Tech

At the heart of clouds are ice crystals. And at the heart of ice crystals, often, are aerosol particles - dust in the atmosphere onto which ice can form more easily than in the open air.

It's a bit mysterious how this happens, though, because ice crystals are orderly structures of molecules, while aerosols are often disorganized chunks. New research by Valeria Molinero, distinguished professor of chemistry, and Atanu K. Metya, now at the Indian Institute of Technology Patna, shows how crystals of organic molecules, a common component of aerosols, can get the job done.

The story is more than that, though - it's a throwback to Cold War-era cloud seeding research and an investigation into a peculiar memory effect that sees ice form more readily on these crystals the second time around.

The research, funded by the Air Force Office of Scientific Research, is published in the Journal of the American Chemical Society.

Throwback to cloud seeding

Molinero's research is focused on how ice forms, particularly the process of nucleation, which is the beginning of ice crystal formation. Under the right conditions, water molecules can nucleate ice on their own. But often some other material, called a nucleant, can help the process along.

After several studies on the ways that proteins can help form ice, Molinero and Metya turned their attention to organic ice nucleants (as used here, "organic" means organic compounds containing carbon) because they are similar to the ice-producing proteins and are found in airborne aerosols.

But a review of the scientific literature found that the papers discussing ice nucleation by organic compounds came from the 1950s and 1960s, with very little follow-up work after that until very recently.

"That made me really curious," Molinero says, "because there is a lot of interest now on organic aerosols and whether and how they promote the formation of ice in clouds, but all this new literature seemed dissociated from these early fundamental studies of organic ice nucleants."

Additional research revealed that the early work on organic ice nucleants was related to the study of cloud seeding, a post-war line of research into how particles (primarily silver iodide) could be introduced into the atmosphere to encourage cloud formation and precipitation. Scientists explored the properties of organic compounds as ice nucleants to see if they might be cost-effective alternatives to silver iodide.

But cloud seeding research collapsed in the 1970s after political pressures and fears of weather modification led to a ban on the practice in warfare. Funding and interest in organic ice nucleants dried up until recently, when climate research spurred a renewed interest in the chemistry of ice formation in the atmosphere.

"There has been a growing interest in ice nucleation by organic aerosols in the last few years, but no connection to these old studies on organic crystals," Molinero says. "So, I thought it was time to "rescue" them into the modern literature."

Going all classic

Phloroglucinol is one of the organic nucleants studied in the mid-20th century. It showed promise for controlling fog, but less for cloud seeding. Molinero and Metya revisited phloroglucinol as it proved potent at ice nucleation in the lab.

One question to answer is whether phloroglucinol nucleates ice through classical or non-classical processes. When ice nucleates on its own, without any surfaces or other molecules, the only hurdle to overcome is forming a stable crystallite of ice (only about 500 molecules in size under some conditions) that other molecules can build on to grow an ice crystal. That's classical nucleation.

Non-classical nucleation, involving a nucleant surface, occurs when a layer of water molecules assembles on the surface on which other water molecules can organize into a crystal lattice. The hurdle to overcome in non-classical nucleation is the formation of the monolayer.

Which applies to phloroglucinol? In the 1960s, researcher L.F. Evans concluded that it was non-classical. "I am still amazed he was able to deduce the existence of a monolayer and infer the mechanism was non-classical from experiments of freezing as a function of temperature alone!" Molinero says. But Molinero and Metya, using molecular simulations of how ice forms, found that it's more complicated.

"We find that the step that really decides whether water transforms to ice or not is not the formation of the monolayer but the growth of an ice crystallite on top," Molinero says. "That makes ice formation by organics classical although no less fascinating."

Holding on to memories of ice

The researchers also used their simulation methods to investigate an interesting memory effect previously observed with organic and other nucleants. When ice is formed, melted and formed again using these nucleants, the second round of crystallization is more effective than the first. It's assumed that the ice melts completely between crystallizations, and researchers have posed several potential explanations.

Molinero and Metya found that the memory effect isn't due to the ice changing the nucleant surface, nor to the monolayer of water persisting on the nucleant surface after melting. Instead, their simulations supported an explanation where crevices in the nucleant can hold on to small amounts of ice that melt at higher temperatures than the rest of the ice in the experiment. If these crevices are adjacent to one of the nucleant crystal surfaces that's good at forming ice, then it's off to the races when the second round of freezing begins.

Something in the air

Other mysteries still remain - the mid-century studies of organic crystals found that at high pressures, around 1500 times atmospheric pressure, that the crystals are as efficient at organizing water molecules into ice as an ice crystal itself. Why? That's the focus of Molinero's next experiments.

More immediately, though, phloroglucinol is a naturally-occurring compound in the atmosphere, so anything that researchers can learn about it and other organic nucleants can help explain the ability of aerosols to nucleate ice and regulate the formation of clouds and precipitation.

"It would be important to investigate whether small crystallites of these crystalline ice nucleants are responsible for the baffling ice nucleation ability of otherwise amorphous organic aerosols," Molinero says.

LOS ALAMOS, N.M., March 18, 2021--A new, simpler solution process for fabricating stable perovskite solar cells overcomes the key bottleneck to large-scale production and commercialization of this promising renewable-energy technology, which has remained tantalizingly out of reach for more than a decade.

"Our work paves the way for low-cost, high-throughput commercial-scale production of large-scale solar modules in the near future," said Wanyi Nie, a research scientist fellow in the Center of Integrated Nanotechnologies at Los Alamos National Laboratory and corresponding author of the paper, which was published today in the journal Joule. "We were able to demonstrate the approach through two mini-modules that reached champion levels of converting sunlight to power with greatly extended operational lifetimes. Since this process is facile and low cost, we believe it can be easily adapted to scalable fabrication in industrial settings."

The team invented a one-step spin coating method using sulfolane, a liquid solvent. The new process allowed the team, a collaboration among Los Alamos and researchers from National Taiwan University (NTU), to produce high-yield, large-area photovoltaic devices that are highly efficient in creating power from sunlight. These perovskite solar cells also have a long operational lifetime.

