Tech

Researchers at Hiroshima University in Japan have blended together various polymer and molecular semiconductors as photo-absorbers to create a solar cell with increased power efficiencies and electricity generation. These types of solar cells, known as organic photovoltaics (OPV), are devices that generate electricity when light is incident upon their photo-absorbers. The efficiency of a solar cell is determined by comparing how much electricity is generated to how much light is incident upon the cell. This is referred to as "photon harvest", or how many particles of light are converted into electrical current. The more efficient the solar cell, the more cost effective and pragmatic the cell is for commercial use.

The team at the Graduate School of Advanced Science and Engineering added only a small amount of a compound that absorbs long wavelengths of light resulting in an OPV that was 1.5 times more efficient than the version without the compound. The compound was able to enhance the absorption intensity due to the optical interference effect within the device. The group went on to show that how they are distributed is key to further improved power generation efficiency.

"The addition of a very small amount of a sensitizer material to an OPV cell, which consists of a semiconducting polymer that we developed previously and along with other materials," said Itaru Osaka, corresponding author of the paper, published November 2020 in Macromolecules.

"This leads to a significant increase in the photocurrent and thereby the power conversion efficiency due to the amplified photon absorption that originates in the optical interference effect. A key is to use a very specific polymer, one that allows us to have a very thick semiconductor layer for OPV cells, which significantly enhances optical interference effect compared to a thin layer."

As for future work, Osaka has his eyes set on pushing the boundaries of state of the art solar cells.

"Our next step is to develop better semiconducting polymers as the host material for this type of OPV and better sensitizer materials that can absorb more photons in the longer wavelength regions. This would lead to the realization of the world's highest efficiency in OPV cells."

The use of plastic mulch (plastic covering on crop lines) is a widespread technique used in agricultural regions in order to increase the profitability of the crops. According to the European Commission, 100,000 tonnes of plastic mulch was used per year in the European Union in 2016. Taking these figures into account and the fact that after the harvest some plastic usually remains in the soil, the accumulation of plastic in territories of intensive agriculture is an environmental problem that is of concern in the sector and also for the public administrations.

Low-density polyethylene (LDPE) is the most used plastic for the mulch and, in turn, is also that which takes longest to degrade. For that reason, another type of plastics has been created - the 'oxo-degradable' (PAC) - which are those that contain pro-oxidant additives that improve degradation in the presence of solar light, or biodegradable plastics, those that can be degraded by the soil's microorganisms.

As pesticides are used in many cases to treat the crops that are under the mulch, a team from the Diverfarming project made up of staff from the universities of Wageningen and Cartagena has analysed the interaction of these plastics with 38 pesticides under laboratory conditions. Although this study had previously been carried out in LDPE plastics, this is the first time that PAC and biodegradable plastics have been analysed.

After analysing the sorption process (retention of a substance by another when they are in contact) of the 38 active ingredients of 17 insecticides, 15 fungicides and 6 herbicides commonly used with plastic mulch in the Region of Murcia with the three types of plastics, it was seen that the bio plastics had a greater percentage of pesticide sorption. On average, the percentage of sorption was 23% in LDPE and PAC, and 50% in Bio. The decomposition of the active ingredients in the presence of plastic was 30% lower than when there was no plastic present.

For one of the researchers involved in the project, Nicolas Beriot, the results lead to two worrying hypotheses: 'the microorganisms responsible for degrading those biodegradable plastics could become contaminated and the efficiency of the pesticides could also be affected since the substances that remain in the plastics are not available in the soil to do their job'. Thus, the modification of the degradation patterns of the active ingredients could affect the community of soil organisms due to the toxicity of the active ingredients.

This laboratory study opens the door to new research in the field to verify how this affects both the question of soil contamination as well as the delay in the degradation capacity of the plastics.

The Diverfarming project seeks a change in paradigm in European agriculture towards a more environmentally and economically sustainable agriculture through crop diversification and the reduction of inputs such as pesticides. In this way, it can contribute to avoiding situations of contamination such as that posed by the interaction between plastics and pesticides.

This novel method was the first to detect conformational changes in the protein TDP-43 in the patients' CSF. The project team headed by Professor Klaus Gerwert and Professor Lars Tönges published their research results in the international journal Annals of Clinical and Translational Neurology from 3 December 2020.

Altered protein structures in ALS

ALS is a fatal neurodegenerative disease causing a rapid loss of motor function, which usually results in a serious condition with early death within a few years. So far, early and precise diagnosis of the disease has been difficult. Stephen Hawking was one of the most prominent patients. In summer 2014, the disease gained media attention through a large-scale fundraising campaign, the so-called Ice Bucket Challenge.

To date, one of the most important challenges in ALS diagnostics is to exclude other mimicking diseases and to reliably verify an exact diagnosis. In ALS, the TDP-43 protein in particular plays a pivotal role. It forms small inclusions in nerve cells. TDP-43 inclusions appear to have a crucial pathomechanistic significance and are the neuropathological markers in sporadic and many genetic ALS cases. They have been detected in numerous brain autopsies of ALS patients. In this study, the Bochum researchers and their colleagues showed that pathologically misfolded forms of the protein also occur in solution in the nerve fluid and can be specifically analysed there.

