Culture

DURHAM, N.H.-- Researchers at the University of New Hampshire have identified a quicker and less expensive way to count sperm in lobsters that could help scientists looking at any animal better understand mating, a key aspect of species survival.

"Scientists used to have to do this using a very tedious or expensive method so it was rarely attempted," said Win Watson, professor emeritus of marine biology. "Now that DNA technology has become so accessible and affordable, we decided to try it and it worked great."

The technique is described in their study which was recently featured in the Journal of Crustacean Biology. Researchers outlined how they were looking to better understand how climate change may alter lobster reproduction by influencing the amount of sperm a male lobster could produce. The challenge they encountered was counting the number of sperm contained in the lobster's spermatophore -- the package of sperm a male lobster transfers to females during mating. Each spermatophore contains about two million sperm cells, so counting them under a microscope is too time-consuming, especially when processing numerous samples. The new DNA method they developed allowed them to determine whether male lobsters experienced declining numbers of sperm when they mated successively, leading to sperm limitation within the population.

"Imagine if it took a week to produce a complete lobster spermatophore. That would mean that male lobsters might only be able to mate once a week," said Watson. "That, in turn, might mean that some female lobsters that might be ready to mate, would not get the chance. Females only mate after they molt, which they do only once per year, and they all tend to do it around the same time. So, limited availability of male sperm could significantly impact the population."

The absence of cost-effective ways to measure lobster sperm meant that testing the sperm limitation hypothesis were rarely attempted, despite concerns about the sustainability of the American lobster population.

"Beforehand, if we wanted to look at questions of reproductive output in lobsters, it took labor-intensive methods and an incredible amount of time," says Ben Gutzler, a recent PhD graduate from UNH in Marine Biology and lead author. "This new DNA method will hopefully make it possible for a broader group of scientists to ask more relevant questions about more animals."

Although the researchers did not find evidence of sperm limitation among male lobsters, they did uncover inconsistent sperm production among the individual lobsters studied. For example, they found that lobsters with severe shell disease, which is very common in southern New England, packaged fewer sperm cells in each spermatophore. This could have implications for population sustainability and prompt further study.

Climate in different parts of the world is undergoing a warming trend, but also significant interdecadal variations that compensate, or exacerbate the former. These variations are associated not only with changes in the radiative forcing, but also to natural variability in the atmospheric and oceanic circulation patterns. Can multi-annual variations in the frequency of North Atlantic atmospheric blocking and mid-latitude circulation regimes be skillfully predicted? Recent advances in seasonal forecasting have shown that mid-latitude climate variability does exhibit significant predictability. Decadal predictions fill the gap between assessing long-term climate trends (climate projections) and predicting short-term climatic anomalies (seasonal forecasting), thus targeting near-term regional climatic anomalies with multi-annual lead time and responding to an increasingly needed service to society.

A study recently published on the Nature Research Journal Climate and Atmospheric Science led by the CMCC Foundation (in particular, with the contribution of the CMCC scientists Panos Athanasiadis, lead author of the study, Alessio Bellucci and Stefano Tibaldi from CSP - Climate Simulations and Predictions Division) illustrates the latest breakthrough in the field of decadal predictions, with a special focus on the documented predictability for the North Atlantic Oscillation (NAO) and blocking in the North Atlantic.

The authors made use of a large ensemble of decadal predictions and found remarkable skill in reproducing the observed multi-annual variations of wintertime blocking frequency over the North Atlantic and of the North Atlantic Oscillation (NAO) itself. Therefore, skillfully predicting the decadal fluctuations of blocking frequency and the NAO may be used in statistical predictions of near-term climate anomalies, and it provides a strong indication that impactful climate anomalies may also be predictable with improved dynamical models.

For years, a scientific puzzle has bedeviled researchers aiming to fight Alzheimer's disease, a common and incurable form of dementia.

The results of numerous lab investigations and population studies support the preventive potential of omega-3 fatty acids, "good fats" found abundantly in fish. However, to date the majority of studies evaluating omega-3s for averting or curtailing cognitive decline in human participants have failed to show benefits.

Now, a small clinical trial from USC provides important clues about this discrepancy, in the first Alzheimer's prevention study to compare levels of omega-3s in the blood with those in the central nervous system. The findings suggest that higher doses of omega-3 supplements may be needed in order to make a difference, because dramatic increases in blood levels of omega-3s are accompanied by far smaller increases within the brain. Among participants who carry a specific mutation that heightens risk for Alzheimer's, taking the supplements raised levels of a key fatty acid far less compared to those without the mutation.

"Trials have been built on the assumption that omega-3s get into the brain," said senior author Dr. Hussein Yassine, associate professor of medicine and neurology at the Keck School of Medicine of USC. "Our study was specifically designed to address this question."

The paper was published today in the journal EBioMedicine.

The researchers recruited 33 participants who had risk factors for Alzheimer's but were not cognitively impaired. All participants had a family history of the disease, a sedentary lifestyle and a diet low in fatty fish. Fifteen carried a gene variant called APOE4, which is linked to inflammation in the brain and increases Alzheimer's risk by a factor of four or more; the other 18 were noncarriers.