"We are excited about this achievement," said Prof. Leeyih Wang, the principal investigator of the NTU group and one of the corresponding authors, "this is a new synthetic route that is widely applicable in the rich perovskite material family." Hsin-Hsiang Huang, a graduate student at NTU and the first author of this paper, said, "We have implemented new chemistry to push it towards a technologically relevant demonstration."

Perovskite photovoltaics, seen as a viable competitor to the familiar silicon-based photovoltaics on the market for decades, have been a highly anticipated emerging technology over the last decade. Commercialization has been stymied by the lack of a solution to the field's grand challenge: scaling up production of high-efficiency perovskite solar cell modules from the bench-top to the factory floor.

The research paper shows a new route to fabrication by introducing sulfolane as an additive in the perovskite precursor, or the liquid material that creates the perovskite crystal through a chemical reaction. As in other fabrication methods, that crystal is then deposited on a substrate.

Through a simple dipping method, the team was able to deposit a uniform, high-quality perovskite crystalline thin film covering a large active area in two mini-modules, one of about 16 square centimeters and the other nearly 37 square centimeters. Fabricating uniform thin film across the entire photovoltaic module's area is essential to device performance.

The mini modules achieved a power conversion efficiency of 17.58% and 16.06%, respectively. Those efficiencies are among the top achievable efficiencies reported to date. The power conversion efficiency is a measure of how effectively sunlight is converted into electricity.

For other perovskite fabrication methods, one of the major roadblocks to industrial-scale fabrication is their narrow processing window, the time during which the film can be laid down on the substrate. To get a uniform crystalline film that's well bonded to the layer below it, the deposition process has to be strictly controlled within a matter of seconds.

Using sulfolane in the perovskite precursor extends the processing window from 9 seconds to 90 seconds, forming highly crystalline, compact layers over a large area while being less dependent on the processing conditions.

The sulfolane method can be easily adapted to existing industrial fabrication techniques, which helps to pave the path toward commercialization.

A perovskite is any material with a particular crystal structure similar to the mineral perovskite. Perovskites can be engineered and fabricated in extremely thin films, which makes them useful for solar photovoltaic cells.

A rare pulmonary disease that is linked to bats has made Alberta home, according to new research led by provincial lab scientists.

Infectious disease experts at Alberta Precision Laboratories (APL) and the University of Alberta have confirmed that histoplasmosis - a fungal infection transmitted through bat and bird droppings - is now found in Alberta. Their study extends the known range of the disease much further northwest from its traditional home in the central United States and parts of southern Ontario and Quebec.

"We were surprised at how many cases were locally acquired, as histoplasmosis has always been considered a travel-related infection," said Dr. Tanis Dingle, APL's lead clinical microbiologist for fungal diseases and an assistant professor in the U of A's Faculty of Medicine & Dentistry. "We now know that it is definitely living in Alberta and has the potential to infect people who come in contact with it."

The fungus can be present in contaminated dust particles, and when inhaled, patients experience respiratory infections with flu-like symptoms, including cough, fever, chills and headache. Cases are typically related to individuals who have come in contact with bat or bird droppings in old homes, churches, construction sites and parks.

Among 45 confirmed cases of histoplasmosis in Alberta between 2011 and 2018, the researchers used epidemiologic data and genetic analysis to determine that 15 of the cases were locally-acquired. The cases were primarily found in rural areas in central Alberta including Sundre, Stettler and county, Stony Plain and Spruce Grove. Previously, the geographic range of the fungus was not thought to expand further northwest than Minnesota, some 2000 km away. The results of the study were published this month in the medical journal The Lancet Microbe. In addition, early looks at the study led scientists at the US Centers for Disease Control and Prevention to include the region in newly drawn maps of areas where the disease is known to occur.

"Knowing that histoplasmosis is here can help improve the diagnosis and treatment of patients who have no history of travel to the traditional risk areas," said Dr. Ilan Schwartz, assistant professor, division of infectious diseases, U of A. "Histoplasmosis can be a challenging disease to diagnosis and to treat, and patients often spend months before the correct diagnosis is made. Awareness that the disease is here is an essential first step for doctors to be able to consider the diagnosis and order the appropriate tests."

The researchers are also exploring whether climate change could be a factor in the spread of histoplasmosis to new geographies. In Alberta, increasing temperatures and decreasing precipitation have been documented over the past several decades, which might have resulted in more favorable conditions for Histoplasma to live in Alberta soils. The disease can survive in soil temperatures ranging from ?18°C to 37°C, the lower end of this range being common in Alberta winters.

The research team hopes to continue their work by further investigating soil samples to determine other areas in Alberta where the disease may be present.

CHARLOTTESVILLE, Va. - Progress in the field of integrated circuits is measured by matching, exceeding, or falling behind the rate set forth by Gordon Moore, former CEO and co-founder of Intel, who said the number of electronic components, or transistors, per integrated circuit would double every year. That was more than 50 years ago, and surprisingly his prediction, now called Moore's Law, came true.

In recent years, it was thought that the pace had slowed; one of the biggest challenges of putting more circuits and power on a smaller chip is managing heat.

A multidisciplinary group that includes Patrick E. Hopkins, a professor in the University of Virginia's Department of Mechanical and Aerospace Engineering, and Will Dichtel, a professor in Northwestern University's Department of Chemistry, is inventing a new class of material with the potential to keep chips cool as they keep shrinking in size -- and to help Moore's Law remain true. Their work was recently published in Nature Materials.

Electrical insulation materials that minimize electrical crosstalk in chips are called "low-k" dielectrics. This material type is the silent hero that makes all electronics possible by steering the current to eliminate signal erosion and interference; ideally, it can also pull damaging heat caused by electrical current away from the circuitry. The heat problem becomes exponential as the chip gets smaller because not only are there more transistors in a given area, which makes more heat in that same area, they are closer together, which makes it harder for heat to dissipate.

"Scientists have been in search of a low-k dielectric material that can handle the heat transfer and space issues inherent at much smaller scales," Hopkins said. "Although we've come a long way, new breakthroughs are just not going to happen unless we combine disciplines. For this project we've used research and principles from several fields - mechanical engineering, chemistry, materials science, electrical engineering -- to solve a really tough problem that none of us could work out on our own."

