Tech

Boston, Mass. - Most people with COVID-19 have relatively mild disease, but a subset of people develop severe pneumonia and respiratory failure, potentially leading to death. Beth Israel Deaconess Medical Center (BIDMC) immunologist Dan H. Barouch, MD, PhD, and colleagues showed in recently published previous work that a candidate COVID-19 vaccine raised neutralizing antibodies that robustly protected non-human primates (NHPs) against SARS-CoV-2, the virus that causes COVID-19. Now, in new research published to-day in Nature Medicine, Barouch and colleagues demonstrated that the optimal vaccine elicited robust im-mune response in Syrian golden hamsters and prevented severe clinical disease -- including weight loss, pneumonia and death.

"We recently reported that an Ad26-based SARS-CoV-2 vaccine provided robust protection in rhesus ma-caques, and this vaccine is currently being evaluated in humans," said Barouch, who is Director of BIDMC's Center for Virology and Vaccine Research. "However, nonhuman primates typically don't get severe clinical disease, and thus it was important to study whether this vaccine could prevent severe pneumonia and death due to SARS-CoV-2 in hamsters, which are more susceptible to clinical disease."

The vaccine - developed through a collaboration between BIDMC and Johnson & Johnson (J&J) - uses a common cold virus, called adenovirus serotype 26 (Ad26), to deliver the SARS-CoV-2 spike protein into host cells, where it stimulates the body to raise immune responses against the coronavirus. Barouch's group and J&J developed a series of vaccine candidates designed to express different variants of the SARS-CoV-2 spike protein, which is the major target for neutralizing antibodies.

In the current study, the researchers immunized Syrian golden hamsters with a single injection of the Ad26-based SARS-CoV-2 vaccine, which induced neutralizing antibodies in all animals. Four weeks later, the ani-mals were exposed to a high dose of SARS-CoV-2. Vaccinated animals lost less weight and had less virus in their lungs and other organs than unvaccinated control animals. Vaccinated animals also demonstrated lower mortality. Moreover, the researchers found that neutralizing antibody responses were inversely correlated with weight loss and viral loads in respiratory tissues. The Ad26.COV2.S vaccine is currently being evaluated in clinical studies to establish the performance of the vaccine candidate in humans.

"This hamster model of severe COVID-19 disease should prove useful to complement current nonhuman pri-mate models in the evaluation of candidate vaccines and therapeutics," said Barouch, who is also the William Bosworth Castle Professor of Medicine at Harvard Medical School, a member of the Ragon Institute of MGH, MIT, and Harvard, and the co-leader of the vaccine working group of the Massachusetts Consortium on Pathogen Readiness.

In July 2020, investigators at BIDMC and other institutions initiated a first-in-human Phase 1/2 clinical trial of the Ad26.COV2.S vaccine in healthy volunteers. Kathryn E. Stephenson, MD, MPH, is the principal investiga-tor for the trial at BIDMC, which is funded by Janssen Vaccines & Prevention, B.V., a pharmaceutical re-search arm of Johnson & Johnson.

Pending clinical trial outcomes, the Ad26.COV2.S vaccine is on track to start a phase 3 efficacy trial in up to 60,000 participants in September 2020.

Distinctive thermal and electrical characteristics make silver nanoparticles perfect for optics and biosensing applications. One increasingly popular application for the nanoparticles is as an antibacterial coating. Silver nanoparticle coatings are used in fabrics, footwear, computer keyboards, and orthopedic and other biomedical devices.

The process of synthesizing the silver nanoparticles involves chemical reduction of silver nitrate salt (AgNO3). A pair of reagents breaks down the AgNO3 molecules, releasing silver ions that are "reduced" through the acceptance of electrons. This favors the formation of silver nanoparticles. However, the reagents are reported to have toxic properties, so since the early 2000s, ecofriendly methods have been sought to reduce silver nitrate and other metal nanoparticles, including gold and platinum.

Researchers David Omar Oseguera-Galindo and Eden Oceguera-Contreras, both of the University of Guadalajara, Mexico, and Dario Pozas-Zepeda of the University of Colima, Mexico, recently studied the effect of habanero pepper in the synthesis of silver nanoparticles. Their research, published in the Journal of Nanophotonics, resulted in a simple, low-cost, ecofriendly method of obtaining silver nanoparticles.

Habaneros were chosen not only for their antioxidant content but also their economic importance as a traditional crop in Mexico. Previous studies showed that high antioxidant capacity promoted the formation of the nanoparticles. Other plants, such as aloe vera, coconut extract, green tea, pineapple, and garlic cloves, have been used in the synthesis of nanoparticles.

The researchers measured pH and oxidation reduction potential--a molecule's ability to gain or lose electrons--in real time to explain the kinetic performance of the nanoparticles. They also suggested an explanation about how the biomolecules may affect nanoparticle formation. Habanero pepper has evolved antioxidant machinery that decreases the effect of oxidative stress. The antioxidants are key to stabilizing molecules through reducing and scavenging electrons.

"The novelty of this research is that it offers a schematic of silver nanoparticle formation by the biosynthesis method," Oseguera-Galindo said. "In this schematic is included a possible mechanism of the biomolecules and its effect in the silver ion reduction for favoring nanoparticle formation."

Experimental results showed that samples prepared using 0.001 M and 0.005 M of AgNO3 yielded particles with an average size of 19.3 and 26.4 nm. The nanoparticles prepared with 0.005 M had an absorption peak shifted toward a larger wavelength, which was expected because these nanoparticles also had a bigger average size.