At random, participants were assigned to a treatment group or control group. Members of the treatment group were asked to take supplements containing more than 2 grams of an omega-3 called docosahexaenoic acid (DHA) daily for six months. Control group members took placebos each day over the same period. Participants in both groups also were asked to take daily B-complex vitamins, which help the body process omega-3s.

Dr. Yassine and his colleagues gathered samples of blood plasma and cerebrospinal fluid -- a gauge for whether the omega-3s reached the brain -- from participants at the outset, and again at the end of the study period. The scientists looked at levels of two omega-3 fatty acids: DHA and eicosapentaenoic acid (EPA), a potent anti-inflammatory that the body derives from a small portion of its DHA intake.

Higher doses for omega-3s to be effective?

The researchers found that at the end of the six months, participants who took omega-3 supplements had 200 percent more DHA in their blood compared to those who took placebos. In contrast, the DHA found in cerebrospinal fluid was only 28 percent higher in the treatment group than the control group. This result hints that measuring omega-3 levels in the blood may not indicate how much is reaching the brain.

Dr. Yassine and his co-authors also report that, within the treatment group, those without the risk-inflating APOE4 mutation showed an increase of EPA (anti-inflammatory omega-3 fatty acid) in their cerebrospinal fluid three times greater than what was seen in carriers of the gene.

"E4 carriers, despite having the same dose, had less omega-3s in the brain," he said. "This finding suggests that EPA is either getting consumed, getting lost or not getting absorbed into the brain as efficiently with the E4 gene."

Notably, the 2-gram dose of DHA in this study far exceeded what has been used in major clinical trials testing the preventive power of omega-3s, which typically administer 1 gram or less daily.

"If you use a lower dose, you can expect a less-than-10-percent increase in omega-3s in the brain, which may not be considered meaningful," Dr. Yassine said.

The sacrifice of study participants advances Alzheimer's research

The investigators worked for two years to recruit participants for the trial. The barrier to entry came from the only method capable of extracting cerebrospinal fluid: a lumbar puncture, also known as a spinal tap. It proved challenging to find people willing to undergo that procedure, which involves a hollow needle piercing the lower back, two times.

Dr. Yassine had high praise for the study participants.

"They were generous with their time, and they were courageous to do the lumbar punctures," he said. "The main reason they did this was their desire to advance science."

The participants' bravery may pay off in the creation of even more knowledge about omega-3s and Alzheimer's.

The preliminary data from the current study was intriguing enough that the scientists were able to attract funding for a larger trial for which recruitment is underway. Following 320 participants over two years, it will examine whether high doses of omega-3s can slow cognitive decline in carriers of the APOE4 gene.

Dr. Yassine believes that the progression from a small study to a bigger one is a good model for developing therapies and preventions targeting the brain.

"These pilot studies are so important as a step toward much larger, more complicated studies," he said. "The bottom line is, before you embark upon very expensive clinical trials, you need to show proof of concept, that your drug is getting into the brain and changing biomarkers of disease in the right direction."

Aspergillus latus, a species of fungus previously found only in soil or plants, has been found for the first time in a hospital environment by an international group of researchers. The group sequenced its genome and discovered that it is actually a hybrid and is up to three times more drug-resistant than the two species from which it derives.

An article on the study is published in Current Biology and coauthored by researchers from Brazil, the United States, Portugal and Belgium. The research was supported by São Paulo Research Foundation - FAPESP .

Aspergillosis is a lung disease caused by fungi of this genus, especially A. fumigatus, which is widely found in plants and soil. All humans regularly inhale spores of Aspergillus, which do not usually cause symptoms in healthy subjects. In patients with weak immune systems, however, the mold can cause pneumonia, build up fungal balls (aspergillomas) in the lungs, and spread to become invasive pulmonary aspergillosis, the most severe form of the disease. A. fumigatus is the most frequent cause of aspergillosis, but other species also cause the condition, including A. flavus, A. niger, A. nidulans and A. terreus.

"In about 90% of cases, infection by Aspergillus is caused by A. fumigatus, but in some human genetic diseases, A. nidulans is a more frequent cause. We therefore started assembling clinical material from various parts of the world to see how often this species occurred in a hospital environment. To our surprise, six out of ten samples contained a fungus that had never before been found to infect people," said Gustavo Henrique Goldman , a professor in the University of São Paulo's Ribeirão Preto School of Pharmaceutical Sciences (FCFRP-USP) in Brazil and coprincipal investigator for the study with Antonis Rokas, a professor at Vanderbilt University in the United States.

Genetic sequencing also revealed that A. latus is a hybrid of two relatively distantly related species and contains complete copies of the DNA of both parental species. Tests performed by other groups have already shown that A. latus can be up to three times more resistant to anti-fungal drugs than its parental species, A. spinulosporus and an unknown relative of A. quadrilineatus. It also more effectively combats human immune cells.

"The fungus gains significant advantages from being a hybrid," Goldman said. "Accurate identification of the species that causes the infection is important in order to decide on the best treatment and avoid resistance to existing drugs."

However, he added, few Brazilian hospitals currently have the resources to perform genetic sequencing in order to identify the fungi that contaminate patients with greater than genus-level precision. Identification is typically achieved by morphological analysis under a microscope, which leaves room for misdiagnosis. The samples of A. latus used in the study, for example, had previously been labeled as A. nidulans by this method.