Hopkins is one of the leaders of UVA Engineering's Multifunctional Materials Integration initiative, which brings together researchers from multiple engineering disciplines to formulate materials with a wide array of functionalities.

"Seeing 'my' problem through someone else's lens in a different field was not only fascinating, it also sparked ideas that ultimately brought advancement. I think we all had that experience," said Ashutosh Giri, a former UVA Engineering senior scientist and Ph.D. student in Hopkins' lab, the co-first author on the Nature Materials paper and a mechanical, industrial and systems engineering assistant professor at Rhode Island University.

"The heart of the project was when the chemical team realized the thermal functionality of their material, understanding a new dimension about their work, and when the mechanical and materials team understood the level of molecular engineering possible with chemistry," Giri said.

"We're taking sheets of polymer that are only one atom thick - we call this 2D - and controlling their properties by layering the sheets in a specific architecture," Dichtel said.

"Our efforts on improving the methods to produce high-quality 2D polymer films enabled this collaborative work."

The team is applying this new material class to try to meet the requirements of miniaturizing transistors on a dense chip, Dichtel said.

"This has enormous potential for use in the semiconductor industry, the industry that that manufactures chips. The material has both low electrical conductivity, or 'low-k,' and high heat transfer capability," he said.

This combination of properties was recently identified by the International Roadmap for Semiconductors as a prerequisite for next-generation integrated circuits.

"For this project, we are focusing on the thermal properties of this new material class, which is fantastic, but even more exciting is that we are just scratching the surface," said Austin Evans, a Ph.D. student in Dichtel's lab at Northwestern and first co-author on the Nature Materials paper. "Developing new classes of materials with unique combinations of properties has amazing technological potential.

"We are already exploring this new class of materials for many applications, for instance, chemical sensing. We can use these materials to determine -- 'sense' -- what chemicals and how much of those chemicals are in the air. This has broad reaching implications. For instance, by knowing about the chemicals in the air, we can optimize food storage, transport, and distribution to reduce global food waste. As we continue exploring, we are likely to find even more traits unique to these new materials," Evans said.

In 1958, a magnitude 7.8 earthquake triggered a rockslide into Southeast Alaska's Lituya Bay, creating a tsunami that ran 1,700 feet up a mountainside before racing out to sea.

Researchers now think the region's widespread loss of glacier ice helped set the stage for the quake.

In a recently published research article, scientists with the University of Alaska Fairbanks Geophysical Institute found that ice loss near Glacier Bay National Park has influenced the timing and location of earthquakes with a magnitude of 5.0 or greater in the area during the past century.

Scientists have known for decades that melting glaciers have caused earthquakes in otherwise tectonically stable regions, such as Canada's interior and Scandinavia. In Alaska, this pattern has been harder to detect, as earthquakes are common in the southern part of the state.

Alaska has some of the world's largest glaciers, which can be thousands of feet thick and cover hundreds of square miles. The ice's weight causes the land beneath it to sink, and, when a glacier melts, the ground springs back like a sponge.

"There are two components to the uplift," said Chris Rollins, the study's lead author who conducted the research while at the Geophysical Institute. "There's what's called the 'elastic effect,' which is when the earth instantly springs back up after an ice mass is removed. Then there's the prolonged effect from the mantle flowing back upwards under the vacated space."

In the study, researchers link the expanding movement of the mantle with large earthquakes across Southeast Alaska, where glaciers have been melting for over 200 years. More than 1,200 cubic miles of ice have been lost.

Southern Alaska sits at the boundary between the continental North American plate and the Pacific Plate. They grind past each other at about two inches per year -- roughly twice the rate of the San Andreas fault in California -- resulting in frequent earthquakes.

The disappearance of glaciers, however, has also caused Southeast Alaska's land to rise at about 1.5 inches per year.

Rollins ran models of earth movement and ice loss since 1770, finding a subtle but unmistakable correlation between earthquakes and earth rebound.

When they combined their maps of ice loss and shear stress with seismic records back to 1920, they found that most large quakes were correlated with the stress from long-term earth rebound.

Unexpectedly, the greatest amount of stress from ice loss occurred near the exact epicenter of the 1958 quake that caused the Lituya Bay tsunami.

While the melting of glaciers is not the direct cause of earthquakes, it likely modulates both the timing and severity of seismic events.

When the earth rebounds following a glacier's retreat, it does so much like bread rising in an oven, spreading in all directions. This effectively unclamps strike-slip faults, such as the Fairweather in Southeast Alaska, and makes it easier for the two sides to slip past one another.

In the case of the 1958 quake, the postglacial rebound torqued the crust around the fault in a way that increased stress near the epicenter as well. Both this and the unclamping effect brought the fault closer to failure.

"The movement of plates is the main driver of seismicity, uplift and deformation in the area," said Rollins. "But postglacial rebound adds to it, sort of like the de-icing on the cake. It makes it more likely for faults that are in the red zone to hit their stress limit and slip in an earthquake."

PROVIDENCE, R.I. [Brown University] -- In 2018, physicists showed that something interesting happens when two sheets of the nanomaterial graphene are placed on top of each other. When one layer is rotated to a "magic angle" of around 1.1 degrees with respect to the other, the system becomes a superconductor -- meaning it conducts electricity with zero resistance. Even more exciting, there was evidence that it was an unconventional form of superconductivity -- a type that can happen at temperatures well above absolute zero, where most superconducting materials function.

Since the initial discovery, researchers have been working to understand this exotic state of matter. Now, a research team led by Brown University physicists has found a new way to precisely probe the nature of the superconducting state in magic-angle graphene. The technique enables researchers to manipulate the repulsive force between elections -- the Coulomb interaction -- in the system. In a study published in the journal Science, the researchers show that magic-angle superconductivity grows more robust when Coulomb interaction is reduced, an important piece of information in understanding how this superconductor works.

"This is the first time anyone has demonstrated that you can directly manipulate the strength of Coulomb interaction in a strongly correlated electronic system," said Jia Li, an assistant professor of physics at Brown and corresponding author of the research. "Superconductivity is driven by the interactions between electrons, so when we can manipulate that interaction, it tells us something really important about that system. In this case, demonstrating that weaker Coulomb interaction strengthens superconductivity provides an important new theoretical constraint on this system."