In a second experiment, the researchers used varying concentrations of habanero (10, 50, and 100 mL), monitoring the pH and oxidation reduction potential. The 100-mL sample had the most intense absorption peak and the highest pH decrease, indicating the most nanoparticle production. This sample had more biomolecules, consistent with more proton removal, which would increase the number of electrons available for the reduction of silver ions.

Thanks to this green method of synthesizing silver nanoparticles, habanero peppers may soon be used to synthesize the antimicrobial silver nanoparticles in your next pair of running shorts or that next squirt of antibacterial hand sanitizer, without toxic effects.

Read the original research article in the Journal of Nanophotonics: David Oseguera-Galindo, Eden Oceguera-Contreras, Dario Pozas-Zepeda, J. Nanophoton. 14(3), 036012 (2020) doi: 10.1117/1.JNP.14.036012

In mummified specimens, DNA has often degraded and is present only in minimal amounts. In fact, faced with a new discovery, the first question experts encounter is how to examine the mummy while continuing to preserve it, without damaging its ancient DNA. Every action has irreversible consequences on DNA fragments, which makes experimenting with new techniques on human finds impossible. Contrastingly, an intact animal mummy is a perfect simulant for research - especially if its conditions are similar to those of the world's other ice mummies, of which ?tzi and the Inca girl Juanita are among the most famous. "Thanks to our previous studies we know the optimal physical and chemical parameters for preservation from a microbiological point of view. In the laboratory we will bring the chamois to those conditions and focus on their effects on DNA. With repeated in-depth analysis we will verify what alterations the DNA undergoes when external conditions change," explains Marco Samadelli, conservation expert at Eurac Research. "Our goal is to use scientific data to develop a globally valid conservation protocol for ice mummies. This is the first time an animal mummy has been used in this way," adds Albert Zink, Director of the Institute for Mummy Studies at Eurac Research.

Upon encountering the chamois, Hermann Oberlechner soon realised the importance of the find. "Only half of the animal's body was exposed from the snow. The skin looked like leather, completely hairless; I had never seen anything like it. I immediately took a photo and sent it to the park ranger, together we then notified the Department of Cultural Heritage".

The discovery site, at 3200 m MSL, is impassable and can only be reached by a six-hour hike. For this reason, following their initial inspection, the researchers decided to ask for the support of the Alpine Army Corps in the recovery of the animal. "The request from Eurac Research came during a training phase of our military mountain rescue team. We plan regular exercises not only in order to always be ready to intervene and protect our personnel in high-altitude missions, but also if we are requested for civil protection too." commented Mario Bisica, Alpine Army Corps Head of Public Information and Communication.

The helicopter flight was organised in collaboration with the army's specialised aviation corps, who have their own regiment in Bolzano, with pilots specifically trained to operate at high altitude. Thanks to the group effort, Eurac Research experts were able to reach the glacier and, with the help of the troops, carry out the scientific operation needed to recover the mummy. The chamois was then wrapped in an inert material casing made to measure by conservationist Marco Samadelli. The remains are now being kept at the Eurac Research Conservation Laboratory at NOI Techpark in refrigerated cell at - 5 C°, ready to be studied.

Glacier melt is leading to the increasingly frequent discovery of finds, including biological ones. Under the supervision of Eurac Research anthropologist Alice Paladin, the blanket of fresh snow and thick layer of ice covering the chamois mummy, were removed using various archaeological excavation tools. The precise operation required everyone's collaboration and commitment to avoid any kind of risk, minimise contamination and ensure the find's preservation.

Imagine a reusable face mask that protects wearers and those around them from SARS-CoV-2, is comfortable enough to wear all day, and stays in place without frequent adjustment. Based on decades of experience with filtration and textile materials, Georgia Institute of Technology researchers have designed a new mask intended to do just that -- and are providing the plans so individuals and manufacturers can make it.

The modular Georgia Tech mask combines a barrier filtration material with a stretchable fabric to hold it in place. Prototypes made for testing use hook and eye fasteners on the back of the head to keep the masks on, and include a pocket for an optional filter to increase protection. After 20 washings, the prototypes have not shrunk or lost their shape.

"If we want to reopen the economy and ask people to go back to work, we need a mask that is both comfortable and effective," said Sundaresan Jayaraman, the Kolon Professor in Georgia Tech's School of Materials Science and Engineering. "We have taken a science-based approach to designing a better mask, and we are very passionate about getting this out so people can use it to help protect themselves and others from harm."

The fundamental flaw in existing reusable cloth masks is that they -- unlike N95 respirators, which are fitted for individual users -- leak air around the edges, bypassing their filtration mechanism. That potentially allows virus particles, both large droplets and smaller aerosols, to enter the air breathed in by users, and allows particles from infected persons to exit the mask.

The leakage problem shows up in complaints about eyeglasses fogging up as exhaled breath leaks around the nose, making people less likely to wear them. The fit problem can also be seen in constant adjustments made by wearers, who could potentially contaminate themselves whenever they touch the masks after touching other surfaces.

To address the leakage challenge, Jayaraman and principal research scientist Sungmee Park created a two-part mask that fastens behind the head like many N95 respirators. The front part -- the barrier component -- contains the filtration material and is contoured to fit tightly while allowing space ahead of the nose and mouth to avoid breathing restrictions and permit unrestricted speech. Made from the kind of moisture-wicking material used in athletic clothing, it includes a pocket into which a filter can be inserted to increase the filtration efficiency and thereby increase protection. The washable fabric filter is made of a blend of Spandex and polyester.

