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The study "The environmental costs of water transfers", published in Nature Sustaintability, studies the proposals for water roads to face the water crisis that affects Chile. Researchers from Universidad de Concepcion, Universidad de Chile, Universidad del Desarrollo, and Universidad del Biobío participated, with an interdisciplinary perspective.

The working group included academics from areas such as oceanography, climatology, ecotoxicology, economics, and limnology, to seek the possible impacts that the implementation of water transfer or waterway projects could have. Considering for this the problems that Chile has faced in the last 30 years in the administration of water resources.

Added to this scenario, there is the prolonged dry period known as mega-drought, which since 2010 has exacerbated the water deficit and anticipated the scenario imposed by climate change in much of the national territory, where rains will be increasingly scarce.

For Cristian A. Vargas, director of the MUSELS Center, who led this analysis, "Chile is entering a phase where it must reconcile the growing demand for water supply by productive sectors such as agriculture, mining and electricity generation, with the provision for human consumption and the health of ecosystems ".

Under ever-intensifying water scarcity across much of the presently semi-arid regions of the world, water transfers
may become inevitable to ease regional water deficits. However, to assure water sustainability, the design and enforcement of future water-use regulations must consider
their long-term implications, recognizing the connections between inland and marine ecosystems, and understanding their socio-ecological consequences under future climate change. Chile, a country where large-scale hydraulic roads are presently under consideration, may raise the bar with the development of stringent regulations and standards.

Koalas are one of the world's most charismatic animals. But there is a lot we still don't know about them. For example, how do the marsupials access water in the treetops? Do they only absorb moisture from the gum leaves they eat? Or do they come down from the trees to drink from a waterhole? Until now, no one really knew.

A study published today in Ethology, led by a researcher from The University of Sydney, has captured koala drinking behaviour in the wild for the first time. The paper describes how koalas drink by licking water running down smooth tree trunks during rain.

The news arrives in time to celebrate Wild Koala Day on Sunday 3 May.

"For a long time, we thought koalas didn't need to drink much at all because they gained the majority of the water they need to survive in the gum leaves they feed on," said Dr Valentina Mella, in the School of Life and Environmental Sciences. "But now we have observed them licking water from tree trunks. This significantly alters our understanding of how koalas gain water in the wild. It is very exciting."

Survival

Australia is currently suffering the longest dry period ever documented, with severe rainfall deficits and record maximum temperatures. Koalas experience severe heat-stress and mass mortality events in prolonged hot and dry conditions and they spend more time drinking from artificial water stations if rain is scarce.

Further research could investigate when and why koalas from different areas need access to free water - not contained in the leaves as moisture but available freely as liquid, such as rain, river water or puddles - and whether water supplementation is necessary for some populations.

"This type of drinking behaviour - licking tree trunks - relies on koalas being able to experience regular rainfall to access free water and indicates that they may suffer serious detrimental effects if lack of rain compromises their ability to access free water," Dr Mella said.

"We know koalas use trees for all their main needs, including feeding, sheltering and resting. This study shows that koalas rely on trees also to access free water and highlights the importance of retaining trees for the conservation of the species."

Koalas rarely drink water

Each day, wild koalas eat around 510 grams of fresh succulent eucalyptus leaves, and the water in the foliage they feed on is believed to contribute about three quarters of their water intake in both summer and winter.

Among their adaptations to the Australian climate, koalas also possess extraordinary urinary concentrating abilities and have restricted respiratory and cutaneous water loss compared to similar-sized mammals.

In captivity, koalas have been observed to drink water, but this behaviour has often been considered unusual and attributed to disease or to severe heat stress.

However, anecdotal reports suggest that koalas in the wild drink from waterholes in summer when temperatures exceed 40 degrees Celsius.

Koalas have also been observed approaching humans to access free water (in bottles, gardens and swimming pools during drought and after fire. But this is considered an unusual occurrence.

Observing licking behaviour

For this study, Dr Mella collated observations of koalas drinking in the wild made by citizen scientists and independent ecologists between 2006 and 2019 at the You Yangs Regional Park in Victoria and the Liverpool Plains in NSW. Each observation was koala behaviour noticed by chance and reported to Dr Mella.

There were 44 observations of free ranging koalas licking water running down a tree trunk during or immediately after rain in the You Yangs Regional Park.

The other two observations of koala drinking behaviour were recorded between the towns of Gunnedah and Mullaley, in the Liverpool Plains. One was an adult female, with a joey, who drank profusely and uninterruptedly for 15 minutes. The other was an adult male who drank at a steady pace for 34 minutes.

"As koalas are nocturnal animals and observation of their behaviour rarely occurs during heavy rainfall, it is likely that their drinking behaviour has gone largely unnoticed and has therefore been underestimated in the past," Dr Mella said. "Our observations probably only represent a minority of the drinking that normally takes place in trees during rainfall."

Koalas were observed accessing water in trees by licking the wet surfaces of branches and tree trunks during rain across a range of weather conditions, even when free-standing water was available in dams.

"This suggests koalas were drinking not as a result of heat stress and that this behaviour is likely to represent how koalas naturally access water," said Dr Mella.

Mars had a global magnetic field much earlier--and much later--in the planet's history than scientists have previously known.

A planet's global magnetic field arises from what scientists call a dynamo: a flow of molten metal within the planet's core that produces an electrical current. On Earth, the dynamo is what makes compass needles point north. But Mars' dynamo has been extinct for billions of years.

New findings from UBC researchers working with colleagues in the U.S. and France, published today in Science Advances, bring us closer to knowing the precise timing and duration of Mars' dynamo.