The original 2018 finding of potentially unconventional superconductivity in magic-angle graphene generated significant interest in the physics community. Graphene -- one-atom-thick sheets of carbon -- is a relatively simple material. If it did indeed support unconventional superconductivity, graphene's simplicity would make it an ideal place to explore how the phenomenon works, Li says.

"Unconventional superconductors are exciting because of their high transition temperature and potential applications in quantum computers, lossless power grids and elsewhere," Li said. "But we still don't have a microscopic theory for how they work. That's why everybody was so excited when something that looked like unconventional superconductivity was happening in magic-angle graphene. Its simple chemical composition and tunability in twist angle promise a clearer picture."

Conventional superconductivity was first explained in the 1950s by a group of physicists that included longtime Brown professor and Nobel Prize winner Leon Cooper. They showed that electrons in a superconductor distort the atomic lattice of a material in a way that causes electrons to form quantum duos called Cooper pairs, which are able to move through that material unimpeded. In unconventional superconductors, electron pairs form in a way that is thought to be bit different from the Cooper mechanism, but scientists don't yet know what that mechanism is.

For this new study, Li and his colleagues came up with a way to use Coulomb interaction to probe electron pairing in magic-angle graphene. Cooper pairing locks electrons together at a specific distance from each other. That pairing competes with the Coulomb interaction, which is trying to push the electrons apart. If it were possible to weaken the Coulomb interaction, Cooper pairs should in theory become more strongly coupled, making the superconducting state more robust. That would provide clues about whether the Cooper mechanism was happening in the system.

To manipulate the Coulomb interaction for this study, the researchers built a device that brings a sheet of magic-angle graphene in very close proximity to another type of graphene sheet called a Bernal bilayer. Because the two layers are so thin and so close together, electrons in the magic-angle sample become ever so slightly attracted to positively charged regions in the Bernal layer. That attraction between layers effectively weakens the Coulomb interaction felt between electrons within the magic-angle sample, a phenomenon the researchers call Coulomb screening.

One attribute of the Bernal layer made it particularly useful in this research. The Bernal layer can be switched between a conductor to insulator by altering a voltage applied perpendicularly to the layer. The Coulomb screening effect only happens when the Bernal layer is in the conducting phase. So by switching between conducting and insulating and observing corresponding changes in superconductivity, the researchers could ensure what they were seeing was due to Coulomb screening.

The work showed that the superconducting phase became stronger when Coulomb interaction was weakened. The temperature at which the phase broke down became higher, and was more robust to magnetic fields, which disrupt superconductors.

"To see this Coulomb effect in this material was a bit surprising," Li said. "We'd expect to see this happen in a conventional superconductor, yet there's lots of evidence suggesting that magic-angle graphene is an unconventional superconductor. So any microscopic theory of this superconducting phase will have to take this information into account."

Li said the results are a credit to Xiaoxue Liu, a postdoctoral researcher at Brown and the study's lead author, who built the device that made the findings possible.

"Nobody has ever built anything like this before," Li said. "Everything had to be incredibly precise down to the nanometer scale, from the twist angle of the graphene to the spacing between layers. Xiaoxue really did an amazing job. We also benefitted from the theoretical guidance of Oskar Vafek, a theoretical physicist from Florida State University."

While this study provides a critical new piece of information about magic-angle graphene, there's much more that the technique could reveal. For example, this first study only looked at one part of the phase space for magic-angle superconductivity. It's possible, Li says, that the behavior of the superconducting phase varies in different parts of the phase space, and further research will unveil it.

"The ability to screen the Coulomb interaction gives us a new experimental knob to turn in helping to understand these quantum phenomena," Li said. "This method can be used with any two-dimensional material, so I think this method will be useful in helping to engineer new types of materials."

WASHINGTON--People who start eating before 8:30 a.m. had lower blood sugar levels and less insulin resistance, which could reduce the risk of developing type 2 diabetes, according to a study presented virtually at ENDO 2021, the Endocrine Society's annual meeting.

"We found people who started eating earlier in the day had lower blood sugar levels and less insulin resistance, regardless of whether they restricted their food intake to less than 10 hours a day or their food intake was spread over more than 13 hours daily," said lead researcher Marriam Ali, M.D., of Northwestern University in Chicago, Ill.

Insulin resistance occurs when the body doesn't respond as well to the insulin that the pancreas is producing and glucose is less able to enter the cells. People with insulin resistance may be at higher risk of developing type 2 diabetes. Both insulin resistance and high blood sugar levels affect a person's metabolism, the breaking down of food to its simpler components: proteins, carbohydrates (or sugars), and fats. Metabolic disorders such as diabetes occur when these normal processes become disrupted.

"With a rise in metabolic disorders such as diabetes, we wanted to expand our understanding of nutritional strategies to aid in addressing this growing concern," Ali said. Previous studies have found that time-restricted eating, which consolidates eating to a shortened timeframe each day, has consistently demonstrated improvement in metabolic health, she noted. Her group wanted to see whether eating earlier in the day affected metabolic measures.

The researchers analyzed data from 10,575 adults who participated in the National Health and Nutrition Examination Survey. They divided participants into three groups depending on total duration of food intake: less than 10 hours, 10-13 hours, and more than 13 hours per day. They then created six subgroups based on eating duration start time (before or after 8:30 a.m.).

They analyzed this data to determine if eating duration and timing were associated with fasting blood sugar levels and estimated insulin resistance. Fasting blood sugar levels did not differ significantly among eating interval groups. Insulin resistance was higher with shorter eating interval duration, but lower across all groups with an eating start time before 8:30 a.m.

"These findings suggest that timing is more strongly associated with metabolic measures than duration, and support early eating strategies," Ali said.

A large gathering of fish tempts harbour porpoises to search for food around oil and gas platforms, even though the noise from these industrial plants normally to scare the whales away. Decommissioned platforms may therefore serve as artificial reefs in the North Sea.

Harbour porpoises are one of the smallest of all whales and the only whale that with certainty breeds in Danish waters. The harbour porpoise was protected in 1967 in Danish Waters, and researchers from Aarhus University, Denmark, have previously shown that underwater noise from ships, and seismic surveys of the seabed scare the porpoises away.