The second part of the mask is fashioned from stretchable material. The stretchable part, which has holes for the ears to help position the mask, holds the front portion in place and fastens with conventional hook and eyelet hardware, a mechanism that has been used in clothing for centuries.

"We want people to be able to get the mask in the right place every time," Jayaraman said. "If you don't position it correctly and easily, you are going to have to keep fiddling with it. We see that all the time on television with people adjusting their masks and letting them drop below their noses."

Beyond controlling air leakage, designing a better mask involves a tradeoff between filtration effectiveness and how well users can breathe. If a mask makes breathing too difficult, users will simply not use it, reducing compliance with masking requirements.

Many existing mask designs attempt to increase filtration effectiveness by boosting the number of layers, but that may not be as helpful as it might seem, Park said. "We tested 16 layers of handkerchief material, and as we increased the layers, we measured increased breathing resistance," she said. "While the breathing resistance went up, the filtration did not improve as much as we would have expected."

"Good filtration efficiency is not enough by itself," said Jayaraman. "The combination of fit, filtration efficiency, and staying in the right place make for a good mask."

The stretchable part of the mask is made from knitted fabric -- a Spandex/Lyocell blend -- to allow for stretching around the head and under the chin. The researchers used a woven elastic band sewn with pleats to cover the top of the nose.

The researchers made their mask prototypes from synthetic materials instead of cotton. Though cotton is a natural material, it absorbs moisture and holds it on the face, reducing breathability, and potentially creating a "petri dish" for the growth of microbes.

"Masks have become an essential accessory in our wardrobe and add a social dimension to how we feel about wearing them," Park said. So, the materials chosen for the mask come in a variety of colors and designs. "Integrating form and function is key to having a mask that protects individuals while making them look good and feel less self-conscious," Jayaraman said.

The work of Jayaraman and Park didn't begin with the Covid-19 pandemic. They received funding 10 years ago from the Centers for Disease Control and Prevention to study face masks during the avian influenza outbreak. Since then Jayaraman has been part of several National Academy of Medicine initiatives to develop recommendations for improved respiratory protection.

Covid-19 dramatically increased the importance of using face masks because of the role played by asymptomatic and pre-symptomatic exposure from persons who don't know they are infected, Jayaraman said. While the proportion of aerosol contributions to transmission is still under study, they likely increase the importance of formfitting masks that don't leak.

Jayaraman and Park have published their recommendations in The Journal of The Textile Institute, and will make the specifications and patterns for their mask available to individuals and manufacturers. The necessary materials can be obtained from retail fabric stores, and the instructions describe how to measure for customizing the masks.

"There is so much misinformation about what face masks can do and cannot do," Jayaraman said. "Being scientists and engineers, we want to put out information backed by science that can help our community reduce the harm from SARS-CoV-2."

As anyone who has ever straightened their hair knows, water is the enemy. Hair painstakingly straightened by heat will bounce back into curls the minute it touches water. Why? Because hair has shape memory. Its material properties allow it to change shape in response to certain stimuli and return to its original shape in response to others.

What if other materials, especially textiles, had this type of shape memory? Imagine a t-shirt with cooling vents that opened when exposed to moisture and closed when dry, or one-size-fits-all clothing that stretches or shrinks to a person's measurements.

Now, researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) have developed a biocompatible material that can be 3D-printed into any shape and pre-programmed with reversible shape memory. The material is made using keratin, a fibrous protein found in hair, nails and shells. The researchers extracted the keratin from leftover Agora wool used in textile manufacturing.

The research could help the broader effort of reducing waste in the fashion industry, one of the biggest polluters on the planet. Already, designers such as Stella McCarthy are reimagining how the industry uses materials, including wool.

"With this project, we have shown that not only can we recycle wool but we can build things out of the recycled wool that have never been imagined before," said Kit Parker, the Tarr Family Professor of Bioengineering and Applied Physics at SEAS and senior author of the paper. "The implications for the sustainability of natural resources are clear. With recycled keratin protein, we can do just as much, or more, than what has been done by shearing animals to date and, in doing so, reduce the environmental impact of the textile and fashion industry."

The research is published in Nature Materials.

The key to keratin's shape-changing abilities is its hierarchical structure, said Luca Cera, a postdoctoral fellow at SEAS and first author of the paper.

A single chain of keratin is arranged into a spring-like structure known as alpha-helix. Two of these chains twist together to form a structure known as a coiled coil. Many of these coiled coils are assembled into protofilaments and eventually large fibers.

"The organization of the alpha helix and the connective chemical bonds give the material both strength and shape memory," said Cera.

When a fiber is stretched or exposed to a particular stimulus, the spring-like structures uncoil, and the bonds realign to form stable beta-sheets. The fiber remains in that position until it is triggered to coil back into its original shape.

To demonstrate this process, the researchers 3D-printed keratin sheets in a variety of shapes. They programmed the material's permanent shape -- the shape it will always return to when triggered -- using a solution of hydrogen peroxide and monosodium phosphate.

Once the memory was set, the sheet could be re-programmed and molded into new shapes.

For example, one keratin sheet was folded into a complex origami star as its permanent shape. Once the memory was set, the researchers dunked the star in water, where it unfolded and became malleable. From there, they rolled the sheet into a tight tube. Once dry, the sheet was locked in as a fully stable and functional tube. To reverse the process, they put the tube back into water, where it unrolled and folded back into an origami star.

"This two-step process of 3D printing the material and then setting its permanent shapes allows for the fabrication of really complex shapes with structural features down to the micron level," said Cera. "This makes the material suitable for a vast range of applications from textile to tissue engineering."