Fungi and COVID-19

The presence of fungi in hospital environments is a well-known factor in disease aggravation and even death. In collaboration with researchers in Germany, Goldman and his group are now assembling samples of fungi present in the lungs of COVID-19 patients with the aim of investigating how these organisms can aggravate their condition as a basis for developing strategies to avoid and combat infections.

"Several COVID-19 patients have died owing to concomitant infection by Aspergillus," Goldman said. "We currently have four strains that were isolated from patients who died of COVID-19 in Europe and will sequence their genomes to identify the species and see if they're favored by the disease."

He is looking for partners to help collect material in Brazil, but the sample isolation procedure entails a strict clinical protocol not yet in use in Brazil that ensures health workers and researchers are not infected by the novel coronavirus. In Europe, the experimental protocol was implemented in time for the pandemic.

Cases of concomitant COVID-19 and infection by fungi of the genus Aspergillus evidence the importance of knowing more about these microorganisms. For example, A. fumigatus is found worldwide and capable of surviving under extreme conditions, such as temperatures of up to 70 °C and a scarcity of nutrients. It can even extract food from water.

"We've now brought to light another feature of the genus, which is the formation of hybrids," Goldman said.

For the recently published study, the researchers assembled ten samples of fungi mainly found in material collected from patients with allergic bronchopulmonary aspergillosis and other disorders, such as chronic granulomatous disease, caused by a genetic dysfunction that impairs the immune system, and chronic obstructive pulmonary disease, including chronic bronchitis and emphysema.

The samples were collected in Portugal, Belgium, the US and Canada. Sequencing confirmed only three to be A. nidulans. One was identified as A. quadrilineatus, a soil fungus that also infects humans, and the other six as A. latus, hitherto found only in soil and plants.

Evolution

A. latus is the first hybrid filamentous fungus known to cause disease in humans, a relatively common property of yeasts such as those of the genus Candida, which causes candidiasis. Another curious feature of A. latus is that it is diploid; i.e., its cells contain two sets of chromosomes, similar to all human cells except egg and sperm cells. Most fungi are haploid, with only one set of chromosomes.

The hybrid also retains the DNA from both parental species, suggesting that the fusion is recent. Genes are recombined in ancient hybrids or species that diverged from a common ancestor eons ago, and some genes are lost or change position during the process of evolution.

Mules are a well-known example of a hybrid. They have 63 chromosomes, a mixture of the mare's 64 and the donkey's 62. In the case of A. latus, however, the genetic material of both parents is preserved in its entirety.

"Another curiosity is that the genetic distance between its two parental species is more or less the same as that between Homo sapiens and the lemur," Goldman said, referring to the 88 species of Lemuroidea primates native to Madagascar in Africa.

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.

SARS-CoV-2 RNA found in a healthy blood donor 40 days after resolution of symptoms

Asymptomatic donors infected with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) may pose a risk to the safety of the blood supply. Researchers from Stanford University School of Medicine report the case of a volunteer blood donor who was healthy on the day of donation but had detectable SARS-CoV-2 RNA levels in their blood at least 40 days after resolution of COVID-19-like symptoms. The donor had symptoms of upper respiratory infection in early March, including body aches and sore throat without fever. The donor did not seek medical attention and was not tested for SARS-CoV-2 at that time. After the donor was notified about the results, and 5 days after the donation date, RT-PCR assay of the donor's nasopharyngeal swab specimen showed no SARS-CoV-2 RNA.

According to the authors, the confirmation of SARS-CoV-2 RNA in donor blood more than 1 month after symptom resolution is concerning in light of current guidelines, which do not recommend screening in the general allogeneic donor population. Although this case is insufficient to recommend universal SARS-CoV-2 blood screening, the authors say their institution will continue to do so. Read the full text: https://www.acpjournals.org/doi/10.7326/L20-0725.

Media contacts: A PDF for this article is not yet available. Please click the link to read full text. The lead authors, Benjamin A. Pinsky, MD, PhD and Tho D. Pham, MD, can be reached through Julie Greicius at jgreicius@stanford.edu or Lisa Kim at LiKim@stanfordhealthcare.org.

Coordinated international action on energy-efficient, climate-friendly cooling could avoid as much as 460 billion tonnes of greenhouse gas emissions - roughly equal to eight years of global emissions at 2018 levels - over the next four decades, according to the Cooling Emissions and Policy Synthesis Report from the United Nations Environment Programme (UNEP) and the International Energy Agency (IEA).

Reductions of between 210 and 460 billion tonnes of carbon dioxide-(CO2) equivalent emissions can be delivered over the next four decades through actions to improve the cooling industry’s energy efficiency together with the transition to climate-friendly refrigerants, according to the report.

The report says countries can institutionalize many of these actions by integrating them into their implementation of the Kigali Amendment to the Montreal Protocol. Signatories to the Kigali Amendment have agreed to reduce the production and use of climate-warming refrigerant gases known as hydrofluorocarbons (HFCs), which has the potential to avoid as much as 0.4°C of global warming by 2100 through this step alone.