A brand new study now shows that in some parts of the year there are actually more porpoises searching for food around the largest Danish oil platform, Dan F, in the North Sea than just three to ten kilometres away from the platform.

21 listening stations in the North Sea

A team of researchers deployed 21 listening stations at the bottom of the North Sea. The innermost listening station was deployed immediately under the very large Dan F-oil and gas platform, while the outermost station was located 25.6 km away from the platform. One of the many listening stations was placed halfway between the inner- and outermost stations near the old oil well, Ragnar, which no longer produces oil.

The listening stations were left in the North Sea for two years to record all sounds below the surface of the sea, including the noise from ships and platforms, but also the sounds produced by porpoises for orientation and the so-called "buzz sounds" telling the researchers that the whales are actively hunting for food.

"With this study, we're presenting the first investigation of the presence and feeding activity of porpoises throughout the year around oil platforms, as far as we know," says senior researcher Jonas Teilmann from the Department of Bioscience, Aarhus University, Denmark, who headed the investigations.

The new discoveries have just been published in the British journal Ecological Solutions and Evidence, and the results from the many data surprised the researchers.

Food attracts more than noise scares

"During the six months from July to January, we heard more porpoises searching for food around the two installations, the Dan-F platform and the Ragnar well, than we did in control areas located 6 and 25 kilometres away from Dan-F. This was even as high as the highest porpoise activity we have seen for Natura 2000 sites in the inner Danish waters," says Jonas Teilmann.

According to the researchers, the installations act as natural reefs where porpoises are provided with favourable living conditions as numerous species of plants and animals settle on the structures and provide hiding places and more food to the fish. Moreover, fishing is prohibited within a radius of 500 metres from the platforms why the seabed is undisturbed from trawling.

At the Dan-F platform, the researchers heard extensive activity by porpoises when searching for food up to 800 metres from the platform. In fact, the researches know that there were up to twice as many porpoises just below the platforms than recorded by the acoustic recorders as the noise from the platform will often drown the sounds made by the porpoises. Not until a distance of 12 kilometres from the platform, the noise disappeared.

The researchers cannot answer the question of whether the porpoises slowly get used to the noise from the drilling platforms, but it is clear that the motivation for finding food is greater than the deterrence effect of the noise.

"Our data show that the porpoises ignored the annoyance of the underwater noise to exploit the greater availability of food around the fixed installations," says Jonas Teilmann.

Should artificial installations be left in place?

Especially during the period from July to January, it is important for the porpoises to consume as much food as possible in order to build up a solid layer of blubber that can bring the animals through the cold winter. It is also during these six months that the mothers need energy so they have sufficient milk for their calves.

In contrast, the researchers found that there are far fewer porpoises searching for food around the artificial installations in the period from February to June.

"The signals from porpoises were far less frequent during this particular period, but the buzz sounds revealed that the porpoises still searched for fish around the Dan-F platform and the Ragnar well from February to June. The noise from the platform is the same all year round, so we interpret the absence of porpoises as a change in the behaviour or the presence of fish," says Jonas Teilmann.

The researchers recorded sounds from porpoises around the clock and could therefore hear that the whales were more actively searching for food at night than during the day, as far as 800 metres from the Dan-F platform.

This came as a surprise to the researchers, but they know that light lures zooplankton, squids and fish up into the upper water column at night. This initiates an efficient food chain that ends with the porpoises. This could explain why the Dan-F platform was especially attractive at night, while the day activity was higher at Regnar, where no light was present.

The OSPAR Convention, which protects the North Sea, requires that all decommissioned oil and gas installations are removed from the North Sea. However, the researchers are now pointing out that the old installations may be left to serve as new artificial reefs in the North Sea, the so-called "Rigs-to Reef" concept. Platforms and other installations can increase the diversity and biodiversity in areas that have been destroyed by trawling or where the original stone reefs have been removed and used for construction projects on land.

A joint research team, affiliated with UNIST has unveiled a novel electrolyte additive that could enable a long lifespan and fast chargeability of high-energy-density lithium-ion batteries (LIBs).

Published in the February 2021 issue of Nature Communications, this research has been carried out by Professor Nam-Soon Choi and Professor Sang Kyu Kwak in the School of Energy and Chemical Engineering, in collaboration with Professor Sung You Hong in the Department of Chemistry at UNIST. It has also been participated by Professor Jaephil Cho in the School of Energy and Chemical Engineering at UNIST.

As the demand for large-capacity batteries (i.e., EV batteries) increases, efforts are actively underway to replace the conventional lithium-ion battery electrodes with large-capacity materials, such as silicon or high-nickel. Although silicon is an attractive anode material to improve the energy density of LIBs, they exhibit poor mechanical strength due to volumetric expansion during charging and discharging. High-Ni cathode materials also suffer from poor chemical stability.

In the study, the research team demonstrated that the creation of a stable and spatially deformable solid electrolyte interphase (SEI) on a high-capacity Si-C anode could tolerate the inevitable volume changes induced by the lithiation of Si and could enable a long lifespan and fast chargeability of high-energy-density LIBs.

According to the research team, when the new additives were added to a large-capacity battery composed of a high-Ni anodes and a Si-mixed anode, the initial capacity was maintained at 81.5% even after 400 charging and discharging cycles--10% to 30% better than the choice of VC (vinylene carbonate) or FEC (fluoroethylene carbonate), as additive in LIBs.

"This achievement is the result of the collaboration of material structure design, experiment, simulation, and synthesis method research to actually make this material structure that can compensate for the shortcomings of existing additives (VC). It suggested a new direction for the development," says Professor Choi, co-corresponding author of the study.

In addition, the research team also found that these additives could remove hydrofluoric acid (HF) from the electrolyte to prevent the metal (nickel) inside the high-Ni anodes from leaking out. The amount of metal inside the anode determines the battery capacity.

"This work presents a breakthrough in the development of electrolyte additives for high-energy-density Li-ion batteries," noted the research team. "We expect that our systematic approach for rational molecular design and DFT-aided mechanism development offers a promising way to discover next-generation additives."

This research has been featured on the Nature Communications Editors' Highlights webpage. This work has been supported by the Korea Institute of Energy Technology Evaluation and Planning's energy technology development project. It has also been partly supported by the Technology Development Program to Solve Climate Changes of the National Research Foundation (NRF).