"We find that the Martian dynamo operated at 4.5 billion and 3.7 billion years ago. Dynamo timing is a big part of a planet's evolution, and what we find is very different from what we have thought so far," said Anna Mittelholz, postdoctoral fellow in UBC's department of earth, ocean and atmospheric sciences, and first author of the study. "The dynamo tells us something about the planet's thermal history, its evolution, and how it got to where it is today, and it is unique for each of the terrestrial planets--Earth, Mars, Venus and Mercury."

Clues about a planet's magnetic history lie in magnetized rocks on and beneath its surface. Rock is like a tape recorder, especially volcanic rocks. They begin as lava, but as they cool and solidify in the presence of a magnetic field, minerals within the rocks align themselves with the global magnetic field. By dating these rocks, scientists can estimate if a dynamo was active at the time the rock was emplaced.

Magnetism in certain rocks on Mars' surface indicate that the Martian dynamo was active between 4.3 and 4.2 billion years ago, but the absence of magnetism over three large basins that formed 3.9 billion years ago has led most scientists to believe the dynamo was inactive by that time.

The UBC researchers analyzed new satellite data and found clear evidence of a magnetic field coming from the Lucus Planum lava flow that formed less than 3.7 billion years ago--much later than the aforementioned basins.

The researchers also detected low-intensity magnetic fields over the Borealis Basin in the planet's northern hemisphere, which formed 4.5 billion years ago and is believed to be one of the oldest features on Mars.

"We have these two observations that point to a dynamo at the earliest known time in Mars' history, and a dynamo that was present half a billion years after many people thought it had already switched off," said Catherine Johnson, a professor in the department of earth, ocean and atmospheric sciences and senior scientist at the Planetary Science Institute in Tucson, Ariz., who also contributed to the study.

The researchers offer two possible explanations for the absence of magnetic fields over the basins: the dynamo may have stopped before the basins formed and then re-started before Lucus Planum formed, or the impacts that created the basins simply displaced the portion of crust containing minerals that can carry strong magnetism.

The new data for this study come from MAVEN, the Mars Atmosphere and Volatile Evolution satellite. Earlier data about magnetism on Mars had been gathered by the Mars Global Surveyor satellite which orbited the planet between 1999 and 2006, mostly at 400 kilometres above the surface. MAVEN, launched in 2013, operates as close as ~135 kilometres from the surface and picks up weaker signals that MGS could not detect.

MAVEN's ability to pick up signals from smaller features on and near the surface helps researchers distinguish whether the magnetism is coming from those, or from older rocks buried more deeply in the planet's crust.

These new insights have researchers wondering what could be revealed if they get even closer. Mittelholz noted that this study focused on two particular features, but craters remain all over Mars with stories to tell. In the future, exploration could progress from satellites to drones or balloons, providing even more detailed data.

A group of researchers from University of Toronto Engineering and SickKids Hospital have developed a new way to deliver molecules that target specific genes within cells. Their platform, which uses a modified form of diptheria toxin, has been shown to downregulate critical genes in cancer cells, and could be used for other genetic diseases as well.

The team, led by professors Molly Shoichet and Roman Melnyk of SickKids Hospital, found inspiration from an unexpected source: diphtheria toxin.

"A major challenge in the field of drug delivery is most therapeutic vehicles cannot escape the acid environment of the endosome once they get into the cell," says Shoichet, the corresponding author of this research. "The diphtheria toxin platform as a delivery vehicle effectively solves that."

Scientists looking to place molecules inside cells have a number of existing tools to choose from, but most suffer from the same drawback -- while the molecule gets inside the cell, it remains trapped in a kind of bubble called an endosome. If the goal is to deliver therapeutics that will interact with the cell's DNA, breaking out of the endosome is critical.

As a natural defense mechanism, bacteria such as Corynebacterium diptheriae produces a protein-based toxin that enters surrounding cells, eventually killing them. Critically, this toxin is known to be capable of escaping from endosomes, which led to the idea of re-engineering it as a delivery platform.

Melnyk's lab specializes in bacterial toxins and invented a non-toxic version of the diphtheria toxin (known as attenuated diptheria toxin). This new molecule has the capacity to enter the cell and efficiently escaping the endosome - and thus excels as a delivery vehicle without any of the toxic effects of diphtheria toxin.

To prove that the concept would work, the researchers used the system to deliver molecules that they believed would be effective against glioblastoma, a form of brain cancer.

"Glioblastoma is a highly invasive disease and patients have a very short life expectancy after initial diagnosis." says Shoichet, "We want to change this and have thus pursued the delivery of gene therapeutics to treat glioblastoma."

The group first targeted glioblastoma neural stem cells, which are thought to be resistant to chemotherapeutics. Specifically, the researchers focused on delivering silencing RNA (siRNA) against two genes: integrin beta 1 (ITGB1), which is associated with the highly invasive nature of glioblastoma (and other cancers), and eukaryotic translation initiation factor 3 subunit b (eIF-3b), which is an essential survival gene. By eliminating this invasive trait, the researchers could potentially limit progression in diseases like cancer.

"ITGB1 is involved in cancer cell migration, which contributes to glioblastoma's invasion into healthy brain tissues," says Laura Smith, a senior PhD student on the publication, "We used an innovative 3-dimensional culture system to significantly reduce cell invasion after treatment with our siRNA-attenuated diptheria toxin system, which suggests that it may be effective in slowing disease progression."

