not only in Puerto Rico, but outside of their native range in the southern United States and other parts of the Caribbean.

"I like to say they are urbanophilic, or urban-loving species," Winchell said. "There are other terms that people use, like urban tolerant or urban-adapting. But I think urbanophilic captures it best. They're exploiting novel niche space that isn't present in the forest environment. But they're not reliant on humans. If humans went away, they would still do fine."

Physicians who identify as "general practitioners" are a group distinct from board-certified "family physicians," according to a new study that was supported, in part, by the American Board of Family Medicine Foundation. Family medicine researchers from the University of Washington, University of Wisconsin, University of Kentucky and the American Board of Family Medicine analyzed national data on physicians in direct patient care, linking records from the American Medical Association to American Board of Family Medicine board certification status, as well as to Centers for Medicare and Medicaid Services and US Department of Health and Human Services data. In their analysis of all 102,604 MD and DO physicians in the United States, the authors of this study describe the personal, professional and practice characteristics of self-identified general practitioners as compared with American Board of Family Medicine certified family physicians.

GPs are more likely to be older (average age 64.6 years for GPs compared with 49.4 for FPs), male (77% of GPs vs. 58% of FPs), DOs (28% vs. 10%), and graduates of non-US medical schools (41% vs. 23%). Few GPs have family medicine residency training (9%); less than half have any residency training directly relevant to primary care (48%). GPs and board-certified FPs practice in similar geographic locations, but GPs are less likely to participate in Medicare (53% vs. 76%) or work in hospitals (13% vs. 22%). GPs are slightly more likely to provide nursing home services (13% vs. 11%) and to make home visits (3% vs. 1%). The authors recommend that GPs and FPs be considered separate groups for research, workforce and policy purposes.

When faced with complex and difficult questions, such as how plants interact with their environment, sometimes the best approach is to bring together many different approaches. Three separate journals--the American Journal of Botany (AJB), Applications in Plant Sciences (APPS), and the International Journal of Plant Sciences (IJPS)--recently joined efforts to bring attention to these interactions from a variety of perspectives.

The February issues of each journal featured research on plant-environment interactions--each from a different angle. Articles in AJB looked at plant stress, reproduction, and mutualisms; articles in APPS focused on novel methods and tools to study plant-environment interactions; and articles in IJPS focused on the paleobotanical and morphological perspectives.

"The breadth of work in these special issues and sections speaks to how modern plant biology pulls from across these disciplines," said Dr. Katy Heath, Associate Professor of Plant Biology at the University of Illinois, and one of the editors of the AJB special issue. For example, "Understanding how plants will respond to future climate change takes an interdisciplinary approach that learns from the past (paleoecology, palynology, evolution) and the present (physiology, ecology, genetics)."

Indeed, the scope of the work is quite broad, spanning from computational modeling of ancient climates based on fossil plant community records (Harbert and Baryiames (2020) in APPS) to a study of stressed-out sex-switching in striped maple trees (Blake-Mahmud and Struwe (2020b) in AJB). But as disparate as the topics and methods in these issues may seem, advances in understanding plant-environment interactions in one dimension can meaningfully inform thinking and experimental techniques in another.

In some cases, different techniques were brought to bear on related questions, such as Dr. Courtney Murren's investigations of how soil characteristics affect natural selection on root traits, and phenotypic plasticity, in Arabidopsis thaliana. Dr. Murren used phenotypic analysis of wild populations growing in the field and in a common garden experiment to investigate natural selection on root traits (Murren et al. (2020) in AJB). She also used mutant gene lines grown in different soil nutrient conditions to study the effect of soil on phenotypic plasticity (Murren et al. (2020) in IJPS). The answers to these different questions, asked at different scales and delivered through different methodologies, help fill in puzzle pieces as to how root traits evolve in response to soil characteristics.

Different fields studying plant-environment interactions can inform each other on a theoretical or conceptual basis, and understanding the broader picture of how plants interact with their environment can also help researchers take a step back and appreciate a broader perspective on their system. "It's a huge challenge, but a worthy one, to think beyond one's study system and particular interaction (biotic or abiotic) to draw analogies with other responses," said Dr. Heath. "It can help us better see how plants leverage their genomes to simultaneously do many things---they are interacting with microbes, they are being consumed by herbivores, they are attempting to be pollinated (or not!)---all while optimizing their responses to myriad abiotic stressors (drought, salt, nutrient limitation)."