A study from Chalmers University of Technology, Sweden, has yielded new answers to fundamental questions about the relationship between the size of an atom and its other properties, such as electronegativity and energy. The results pave the way for advances in future material development. For the first time, it is now possible under certain conditions to devise exact equations for such relationships.

"Knowledge of the size of atoms and their properties is vital for explaining chemical reactivity, structure and the properties of molecules and materials of all kinds. This is fundamental research that is necessary for us to make important advances," explains Martin Rahm, the main author of the study and research leader from the Department of Chemistry and Chemical Engineering at Chalmers University of Technology.

The researchers behind the study, consisting of colleagues from the University of Parma, Italy, as well as the Department of Physics at Chalmers University of Technology, have previously worked with quantum mechanical calculations to show how the properties of atoms change under high pressure. These results were presented in scientific articles in the Journal of the American Chemical Society and ChemPhysChem.

The new study, published in the journal Chemical Science, constitutes the next step in their important work, exploring the relationship between the radius of an atom and its electronegativity - a vital piece of chemical knowledge that has been sought since the 1950s.

Establishing useful new equations

By studying how compression affects individual atoms, the researchers have been able to derive a set of equations that explain how changes in one property - an atom's size - can be translated and understood as changes in other properties - the total energy and the electronegativity of an atom. The derivation has been made for special pressures, at which the atoms can take one of two well-defined energies, two radii and two electronegativities.

"This equation can, for example, help to explain how an increase in an atom's oxidation state also increases its electronegativity and vice versa, in the case of a decrease in oxidation state," says Martin Rahm.

A key question for the science of unexplored materials

One aim of the study has been to help identify new opportunities and possibilities for the production of materials under high pressure. At the centre of the earth, the pressure can reach hundreds of gigapascals - and such conditions are achievable in laboratory settings today. Examples of areas where pressure is used today include the synthesis of superconductors, materials which can conduct electric current without resistance. But the researchers see many further possibilities ahead.

"Pressure is a largely unexplored dimension within materials science, and the interest in new phenomena and material properties that can be realised using compression is growing," says Martin Rahm.

Creating the database they themselves wished for

The large amounts of data that the researchers have computed through their work have now been summarised into a database, and made available as a user-friendly web application. This development was sponsored by Chalmers Area of Advance Materials and made possible through a collaboration with the research group of Paul Erhart at the Department of Physics at Chalmers.

In the web application, users can now easily explore what the periodic table looks like at different pressures. In the latest scientific publication, the researchers provide an example for how this tool can be used to provide new insight into chemistry. The properties of iron and silicon - two common elements found in the earth's crust, mantle and core - are compared, revealing large differences at different pressures.

"The database is something I have been missing for many years. Our hope is that it will prove to be a helpful tool, and be used by many different chemists and materials researchers who study and work with high pressures. We have already used it to guide theoretical searches for new transition metal fluorides," says Martin Rahm.

Mass movements such as landslides and hill-slope debris flows cause billions of euros in economic damage around the world every year. Between 20 and 80 million euros are spent annually from the disaster fund to repair disaster damage in Austria, 15 to 50 percent of which is attributable to mud flows and landslides. Now, a team of geologists from Graz University of Technology (TU Graz), in cooperation with the Burgenland state road administration, identified for the first time the chemical influencing factors and triggers for recurrent mass movements in fine-grained sediments. From results published in the journal Science of the Total Environment, preventive measures and strategies can be derived to guard against such events.

Factors favouring mass movements

The basis for the investigations is a well-documented landslide in southern Burgenland, which has occupied the local state road administration for four decades now. Through analysis of terrain data, soil samples, drainage waters, and laboratory tests, it has been shown that the sensitivity of the subsurface to external influences is favoured by natural (geogenic) chemical weathering processes that take place over long periods of the Earth's history and define or weaken the nature of the subsurface. On the other hand, man-made (anthropogenic) chemical influencing factors also play a central role, such as agricultural activities, seeping road run-off or winter road maintenance. "In the study area, fine-grained sedimentary deposits dominate, as they are widespread in the basin areas in eastern Austria," says Volker Reinprecht, co-author of the study and geologist at the Office of the State Government of Burgenland. "Heavy rain events and periods of dew, as well as continuous vibration from road traffic, have in the past caused the soil to literally 'wash away' and the affected road to require periodic rehabilitation."

Focus on soil drainage and the overall system

A decisive improvement of the situation was achieved by adapting the drainage system. The previous drainage system using transverse ribs, in which rainwater and seepage is captured in the area in contact with the sliding surface, was replaced by a longitudinal drainage system so that the water is removed from the subsoil within a few days and both backwater and chemical interaction processes are prevented. "Rapid drainage of the water reduces the soaking of the subsoil, reduces the formation of zones of weakness (sliding horizons) and thus increases the stability of the soil or the overall system," explains Andre Baldermann from the Institute of Applied Geosciences at TU Graz and head of the study. The geoscientist already sees the new drainage system as a first measure to prevent mass movements. "We were able to demonstrate that backwater formation in the subsurface can activate the slip zones via chemical processes. This is prevented with longitudinal drainage and the resulting faster drainage." Baldermann recommends that in future construction projects in zones at risk from sink holes, landslides or similar events, greater consideration be given to possible interactions between the drainage system and the subsoil as early as the planning stage."

Further similar studies in progress

Andre Baldermann and Volker Reinprecht are currently working on extending the study design (see additional information "investigation methods used") to other affected regions with similar geological conditions. A view of the total system is important, explains Baldermann, because: "The structure of the subsurface, as well as other region-specific factors, has a major influence on the nature, intensity, and periodicity of mass movements. The results and practical recommendations from the reference project are therefore not transferable one-to-one to other affected regions. But they are a first example of how to approach such problems in the future."

Lenexa, Kan. -- The Infusion Nurses Society has expanded its guidance on the use of needleless connectors to include anti-reflux technology in its recently published 2021 Infusion Therapy Standards of Practice, according to Nexus Medical, makers of the Nexus TKO®-6P Anti-Reflux connector.