"Whether you are using fibers like this to make brassieres whose cup size and shape can be customized every day, or you are trying to make actuating textiles for medical therapeutics, the possibilities of Luca's work are broad and exciting," said Parker. "We are continuing to reimagine textiles by using biological molecules as engineering substrates like they have never been used before."

If you have any children in your life, imagine for a moment that they don't look anything like their parents, they don't eat anything humans normally eat, and they're active only while adults sleep.

While that might sound like an idea from a work of surreal fiction, it's actually the norm rather than the exception in the animal kingdom. Most animals go through what biologists call a complex life cycle, starting as larvae that often have little, if anything, in common with their parents.

To become adults, they have to go through a process known as metamorphosis, which is one of nature's most remarkable feats. During this process, the larval bodies of many animal species undergo dramatic changes that turn them into adults that have little, if any resemblance with their juvenile stage. Butterflies may be the most familiar example of this. Yet, despite complex lifecycles being widespread, surprisingly little is known about how they evolve, specifically the extent to which evolution in one life stage impacts the others.

To better understand the evolutionary consequences of a complex life cycle across a large group of related species, University of Arizona biologists studied another familiar example: frogs and their tadpoles.

Tung Phung, Joao C. S. Nascimento and John J. Wiens of the UArizona Department of Ecology and Evolutionary Biology took a closer look at the evolution of body size across 542 frog species belonging to 42 families, most of which have a tadpole stage. The study, which was co-authored by Alexander Novarro of The Nature Conservancy, is published in the scientific journal Proceedings of the Royal Society B.

"We wanted to know, do large frogs have large tadpoles and small frogs small tadpoles, or are the sizes between the two decoupled?'" Wiens said, alluding to a prevailing hypothesis in evolutionary biology that states that larvae and adults should evolve rather independently, especially in species in which the two life stages have very different lifestyles.

If larval and adult stages evolve completely independently of each other, there should be little correlation between larval size and adult size among species. In other words, big frogs could have little tadpoles, and big tadpoles could become small frogs, with no relationship between the size of frogs and tadpoles.

The team scoured the scientific literature for data on the sizes of tadpoles and adult frogs for each species, assembled an evolutionary tree among the species, and applied statistical analytical tools.

The team discovered that while there is a striking amount of variability among frog families, the association is not completely random. Across frogs as a group, larval and adult body sizes are significantly and positively related.

"It's not just 'anything goes,'" Wiens said. "We included almost every family of frogs that has a tadpole stage, and we did find there is constraint. In some cases, it's really strong; adult size strongly predicts larval size in many of the families we looked at."

In other families included in the study, the researchers found the relationship to be much more variable. For example, in the spadefoot toad (Scaphiopodidae) family, species with large adults have small tadpoles and species with small adults have large tadpoles.

There was also variation in the relative size of adults and tadpoles among families. For example, the paradox frog, Pseudis paradoxa, is a species with normal-sized adults that develop from giant tadpoles that are three to four times bigger than the adult. On the other end of the spectrum are some giant South American toads, whose tadpoles are about a tenth the size of the adult.

"Overall, the size of tadpoles relative to adults changes widely across frogs, but why, we don't know," Wiens said.

The authors also compared the rates of evolution in body sizes between tadpoles and adults. These were found to be clearly decoupled. For example, in glass frogs, the tadpole stage runs a broad gamut of sizes, indicating it has been evolving very quickly, while the adults vary much less in size. Other groups, such as the true toads, have fast evolutionary rates in both stages, while yet others, such as the African bullfrogs, show the opposite pattern, with adults evolving fast and tadpoles changing slowly.

Once tadpoles, which are confined to water, morph into frogs that spend most of their time hopping around on land, their bodies undergo an extreme makeover: The tissues that make up their powerful tail, used to propel them underwater, are recycled into other tissues; appendages begin sprouting beginning with the legs, then the arms, and they lose their feeding apparatus. This feeding system usually consists of a big beak, bordered by five or more rows of tiny teeth, which themselves are surrounded by a ring of short, fleshy tentacles. Inside, a filter system uses streams of slime to extract food from the water. Some tadpoles seem to use the teeth and beak to scrape algae off of rocks. Others suck up decaying organic matter from the bottoms of their freshwater habitats. But some tadpoles are carnivorous and may even be cannibalistic.

"Their feeding mechanism is so weird that people still don't know exactly how it works or even what most tadpoles eat," Wiens said. "In adult frogs, the mouthparts are completely different, so they have to take this whole system down and rebuild during metamorphosis."

While the huge variability in tadpole size relative to adults makes frogs especially interesting to Wiens and his research team, he said another reason for choosing frogs for this study was their status as endangered animals that are highly beneficial to the natural environment.

Of the more than 7,200 frog species that have been described, most live in the tropics, and many have been disappearing at an alarming rate, Wiens said. This is worrisome as they play critical roles in ecosystems across the globe - for example, acting as a natural pest control.

"Many of them eat insects that destroy crops, so they are really useful that way," he said.

While the current study is limited to amphibians, it does open up questions for other groups of animals, said the paper's first author, Tung Phung, a first-year doctoral student in Wiens' lab who did most of the work while still an undergraduate.

"Our study is the first to address evolutionary rates of larval and adult life stages at a large scale," he said.

While 'trolls' have been around almost as long as the Internet, 'Incels' are a more recent and distinctly different cyber sub-culture which warrants more study says a QUT researcher.

QUT behavioural economist Dr Stephen Whyte has co-authored a new paper which examines data collected during the national online Australian Sex Survey in 2016, a research collaboration with adultmatchmaker.com and the Eros Association.