Nations must deliver massive cuts in their greenhouse gas emissions to get on track to limit global temperature rise this century to 1.5°C. This is critical to minimizing the disastrous impacts of climate change. As nations invest in COVID-19 recovery, they have an opportunity to use their resources wisely to reduce climate change, protect nature and reduce risks of further pandemics. Efficient, climate-friendly cooling can help to achieve all of these goals," said Inger Andersen, UNEP Executive Director.

The report highlights the importance of cooling to maintaining healthy communities; fresh vaccines and food; a stable energy supply, and productive economies. The essential nature of cooling services is underlined by the COVID-19 pandemic, as temperature-sensitive vaccines will require quick deployment around the globe; lockdowns forcing people to stay at home for long periods of time are a health concern in many hot countries.

However, increasing demand for cooling is contributing significantly to climate change. This is the result of the emissions of HFCs, CO2, and black carbon from the mostly fossil fuel-based energy that powers air conditioners and other cooling equipment.

"As governments roll out massive economic stimulus packages to deal with the economic and social impacts of the COVID-19 crisis, they have a unique opportunity to accelerate progress in efficient, climate-friendly cooling.Higher efficiency standards are one of the most effective tools governments have to meet energy and environmental objectives. By improving cooling efficiency, they can reduce the need for new power plants, cut emissions and save consumers money. This new report gives policy makers valuable insights to help them address the global cooling challenge" said Dr Fatih Birol, IEA Executive Director.

Worldwide, an estimated 3.6 billion cooling appliances are in use. The report says that if cooling is provided to everybody who needs it - and not just those who can afford it - this would require as many as 14 billion cooling appliances by 2050.

The IEA estimates that doubling the energy efficiency of air conditioning by 2050 would reduce the need for 1,300 gigawatts of additional electricity generation capacity to meet peak demand - the equivalent of all the coal-fired power generation capacity in China and India in 2018. Worldwide, doubling the energy efficiency of air conditioners could save up to USD 2.9 trillion by 2050 in reduced electricity generation, transmission and distribution costs alone.

Action on energy efficiency would bring many other benefits, such as increased access to life-saving cooling, improved air quality and reduced food loss and waste, the report says.

The report lays out the available policy options available that can make cooling part of climate and sustainable development solutions, including:

International cooperation through universal ratification and implementation of the Kigali Amendment and initiatives such as the Cool Coalition and the Biarritz Pledge for Fast Action on Efficient Cooling

National Cooling Action Plans that accelerate the transition to climate friendly cooling, and identify opportunities to incorporate efficient cooling into stronger Nationally Determined Contributions under the Paris Agreement

Development and implementation of Minimum Energy Performance Standards and energy efficiency labelling to improve equipment efficiency

Promotion of building codes and other considerations to reduce demand for refrigerant and mechanical cooling, including integration of district and community cooling into urban planning, improved building design, green roofs, and tree shading

Campaigns to stop environmentally harmful product dumping to transform markets and avoid the burden of obsolete and inefficient cooling technologies

Sustainable cold-chains to both reduce food loss - a major contributor to greenhouse gas emissions - and reduce emissions from cold chains

The 48-page peer-reviewed report was authored by a range of experts under the guidance of a 15-member steering committee co-chaired by Nobel laureate Mario Molina, President, Centro Mario Molina, Mexico, and Durwood Zaelke, President, Institute for Governance & Sustainable Development, USA. The report is supported by the Kigali Cooling Efficiency Programme (K-CEP).

Researchers of the MTA-ELTE 'Lendület' Neuroethology of Communication Research Group at the Department of Ethology at the Faculty of Science, Eötvös Loránd University, Budapest (ELTE) compared human-oriented communicative behaviours of young miniature pigs and dogs kept as companion animals. They found that in a neutral situation pigs turn to humans, initiating interactions as much as dogs do. But in a problem solving situation the two species behave differently: whereas pigs keep trying to solve the task on their own, dogs often stop trying alone and display human-oriented communicative behaviours. Natural differences between pigs and dogs prevail despite similar socialization if an exciting challenge comes, the research suggests. The study is published in Animal Cognition.

Dogs are known to look at humans in a problem-solving context to establish joint attention and initiate communicative interactions, already from an early age. Is it really dogs' specialty, or would other companion animals do the same? "Similarly socialized wolves and cats communicate less with humans than dogs in the same problem-solving context, but maybe it is because wolves are not domesticated, and cats are not a social species. So we designed a study to compare dogs' behaviour with that of another domestic and social species, the pig" - explains PhD student Paula Pérez.

The miniature variant of the domestic pig is a popular companion animal occupying a similar "social niche" in the human families as the family dog. "We launched the Family Pig Project in 2017 at the Department of Ethology, Budapest. The animals are raised in a similar environment as family dogs, providing the basis for unique comparative investigations between the two species" - says Attila Andics, principal investigator of the MTA-ELTE 'Lendület' Neuroethology of Communication Research Group.

"We used the so called 'Unsolvable task paradigm', where the animal first faces a problem that he can solve, in our case an easy-to-open box with food inside. After some trials, the problem becomes unsolvable because the box is securely closed" - adds Pérez. "When the box was first in the room without food in it, pigs and dogs performed similar human-oriented behaviours" - says Linda Gerencsér, research fellow at the Research Group. "The differences appeared when we put food in the box and opening it became an exciting challenge. Pigs were faster than dogs already in solving the task and getting the reward, perhaps due to their better manipulative capacities. Then, when the task became unsolvable, dogs turned to the humans more than before. In contrast, pigs performed less human-oriented behaviours, but they were more persistent than dogs in trying to solve the task, which may reflect their predisposition to solve problems independently."