Dr. Rene Günther, one of the lead authors of the study and head of the research group and specialist outpatient clinic for motor neuron diseases at the Department of Neurology of the Carl Gustav Carus University Hospital at the Technical University of Dresden, explains: "Biomarker research plays a crucial role in improving early detection and securing the diagnosis of amyotrophic lateral sclerosis. In addition, biomarkers are a basis for successful drug testing and therapy development in this dramatically progressing and difficult to treat disease. So far, only disease-unspecific biomarkers are available. In our pilot study, we successfully identified conformational changes of TDP-43 proteins in the cerebrospinal fluid of patients with amyotrophic lateral sclerosis for the first time using this innovative method."
Pilot study shows potential

The team led by Lars Tönges and Klaus Gerwert succeeded in securing a diagnosis of the disease based on the altered structure of the protein TDP-43. In the process, the researchers showed that the proteins fold from predominantly disordered and helical structures to so-called ß-sheets. These shapes promote damage assemblies and deposits of the protein in nerve cells. In the analysis, 36 ALS patients were distinguished from 30 Parkinson's patients by means of the TDP-43 signal with a sensitivity of 89 per cent and a specificity of 77 per cent. In addition, a control group with neurologically inconspicuous patients was differentiated with a sensitivity of 89 per cent and a specificity of 83 per cent. By analysing TDP-43, the researchers were thus able to exclude other diseases that affect motor function, such as Parkinson's disease. These results will be verified and validated in a larger study.

Optimisation of the Alzheimer's sensor

Klaus Gerwert's immuno-infrared sensor has already been used in earlier studies to detect pathologically altered proteins in the blood of patients with Alzheimer's disease before symptoms occur. In this case, the technology has been optimised and refined for use in the cerebrospinal fluid of patients with ALS. This shows that the potential of the method for other neurological diseases should also be explored. In close collaboration with Professor Ralf Gold, Director of the Department of Neurology at St. Josef-Hospital Bochum and Head of Research at the Prodi Department of Experimental Medicine, further projects are currently being undertaken to gain a better understanding of neurological disease processes.

Léon Beyer, one of the lead authors of the study and PhD student at the Prodi Biospectroscopy Department, says: "This achievement may provide new insight into the mechanisms of the disease. Compared to other methods that reflect concentrations of certain proteins, our infrared sensor technology gives insights into molecular events and may therefore become a crucial tool in the future for diagnosing and for developing clinical therapies. First and foremost, however, it will contribute greatly to a more precise understanding of diseases."

Future will reveal value for clinical applications

In the future, the results of validation studies should provide information on whether the pathologically modified TDP-43 proteins can be used in clinical applications to facilitate earlier and more precise diagnoses and to gain new molecular insights.

Perovskites are materials made up of organic compounds bound to a metal. Propelled into the forefront of materials' research because of their structure and properties, perovskites are earmarked for a wide range of applications, including in solar cells, LED lights, lasers, and photodetectors.

That last application, photo - or light - detection, is of particular interest to scientists at EPFL's School of Basic Sciences who have developed a perovskite that can detect gamma rays. Led by the labs of Professors Lászlo Forró and Andreas Pautz, the researchers have published their work in Advanced Science.

"This photovoltaic perovskite crystal, grown in this kilogram size, is a game changer," says Forró. "You can slice it into wafers, like silicon, for optoelectronic applications, and, in this paper, we demonstrate its utility in gamma-ray detection."

Monitoring gamma rays

Gamma-rays are a kind of penetrating electromagnetic radiation that is produced from the radioactive decay of atomic nuclei, e.g., in nuclear or even supernovae explosions. Gamma-rays are on the shortest end of the electromagnetic spectrum, which means that they have the highest frequency and the highest energy. Because of this, they can penetrate almost any material, and are used widely in homeland security, astronomy, industry, nuclear power plants, environmental monitoring, research, and even medicine, for detecting and monitoring tumors and osteoporosis.

But exactly because gamma rays can affect biological tissue, we have to be able to keep an eye on them. To do this, we need simple, reliable, and cheap gamma-ray detectors. The perovskite that the EPFL scientists developed is based on crystals of methylammonium lead tribromide (MAPbBr3) and seems to be an ideal candidate, meeting all these requirements.

Crystal-clear advantages

Perovskites are first "grown" as crystals, and the quality and clarity of the crystals determines the efficiency of the material when it is turned into thin films that can be used in devices like solar panels.

The perovskite crystals that the EPFL scientists made show high clarity with very low impurities. When they tested gamma-rays on the crystals, they found that they generated photo-carriers with a high "mobility-lifetime product", which is a measurement of the quality of radiation detectors. In short, the perovskite can efficiently detect gamma rays at room temperatures, simply by resistivity measurement.

Cheaper and scalable synthesis

The MAPbBr3 part of the "metal halide" family of perovskites, meaning that, unlike market-leading crystals, its crystals can be grown from abundant and low-cost raw materials. The synthesis takes place in solutions close to room temperature without needing expensive equipment.

Of course, this is not the first perovskite made for gamma ray-detection. But the volume of most lab-grown metal halide perovskites used for this is limited to about 1.2 ml, which is hardly scalable to commercial levels. However, the team at EPFL also developed a unique method called 'oriented crystal-crystal intergrowth' that allowed them to make a whole liter of crystals weighing 3.8 kg in total.