Beyond these conceptual dividends, there are real, practical benefits to following researchers in different fields studying other aspects of plant-environment interactions, such as learning new tools, study designs, and techniques. "As one obvious example, the sequencing revolution developed originally in the context of in-depth sequencing of individual genomes," said Dr. Heath, "but look how much we now know about plant-microbiome interactions as a result of our ability to sequence thousands of taxa at once!"

These special issues arose out the 2018 Green Life Science Symposium, an effort to gather diverse researchers together to discuss plant-environment interactions from different perspectives, and to share research from siloed fields. "This takes some willingness to talk across fields, since we tend to run into issues even speaking the same language---since we use the same words to mean different things and different words to mean the same thing!" said Dr. Heath. "But it's already happening." Indeed it is, as these articles show.

PRINCETON, N.J.--Five social scientists holed up in an Amsterdam hotel for a week with the goal of reaching a scientific consensus on how people form stereotypes. Remarkably, they were encouraged by the fact that none of them actually agreed with each other.

At a conference in Europe the year before, they had presented their conflicting theories. Those in the audience -- also social scientists -- wondered how they could comprehensively study stereotypes if they had to choose one model and reject the others.

"People came up to us in complete and utter confusion. We worried that researchers might abandon the entire line of work altogether, so we decided we had to isolate ourselves -- like Camp David -- until we could reach a consensus," said co-author Susan Fiske, Eugene Higgins Professor of Psychology at Princeton University's Woodrow Wilson School of Public and International Affairs.

After the weeklong retreat in Amsterdam, the team emerged with a joint theory paper. Inspired by the experience, they also published a how-to guide March 9 in the Proceedings of the National Academy of Sciences (PNAS). They describe what worked -- and what didn't -- to bring the adversaries to agreement. Their methods and their success suggest that government funding agencies and foundations might consider other efforts that bring together academics with differing viewpoints for the betterment of science.

"If people are willing to get in a room together and debate their differences, science can be improved," Fiske said. "Given that we've all been published in reputable journals, we never thought of it as one theory being right, or the other one being wrong. Instead, we thought there would be subtle differences in how these theories play out. After our week together, that's what we found."

Fiske worked on the project with Naomi Ellemers of the University of Utrecht, Andrea Abele of the University of Erlangen-Nürnberg, Alex Koch of University of Chicago, and Vincent Yzerbyt of University of Louvain.

Fiske's work has long shown that people form stereotypes based on how they perceive the other people's competence and warmth. Yet, her adversarial collaborators pointed to other perceived factors such as ideology. Or they broke down warmth into being trustworthy and friendly. Or advocated morality over everything else.

Fiske and her co-authors reached the agreement that the perceived competence of the person/people being considered is clearly one factor in determining stereotypes. A second factor at play is some form of warmth or trustworthiness. This could depend on shared political beliefs, depending on the situation.

Perhaps what's most important, however, is that the researchers were able to reach an agreement at all. By engaging in "adversarial collaboration," a concept pioneered by Princeton's Daniel Kahneman, a prominent psychologist and Nobel Prize-winning economist, they were able to design research to answer unresolved issues.

By engaging in the new idea of "adversarial alignment" of their theories, they determined that none of them were invalid. Rather, each theory is valid based on the situation, or the different circumstances in which one theory on stereotypes should be employed over the other. For example, Fiske's emphasis on warmth and competence works well for groups that people encounter in person, as in new kinds of people in the neighborhood. But for Koch, another researcher in the group, status and ideology works well for an overall analysis of groups' location in society.

The idea for this collaboration actually arose even earlier than the first conference -- thanks to Koch, who, as a graduate student presented work at a conference that contradicted Fiske's 20 years of research on stereotypes. Like Fiske, Koch's work also found evidence that competency played a role in stereotypes, but instead of warmth, his research pointed to political ideologies.

"I thought, certainly these are important, but if you're walking down a dark alley at night, you don't want to know who someone voted for," Fiske said. "You want to know if they intend to mug you."

Nevertheless, Fiske and Koch evaluated their models and debated their differences after which Koch asked if he could visit Fiske's lab. "I'm a scientist, so I had to say yes." Fiske said. "We started several studies aimed at solving the puzzle together."