The study is the first to compare family dogs and pigs in a problem-solving situation. "The similarities that we found between the two species point to their similar capacities for engaging in communicative interactions with humans" - notes Pérez. "However, species-specific predispositions might be responsible for the found differences. Dogs are naturally more dependent on and cooperative with humans. This explains their unique success in interacting with us."

Biodiversity is severely threatened both in Switzerland and worldwide, and numerous organisms are facing massive declines - particularly in freshwater ecosystems. All the species living in rivers - including fish, bacteria and many different aquatic invertebrates, such as mayflies, stoneflies and caddisflies - are crucial for the functioning of these ecosystems. But many species are under threat due to habitat homogenization, pollution by pesticides and nutrients, and the spread of non-native species. In order to understand and protect riverine ecosystems, assessing their biodiversity is essential.

Combining environmental DNA and hydrological models

In a new study, the research group of Florian Altermatt, professor at the Department of Evolutionary Biology and Environmental Studies of the University of Zurich (UZH) and the Swiss Federal Institute of Aquatic Science and Technology (Eawag), developed a novel approach to predict biodiversity patterns in river ecosystems. "For the first time, we combined the use of environmental DNA with hydrological models in order to make predictions on the state of biodiversity at a very fine resolution across catchments of hundreds of square kilometers," says Altermatt.

Biodiversity predictions with high accuracy

All organisms constantly shed their DNA into the environment. By collecting water samples and extracting and sequencing the so-called environmental DNA (eDNA), the biodiversity can be determined faster, less invasively and more comprehensively than by identifying the organisms themselves. Since the DNA in rivers can be transported downstream by stream flow for many kilometers, information on the occurrence of organisms in the upstream catchment is also received. Using mathematical models based on hydrological principles, the scientists were able to reconstruct biodiversity patterns for the whole 740 square kilometer basin of the Thur in north-eastern Switzerland with a resolution of stream sections of one kilometer. "Our model matches the direct observation of aquatic insects' local occurrence with an unprecedented accuracy of 57 to 100%," says Luca Carraro, first author of the study.

Identifying unseen biodiversity hotspots

The Thur catchment is representative of many land-use types, including forest, agriculture and settlements. It thus serves as a generalizable example for many riverine ecosystems. Furthermore, the new method can be used for large-scale and high-resolution assessments of biodiversity state and change even with minimal prior knowledge of the riverine ecosystem. "Specifically, the approach enables biodiversity hotspots to be identified that might be otherwise overlooked, thus enabling focused conservation strategies to be implemented," adds Altermatt.

Rapid application of research findings in Switzerland

Many countries are currently establishing aquatic biomonitoring using eDNA, and could profit from the novel method. According to Florian Altermatt, Switzerland has a leading role in this field: "The transfer from scientific findings to application is very rapid. We are now finalizing guidelines for the Federal Office for the Environment on how to use eDNA in standard biodiversity monitoring." This will make it easier to describe and monitor biodiversity for the whole network of Swiss rivers and streams, which is about 65,000 kilometers in total.

In a report published in NANO, a team of researchers from Sichuan University of Science and Engineering, China have developed N-doped carbon encapsulated transition metal catalysts for oxygen reduction reactions (ORR) and oxygen evolution reactions (OER) to optimize performance of zinc-air batteries.

Three-dimensional porous graphene-like carbon layer encapsulated Fe/Fe3C (Fe@NCG) was prepared by pyrolysis of the mixture of Fe- chitosan chelate assembled without solvent and urea with small molecular nitrogen source. The space limiting effect of the chelate suppressed the agglomeration of Fe3+ ions, and the small molecular nitrogen source promoted the regulation of N configuration. The zinc-air battery assembled with Fe@NCG catalyst shows good performance.

The catalyst Fe@NCG shows remarkable ORR/OER bifunctional catalytic activity with a half wave potential of 0.86 V for ORR and a moderate potential difference of 0.85 V in alkaline medium. "The zinc-air battery assembled with Fe@NCG as positive and negative catalyst showed good discharge platform, high peak power density, high energy density, and high cycle stability." says Lei Ying, PhD, the corresponding author of the paper.

What is special about the study is that the Fe@NCG was prepared by pyrolyzing solvent-free formed fechitosan chelates and additional small molecule nitrogen source urea. The in-situ nitrogen doping and etching of self-nitrogen-doped carbonized chitosan by CN gas produced by g-C3N4 decomposition (such as C2N2+, C3N2+, C3N3+) is helpful to the regulation of electronic structure and the formation of pore structure in the carbon skeleton.

Moreover, the uniform distribution of Fe could be attributed to the molecular-level chelating space confinement effect of Fe-chitosan chelate compound precursor, wherein chitosan molecular served as a "fence" to effectively reduce excess aggregation of Fe3+ ions. The group then tested the product electrocatalytic performance.