"Personally, I enjoyed very much to work at the common frontiers of condensed matter physics, chemistry and reactor physics, and to see that this collaboration could lead to important application to our society," says Pavao Andričevic, the lead-author.

Researchers from Skoltech and their colleagues have built two models that accurately explain the light-emitting behavior of semiconductor nanoplatelets, minuscule structures that can become the building blocks for optoelectronics of the future. The paper was published in the journal Physical Chemistry Chemical Physics.

Optoelectronics, a field of photonics that exploits quantum mechanical effects of light on electronic materials, in particular semiconductors, has gained a lot of traction for its promise in all sorts of applications. These range from solar cells and LEDs to colloidal lasers, a technology expected to replace conventional semiconductor laser diodes used in barcode scanners and fiber optic communications.

In the search for materials with better optical properties more suitable for use in optoelectronics, research has focused on nanoplatelets, which are highly promising low-dimensional semiconductor nanocrystals. These are flat structures, just a few nanometers in size, and remarkably versatile and tunable. Modern precision synthesis techniques allow researchers to grow them essentially on-demand, controlling their shape, thickness, and crystal structure. These parameters directly affect the photoluminescence capability and properties.

"Tailoring the synthesis of photoluminescent nanocrystals for specific applications may require predictions of spectral and relaxation characteristics. Hence, we need a detailed understanding and modeling of the underlying kinetics," Skoltech Provost Keith Stevenson, professor at the Center for Energy Science and Technology and a co-author of the paper, explains.

Stevenson, PhD graduate Aleksandr Kurilovich and Vladimir Palyulin, Assistant Professor at the Center for Computational and Data-Intensive Science and Engineering, joined their colleagues in focusing on a way to explain non-trivial kinetics of semiconductor nanoplatelet photoluminescence in experiments. According to the researchers, earlier theoretical descriptions and experimental findings have always assumed an exponential decay of photoluminescence intensity in nanoplatelets. But more recent measurements showed a stark power-law behavior of the long-time, pointing to complexity.

The team built two models, a simulation one and a theoretical one, describing the kinetics of photoluminescence in nanoplatelets through the activity of excitons, quasiparticles in the semiconductor that are responsible for light emission in the case of their recombination. The models point to trapping of excitons at surface defects and its interplay with diffusion as key reasons for the complex kinetics. This allowed to successfully interpret experimental results from composite nanoplatelets made of cadmium selenide and cadmium sulfide.

"The model shows the importance of defects at long times and their ability to delay the recombination. This could be used to estimate the needed defect density for slowing down the emission, thus, extending the emission time," Stevenson says.

Other organizations involved in this research include Lomonosov Moscow State University, Institute for Physics & Astronomy at the University of Potsdam, and Akhiezer Institute for Theoretical Physics, National Science Center "Kharkov Institute of Physics and Technology".

Humans have taken spiders into space more than once to study the importance of gravity to their web-building. What originally began as a somewhat unsuccessful PR experiment for high school students has yielded the surprising insight that light plays a larger role in arachnid orientation than previously thought.

The spider experiment by the US space agency NASA is a lesson in the frustrating failures and happy accidents that sometimes lead to unexpected research findings. The question was relatively simple: on Earth, spiders build asymmetrical webs with the center displaced towards the upper edge. When resting, spiders sit with their head downwards because they can move towards freshly caught prey faster in the direction of gravity.

But what do arachnids do in zero gravity? In 2008, NASA wanted to inspire middle schools in the US with this experiment. But even though the question was simple, the planning and execution of the experiment in space was extremely challenging. This led to a number of mishaps.

Two specimens from different spider species flew to the International Space Station (ISS) as "arachnauts," one (Metepeira labyrinthea) as the lead and the other (Larinioides patagiatus) as a reserve in case the first didn't survive.

The reserve spider escaped

The reserve spider managed to break out of its storage chamber and into the main chamber. The chamber couldn't be opened for safety reasons, so the extra spider could not be recaptured. The two spiders spun somewhat muddled webs, getting in each other's way.

And if that were not enough, the flies included as food reproduced more quickly than expected. Over time, their larvae crawled out of the breeding container on the floor of the case into the experimental chamber, and after two weeks covered large parts of the front window. After a month, the spiders could no longer be seen behind all the fly larvae.

This failure long nagged at Paula Cushing of the Denver Museum of Nature & Science, who participated in the planning of the spider experiment. When the opportunity for a similar experiment on board the ISS cropped up again in 2011, the researcher got Dr. Samuel Zschokke of the University of Basel involved to prepare and analyze the new attempt. This time, the experiment started with four spiders of the same species (Trichonephila clavipes): two flew to the ISS in separate habitats, two stayed on Earth in separate habitats and were kept and observed under identical conditions as their fellows traveling in space - except that they were exposed to terrestrial gravity.

The females were males

The plan was originally to use four females. But another mishap occurred: the spiders had to be chosen for the experiment as juveniles and it is extremely difficult to determine the sex of juvenile animals. In the course of the experiment, two of the spiders turned out to be males, which differ markedly in body structure and size from females of this species when fully grown. But finally there was a stroke of luck - one of the males was on board the space station, the other on Earth.