"I sexually identify as an Attack Helicopter": Incels, trolls and non-binary gender politics online has just been published by open access journal First Monday.

"Trolling, cyber-aggression and general anti-social behaviour on the internet are not new but while trolls are often motivated by boredom, attention-seeking and, sometimes, revenge, Incels are aggrieved and appear to possess more undesirable characteristics like envy and jealousy," said Dr Whyte.

"Trolls see the world wide web as an entertainment venue while Incels see it as a weapon. These are men who display much more aggression towards questions of gender and use terms like 'Attack Helicopter' to parody gender classification and which are beloved of conservative right-wing ideologists.

"While the internet is such a positive tool for the majority in everyday life, its anonymity, at times, can mean some use it as a vessel for negative or aggressive anti-social behaviours.

"Understanding new emerging online groups such as Incels is critically important in addressing broader online anti-social behaviours such as cyber-aggression and abuse, sexism, and racism."

Dr Whyte said he and colleagues from QUT's Business School and Centre for Behavioural Economics, Society & Technology (BEST) PhD candidate Ms Megan Godwin, along with Dr Khandis Blake from the University of Melbourne, School of Psychological Sciences, collected data from more than 12,000 Australians, with this study focussed primarily on the unique responses of just 20 particular participants.

"Since chat rooms first surfaced, up to the present day on social networking sites like Facebook and Instagram, labelling of gender or sex has been an integral part of online experiences and behaviours," he said.

"Over the last 10 years, policy, industry and social networks have begun to recognise and embrace a myriad of new non-binary titles in practice; terms like 'bigender', 'genderfluid', 'pangender', 'trigender', 'demigirl', 'nonbinary' and 'intersex'.

"However, not all online communities and their participants have welcomed such diversity and inclusion. This is the case of Incels, a small but potent group with a vivid online presence, and who fall under the broader umbrella of men's rights activists opposed to the feminist movement.

"Incels have gained attention in recent years due to their association with a disproportionate number of mass violence events. They believe they are entitled to sex but are victims of women and society.

"Almost nothing is known about the demographic characteristics of Incels but some insight can be gained by analysing linguistic content in their social media posts which often centre on their own perceived ugliness and low social worth.

"Many of their posts advocate sexual and physical violence, racism and homophobia, with strong elements of misogyny and anti-feminism.

"It's important to understand what drives or motivates certain individuals or groups to better ensure equitable outcomes for all in cyber domains.

"So, our study explores key traits, behaviours and demographic characteristics of those who choose to gender identify as inanimate objects of modern warfare, or simply reject the notion of non-binary alternatives in other ways."

"The Australian Sex Survey included an option to identify with one of 33 different gender options. Participants were also offered a free text response option to self-report an alternative gender title and/or comment. Data for our study was based on these free-form response options," he said. Several of the studies respondents described their gender as either 'Attack Helicopters' or 'Apache Attack Helicopter'

Dr Whyte said it was the first study to offer qualitative archetype description and differentiation between trolls and Incel's based on their behaviour in relation to the online non-binary gender debate.

Dye-sensitised solar cells used in low-light conditions could perform more consistently thanks to improved understanding of the role additives play in optimising electrolytes.

Laptops and mobile phones, among other devices, could be charged or powered indoors, away from direct sunlight, using dye-sensitised solar cells (DSCs), which have achieved efficiencies of up to 34% at 1000 lux from a fluorescent lamp.

Copper-based electrolytes containing various combinations of additives have been used to achieve these efficiencies, with varying results to date.

Interaction of these additives with the copper species in the electrolyte has been a concern over the last few years, and progress has been undermined by a lack of understanding about the true effect of the different additives.

Now, research funded by the Australian Centre for Advanced Photovoltaics (ACAP) and supported by the ARC Centre of Excellence in Exciton Science, has demonstrated the crucial importance of the molecules 4-tert-butylpyridine (tBP) and 1-methyl-benzimidazole (NMBI) as optimal additives for maximising the performance of the copper redox mediators.

The results have been published in the journal Advanced Energy Materials.

X-ray diffraction analysis, absorption, and nuclear magnetic resonance spectroscopy were used to find the combination of additives that most efficiently suppresses recombination losses, resulting in improved solar cell performance.

Joint first author Dr Sebastian Fürer of Monash University and Exciton Science said: "Researchers were previously a bit worried because tBP can interact with copper complexes and everyone said, 'let's try to avoid it'. People thought this is detrimental to the solar cell performance but we had a closer look at this.

"We actually found that it's really important to keep it in because it reduces one of the main loss mechanisms.

"That's a really exciting find. So, from here onwards, people need to think of that interaction in order to have high efficiencies for these devices."

According to Sebastian, employing the correct additive in new copper redox mediators is now likely to become standard in future efforts to improve DSC performance.

"You can't leave it out, because the solar cell goes from 9% efficiency to less than 1%. It's really a huge difference," he said.

"Instead of trying to avoid that interaction, for the future, researchers will need to make sure this interaction happens but only in a beneficial way. We've looked at all the different parts and solved a big question. The results are very conclusive."

Joint first author Dr Rebecca Milhuisen, also of Monash University, added: "Our findings identify crucial performance-deterring loss mechanisms and are a step further towards the development of low-cost charge transporting materials for next generation solar cells."

Senior author Professor Udo Bach of Monash University believes the findings will enable researchers to successfully design and create a more efficient next generation of materials.

"Printable low-cost dye-sensitized solar cells have seen a considerable efficiency boost over the past years," he said.