As INS' most recognized publication, the updated Standards outline specific categories of needleless connector technology based on the device's internal mechanism for fluid displacement -- negative displacement, positive displacement, neutral and anti-reflux. Of all the categories, the authors note that anti-reflux needleless connectors cause the least amount of blood reflux, which can be associated with a variety of catheter-related complications that threaten patient safety, including intraluminal thrombotic occlusions, catheter failure and even infections.

"For such a small device, needleless connectors are much more complex than most clinicians realize, and not using them correctly can have serious patient safety implications," said Lisa Gorski, MS, RN, HHCNS-BC, CRNI, FAAN, lead author of the Standards and a clinical nurse specialist in Milwaukee, Wis. "It is important for nurses to understand the different categories and how to use each one properly in order to minimize blood reflux, as well as encourage organizations to standardize the type of connector being used to reduce confusion and improve clinical outcomes."

Blood reflux is caused by both mechanical and physiological pressure changes in a closed IV system, which is known to force blood into the catheter lumen. Over time, this uncontrolled movement of blood contributes to catheter occlusions. When occlusions occur, they can be treated with thrombolytics to potentially clear the clotted blood from the catheter lumen. However, the use of thrombolytics adds cost, nursing time, and has been linked to a greater risk of infection. Studies show that patients who received thrombolytics for occluded catheters have a 3.59 times greater chance of developing a central-line associated bloodstream infection (CLABSI).

The Nexus TKO anti-reflux connector has a unique, pressure-activated diaphragm that controls fluid movement, automatically eliminating unintentional blood reflux due to both internal and external pressure changes. It has been proven to produce the least amount of blood reflux compared to any other needleless connector.

Moreover, the Nexus TKO prevents blood reflux in a way that also reduces variation and simplifies the complexity of IV therapy. Most needleless connectors require specific sequences for flushing, clamping and disconnection in order to minimize blood reflux. In contrast, the Nexus TKO's provides bidirectional flow control automatically which prevents blood reflux due to sudden pressure changes, eliminating the need for user-dependent clamping sequences.

"The TKO technology is the result of more than a decade of research and product development, and it is the most studied needleless connector on the market. We're gratified that the latest INS Standards have been expanded to include anti-reflux technology," said Cary Dikeman, Chairman and President of Nexus Medical. "We are committed to helping improve patient safety, increase nursing efficiency, and lower healthcare costs by reducing the incidence of complications that can happen as a result of blood reflux."

The INS Standards are revised and released every five years to provide clinicians with an evidence-based framework to develop infusion-based policies and procedures for all practice settings. Lee Steere, RN, CRNI, VA-BC, Unit Leader of IV Therapy Services at Hartford Hospital, Hartford, Conn., uses the Standards to create new protocols and help educate his IV therapy team. He says awareness of the different types of connectors and how they contribute to blood reflux will have an important impact on patient safety.

In 2015, Hartford Hospital switched from a neutral needleless connector to the Nexus TKO anti-reflux connector as part of a study on reducing occlusions in central vascular access devices (CVAD). The initial two-year results were published in the Journal of the Association for Vascular Access in 2018.

"We found that the anti-reflux needleless connector design plays a huge part in improving our patient care. We saw an immediate reduction in catheter occlusions, and we've reduced our use of thrombolytics by more than 69 percent over the last five years," Steere said.

"In order to avoid complications that threaten patient safety, we need to shift our focus from simply treating occlusions to preventing them altogether by addressing the root cause of these issues -- blood reflux," he added.

March 18, 2021 -- A study conducted at Columbia University Mailman School of Public Health reports a high global prevalence of both depression and anxiety during the COVID-19 pandemic and shows how implementation of mitigation strategies including public transportation and school closures, and stay-at-home orders impacted such disorders. The results are published in Psychological Medicine.

"Our research found an elevated global prevalence of these mental health issues during COVID-19 and also revealed there was a wide variance in each at the region- and country-level," said, João Castaldelli-Maia, MD, PhD, NIDA-INVEST Postdoctoral Fellow in the Department of Epidemiology, and lead author. In particular, Asia (most studies came from China) presented lower levels of both anxiety and depression, compared to the other regions of the world. Closure of public transportation increased levels of anxiety, whether it was two weeks or four weeks past the passage of closure enactment, especially in Europe."

Using an end date of July 29th, 2020, the researchers analyzed data from Pubmed, MEDLINE, Web of Science, and medRxiv, among other databases, for depression and anxiety prevalence. They also reviewed the Oxford Covid-19 Government Response Tracker for the containment and closure policies indexes; and the Global Burden of Disease Study for previous levels of depression and anxiety. The WHO database which includes COVID literature for studies published by the same date was also used.

In total, 226,638 individuals were assessed within 60 included studies. Global prevalence of both depression and anxiety during the COVID-19 pandemic were 24 percent and 21 percent, respectively. Asia with rates of 18 percent for each, and China especially, had the lowest prevalence of both disorders. Regarding the impact of mitigation strategies on mental health -- whether it was public transportation closures, school closings, workplace closures, cancellation of public events, or restrictions on gathering -- only public transportation closures increased prevalence of anxiety, especially in Europe.

Castaldelli-Maia and colleagues found a 21 percent global prevalence of anxiety. Asia had lower levels of anxiety (18 percent) compared to other regions of the world (29 percent). In this case, Europe did not differ from Asia and other regions of the world. Again, a subgroup analysis at the country-level showed that China had a lower prevalence of anxiety at 15.5 percent compared to all other countries at 26 percent.

"Our study confirms how critical it is to investigate levels of mental health disorders and the possible impacts of social distancing measures on mental health outcomes, according to Silvia Martins, MD, PhD, associate professor of Epidemiology at Columbia Mailman School, and senior author. "Mental health concerns should not be viewed only as a delayed consequence of the COVID-19 pandemic, but also as a concurrent epidemic."

Within the subgroup of Asian countries, estimates of depression prevalence ranged from 15 percent to 20 percent. When comparing the prevalence of depression in the pre-and post-COVID-19 eras, the estimates ranging from 1.3-3.4 percent, are demonstrably larger after the initiation of COVID-19.

Depression was observed among 26 percent of the population in Europe, and among 39 percent in other non-Asia regions of the world. A further analysis showed that China had a lower prevalence of depression, 16 percent compared with 29 percent in other countries.