To demonstrate the breadth of this platform, the researchers also delivered a different nucleic sequence that knocks down eIF-3b, which participates in the 'survival pathway' of cancer cells.

"We treated the cells with the attenuated diphtheria toxin-siRNA against eIF-3b and observed down-regulation at genetic and phenotypic levels." says Amy E. Arnold, a recent PhD graduate from the Shoichet lab and first author on this paper.

The group is planning on using this delivery vehicle to treat other diseases in the future.

"We recognize the strength of this platform strategy and are actively testing it for the delivery of RNA and other cargoes," says Shoichet, providing exciting prospects for the future.

Below please find a summary and link(s) of new coronavirus-related content published today in Annals of Internal Medicine. The summary below is not intended to substitute for the full article as a source of information. A collection of coronavirus-related content is free to the public at http://go.annals.org/coronavirus.

1. Investing in Our First Line of Defense: Environmental Services Workers

Environmental services personnel are a critical first line of defense against the spread of COVID-19. In a new commentary published in Annals of Internal Medicine, authors from Harvard Medical School, Boston, and Cambridge Health Alliance discuss the importance of environmental cleaning during the pandemic and the essential role of environmental services personnel in patient safety. Read the full text: http://annals.org/aim/article/doi/10.7326/M20-2237.

Media contacts: A PDF for this article is not yet available. Please click the link to read full text. The lead author, Kevin Tyan, BA, can be reached directly at kevin_tyan@hms.harvard.edu.

A new USC study suggests that temporarily suppressing the body's immune system during the early stages of COVID-19 could help a patient avoid severe symptoms.

That's because the research, just published online in the Journal of Medical Virology, shows that an interaction between the body's two main lines of defense may be causing the immune system to go into overdrive in some patients.

The body's first line of defense, the innate immune response, starts right after an infection, like an infantry going after a foreign invader, killing the virus and any cells damaged by it. The second line of defense, the adaptive immune response, kicks in days later if any virus remains, employing what it has learned about the virus to mobilize a variety of special forces such as T cells and B cells.

Using the "target cell-limited model," a common mathematical model developed to understand the dynamics of viral infections, the researchers examined how the two immune responses work in COVID-19 patients compared to patients who have the flu.

The flu is a fast-moving infection that attacks certain target cells on the surface of the upper respiratory system and kills almost all of the target cells within two to three days. The death of these cells deprives the virus of more targets to infect and allows the innate immune response time to clear the body of almost all of the virus before the adaptive system comes into play.

Adaptive immune response kicking in too soon

But COVID-19, which targets surface cells throughout the respiratory system including in the lungs, has an average incubation of six days and a much slower disease progression. Mathematical modeling suggests that the adaptive immune response may kick in before the target cells are depleted, slowing down the infection and interfering with the innate immune response's ability to kill off most of the virus quickly.

"The danger is, as the infection keeps going on, it will mobilize the whole of the adaptive immune response with its multiple layers,” said Weiming Yuan, associate professor in the Department of Molecular Microbiology and Immunology at the Keck School of Medicine of USC, and co-corresponding author of the study. "This longer duration of viral activity may lead to an overreaction of the immune system, called a cytokine storm, which kills healthy cells, causing tissue damage."

The interaction of the innate and the adaptive immune responses might also explain why some COVID-19 patients experience two waves of the disease, appearing to get better before eventually getting much worse.

"Some COVID-19 patients may experience a resurgence of the disease after an apparent easing of symptoms," said Sean Du, adjunct researcher and lead author of the study. "It's possible that the combined effect of the adaptive and the innate immune responses may reduce the virus to a low level temporarily. However, if the virus is not completely cleared, and the target cells regenerate, the virus can take hold again and reach another peak."

Counterintuitive treatment

The most provocative result of the research is the kind of treatment it suggests to prevent this interaction between the two immune responses.

"Based on the results of the mathematical modeling, we proposed a counterintuitive idea that a short regimen of a proper immunosuppressant drug applied early in the disease process may improve a patient's outcome," said Du. "With the right suppressive agent, we may be able to delay the adaptive immune response and prevent it from interfering with the innate immune response, which enables faster elimination of the virus and the infected cells."

Small studies out of China, including a recent one of COVID-19 patients and one of SARS patients in 2003 show patients who received immunosuppressants such as corticosteroids had better results than those who did not.

The researchers said a possible next step could be to take daily measurements of viral loads and other biomarkers in COVID-19 patients, to see if the data validates the mathematical modeling. More preclinical studies including experiments in animal models will also be needed to prove the efficacy of an early immune suppressing treatment.

Like people, neurons need to talk to one another. But instead of turning thoughts into words, these cells convert electrical signals into chemical ones. For nearly 30 years, biochemist Edwin Chapman has studied how one protein triggers this crucial conversion.

Now, his team has figured out how mutations in this protein, called synaptotagmin-1 or syt1, can lead to a rare condition known as syt1-associated neurodevelopmental disorder. The scientists' discovery led them to identify a possible treatment, Chapman and his colleagues report May 1, 2020, in the journal Neuron.

An email prompted the team's investigation. In 2015, Chapman, a Howard Hughes Medical Institute (HHMI) Investigator at the University of Wisconsin-Madison, received a message from the mother of a two-year-old girl who had learned to walk only with intensive physical therapy, and who could not yet speak or play like a typical child her age.

After testing her daughter, doctors told the mother that a mutation in the SYT1 gene could be the cause. The woman later introduced Chapman to another family who had a child with a similar disorder.