"This increase has been mainly fuelled by the incorporation of new copper-based compounds that help with the separation of the photo-generated charges.

"In our paper we reveal previously unknown details about the interplay of these compounds with other additives in the cell which are the key to their outstanding performance.

"Equipped with this new knowledge, we can now design the next generation of copper-based charge transport materials which should be even more efficient."

A common notion is to walk 10,000 steps a day to improve ones' physical fitness, so pedometers have been a popular wearable health device from before the days of fitness trackers and smartphones. However, simply walking 10,000 steps does not improve physical fitness or improve lifestyle-related illnesses. The international standard of improving physical fitness is to measure the maximum oxygen intake and to have the individual work at more than 60% of that. Interval training uses an individuals' peak aerobic capacity to efficiently and effectively improve physical fitness. However, this requires going to the gym and training with a machine on a regular basis, which is both time consuming and costly. Therefore, a team at Shinshu University led by Dr. Shizue Masuki who was a part of Dr. Hiroshi Nose's group (also of Shinshu University and corresponding author of this study) that developed Interval walking training (IWT) in an earlier study set out to see whether physical fitness could be easily determined and exercise intensity during training could be continuously monitored in the field without going to the gym.

The team developed a training system using the internet of things (IoT) to motivate and track the exercise intensity levels of the trainees. The team found that with five months of training, a group with an average age of 63 were able to increase their physical fitness back to a level 10 years younger than they previously scored before the exercise protocol. Expensive machines and gyms are not necessary to achieve these results. With the use of triaxial accelerometer and the "3-step step-up walking method", researchers are able to measure physical fitness accurately and monitor exercise intensity during training. The method to increase physical fitness to a level 10 years younger utilizes the IWT, to walk at a speed of more than 70% of maximum effort for 3 minutes, and switch to a 40% capacity for another 3 minutes and repeat. To increase physical fitness, the key is the amount of time spent walking at a level of 70% or more, which the walker feels is sufficiently strenuous.

Dr. Shizue Masuki states, "the importance of high-intensity exercise has now been recognized even among middle-aged and elderly people, but at the time of its development, the emphasis was placed on the amount of exercise using a pedometer, and the concept of the "intensity of exercise" was not understood or appreciated. It was very difficult in the beginning to get a paper published with this approach."

However, she states that, "with this IoT system, it is possible to measure physical fitness, prescribe an individual exercise program without constant contact, and monitor energy expenditure at every training session throughout an intervention period." They were able to conduct a dietary survey remotely and create an appropriate nutritional supplement protocol based on their exercise data and blood tests. They even discovered "exercise training responsive genes" through the study.

Recently, with the help of AMED, a Japanese fund promoting integrated research and development in the field of medicine, Dr. Masuki has succeeded in developing a smartphone app that enhances the versatility of their system. Using this application, they aim to build a database of tens of thousands on the effect of IWT. They expect not only will the verification of lifestyle-related disease improvement by exercise training be accelerated, but so will the verification of the combined use of health foods, more easily than before. Furthermore, they aim to apply IWT to a wide range of clinical medicine applications.

There are currently 8,700 participants of the IoT IWT throughout Japan, and the number is increasing. This system greatly reduces the cost of healthcare and standard exercise regimen (IWT is only 13% of standard costs) and the smartphone app will only reduce this cost even more. This technology greatly improves the motivation of participants to train at high-intensity, contributing to the long-standing health improvement of populations.

Dr. Masuki and her colleagues hopes to now establish a new preventive medicine centered on exercise. Through the development of this IoT system, she and her team would like to shift from "therapeutic medicine" to "preventive medicine".

Elias H. Barriga, principal investigator of the Mechanisms of Morphogenesis research group at the Instituto Gulbenkian de Ciência, studies directed collective cell migration, the coordinated motion of a group of cells travelling to their target tissues, guided by external signals. This migratory function is essential for a myriad of processes that range from embryonic development, to tissue repair and cancer metastasis. Regardless of its wide biological relevance the mechanisms that guide directional collective cell migration in the native environments remain unclear.

With the ERC Starting Grant, Elias, and his team, aim at better understanding how cells migrate in complex environments which are present in our bodies. Intriguingly, in such an environment cells need to constantly sense and respond to multiple biochemical and biophysical signals - however the interplay between these cues remains largely unknown.

"It is of particular interest to our research the mechanism by which biochemical and biophysical stimuli are integrated into a coherent directional and collective migratory behavior" explains Elias Barriga. With the ERC Starting Grant "our research group expects to contribute with unique perspectives to a wide range of fields, especially to the field of embryonic development and the study of congenital defects, as well as the field of cancer and regeneration".

Hall effect plays an important role in the development of condensed matter physics. The classical Hall effect was discovered by American physicist E. H. Hall in 1879. When an electric current passes through a conductor under an out-of-plane magnetic field, a transverse Hall voltage appears in the direction perpendicular to both the magnetic field and the current. In condensed matter systems, apart from the dynamical phase of a Bloch electron, geometrical phase (Berry phase) must also be considered. The Berry curvature corresponding to Berry phase will generate an anomalous velocity that is perpendicular to the applied electric field, leading to transverse Hall signals. Recent studies have shown that in topological materials, when the magnetic field and current are coplanar, Berry curvature will induce planar Hall effect (PHE). On one hand, different from classical Hall effect, planar Hall resistivity ρyx is an even function of magnetic field (namely, symmetric to magnetic field, ρyx (-B)=ρyx(B)). On the other hand, PHE will vanish when in-plane magnetic field is perpendicular (B?I) or parallel (B?I) to the current, same as the classical Hall effect.