The work of this team of researchers from Sichuan University of Science & Engineering has led to the exciting development of electrocatalytic materials. This work suggests that a simple and universal strategy can also be extended to the synthesis of other transition metal electrocatalysts coated with carbon.

One of the most fascinating frontiers in this research field might be combining chelating space confinement strategy and regulation of N configuration. Understanding these processes will improve the performance of materials and equipment, which will improve the lives of all of us. More recently, the group has been working on multifunctional conversions of electrocatalytic materials and assembly of devices.

They say it's better to have had something special and lost it than to have never had it at all. Who would have thought that sentiment holds true for metal oxide catalysts? According to scientists at Lawrence Berkeley National Laboratory (Berkeley Lab) and Caltech, copper that was once bound with oxygen is better at converting carbon dioxide into renewable fuels than copper that was never bound to oxygen.

For their study, now published in the journal ACS Catalysis, the scientists performed X-ray spectroscopy on working solar fuel generator prototypes to demonstrate that catalysts made from copper oxide are superior to purely metallic-origin catalysts when it comes to producing ethylene, a two-carbon gas with a huge range of industrial applications - even after there are no detectable oxygen atoms left in the catalyst.

"Many researchers have shown that oxide-derived copper catalysts are better at making fuel products from CO2, however, there is debate about why this occurs," said research co-leader Walter Drisdell, a Berkeley Lab chemist and member of the Joint Center for Artificial Photosynthesis (JCAP). JCAP's mission is to develop efficient, solar-powered technologies that can convert atmospheric CO2 into petroleum alternative fuels. Drisdell and his colleagues say their discovery is an important advance towards that goal.

He explained that under operating conditions for fuel generation - which involves first converting the CO2 into carbon monoxide then building hydrocarbon chains - the copper-bound oxygen is naturally depleted in the catalyst. However, some researchers believe that small amounts of oxygen remain in the metal structure, and that this the source of the increased efficiency.

To resolve the debate, the team brought a gas chromatography (GC) system to the X-ray beamline so they could detect ethylene production in real time. "Our collaborators from Caltech drove the GC all the way from Pasadena and installed it at the X-ray facility in Palo Alto," said Soo Hong Lee, a postdoctoral researcher at Berkeley Lab and co-lead author of the study. "With it, we showed that there is no correlation between the amount of oxygen ('oxide') in the catalyst and the amount of ethylene produced. So, we think that oxide-derived catalysts are good, not because they have oxygen remaining while they reduce carbon monoxide, but because the process of removing the oxygen creates a metallic copper structure that is better at forming ethylene."

The team further showed that although oxide-derived catalysts' efficiency wanes over time, it can be regularly "reactivated" by re-adding and re-removing oxygen during a simple maintenance process. Their next step is to design a fuel-generating cell that can operate with X-ray scattering instruments, allowing them to directly map the changing structure of the catalyst while it converts carbon monoxide into ethylene.

The research team also included Ian Sullivan and Chengxiang Xiang at Caltech, and David Larson, Guiji Liu, and Francesca Toma at Berkeley Lab. This work was supported by the U.S. Department of Energy (DOE) Office of Science. JCAP is a DOE Energy Innovation Hub.

'Water plants are a nuisance in streams, blocking the flow. You should remove them'. This notion has for many years determined how streams were managed to prevent flooding during high rainfall events. Research by NIOZ scientist Loreta Cornacchia, published in the journal Proceedings of the Royal Society B, in cooperation with Utrecht University and British and Belgian partners, shows how vegetation in streams can actually buffer water levels, by adjusting vegetation cover. By adapting the patterning of plant clumps to changes in discharge, river plants can both counter flooding as well as prevent drying out, thereby protecting biodiversity. Cornacchia: 'They provide a natural buffer against hydrological changes.'

Huge implications for water management

'The implications for water management are huge', says Cornacchia. The current strategy of plant removal does not only threaten a naturally balanced water level, it also threatens a stream's biodiversity. Inland waters are freshwater hotspots for biodiversity and vegetation is its guardian. It provides habitats and food for invertebrate and fish, helps stabilize the river banks, and removes excess nutrients from the water.

Surprisingly, during extensive empirical research and sampling at two stream sites in the United Kingdom, the researchers observed that plant cover adjustments led to a more constant water level and flow regime. Cornacchia: 'We actually observed that the plants determined the water flow, rather than the other way around. In this way, submerged aquatic vegetation in rivers ensures that organisms that depend on the aquatic environment to persist can remain in the stream year-round.'

A nature-based solution

At high flows, the vegetation is pushed to the side or even dislodged, keeping an open lane in the middle for high-flow traffic. During periods of low flows, aquatic plants gradually clog up the stream, and thereby prevent the water from draining quickly. This so-called self-organization process counteracts the variation in waterflow that streams experience through the seasons. Geraldene Wharton, Professor at Queen Mary University of London in the UK and co-author of the study, adds: 'Our research shows the important buffering capacity of instream vegetation against both low flows and high flows which also maintains healthy ecosystems: a nature-based solution to flow regulation.'

Cornacchia: 'This more nature-based approach to the control of water levels harnesses natural processes rather than human control to maintain biodiversity hotspots.' An approach that is especially relevant in the light of a predicted increase in heavy rainfall and drought through climate change. The vegetation's ability to adapt through self-organization shows great potential to mitigate the effects of both floods and low water levels. Cornacchia: 'Insight in self-organizing plants and understanding their role in ecosystem resilience is essential in a future governed by global change.'