"What was remarkable for me at a personal level was how keen they were to find out exactly what had happened," Chapman says. "I knew we could figure out the precise problem, and with the support of the parents, we delved into it."

Syt1-associated neurodevelopmental disorder is extremely rare, with only 11 confirmed cases. These patients suffer from a constellation of difficulties, including developmental delays, eye abnormalities, involuntary movements, and agitation that can cause them to hurt themselves.

Chapman and MD/PhD student Mazdak Bradberry's study of the disorder relied on their research on neurons. Within these cells, information travels as an electrical pulse. When the pulse reaches the end of a neuron, it triggers an influx of calcium ions. Syt1's job, Chapman's team had previously shown, is to detect and grab calcium. Then, the protein inserts itself into the neuron's membrane, and sparks the release of chemicals known as neurotransmitters. These chemicals carry information to the next neuron.

Scientists have studied this process thoroughly, but they know much less about how mutations in the syt1 protein can interfere with neuron-to-neuron communication. Chapman, Bradberry, and their colleagues took a close look at the mutated proteins made by the girl and two other patients.

Lab experiments with neurons in culture dishes showed that each patient's mutation interfered with neurotransmitter release, but to different degrees. In all cases, however, the altered syt1 protein became less responsive to calcium -- in other words, it had a hard time detecting the signal to send out neurotransmitters, the researchers say.

"That made us think that if there was some way we could enhance calcium signaling, we might be able to help compensate for the protein's defects," Bradberry says.

He learned that a familiar drug, known as 4-AP, was already approved to treat the disorder multiple sclerosis. Because 4-AP prompts a greater-than-normal influx of calcium into neurons, Bradberry suspected it could help patients with SYT1 mutations.

In preliminary experiments to test the drug's potential, the researchers used a technique devised by Loren Looger, a group leader at HHMI's Janelia Research Campus, to make neurons in culture fluoresce when they release neurotransmitters. Neurons containing mutated syt1 proteins flashed only dimly under the microscope. But adding 4-AP boosted their fluorescence.

Because the drug has already been approved by the U.S. Food and Drug Administration, doctors for the three patients should be able to quickly get permission to treat them with it, says Hugo Bellen, an HHMI Investigator at Baylor College of Medicine who was not involved with the study. The new work helps explain how certain genetic errors can disrupt neurotransmitter release and lead to a neurological disorder, he says.

Bradberry has cautiously shared the results of the team's 4-AP experiments with the patients and their doctors, so they can decide if they want to try it. He and Chapman emphasize that a drug like 4-AP will not cure patients like the three in the study, because it cannot reverse changes that have already occurred in the developing brain. However, it might reduce symptoms.

"Behaviors seen in this condition, like self-injurious hitting, impact patients' and caregivers' lives, and it's possible these could be addressed by whatever treatment we are able to offer," Bradberry says.

Chapman agrees. "If it brings any relief at all, it will be incredibly satisfying for us."

Two-dimensional (2D) materials, which consist of a single layer of atoms, have attracted a lot of attention since the isolation of graphene in 2004. They have unique electrical, optical, and mechanical properties, like high conductivity, flexibility and strength, which makes them promising materials for such things as lasers, photovoltaics, sensors and medical applications.

When a sheet of 2D material is placed over another and slightly rotated, the twist can radically change the bilayer material's properties and lead to exotic physical behaviours, such as high temperature superconductivity - exiting for electrical engineering; nonlinear optics - exciting for lasers and data transmission; and structural super-lubricity- a newly discovered mechanical property which researchers are only beginning to understand. The study of these properties has given birth to a new field of research called twistronics, so-called because it's a combination of twist and electronics.

Aalto University's researchers collaborating with international colleagues have now developed a new method for making these twisted layers on scales that are large enough to be useful, for the first time. Their new method for transferring single-atom layers of molybdenum disulfide (MoS2) allows researchers to precisely control the twist angle between layers with up to a square centimetre in area, making it record-breaking in terms of size. Controlling the interlayer twist angle on a large scale is crucial for the future practical applications of twistronics.

'Our demonstrated twist method allows us to tune the properties of stacked multilayer MoS2 structures on larger scales than ever before. The transfer method can also apply to other two-dimensional layered materials', says Dr Luojun Du from Aalto University, one of the lead authors of the work.

A significant advancement for a brand-new field of research

Since twistronics research was introduced only in 2018, basic research is still needed to understand the properties of twisted materials better before they find their ways to practical applications. The Wolf Prize in Physics, one of the most prestigious scientific awards, was awarded to Profs. Rafi Bistritzer, Pablo Jarillo-Herrero, and Allan H. MacDonald this year for their groundbreaking work on twistronics, which indicates the game-changing potential of the emerging field.

Previous research has demonstrated that it is possible to fabricate the required twist angle by transfer method or atomic force microscope tip manipulation techniques in small scales. The sample size has usually been in the order of ten-microns, less than the size of a human hair. Larger few-layer films have also been fabricated, but their interlayer twist angle is random. Now the researchers can grow large films using an epitaxial growth method and water assistant transfer method.

'Since no polymer is needed during the transfer process, the interfaces of our sample are relatively clean. With the control of twist angle and ultra-clean interfaces, we could tune the physical properties, including low-frequency interlayer modes, band structure, and optical and electrical properties', Du says.

'Indeed, the work is of great significance in guiding the future applications of twistronics based on 2D materials', adds Professor Zhipei Sun from Aalto University.

The results were published in Nature Communications.

Honey bee colonies from across the UK are increasingly suffering from a viral disease, a new study has shown.