The arachnids spun their webs, dismantled them, and spun new ones. Three cameras in each case took pictures every five minutes. Zschokke, Cushing and Stefanie Countryman of the University of Colorado's BioServe Space Technologies that oversaw the design and launch of the space flight certified habitats containing the spiders and fruit fly larvae and camera system to the International Space Station analyzed the symmetry of 100 spider webs and the orientation of the spider in the web using about 14,500 images.

It turned out that the webs built in zero gravity were indeed more symmetrical than those spun on Earth. Their center was closer to the middle and the spiders did not always keep their heads downwards. However, the researchers noticed that it made a difference whether the spiders built their webs in lamplight or in the dark. Webs built on the ISS in lamplight were similarly asymmetrical as the terrestrial webs.

Light as a back-up system

"We wouldn't have guessed that light would play a role in orienting the spiders in space," says Zschokke, who analyzed the spider experiment and published the results with his colleagues in the journal Science of Nature. "We were very fortunate that the lamps were attached at the top of the chamber and not on various sides. Otherwise, we would not have been able to discover the effect of light on the symmetry of webs in zero gravity."

Analysis of the pictures also showed that the spiders rested in arbitrary orientations in their webs when the lights were turned off, but oriented themselves away - i.e. downwards - when the lights were on. It seems spiders use light as an additional orientation aid when gravity is absent. Since spiders also build their webs in the dark and can catch prey without light, it had previously been assumed that light plays no role in their orientation.

"That spiders have a back-up system for orientation like this seems surprising, since they have never been exposed to an environment without gravity in the course of their evolution," says Zschokke. On the other hand, he says, a spider's sense of position could become confused while it is building its web. The organ responsible for this sense registers the relative position of the front part of the body to the back. During construction of the web, the two body parts are in constant motion, so an additional orientation aid based on the direction of the light is particularly useful.

Exercise plays a key role in maintaining good physical and mental health throughout life. There is an increasing amount of scientific evidence that some of the immune system and metabolism benefits provided by sport are related to the thousands of millions of bacteria that colonize the digestive tract, from the mouth to the intestines, known as microbiota. Although most studies in this field have traditionally focused on the microorganisms present in the intestine, in recent years it has been found that the bacteria in the mouth, the second most complex microbiome in the body, after the intestine, also play an important role.

Researchers from the University of Plymouth (United Kingdom) and the Universitat Oberta de Catalunya (UOC) have carried out research and assessed the scientific evidence available regarding the impact of physical exercise on the oral cavity, especially on saliva buccal microbiota, and they have published part of the results in the journal PharmaNutrition.

"The majority of bacteria in the mouth are essential for us to be healthy. Only a minority produce illnesses such as caries or periodontitis," the researchers point out in the study. "In fact, previous studies have shown that if you inhibit the activity of the bacteria in the mouth, the cardiovascular benefits of sport are reduced," said Raúl Bescós, professor of Physiology at the University of Plymouth and first author of the study.

"There were indications of the connection between sport and oral microbiota, but also a lot of gaps, which is why we wanted to review what impacted on oral microbiota and how that could affect the benefits of sport," he added.

Diet, a key factor

Recent studies have verified the relationship between the consumption of nitrates - present in leafy green vegetables such as rocket, broccoli and spinach, and also in beetroot - and sporting performance and cardiovascular health.

The study led by Bescós with the assistance of Patrícia Casas-Agustench, professor at the UOC Faculty of Health Sciences and associate researcher at the University of Plymouth, indicates that the nitrate is a molecule that we either consume in food or produce endogenously during physical activity. It acts as a nutrient for the bacteria in the mouth, which then convert it into nitrite. This nitrite can be used in the stomach and blood vessels, increasing the flow of blood to the muscles and reducing blood pressure.

This is why leading sports clubs such as FC Barcelona ensure that the diets of their players include foods rich in nitrates. Paradoxically observational studies suggested that the prevalence of oral disorders, including dental erosion, caries and periodontitis, among elite athletes is similar to or greater than it is among the general population. And it was felt that the reason could be related to diet and hydration.

"Sportsmen consume a lot of drinks containing sugar and acid that can affect oral health and the abundance of bacteria. They also consume a lot of carbohydrates, including products with a lot of sugar like energy bars and gel, that can alter the microbiota in the mouth," said Casas-Agustench, co-author of the study. The most notable results of these studies were presented during the #SportsTomorrow conferences organized by Barça Innovation Hub.

As well as diet, other factors must be taken into account, such as dehydration or dryness of the mouth, occurring when athletes run or cycle, that can affect the diversity and abundance of oral microbiota and reduce protection for the teeth. "Some athletes often vomit as a result of the anxiety they feel before competing or during competitions because of the effort they are making, and that leads to alterations to the pH level in their mouths, erodes the enamel and alters the composition of the bacteria," she added.