Similarly, the prevalence of anxiety, as reported in the subgroup of Asian countries is higher post-COVID-19. Rates of anxiety prior to COVID-19 ranged from 2.1 to 4.1 percent vs. 18 percent in the present study. Increases in anxiety can be observed in countries outside Asia and Europe (3 to 7 percent vs. 29 percent).

"The lower levels of depression and anxiety that we found in Asian countries could be culture-dependent," observes Martins.

The effect of public transportation closures on anxiety levels points to the importance of these systems to global populations, particularly the results in Europe but not in Asia. "These findings could be linked to the fact that Europe has a more effective and implemented public transport network on average, making Europeans depending more on public transportation than people in Asian countries," noted Martins.

"The COVID-19 pandemic, and the resulting physical distancing measures to mitigate viral spread, has certainly impacted population mental health worldwide, and the high prevalence of mental health disorders is a considerable concern during the COVID era," said Castaldelli-Maia. "These results have important implications for policymakers and show the urgent need for the healthcare sector to increase support now for prevention and early intervention of depression and anxiety."

Biodiversity is increasingly ruined by humanity's many impacts, a major aspect of which is biological invasion. Although there are a lot of studies reporting that invasive predators decrease the population size of native species, only a few studies have reported impact on phenotypic traits such as morphology and performance of native species. Particularly island ecosystem is very sensitive to invasive predators because strong predators such as mammalian predators are not in such environment.

Researchers at Tokyo University of Agriculture and Technology (TUAT) analyzed predators' effect on frogs in a Japanese island and their findings were reported in Biological Invasions on January 3rd.

Mongooses were introduced many areas worldwide and damaged native ecosystem seriously. In 1979, these were brought to Amami Island in Japan. As a result, Amami tip-nosed frog, which is a relatively large forest species, is one of the species at risk of extinction in near future due to the invasive mongoose.

"We hypothesized the strong predation pressure of mongoose drove rapid change in morphology and performance of the native frog," said Hirotaka Komine, first author of the paper, assistant professor (when this research was done) at TUAT.

"We recorded hind limb length and two types of performance traits: burst movement ability (evaluated based on jump distance) and endurance (evaluated based on number of jumps), " said Komine. For jump distance, the researchers measured the distance of the first jump after the frog was released. For the number of jumps, they analysed the number of jumps in the net upon capture until the frog was exhausted (i.e., stopped jumping). "We then estimated the relationship between hind limb length and explanatory variables (proxy of mongoose impact, sex, year), and the relationship between performance traits and the explanatory variables using a spatial regression model, " Komine explains.

Interestingly, the results showed that the hind limb length of the frog was longer under the strong predation effect of the mongoose, which may have acted as a selective agent to induce rapid morphological responses. The endurance, but not the burst movement ability, of the frog was higher under the strong effect of predation by the mongoose. "Our results suggest that endurance was a specific target of natural selection and that the performance of the native prey changed in response to the new predation type," said Komine.

When their research was carried out it was at least 7 years after the mongooses were mostly removed and population size of the native frog recovered owing to the eradication project run by the Ministry of the Environment of Japan. Therefore, apparently their result suggested that impact of invasive mongooses on phenotypic traits of native frog remained even after the invasive predator mostly removed.

"Island ecosystem is often unique in terms of behavior, morphology, and performance, reflecting its evolutionary uniqueness. Hence, the recovery of traits in native species after the removal of invasive species may be a useful measure of the success of eradication projects," concludes Komine.

Anemia, a condition characterized by the lack of healthy red blood cells in the body, is common in patients with chronic kidney disease who need to undergo routine hemodialysis (a process that helps to "clean" the blood when the kidneys don't function well). Thus, red blood cell-stimulating agents (called "erythropoiesis-stimulating agents" or ESAs) and iron supplements (ISs) are administered as part of this process. But, complications can arise if the patients have an altered iron metabolism or poor response to medications. Moreover, the medications tend to be expensive and impose a heavy financial burden on public health. Thus, with such patients currently on the rise but not enough physicians suitably trained to administer treatment, additional support systems with smart decision-making capabilities are highly sought after. One option is to turn to artificial intelligence (AI), which seems promising but demands a large dataset and is not practical owing to diverse health conditions of patients.

So, can something be done to improve the situation? In a recent study published in the International Journal of Medical Sciences, medical researchers from Japan tried to find the answer. They came up with a new approach: instead of making the AI learn from the complex physiology of the patient's body, they opt for a prediction model based on the decisions of experienced physicians. Assistant Professor Toshiaki Ohara from Okayama University, Japan, the lead scientist on the study, explains, "We got the idea while contemplating the thought process of seasoned physicians. After all, they do not calculate detailed values of vital reactions in a patient's body when deciding dosages, which means prediction models based on biochemistry are not necessary."

The researchers started off by collecting clinical data at two hospitals in Japan and then preparing two datasets for each hospital: one for training their model and the other for testing and validating its predictions. Simultaneously, they recorded the dosage directions of physicians at both hospitals and considered responses for the two medications used during hemodialysis: ESAs and ISs.

Based on these, they constructed an AI-based model called an "artificial-intelligence-supported anemia control system" (AISACS), which received a total of five inputs (four items of blood examination and dosage history) and churned out dosage direction probabilities for the two medications as outputs. In addition, to make the training process more efficient, they compensated for the time lag between blood examination and dosage decisions by using "data rectification" to match the decision dates with the examination dates.

To the researchers' delight, AISACS showed a high prediction accuracy with correct classification (directions matching those of physicians) rates of 72%-87%. But what was even more interesting was that it provided "clinically appropriate" classifications at even higher rates (92%-97%). These were directions that didn't match those of physicians (and were sometimes provided ahead of them) but were still considered appropriate from a medical viewpoint.

With these results, researchers are hopeful about AISAC's future prospects. "By preventing anemia, our system can help alleviate the burdens on physicians and medical insurance systems. Moreover, it has the potential to share the knowledge and experiences related to medications," comments an excited Dr. Ohara.

Hopefully, this new AI-based approach provides some hope to both patients undergoing hemodialysis and physicians treating them.