Recently, Professor Jian Wang in collaborated with Professor Xincheng Xie at Peking University, Professor Haiwen Liu at Beijing Normal University, Dr. Jiaqiang Yan and Professor David Mandrus at Oak Ridge National Laboratory etc discovered unconventional Hall effect in non-magnetic topological material ZrTe5 devices. Nonzero Hall effect was observed when in-plane magnetic field is perpendicular (B?I) or parallel (B?I) to the current. The paper entitled "Unconventional Hall Effect induced by Berry Curvature" was published online in National Science Review. Professor Jian Wang and Professor Xincheng Xie at Peking University are corresponding authors of this paper. PhD candidate Jun Ge and Dr. Da Ma at Peking University contribute equally to this work.

The research team performed systematic transport measurements on ZrTe5 devices (Fig. 1(a)) in both Physical Property Measurement System and a dilution refrigerator with triple axes vector magnet. With well-controlled angular-dependent transport measurements (Fig. 1(b)), the research team excluded the extrinsic influence of longitudinal resistance and classical Hall effect, and detected intrinsic in-plane Hall response of ZrTe5 devices. The observed in-plane Hall signal of ZrTe5 devices contains both symmetric (Fig. 1(c)) and asymmetric (Fig. 1(d)) components with respect to the magnetic field. More interestingly, nonzero in-plane Hall signal is detected for B?I (Fig. 2(a-c)) and B?I (Fig. 2(d-f)) situations. These discoveries are beyond the expectations of classical Hall effect and previously suggested PHE in topological materials.

The origin of the observed unconventional Hall effect is revealed by theoretical calculations. The researchers find that ZrTe5 can be considered as a Weyl semimetal with tiled Weyl cones under external magnetic field. The tilt of Weyl cones, the anomalous velocity induced by Berry curvature, the chiral chemical potential, and phase volume effect together give rise to the observed unconventional Hall effect. A new formula for in-plane Hall signal is proposed, which can well fit the experimental observation (Fig. 3).

The nonzero in-plane Hall signals when magnetic field is parallel or perpendicular to the current adds a new member to the Hall effect family. This work provides a new platform to investigate Berry curvature related physics in condensed matter systems.

Imagery from the VIIRS instrument aboard NASA/NOAA's Suomi NPP satellite highlights the burn scars from the Elkhorn Fire in northern California on Sep. 01, 2020. This false-color image of the firescape made by using the reflective solar bands on Suomi NPP highlights those areas which have been burned. Suomi NPP's corrected reflectance solar bands (Bands M11-I2-I1) are most useful for distinguishing burn scars from naturally low vegetation or bare soil. In addition, these reflectance bands are able to show the following: "Burned areas or fire-affected areas are characterized by deposits of charcoal and ash, removal of vegetation and/or the alteration of vegetation structure. When bare soil becomes exposed, the brightness in Band I1 may increase, but that may be offset by the presence of black carbon residue; the near infrared (Band I2) will become darker, and Band M11 becomes more reflective. When assigned to red in the image, Band M11 will show burn scars as deep or bright red, depending on the type of vegetation burned, the amount of residue, or the completeness of the burn."

This information is from the Worldview application website where the images in this story were downloaded. Another interesting point to note is that in this image, the fire line can be seen about a third of the way down the image. At this point the smoke is the heaviest and there is a demarcation line marking where the fires have burned and also where the fires are heading. Using the reflective bands on Suomi NPP vegetation shows up as a bright green color. All of this information is very valuable to both firefighters and scientists in finding out the line of the fire and where that fire is heading.

Lastly, this second image taken by the true-color image bands of Suomi NPP's satellite of the same exact area show huge smoke plumes pouring off the fire. This image is of natural-looking land surface, oceanic and atmospheric features.

The Elkhorn Fire began on Aug. 17, 2020 with a lightning strike that occurred during the very aggressive storms that hit northern California on that weekend (Aug. 15-17). At present the Elkhorn Fire is 40,495 acres which will continue to threaten communities to the north east. Personnel will continue to plan and implement evacuation plans as needed. The Elkhorn Fire is currently 42% contained. Crews continue to engage with the fire on the northwest, west, south west, and south flanks of the fire.

NASA's satellite instruments are often the first to detect wildfires burning in remote regions, and the locations of new fires are sent directly to land managers worldwide within hours of the satellite overpass. Together, NASA instruments detect actively burning fires, track the transport of smoke from fires, provide information for fire management, and map the extent of changes to ecosystems, based on the extent and severity of burn scars. NASA has a fleet of Earth-observing instruments, many of which contribute to our understanding of fire in the Earth system. Satellites in orbit around the poles provide observations of the entire planet several times per day, whereas satellites in a geostationary orbit provide coarse-resolution imagery of fires, smoke and clouds every five to 15 minutes. For more information visit: https://www.nasa.gov/mission_pages/fires/main/missions/index.html

NASA's Earth Observing System Data and Information System (EOSDIS) Worldview application provides the capability to interactively browse over 700 global, full-resolution satellite imagery layers and then download the underlying data. Many of the available imagery layers are updated within three hours of observation, essentially showing the entire Earth as it looks "right now." Actively burning fires, detected by thermal bands, are shown as red points. Image Courtesy: NASA Worldview, Earth Observing System Data and Information System (EOSDIS). Caption: Lynn Jenner with information from Worldview and Inciweb.