Publishing their findings in the journal Nature Communications, the team led by Professor Giles Budge of Newcastle University, UK, found that the number of honey bee colonies affected with chronic bee paralysis rose exponentially between 2007 and 2017.

Data collected from visits to over 24,000 beekeepers confirmed that while chronic bee paralysis was only recorded in Lincolnshire in 2007, a decade later it was present in 39 of 47 English and six of eight Welsh counties. The scientists also found that clusters of chronic bee paralysis, where disease cases are found close together, were becoming more frequent.

Chronic bee paralysis symptoms include abnormal trembling, an inability to fly, and the development of shiny, hairless abdomens. The disease is caused by a virus known as chronic bee paralysis virus (CBPV), and infected bees die within a week. This leads to piles of dead bees just outside honey bee hives and whole colonies are frequently lost to the disease.

Study lead, Professor Budge, from Newcastle University's School of Natural and Environmental Sciences, said: "Our analysis clearly confirms that chronic bee paralysis has been emerging across England and Wales since 2007 and that apiaries owned by professional beekeepers are at greater risk of the disease."

The study was completed in association with the Bee Farmers' Association, who represent professional beekeepers in the UK. Rob Nickless, the Chairman of the Bee Farmers' Association, said: "We are pleased to be part of this project and welcome these early results. This is the sort of research that brings practical benefits to the industry - helping bee farmers at grassroots level to improve honey bee health and increase UK honey production."

Professor Budge said: "We do not yet know why colonies of bee farmers are at increased risk from this damaging disease, but many management practices are known to differ significantly between amateur and professional apiarists."

The study also investigated whether disease risk was associated with honey bee queen imports. Honey bee queens head up honey bee colonies and beekeepers use imported honey bee queens to replenish their stocks. The scientists used data from 130,000 honey bee imports from 25 countries to show for the first time that the disease was nearly twice as likely in apiaries owned by beekeepers who imported honey bees.

This work is being completed as a collaboration between Newcastle and St Andrews Universities, the Bee Farmers' Association and the National Bee Unit of the Animal and Plant Health Agency with funding from the BBSRC
The researchers highlight the need for further studies focussing on different virus genotypes, which will be completed at the University of St Andrews.

Future work will concentrate on the susceptibility of different honey bee races and comparing the management practices of professional and amateur beekeepers to help discover the reasons behind the current disease emergence. This work will have the potential to reduce or mitigate the damage of this emerging disease to our most important managed pollinator.

Inland waters such as rivers, lakes and reservoirs play an important role in the global carbon cycle. Calculations that scale up the carbon dioxide emissions from land and water surface areas do not take account of inland waters that dry out intermittently. This means that the actual emissions from inland waters have been significantly underestimated - as shown by the results of a recent international research project led by scientists at the Helmholtz Centre for Environmental Research (UFZ) in Magdeburg and the Catalan Institute for Water Research (ICRA). The study was published in Nature Communications.

"It all began in 2013, during a measurement campaign in Catalonia in Spain," says Dr Matthias Koschorreck, a biologist in the Department of Lake Research at UFZ. Together with a Spanish team, he was studying the release of greenhouse gases in the catchment of a small river. "It was summer and parts of the riverbed were dry. On a whim, we decided to take some measurements in those areas too," Koschorreck explains. "The results surprised us - these dry, gravelly areas of the riverbed released unexpectedly high levels of carbon dioxide." Koschorreck and his colleague Dr Rafael Marcé from ICRA in Girona (Spain), decided to investigate that further. Results from various locations in Spain and Germany all produced the same finding: dry inland waters released readily measurable and sometimes considerable levels of carbon dioxide. "We wondered whether this might be the case in other regions of the world, and whether greenhouse gas emissions from inland waters might be fundamentally underestimated," says Koschorreck. "In studies that scale up emissions of greenhouse gases from land and water surface areas, inland waters that dry out intermittently haven't previously been taken into account."

To investigate these questions, in 2016 Koschorreck and Marcé together with a core team of six German and Spanish scientists launched the dryflux research project, with the aim of measuring greenhouse gas emissions from dry inland waters. As part of a workshop held at the UFZ's Magdeburg site, they developed a measurement and sampling concept for their study. They then engaged the help of their international networks. "Every participant at the workshop got in touch with research teams all over the world to see whether they would be interested in taking part in measurement campaigns on freshwater systems in their area," explains Koschorreck. "The response was amazing. Twenty four research teams from all over the world took part, which meant that we were able to collect data from 196 different sites on every continent except Antarctica." Each team carried out three closed-chamber measurements in dry areas of at least three freshwater systems in their region - a river, lake, reservoir or pond. This involves placing a special measuring container with its open end downwards on the ground, separating the air inside the container from the ambient air. An analytical device is then used to measure the change in the amount of carbon dioxide inside the container. At the same location, the project partners also took samples of the dry sediment and measured its moisture, organic matter and salt content, temperature, and pH.

The large, complex dataset was evaluated by Philipp Keller, a doctoral researcher in the Department of Lake Research at the UFZ and first author of the study, who came to some interesting conclusions. "We found significant carbon dioxide emissions from dry areas of inland waters across all climate zones," says Keller. "So this really is a global phenomenon." The researchers also discovered that these emissions are in fact often higher than typical emissions from water surfaces of the same size. "We were able to show that dry areas of inland waters actually account for a significant proportion of total carbon dioxide emissions from these freshwater systems," says Koschorreck. "If you take account of this in global calculations for inland waters, the carbon dioxide emissions increase by six percent." But what mechanisms are responsible for the release of carbon dioxide from dry inland water sediments? "Respiration processes of microorganisms," says Philipp Keller. "The more substrate available - the more organic matter in the soil - and the more favourable the conditions like temperature and sediment moisture, the more active they are and the more carbon dioxide is released." From the results of the study, the researchers concluded that the factors responsible for carbon dioxide release are essentially the same all over the globe. "The interaction of local conditions like temperature, moisture and the organic matter content of the sediments is crucial, and it has a bigger influence than regional climate conditions," Keller explains.