Antibacterial mouthwash, only with a doctor's prescription

Another factor that has also been seen to have a negative effect on the composition and balance of oral microbiota is the use of antibacterial mouthwashes, like those containing chlorhexidine, when not prescribed by a doctor. "They inhibit the bacteria in the mouth and it has been observed that when chlorhexidine is used, the positive effects of exercise on blood pressure are drastically reduced," said Bescós, who reminded us that "oral microbiota is essential in the cardiovascular response to physical exercise. If the mouth is healthy, the bacteria help to break the nitrates down into nitrites. Otherwise, we lose much of the benefit of exercise".

The researchers also point out that there is a close relationship between oral and intestinal microbiomes, as detailed in various recent studies. We swallow nearly a litre of saliva every day and this contains a large amount of oral bacteria. Many are destroyed by the acids in the stomach but some can resist and reproduce there, a case in point being Helicobacter pylori, which causes stomach ulcers. Others can reach the colon, which they can colonize and where they will reproduce. As a result, according to Bescós and Casas-Agustench, oral health can affect intestinal health and vice versa.

The importance of chewing

"The best way to look after oral microbiota and improve sporting performance and cardiovascular health is to eat more vegetables that are rich in nitrates, but also to chew more. It helps you to salivate, and saliva is essential for regulating the pH in the mouth, and the composition and activity of bacteria in the mouth. So, products rich in fibre, like fruit, vegetables and nuts should be included in your diet," Bescós and Casas-Agustench advised.

What causes the characteristic slowing of movement in patients with Parkinson's disease? Electrical oscillations of nerve cells deep inside the brain and the cortex are pathologically coupled with each other. Researchers know this from recordings taken from the brains of Parkinson's patients during surgery to fit a brain pacemaker.

But is it possible to detect this coupling if the electrical nerve activity is only derived from the patient's scalp, by electroencephalogram (EEG)? Doctoral researcher Ruxue Gong investigated this with a team of scientists led by Professor Joseph Claßen, Director of the Department of Neurology at Leipzig University Hospital, and Professor Thomas Knösche from the MPI for Human Cognitive and Brain Sciences.

In the EEG measurements, which lasted just five minutes, the researchers really did find such couplings in Parkinson's patients. Compared to healthy subjects, these couplings are enhanced in brain regions that serve to control movement. The breaking of coupling between oscillations at different locations could be particularly important for therapeutic approaches to address Parkinson's symptoms. "Using external electrical or magnetic stimulation, we hope that in future it will be possible to correct the coupled electrical oscillations in Parkinson's patients without the need for surgery," said Claßen. "With our mathematical modelling, we want to find out what characteristics such novel therapies would need to ensure their success. These new findings may represent an important building block in this respect," said Knösche.

Moreover, pathological coupling was also detected in an individual area of the cerebral cortex which is only slightly involved in motor control. "Perhaps the cognitive disorders that exist in some Parkinson's patients have a common cause with motor disorders," said Claßen. Future studies will investigate this thesis further.

They signal across tissues from the site of injury to the brain, sending a message to increase sleep and raise the chances for surviving the injury. The results have been published in the journal Current Biology.

Sleep is the best medicine, as the old saying goes. Indeed, studies showed that longer sleep leads to a better recovery. It is no surprise that our brains respond to an injury by extending our sleep. But how does that happen? How does the brain know about the injury? Is there some kind of long-range message sent to the brain from the wound?

A team of scientist focused on these questions by looking at injury and sleep in worms. "C. elegans worm is the simplest animal which we could look at to study sleep. It is a model that allows for a wide range of molecular biology techniques to explore fundamental biological processes in detail" explains Prof. Bringmann, research group leader at the Biotechnology Center (BIOTEC) of the TU Dresden and guest group leader at Max Planck Institute for Biophysical Chemistry.

A team led by Prof. Bringmann started by looking for genes responsible for prolonging sleep in worms. They conducted a large-scale genetic screen and analyzed over 4,500 different genetic mutations. One of the genes they found caught their particular attention. Boosting activity of that gene led to an enormous increase in production of antimicrobial peptides (AMPs). The AMPs are natural antibiotics that the body produces inside the wound to fight off the pathogens locally.

To find out the connection between the antimicrobial peptides and sleep signaling, the scientists from Dresden worked with immunologists, Dr. Nathalie Pujol and Dr. Jonathan Ewbank from Centre d'Immunologie de Marseille-Luminy (CIML) in France. Together, the team has manipulated gene expression of worms. They switched off production of the natural antibiotics and looked at what happens to the injured worms. What sounds like flipping a switch was in reality not an easy task at all. It turned out that antimicrobial peptides are highly redundant. The scientists found that a total of 19 different genes responsible for producing AMPs had to be simultaneously switched off to observe a striking difference. "We have seen that the worms which did not produce antimicrobial peptides had much less sleep following an injury" explains Prof. Bringmann. "Normally, worms survive injuries quite well. However, we observed that sleep loss increased the number of worms that did not survive a seemingly non-threatening injury" adds Prof. Bringmann.

The researchers could show that once released from the skin wound, the AMPs act as a messenger and activate receptors in the brain. This activation works as a switch and further prompts sleep neurons to increase sleep. "AMPs have long been known to act locally, but our work suggested that they also act as long-range messenger molecules to signal need for sleep from wounds to the nervous system" says Prof. Bringmann.