Approximately 5% of people with Covid-19 progress to a severe or critical form, including the development of severe pneumonia that progresses to acute respiratory distress syndrome. While these forms sometimes occur early in the course of the disease, clinical observations generally describe a two-stage progression of the disease, beginning with a mild to moderate form, followed by respiratory aggravation 9 to 12 days after the onset of the first symptoms. This sudden progression suggests deregulation of the host inflammatory response.

A growing number of indications suggest that this aggravation is caused by a large increase in cytokines. This runaway inflammatory response is correlated with massive infiltration in the lungs of innate immune cells, namely neutrophils and monocytes, creating lung damage and acute respiratory distress syndrome.

By analogy with a genetic disease leading to a similar pulmonary pathology identified at Institut Imagine by the team of Inserm researcher Frédéric Rieux-Laucat, the initial hypothesis assumed excessive production of interferon (IFN) type I, a marker of the response to infections. However, in seriously ill patients, the teams of Darragh Duffy (Dendritic Cell Immunobiology Unit, Institut Pasteur/Inserm), Frédéric Rieux-Laucat (Laboratory of Immunogenetics of Pediatric Autoimmune Diseases at Institut Imagine - Inserm/Université de Paris), Solen Kernéis (Mobile Infectiology Team, AP-HP. Centre - Université of Paris) and Benjamin Terrier (Department of Internal Medicine, AP-HP. Centre - Université of Paris) show that the production and activity of type-I IFN are strongly reduced in the most severe forms of Covid-19.

In addition, there is a persistent blood viral load, indicating poor control of viral replication by the patient's immune system which leads to an ineffective and pathological inflammatory response. The inflammation, caused by the transcription factor NF-kB, also leads to increased production and signaling of tumor necrosis factor (TNF)-alpha and the pro-inflammatory cytokine interleukin IL-6.

Distinct type-I IFN responses may be characteristic of each stage of the disease

This low signature of type-I IFN differs from the response induced by other respiratory viruses such as human respiratory syncitial virus or influenza A virus, both of which are characterized by high production of type-I IFN.

The study also showed that low levels of type-I IFN in plasma precede clinical worsening and transfer to intensive care. Levels of circulating Type 1 IFN could even characterize each stage of disease, with the lowest levels observed in the most severe patients. These results suggest that in SARS-CoV-2 infection, the production of type-I IFN is inhibited in the infected host, which could explain the more frequent severe forms in individuals with low production of this cytokine, such as the elderly or those with co-morbidities.

Therefore, type-I IFN deficiency could be a signature of severe forms of COVID-19 and could identify a high-risk population.

These results further suggest that the administration of IFN-alpha/Beta combined with anti-inflammatory therapy targeting IL-6 or TNF-α, or corticosteroids such as dexamethasone, in the most severe patients could be a therapeutic avenue to be evaluated for severe forms of COVID-19.

Concern over the risk of infection and financial strain. More people will develop stress, irritability, anxiety and depression...

Expectations for our mental health during and after the corona lockdown were pessimistic, but thus far the situation has not turned out to be quite as bad as feared. Danes, and in particular Danish women, appear to have reacted with reduced psychological well-being as the infection rate and death toll peaked in the beginning of April. But already three weeks later, the general psychological well-being - as measured by the World Health Organization's well-being index, WHO-5 - had moved in a positive direction.

This is shown in a recent survey by a research group, which includes Søren Dinesen Østergaard who is professor at the Department of Clinical Medicine at Aarhus University in Denmark, and affiliated with the Department of Affective Disorders at Aarhus University Hospital - Psychiatry.

"The proportion of Danes with a well-being index of 80 or above, which is a sign of great thriving, grew from 22 per cent at the end of March/beginning of April to 28 per cent three weeks later, i.e. at the end of April, when the same people were asked again. This seems consistent with the development of the pandemic in Denmark between the two rounds of the survey. Namely, a significant decline in the rate of infection and the number of corona-related deaths, which led to a gradual reopening of the Danish society after a long period of lockdown," says Søren Dinesen Østergaard.

The WHO-5 well-being index is also used by general practitioners to screen for depression. The WHO-5 consists of five simple questions and the resulting well-being score ranges from 0-100, where higher scores represent higher psychological well-being. If the score is below 50, it is indicative of depression.

"The proportion of respondents that scored below 50 fell from 26 per cent to 20 per cent from the first to the second round of the survey. In absolute figures, the average increase in the well-being index slightly above 3 points, which is not a big difference. However, it nevertheless shows that there is light at the end of the tunnel - and that's a story worth telling," says Søren Dinesen Østergaard.

He is pleased to be able to deliver some good news during very difficult times.

"Our results indicate a clear and plausible correlation between the intensity of the corona pandemic and the psychological well-being of the Danish population. With a bit of luck, it may also be a predictor of how things will go elsewhere, for example in the United States and in South America where the coronavirus is currently on the rise. However, not all societies resemble the Danish - and that no one knows if, when and how a potential second wave of the pandemic will affect the world," says Søren Dinesen Østergaard.