So what do the results of the study mean for the future assessment of carbon dioxide emissions from inland waters? "Our study shows that carbon dioxide emissions from inland waters have been significantly underestimated up until now," says Koschorreck. "We hope that our work will help ensure that dry areas of freshwater systems are included in future calculations. With the progression of climate change, more surface waters are probably drying out and thus, CO2 emissions will likely increase."

At the Paul Scherrer Institute PSI, researchers have gained insights into a promising material for organic light-emitting diodes (OLEDs). The substance enables high light yields and would be inexpensive to produce on a large scale - that means it is practically made for use in large-area room lighting. Researchers have been searching for such materials for a long time. The newly generated understanding will facilitate the rapid and cost-efficient development of new lighting appliances in the future. The study appears today in the journal Nature Communications.

The compound is a yellowish solid. If you dissolve it in a liquid or place a thin layer of it on an electrode and then apply an electric current, it gives off an intense green glow. The reason: The molecules absorb the energy supplied to them and gradually emit it again in the form of light. This process is called electroluminescence. Light-emitting diodes are based on this principle.

This green luminescent substance is a hot candidate for producing OLEDs, organic light-emitting diodes. For about three years now, OLEDs have been found in the displays of smartphones, for example. In the meantime, the first flexible television screens with these materials have also come onto the market.

In addition, OLEDs make cost-efficient room lighting with a large surface area possible. First, however, the materials best suited to this application need to be found. That's because many substances under consideration for OLEDs contain expensive materials such as iridium, and this impedes their application on a large scale and on extensive surfaces. Without such additives, the materials can actually emit only a small part of the energy supplied to them as light; the rest is lost, for example as vibrational energy.

The goal of current research is to find more efficient materials for cheaper and more environmentally friendly displays and large-area lighting. Here, inexpensive and readily available metals such as copper promise progress.

Under close examination

Researchers have now made a more precise examination of the copper-containing compound CuPCP. There are four copper atoms in the middle of each molecule, surrounded by carbon and phosphorus atoms. Copper is a relatively inexpensive metal, and the compound itself can be easily produced in large quantities - ideal preconditions for use over large extensive surfaces.

"We wanted to understand what the excited state of the compound looks like," says Grigory Smolentsev, a physicist in the operando spectroscopy research group. That is: How does the substance change when it absorbs energy? For example, does the structure of the molecule change? How is the charge distributed over the individual atoms after excitation? "This reveals how high the losses of energy that will not be released as light are likely to be," added Smolentsev, "and it shows us how we can possibly minimise these losses."

Using two large research facilities at PSI - the Swiss Light Source SLS and the X-ray free-electron laser SwissFEL - as well as the European Synchrotron Radiation Facility in Grenoble, France, Smolentsev and his collaborators took a closer look at the short-lived excited states of the copper compound.

The measurements confirmed that the substance is a good candidate for OLEDs due to its chemical structure. The compound's quantum chemical properties make it possible to achieve a high light yield. One reason for this is that the molecule is relatively stiff, and its 3D structure changes only slightly when excited. Now researchers can start to further optimise this substance for use in OLEDs.

Tools for the future

What's more, the measurements at the three large research facilities ? at PSI and in Grenoble ? were significant not only for the investigation of this one copper-containing compound. There was more at stake: The experimental data obtained this way are also helpful in improving theoretical calculations regarding molecules in general. "So in the future it will be possible to better predict which compounds are more suitable for OLEDs and which less," says Grigory Smolentsev. "The measurement data will help the chemists understand which part of the molecule stands in the way of high efficiency. And of course: how the compound can be improved to increase its light output."

CU Boulder researchers have developed a method that could enable scientists to accurately forecast ocean acidity up to five years in advance. This would enable fisheries and communities that depend on seafood negatively affected by ocean acidification to adapt to changing conditions in real time, improving economic and food security in the next few decades.

Previous studies have shown the ability to predict ocean acidity a few months out, but this is the first study to prove it is possible to predict variability in ocean acidity multiple years in advance. The new method, described in Nature Communications, offers potential to forecast the acceleration or slowdown of ocean acidification.

"We've taken a climate model and run it like you would have a weather forecast, essentially - and the model included ocean chemistry, which is extremely novel," said Riley Brady, lead author of the study, and a doctoral candidate in the Department of Atmospheric and Oceanic Sciences.

For this study the researchers focused on the California Current System, one of four major coastal upwelling systems in the world, which runs from the tip of Baja California in Mexico all the way up into parts of Canada. The system supports a billion-dollar fisheries industry crucial to the U.S. economy.

"Here, you've got physics, chemistry, and biology all connecting to create extremely profitable fisheries, from crabs all the way up to big fish," said Brady, who is also a graduate student at the Institute of Arctic and Alpine Research (INSTAAR). "Making predictions of future environmental conditions one, two, or even three years out is remarkable, because this is the kind of information that fisheries managers could utilize."

The California Current System is particularly vulnerable to ocean acidification due to the upwelling of naturally acidic waters to the surface.