These results further strengthen the role of sleep in recovery from injuries. "Since sleep occurs in virtually all animals, our results hint at how sleep could be crucial to recover and survive an injury not only for C. elegans worms but also for other animals and possibly even humans" concludes Prof. Bringmann. His group is funded by the European Research Council (ERC) Starting Grant SLEEPCONTROL.

Although most of the planet is covered by water, only a fraction of it is clean enough for humans to use. Therefore, it is important to recycle this resource whenever possible. Current purification techniques cannot adequately handle the very hot wastewater generated by some industries. But now, researchers reporting in ACS Applied Materials & Interfaces have embedded amine-enhanced nanodiamond particles into membranes to address this challenge.

Some oil recovery methods and other industrial processes result in hot wastewater, which requires energy-intensive cooling before it can be purified through traditional reverse osmosis membranes. After purification, the water then needs to be heated before it can be re-used. At such high temperatures, traditional reverse osmosis membranes filter slowly, allowing more salts, solids and other contaminants to get through. Researchers have embedded extremely tiny nanodiamonds -- carbon spheres produced by explosions in small, closed containers without oxygen present -- onto these membranes in previous studies. Although the membranes effectively and quickly filtered large volumes of water and can protect against fouling, they were not tested with very hot samples. To optimize the membranes for use with hot wastewater, Khorshidi, Sadrzadeh and colleagues wanted to modify the nanodiamond spheres and embed them in a new way.

The team attached amines to nanodiamonds and bathed them in an ethyl acetate solution to prevent the spheres from clumping. Then, a monomer was added that reacted with the amines to create chemical links to the traditional membrane base. Synergistic effects of the amine links and the ethyl acetate treatment resulted in thicker, more temperature-stable membranes, contributing to improvements in their performance. By increasing the amount of amine-enhanced nanodiamonds in the membrane, the researchers obtained higher filtration rates with a greater proportion of impurities being removed, even after 9 hours at 167 F, when compared to membranes without nanodiamonds. The new method produced membranes that could more effectively treat wastewater at high temperatures, the researchers say.

Once used to prepare cuisine in only the finest restaurants, sous vide is now making its way into home chefs' kitchens. French for "under vacuum," the technique involves vacuum sealing food in a plastic pouch and then slowly cooking it in warm water. Now, researchers reporting in ACS' Journal of Agricultural and Food Chemistry have found that, compared with boiling or roasting, sous vide increases beef protein digestibility during simulated digestion.

The heat of cooking causes meat proteins to undergo various changes, such as in their structure, oxidation and aggregation, which could affect how easily the proteins are broken down by digestion into small peptides or amino acids that can be absorbed into the bloodstream. The relatively low heat of sous vide -- typically about 140 F -- and the low-oxygen conditions can produce a tender, juicy, evenly cooked steak. Wangang Zhang and colleagues wondered if the culinary technique could also increase beef protein digestibility compared with boiling (cooking in water at 212 F) or roasting (cooking in an oven above 300 F). Beef that is more digestible could be more nutritious and less likely to cause gastrointestinal problems.

The researchers studied the effects of the different cooking methods on changes in beef protein oxidation and structure, which are known to influence digestibility. In cooked meat, they examined two markers of protein oxidation, finding that roasted meat was the most highly oxidized, followed by boiled meat and then the sous vide beef. Sous vide also caused less protein aggregation and fewer changes in the proteins' structures than the other cooking methods. When the team placed the cooked beef in simulated gastric and intestinal fluids, the meat cooked by sous vide released a greater quantity and variety of peptides than meat cooked by the other methods, indicating increased digestibility. Further studies are needed to determine the effects of peptides from meat cooked with different methods on the gut microbiome and human health, the researchers say.

Washington, DC, December 9, 2020 - Individuals diagnosed with autism spectrum disorder (ASD) face a lifelong challenge characterized by qualitative impairments in both communication and social interaction. However a new study appearing in the Journal of the American Academy of Child and Adolescent Psychiatry (JAACAP), published by Elsevier, reports that in a cohort of 126 individuals with ASD, IQ increased on average 7.48 points from ages 12 to 23 years old. The study showed that IQ increases were greatest among those participants who had experienced early regression in language skills and had greater communication problems at age 12. Individuals with ASD with a history of regression had an IQ increase of 15.4 points compared to 6.6 points in those not reporting early regression.

In contrast to the IQ improvement, parent-reported overall trajectories of autistic traits, while variable, did not change over the same time period on average. Attending mainstream education, as compared to a specialist placement, was linked to relative improvement in autistic symptoms -- a finding that remained after accounting for possible confounders.

"We followed up this unique population-based cohort of autistic children to better understand their outcomes in early adulthood," said lead investigator Emily Simonoff, Professor of Child and Adolescent Psychiatry, King's College London. "So much of our current understanding of how autistic children fare in adult life is based on clinical cohorts that often includes the most severe end of the spectrum."

Based on the UK Special Needs and Autism Project (SNAP) cohort, a population-based cohort first studied in the year 2000 to estimate autism prevalence, the sample was originally drawn from a population of over 56,000 children aged 9-10 years of age living in South-east England. The sample also included those with special educational needs for any reason or having received a clinical diagnosis of autism. A total of 158 children seen at age 12 years received an autism research diagnosis and have been followed up at ages 16 and 23 years respectively. IQ and autistic traits are amongst the most important predictors of independent functioning in adult life for autistic people.