All of this set the stage for Koch and Fiske, along with the three other researchers, to compare their competing theories in Amsterdam. To negotiate some common ground and identify some remaining challenges, they satisfied two preconditions and followed specific guidelines. Throughout their days together, Ellemers, the lead author of the latest paper in PNAS and a social/organizational psychologist, made sure the group stuck to the rules.

They began by reframing their interactions away from competitive rivalry into the pursuit of a joint goal. They also agreed that everyone shared trustworthy intentions, as well as scientific competence, with relation to the goal.

Days began with a full European breakfast and strong coffee, Fiske joked, before the team got down to business. They spent their days in a glass-walled conference room, projecting their theory models and figures onto the screen.

To start, they "leveled the playing field," which meant only one researcher from each research group attended, that seniority did not convey privilege, and that prepared descriptions of each model had the same page allotments. They began their discussions with agreed-upon premises before debating their differences. They "capitalized on shared curiosity" as scientists.

From there, they moved into "producing measurable progress," and split off in pairs, to begin writing the paper. All of this kept in mind what they called "working toward mutual gain," as well as the realization that not reaching a resolution would be an unacceptable "downside alternative." This created a sense of urgency throughout the experience.

A week later, a draft theory paper had formed. The team spent a year revising, submitting, and revising the paper for a theory journal. Meanwhile, they distilled the main ingredients of their process into a Perspectives paper, "Adversarial Alignment Enables Competing Models to Engage in Cooperative Theory-Building, toward Cumulative Science," published March 9 in PNAS.

The methods have clear implications for academia, as well as for policy and the media. Adversarial collaborations on data and adversarial alignments on theory both can enhance scientific credibility among journalists, the public, and members of Congress, which is especially important in an age of misinformation and distrust, the researchers said.

"We used the behavioral science of multi-party negotiations to resolve our own polarized science, building on the models' shared insights that we needed to respect each other's competence and trust each other's intentions," Fiske noted. "Contrasting viewpoints on policy, politics, and social norms might profit from our experience as a 'team of rivals.'"

Scientists from the RIKEN Cluster for Pioneering Research and RIKEN Center for Emergent Matter Science have succeeded, in collaboration with international partners, in creating an ultrathin organic solar cell that is both highly efficient and durable. Using a simple post-annealing process, they created a flexible organic cell that degrades by less than 5 percent over 3,000 hours in atmospheric conditions and that simultaneously has an energy conversion ratio--a key indicator of solar cell performance--of 13 percent.

Organic photovoltaics are considered to be a promising alternative to silicon-based conventional films, being more environmentally friendly and cheap to produce. Ultrathin flexible solar cells are particularly attractive, as they could provide large power per weight and be used in a variety of useful applications such as powering wearable electronics and as sensors and actuators in soft robotics. However, ultrathin organic films tend to be relatively efficient, typically having an energy conversion ratio of around 10 to 12 percent, significantly lower than the ratio in silicon cells, which can be as high as 25 percent, or of rigid organic cells, which can be up to around 17 percent. Ultrathin films also tend to degrade rapidly under the influence of sunlight, heat, and oxygen. Researchers are trying to create ultrathin films that are both energy efficient and durable, but it is often a difficult tradeoff.

In research published in Proceedings of the National Academy of Sciences of the United States of America, the group succeeded in showing that an ultrathin cell can be both durable and efficient. The group began with a semiconductor polymer for the donor layer, developed by Toray Industries, Inc., and experimented with a new idea, of using a non-fullerene acceptor, increasing the thermal stability. On top of this, they experimented with a simple post-annealing process, where the material was heated to 150 degrees Celsius after an initial annealing at 90 degrees. This step proved to be critical in increasing the durability of device by creating a stable interface between the layers.

According to Kenjiro Fukuda, one of the authors of the study, "By combining a new power generation layer with a simple post-annealing treatment, we have achieved both high energy conversion efficiency and long-term storage stability in ultra-thin organic solar cells. Our research shows that ultra-thin organic solar cells can be used to supply high power in a stable way over long periods of time, and can be used even under severe conditions such as high temperature and humidity. I very much hope that this research will contribute to the development of long-term stable power supply devices that can be used in wearable electronics such as sensors attached to clothes."