"The ocean has been doing us a huge favor," said study co-author Nicole Lovenduski, associate professor in atmospheric and oceanic sciences and head of the Ocean Biogeochemistry Research Group at INSTAAR.

The ocean absorbs a large fraction of the excess carbon dioxide in the Earth's atmosphere derived from human activity. Unfortunately, as a result of absorbing this extra man-made carbon dioxide - 24 million tons every single day - the oceans have become more acidic.

"Ocean acidification is proceeding at a rate 10 times faster today than any time in the last 55 million years," said Lovenduski.

Within decades, scientists are expecting parts of the ocean to become completely corrosive for certain organisms, which means they cannot form or maintain their shells.

"We expect people in communities who rely on the ocean ecosystem for fisheries, for tourism and for food security to be affected by ocean acidification," said Lovenduski.

This spells trouble for the California Current System, with its naturally corrosive waters. This extra acidification could push its fragile ecosystems over the edge.

The fortune and frustration of forecasting

People can easily confirm the accuracy of a weather forecast within a few days. The forecast says rain in your city? You can look out the window.

But it's a lot more difficult to get real-time measurements of ocean acidity and figure out if your predictions were correct.

But this time, CU Boulder researchers were able to capitalize on historical forecasts from a climate model developed at the National Center for Atmospheric Research. Instead of looking to the future, they generated forecasts of the past using the climate model to see how well their forecast system performed. They found that the climate model forecasts did an excellent job at making predictions of ocean acidity in the real world.

However, these types of climate model forecasts require an enormous amount of computational power, manpower, and time. The potential is there, but the forecasts are not yet ready to be fully operational like weather forecasts.

And while the study focuses on acidification in one region of the global ocean, it has much larger implications.

States and smaller regions often do their own forecasts of ocean chemistry on a finer scale, with higher resolution, focused on the coastline where fisheries operate. But while these more local forecasts cannot factor in global climate variables like El Niño, this new global prediction model can.

This means that this larger model can help inform the boundaries of the smaller models, which will significantly improve their accuracy and extend their forecasts. This would allow fisheries and communities to better plan for where and when to harvest seafood, and to predict potential losses in advance.

"In the last decade, people have already found evidence of ocean acidification in the California current," said Brady. "It's here right now, and it's going to be here and ever present in the next couple of decades."

A technique for studying individual circuits in the brains of mice has been hampered because the light needed to stimulate neural activity briefly overwhelms the electrodes "listening" for the response. Now, improved shielding within the neural probe enables those lost signals to be captured.

"Consider a conversation, in which the first few and the last few words of a sentence are omitted or distorted. In such a dialogue, not much information can be reliably deciphered. This is the same situation in our research," said György Buzsáki, the Biggs Professor of Neuroscience at New York University School of Medicine and a co-author of the new paper describing the results.

"Our dialogue with brain circuits starts with a question in the form of a light pulse. If the beginning and the end of the pulse--our 'question'--produce large artifacts, we lose the instantaneous and often very critical neuronal responses."

To address this problem, a team of engineers at the University of Michigan set out to improve their neural probe so that it could record complete answers. This enables experiments that were previously impossible.

"As an example, we can mimic a brain wave by turning on the micro-LEDs at a certain frequency and see how the neural circuit behaves. We can also implement what is called a closed-loop control and make the LEDs turn on as soon as we detect a certain brain signal," said Kanghwan Kim, first author on the new paper in Nature Communications and a recent Ph.D. graduate in electrical and computer engineering from U-M.

Understanding communication among brain cells is key to advancing our understanding of the brain and developing treatments for neurological diseases such as Alzheimer's Disease. One of the new experiments that the team has in mind would explore memory.

"For example, we can make neurons in the hippocampus fire in a pattern that would enhance memory consolidation and see if the memory is actually improved," said Euisik Yoon, senior author on the paper and a professor of electrical engineering and computer science at U-M.

The probe is designed for a technique called optogenetics, in which mice have been genetically modified so that their neurons can be stimulated with light. The trick is to make LEDs small enough that they can prod a single neuron, rather than the tens of them stimulated by conventional electrical pulses.

Michigan's neural probe team accomplished this five years ago with the smallest known light sources on implantable probes. But the signals that turn the LED on and off briefly overwhelm the electrodes that listen for the response.

"It is like if there is a big bang sound--like a gunshot or an explosion. You may not hear for a while until your ears recover," Yoon said.

To address this problem, Kim added a layer of electrical shielding to the design. But even the light itself can pose a problem, as it is absorbed by the silicon of the probe and converted into electrical noise sensed by the electrodes. For this, Kim added boron to the silicon. This increased the silicon's conductivity, enabling the silicon to keep the noise away from the electrodes.

"Now that the artifact is removed, we can modulate neurons in nearly any area of the brain and determine exactly where in the brain the neurons are located, and how they are influencing neighboring neurons," Yoon said.

The researchers can also turn on multiple light sources simultaneously, making it possible to study the brain's complex neural circuits at near-cellular resolution. The devices have been successfully demonstrated in mice.

Overview

The research team of Assistant Professor Miyaji of the Department of Electrical and Electronic Information Engineering at Toyohashi University of Technology has developed a self-interference cancellation filter that is indispensable for the realization of in-band full duplex using the same frequency to transmit and receive simultaneously in wireless communications. The developed self-interference cancellation filter can estimate the distortion caused by radio and the distortion of the radio channel with high accuracy and cancel self-interference. In addition, it can quickly reach the solution of the filter with low computational complexity. It is expected to be applied to next-generation wireless communication technology.