A strength of the study is the use of the same measures at each timepoint, making comparisons easier to interpret. The statistical approach (latent growth curve modelling) identifies factors that influence overall level of IQ/autistic traits, as well as the factors that predict change compared to the rest of the cohort. The cohort includes participants from the full IQ range seen in autistic people, from severely intellectually disabled (IQ 120). Because IQ is standardized for every age, it is not expected to change over time. The mean increase of 7.48 is a substantial increase and would be noticeable by parents and teachers.

"While we can't exclude the improvement is partly due to increased motivation or ability to access IQ tests, rather than an intrinsic improvement in learning ability, these alternatives are also important aspects of real-life functioning that may open new educational and employment opportunities for autistic people," Dr. Simonoff added. Lower level of language and greater severity of autism at 12 years predicted the overall level of IQ (but not relative change).

This is the first study to show that early language regression affects IQ trajectory. An earlier report from this cohort showed that those with regression had more advanced early cognitive development than the rest of the cohort; one possible explanation to be pursued is the idea that regression is an observable marker of a perturbation in developmental course and this subgroup continue to revert to their underlying cognitive trajectory.

Autistic symptoms from earlier childhood and mental health problems predict the overall level of autistic traits from late childhood to adulthood. The present finding that more mainstream education as compared to specialist provision for autism and/or intellectual disability predicts fewer autistic symptoms has potentially important policy implications.

"Our statistical approach attempts to account for possible confounders, children were not randomly assigned to school type and we can't fully exclude that unmeasured characteristics are driving this result. Nevertheless, it suggests social benefits of inclusive education for autistic pupils," concluded Dr. Simonoff.

As not all pupils can access mainstream education, identifying the most important active ingredients to dd to specialist educational provision could improve autistic outcomes more widely.

In recent years, the energy consumption in developed countries has been rather wasteful. Nearly two-thirds of the total energy is typically discarded into the environment as "waste heat," which ends up contributing to global warming. Finding a way to productively use this heat has been at the forefront of every material researcher's priority.

One of the various possible ways to recover this waste heat as electricity is using what is known as "thermoelectric conversion"--a process that uses temperature difference in semiconductors to directly convert into electric voltage. Thermoelectric devices include p-type and n-type semiconductors with two types of charge carriers, i.e. electron and hole. The p-type and n-type semiconductors are connected in series to produce a large thermoelectric voltage (Figure 1). Therefore, it is necessary to develop the both p-type and n-type semiconductors with high thermoelectric conversion efficiency.

One particular semiconductor material that scientists have recently turned their attention to is tin monoselenide (SnSe), which reportedly exhibits the world's highest thermoelectric conversion performance index ZT value. However, SnSe is incapable of controlling the charge carrier type with ease. Doping with alkali ions improves p-type thermoelectric performance but the alkali ions are volatile and diffusive elements, and are not suitable for high-temperature applications. Adding bismuth and iodine to make it n-type, on the other hand, results in low electron concentrations.

In a new study published in Advanced Functional Materials, a team of scientists from Tokyo Tech, Japan, led by Prof. Takayoshi Katase discovered that when doped with antimony (Sb), SnSe, denoted as (Sn1-xSbx)Se, exhibits a peculiar switching of conduction type. Specifically, the team observed that at low doping concentrations, (Sn1-xSbx)Se started out with p-type conduction but switched to n-type with increasing doping, and finally switched back to p-type for high concentrations (see Figure 2). The elaborate analyses and calculations revealed an interesting charge type switching mechanism which, the team found, has to do with the distribution of Sb substitution sites between Sn and Se. They attributed this switching behavior to a switching of major Sb substitution site from Se (SbSe) to Sn (SbSn) with increasing doping.

Scientists explained that at very low Sb concentrations, the p-type conduction occurs solely due to holes supplied by Sn vacancy. But as doping increases, SbSn starts to donate electrons while SbSe forms an "impurity band" that allows conduction through it, resulting in the observed n-type behavior. However, as doping level goes up further, the Fermi level approaches the midgap level located between the SbSe impurity band and conduction band minimum, resulting in the p-type conduction.

With such remarkable insights to offer, the results are undoubtedly a potential game changer for SnSe. However, Prof. Takase foresees an even broader scope. "Now that we understand the mechanism at play in the polarity switching of Sb-doped SnSe, we can hope to optimize the bulk synthesis process to further improve its thermoelectric performance and, in turn, realize high-performance thermoelectric conversion devices with it," surmises Prof. Katase.