He also emphasises that the present study does not uncover how people with mental disorders, who may be a particularly vulnerable group with regard to the psychological impact of the pandemic, have fared. For this reason, his research group is currently conducting a survey specifically targeting people with contact to the mental health services. The results of this follow-up study are expected to be published later this summer.

The research results - more information:

- The study was carried out as a survey conducted by Epinion based on the WHO-5 well-being index. Epinion received payment for carrying out the survey. A total of 2458 people participated in the first wave of the survey, and 2149 from the same group also participated in the second wave of the survey. The results are weighted so that they are representative of the Danish population on a number of parameters.

- The following were partners in the project: Professor Kim Mannemar Sønderskov and Professor Peter Thisted Dinesen from the Department of Political Science at Aarhus University, Denmark, and the University of Copenhagen, Denmark, respectively; and Postdoc Ziggi Ivan Santini from the Department of Public Health at the University of Southern Denmark.

The high energy consumption of artificial neural networks' learning activities is one of the biggest hurdles for the broad use of Artificial Intelligence (AI), especially in mobile applications. One approach to solving this problem can be gleaned from knowledge about the human brain. Although it has the computing power of a supercomputer, it only needs 20 watts, which is only a millionth of the energy of a supercomputer. One of the reasons for this is the efficient transfer of information between neurons in the brain. Neurons send short electrical impulses (spikes) to other neurons - but, to save energy, only as often as absolutely necessary.

Event-based information processing

A working group led by two computer scientists Wolfgang Maass and Robert Legenstein of TU Graz has adopted this principle in the development of the new machine learning algorithm e-prop (short for e-propagation). Researchers at the Institute of Theoretical Computer Science, which is also part of the European lighthouse project Human Brain Project, use spikes in their model for communication between neurons in an artificial neural network. The spikes only become active when they are needed for information processing in the network. Learning is a particular challenge for such less active networks, since it takes longer observations to determine which neuron connections improve network performance.

Previous methods achieved too little learning success or required enormous storage space. E-prop now solves this problem by means of a decentralized method copied from the brain, in which each neuron documents when its connections were used in a so-called e-trace (eligibility trace). The method is roughly as powerful as the best and most elaborate other known learning methods. Details have now been published in the scientific journal Nature Communications.

Online instead of offline

With many of the machine learning techniques currently in use, all network activities are stored centrally and offline in order to trace every few steps how the connections were used during the calculations. However, this requires a constant data transfer between the memory and the processors - one of the main reasons for the excessive energy consumption of current AI implementations. e-prop, on the other hand, works completely online and does not require separate memory even in real operation - thus making learning much more energy efficient.

Driving force for neuromorphic hardware

Maass and Legenstein hope that e-prop will drive the development of a new generation of mobile learning computing systems that no longer need to be programmed but learn according to the model of the human brain and thus adapt to constantly changing requirements. The goal is to no longer have these computing systems learn energy-intensively exclusively via a cloud, but to efficiently integrate the greater part of the learning ability into mobile hardware components and thus save energy.

First steps to bring e-prop into the application have already been made. For example, the TU Graz team is working together with the Advanced Processor Technologies Research Group (APT) of the University of Manchester in the Human Brain Project to integrate e-prop into the neuromorphic SpiNNaker system, which has been developed there. At the same time, TU Graz is working with researchers from the semiconductor manufacturer Intel to integrate the algorithm into the next version of Intel's neuromorphic chip Loihi.

With over 1.2 million people affected in Germany alone and over 50 million people worldwide, Alzheimer's disease, also referred to simply as Alzheimer's, is one of the greatest medical and social challenges of our time. Due to pathological changes in the brain, patients become increasingly forgetful and disoriented as the disease progresses. In the worst cases, even close relatives are no longer recognized and simple household tasks can no longer be carried out independently. This means care is needed for those affected. Despite intensive research, Alzheimer's disease is still considered incurable today. Researchers at the University of Göttingen and the Fraunhofer Institute for Cell Therapy and Immunology Leipzig-Halle have described a promising approach to treating Alzheimer's disease. The results have been published in the journal Biochemistry.

For the study, Professor Kai Tittmann from the Göttingen Centre for Molecular Biosciences worked together with researchers from the Faculty of Chemistry at the University of Göttingen and the team led by Professor Hans-Ulrich Demuth from Fraunhofer IZI in Halle. Several years ago, the team from Halle discovered that a specific enzyme that is part of the human brain's hormone metabolism plays a critical pathophysiological role in the development of Alzheimer's disease, in addition to its actual biological function of hormone maturation. The first inhibitors of this enzyme, which inhibit specific pathological processes, have already produced promising results.

In order to give these active ingredients a chemical "tailor-made suit", the research team investigated the enzyme's reaction mechanism using protein crystallography. "This enabled us to obtain 'snapshots' of the working enzyme for the first time," says senior author Tittmann. This made it possible to build novel inhibitors where the principle of the design is based on the natural reaction. These inhibitors therefore lead to highly selective binding without the risk of dangerous side effects. The scientists also succeeded in determining an atomic structure of the human enzyme with the new substance. This forms an important basis for further development of the inhibitors. "We are confident that our results will lead to the development of a new, highly selective generation of Alzheimer's drugs," explained Demuth.