Details

In wireless communications, simultaneous transmission and reception using the same frequency (in-band full duplex) is a very difficult task. Even in the latest wireless communication standard 5G, this in-band full duplex has not been realized. Currently, it is necessary to divide the time when transmitting and receiving at the same frequency, or to divide the frequency when transmitting and receiving at the same time. It is necessary to separate one of them (time or frequency) because the strength of the radio wave that it emits is up to several hundred million times greater than the strength of the radio wave to receive (self-interference).

The filters considering multiple distortions that have been developed so far remove the self-interference with high precision, but also require high computational complexity and take a long time to obtain the solution of the filter. Therefore, the research team of Assistant Professor Miyaji worked on the development of a self-interference cancellation filter that simultaneously satisfies the conditions of high precision, high speed, and low computational complexity.

The first author, Kazuki Komatsu, in the doctoral program (JSPS Research Fellow), explains, "Compared to base stations, low-cost radios such as smartphones have complex distortions, and self-interference cancellation in such devices is a very difficult problem. To solve a complex problem, it is important to boil the problem down to an essence and break it down into multiple smaller problems. We have decomposed the problem of self-interference cancellation due to the complex distortion of radio equipment into five small problems and expressed each using mathematical operators. As a result, it was clarified that the solution method of each small problem and the solution method of the big problem which connected them could be derived using five operators and their inverse operators. By applying the derived solution to a filter, we were able to cancel self-interference with higher precision, higher speed, and lower computational complexity than before. The developed filter increases the feasibility of in-band full-duplex communications in small and inexpensive radios such as smartphones."

Future outlook

The research team is planning theoretical performance analysis and field evaluation of the developed self-interference cancellation filter. They also believe that by using the developed filter, it can be applied to wireless networks that cooperate with small mobile objects such as drones. Since it is necessary to recreate the filters periodically according to changes in the radio environment due to movement, we can expect contributions from this technology, which has the features of high precision, high speed, and low calculation complexity.

Bronx, NY (May 1, 2020) People with cancer who develop COVID-19 are much more likely to die from the disease than those without cancer, according to physician-researchers at Montefiore Health System and Albert Einstein College of Medicine. The study, published today in the online edition of Cancer Discovery, is the largest so far to assess outcomes for patients with cancer who have also been infected with COVID-19.

"Our findings emphasize the need to prevent cancer patients from contracting COVID-19 and--if they do--to identify and closely monitor these individuals for dangerous symptoms," said Vikas Mehta, M.D., M.P.H., a co-lead author of the study, a surgical oncologist at Montefiore and associate professor of otorhinolaryngology--head and neck surgery at Einstein. "We hope that our findings can inform states and communities that have not yet been so severely struck by this pandemic about the unique vulnerability cancer patients face."

The study involved 218 cancer patients who tested positive for COVID-19 from March 18 to April 8, 2020 at Montefiore Medical Center in the Bronx, New York City, one of the regions in the United States hit hardest by the pandemic. A total of 61 cancer patients died from COVID-19, a dramatically high case-fatality rate of 28%. (The mortality rate for COVID-19 in the United States is 5.8%, according to the World Health Organization.)

"A key element is that mortality appears to be more closely related to frailty, age, and co-morbidities than to active therapy for cancer," said co-senior author Balazs Halmos, M.D., M.S., director of the Multidisciplinary Thoracic Oncology Program at Montefiore and professor of medicine at Einstein.

"Our data suggest that we should not stop lifesaving cancer therapies, but rather develop strategies to minimize potential COVID-19 exposures and re-evaluate therapies for our most vulnerable cancer populations," explained co-senior author Amit Verma, M.B.B.S., director of the division of hemato-oncology at Montefiore and professor of medicine and of developmental and molecular biology at Einstein.

The time period during which these patients were treated was earlier in the epidemic when testing was almost exclusively done in sicker, symptomatic patients who required hospitalization. This may partially explain the high fatality rate within the study's cancer population. However, even when compared to mortality rates in non-cancer patients at Montefiore and across New York City during the same time period, cancer patients demonstrated a significantly higher risk of dying from COVID-19.

As a group, COVID-19 patients with hematologic (blood) cancers, such as leukemia and lymphoma, had the highest mortality rate: 37% (20 of 54 patients). For patients with solid malignancies, the mortality rate was 25% (41 of 164). Striking differences were observed among specific solid cancers: the mortality rate for patients with lung cancer was 55% and colorectal cancer was 38%, compared with mortality rates of 14% for breast cancer and 20% for prostate cancer.

Certain underlying conditions--older age, hypertension, heart disease, and chronic lung disease--were significantly associated with increased mortality among cancer patients with COVID-19.

A detailed analysis of patients with cancer who died from COVID-19 shows that more than half of these individuals--37 of 61--had been in places with a higher risk of exposure to COVID-19, such as nursing homes, hospitals or emergency departments within the 30 days before being diagnosed with COVID-19. This was before widespread social distancing had been implemented.

Montefiore has already changed clinical practice as a result of the study's findings, by using telemedicine and early and aggressive social distancing for cancer patients, and by opening a dedicated cancer outpatient and inpatient clinical service. It has also instituted bilingual peer counseling and deployed social workers and food deliveries to its at-risk population.

Montefiore is able to quickly identify patients with a known history of cancer who test positive for COVID-19 based on a daily collection and collation of data across the health system. This allows the care team to act immediately to ensure appropriate care for these individuals and track outcomes.