What's more, the researchers also expect that the doping-site-switching based polarity control will become more versatile in the future and can be applied to other semiconductor materials whose carrier types are difficult to control otherwise. Here's hoping that this leads to a future where waste heat won't be a waste anymore!

p>New research shows that conservation efforts in the Atlantic Ocean may be working for one of the most popular — and endangered — species that ends up in the global shark fin trade. Diego Cardeñosa — an FIU postdoctoral researcher in the Institute of Environment — led a new study in collaboration with scientists in Hong Kong that uses DNA analysis to track where fins in the global shark fin trade originate. They focused on silky sharks (Carcharhinus falciformis) — the second most common species found in the fin trade. Testing revealed 99.8 percent of the fins sampled from retail markets in Hong Kong and China originated from the Indo-Pacific Ocean. Virtually none came from the Atlantic Ocean, which provides the first evidence that conservation efforts could be making an impact. According to FIU research, around 100 million sharks are killed every year. Nearly one-third of the shark species in the global shark fin trade are at risk of extinction. Open ocean sharks, like silky sharks, face a considerable risk of overexploitation because they get caught in nets and longlines set by fishing fleets targeting tuna. High demand for shark fins in Asia means that although they are considered accidental by-catch, they are by-catch worth keeping. Silky sharks are protected under Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) — an international agreement protecting animals and plants from overexploitation in international trade. Listed in Appendix II, all trade of these sharks requires permits certifying they were legally caught, catch is sustainable, and traceable through the supply chain. The Regional Fisheries Management Organizations oversees fishing regulations and shark management decisions. In 2011, one of these organizations — the International Commission for the Conservation of Atlantic Tuna (ICCAT) — prohibited the fishing, retention and transshipment of silky sharks by all fisheries operating under its jurisdiction. Only developing nations are allowed to fish for these sharks as a source of food.  “This study shows that there is good news for ICCAT and the Atlantic silkies,” said Cardeñosa, who was recently named a Distinguished Postdoctoral Scholar in the College of Arts, Sciences & Education. “While it doesn’t necessarily mean that the Atlantic population is recovering or that fishing mortality is decreasing, it’s a good assessment that there’s high compliance with the retention and export ban by ICCAT parties.”

Cardeñosa’s DNA detective work is helping uncover the mysteries of the shark fin trade. 

The long-term goal of Cardeñosa’s research is to provide information about where shark fins originate in order to better direct more concentrated shark conservation efforts and fisheries management. This study emphasizes the need for increased monitoring, as well as better implementation of CITES regulations. The reality is illegal, unreported trade continues to happen. In fact, earlier this year Hong Kong customs officials intercepted an illegal shipment lacking proper CITES documentation from Ecuador that included silky and pelagic thresher shark fins. The secret tool behind this historic seizure of shark fins was a DNA testing kit co-developed by Cardeñosa and Demian Chapman, an FIU marine scientist in the Institute of Environment. Created with funding from the Paul G. Allen Family Foundation, the tool is being used in airports and shipping ports to help customs officials identify protected shark species. “Understanding which species are most prevalent in the shark fin trade can help identify the species in need of conservation intervention,” Cardeñosa said. “Tracing the populations of origin can help identify the key management jurisdictions that can lead proper interventions.” 

FORT LAUDERDALE/DAVIE, Fla. - In a year like no other, it's certainly fitting that we had hurricane season that followed suit. It seemed every time we turned around, there was a tropical disturbance brewing that eventually became a named storm.

As these storms made their way through the Atlantic Ocean or Caribbean Sea, those in the "cone of concern" watched intently to see where it was heading, its intensity and if it was time to put up their shutters. The science of forecasting storms has come a long way from the days of Hurricane David or Andrew, but scientists know there's more than can be learned.

Step in a team of research scientists, led by a group from Nova Southeastern University's Halmos College of Arts and Sciences and Guy Harvey Oceanographic Research Center, who have just had a paper - Potential Effect of Bio-Surfactants on Sea Spray Generation in Tropical Cyclone Conditions - published by Nature Scientific Reports. The research paper can be found online (https://rdcu.be/b9H8C).

Rapid storm intensification and decay remain a challenge for hurricane forecasts. Many factors are involved and some of them are either poorly known or not yet identified. One such factor appears to be the presence of surface-active materials of biological (e.g., coral reefs) or anthropogenic (e.g., oil spills) origin. This new research paper was authored by an ad hoc team of researchers from NSU, The University of Miami (UM), The University of Hawaii (UH), The University of Rhode Island (URI) and the high-performance computing company Ansys, Inc.

"We have conducted computational and laboratory experiments and found that under certain environmental conditions, surface-active materials significantly alter the size distribution of sea spray," said Breanna Vanderplow, a NSU Halmos College Ph.D. student, who is the first author of this paper. "Since sea spray is 'fuel' for hurricanes, the hurricane intensity can be altered."

Improved tropical cyclone prediction is particularly critical during pandemics, such as the COVID-19 outbreak, where poor prediction could cost lives if unnecessary sheltering of large groups occurs.

Breanna presented her work on surfactants and sea spray at the 2019 Tropical Cyclone Ocean Interaction (TCOI 2019) conference in Jeju Island, South Korea and received feedback from the tropical cyclone community. Subsequently, she submitted the collaborative paper to Nature Scientific Reports.

"Surfactants reduce interfacial tension between air and water, which results in an increased rate of sea spray generation," said Alexander Soloviev, Ph.D., a professor, and principal investigator at NSU's Halmos College's Department of Marine and Environmental Sciences. "Evaporating sea spray is part of tropical cyclone thermodynamics. Spray particles also produce additional resistance to the air-low since they increase the total surface exposed to the wind. Yet, surfactants have never previously been considered as a factor in tropical cyclone thermodynamics. Breanna has identified a new phenomenon, which may contribute to improving hurricane intensity forecasts."