Zika virus infection during pregnancy can cause severe abnormalities in the fetus, including malformations such as microcephaly. In a small proportion of cases, the disease may lead to miscarriage and perinatal death. A network of more than 30 Brazilian researchers set out to find the causes of these problems with the support of FAPESP and obtained important results after half a decade of hard work. A paper describing their findings has been published in the journal Science Signaling.

“We show for the first time what happens in the fetal brain affected by congenital Zika syndrome [CZS],” Helder Nakaya, who is the last author of the paper, told Agência FAPESP. Nakaya is a bioinformatics specialist, a professor at the University of São Paulo’s School of Pharmaceutical Sciences (FCF-USP), and a senior scientist at the Center for Research on Inflammatory Diseases (CRID), which is one of the Research, Innovation and Dissemination Centers (RIDCs) funded by FAPESP.

The researchers compared brain tissue from babies who died from CZS with tissue samples from babies that died from other causes. “The parents who gave us permission to collect these samples at a time of such grief were exceptionally altruistic. They were motivated by the knowledge that this donation helped science and that science could help others in future,” Nakaya said.

The comparison revealed several anomalies in the brains of the babies with CZS. “Analysis of the brain genome [all DNA], transcriptome [RNAs transcribed from genes] and proteome [proteins produced using messenger RNAs] showed a number of significant molecular alterations in genes related to neuron development, the possible dysregulation of neurotransmitters such as glutamate and even alterations in different types of collagen,” Nakaya said.

The researchers integrated transcriptomics and proteomics data to identify microRNAs (miRNAs) that do not encode proteins but regulate gene expression and may be linked to CZS. One of these, mir-17-5p, was found in previous research to be associated with viral infection in cultured astrocytes, the most abundant type of central nervous system cell.

“Other important findings include genetic variants of key proteins involved in the development of the immune system and nervous system,” Nakaya said. “These findings may explain the increased susceptibility to CZS in babies that have these genetic variants. Finally, when we integrated all three types of data [genomics, transcriptomics and proteomics], we found alterations in signaling pathways related to the organization of the extracellular matrix, which may partly explain the features of CZS.” The extracellular matrix is an array of macromolecules secreted by cells that acts as a structural scaffold that regulates cell differentiation and tissue growth and contributes to organ maintenance, among other functions.

The bioinformatics part of the study was intense because of the enormous volume of data generated, according to Nakaya. “Human DNA contains 3.2 billion base pairs, which can generate 150,000 transcripts [both protein-encoding and noncoding RNAs] and encode more than 25,000 proteins,” he said. “Integration of so much biological information was possible only by a multidisciplinary team that included scientists from several excellent research institutions.”

Science takes time, and this is not always understood, Nakaya added. “The Zika outbreak began in 2015, and only now do we have these results. Scientific research cannot be performed overnight. I know everyone wants answers quickly, but the fact is that if you speed up the process artificially, you risk getting bad science,” he said.

The raw data are publicly available so that the scientific community can perform their own analyses and investigate in depth the role of every molecule described in the paper.

The study was funded by FAPESP via the following projects: “Long noncoding RNA interplay with the host microbiome may determine mucosal influenza vaccine immunogenicity”, “Systems biology of long noncoding RNAs”, “Integrative biology applied to human health”, and “Network statistics: theory, methods, and applications”.

The article “Molecular alterations in the extracellular matrix in the brains of newborns with congenital Zika syndrome” can be retrieved from stke.sciencemag.org/content/13/635/eaay6736.

Journal

Science Signaling

DOI

10.1126/scisignal.aay6736

Every four years, U.S. presidential campaigns collectively spend billions of dollars flooding TV screens across the country with political ads. But a new study co-authored by Yale political scientist Alexander Coppock shows that, regardless of content, context, or audience, those pricey commercials do little to persuade voters.

The study, published Sept. 2 in the journal Science Advances, measured the persuasive effects of 49 high-profile advertisements from the 2016 presidential campaign on a nationally representative sample of 34,000 people through a series of 59 randomized experiments. Expanding on prior research suggesting that political ads have little impact on voters' preferences, the study shows that those weak effects are consistent irrespective of a number of factors, including an ad's tone, timing, and its audience's partisanship.

"There's an idea that a really good ad, or one delivered in just the right context to a targeted audience, can influence voters, but we found that political ads have consistently small persuasive effects across a range of characteristics," said Coppock, an assistant professor of political science in the Faculty of Arts and Sciences. "Positive ads work no better than attack ads. Republicans, Democrats, and independents respond to ads similarly. Ads aired in battleground states aren't substantially more effective than those broadcast in non-swing states."

Coppock and his co-authors -- University of California-San Diego political scientist Seth J. Hill and UCLA political scientist Lynn Vavreck -- conducted the study throughout the 2016 presidential primaries and general election.

Over 29 weeks, a representative sample of Americans was divided at random into groups and assigned to watch campaign advertisements or a placebo advertisement -- a car-insurance commercial -- before answering a short survey.

The researchers selected ads using real-time, ad-buy data and news coverage of each week's most important ads. They tested ads attacking or promoting Republican candidate Donald Trump and Democratic candidate Hillary Clinton as well as commercials concerning primary candidates, such as Republican Ted Cruz and Democrat Bernie Sanders. They analyzed the ads' effects on survey respondents across several variables, including the candidate, party, or political action committee that sponsored them; whether they were positive or negative in tone; the partisanship of those viewing the ads; the time to Election Day when they aired; whether they were viewed in a battleground state or not; and whether they aired during the primary or general election.

They found that, on average and across all variables, the ads moved a candidate's favorability rating respondents only .05 of a point on the survey's five-point scale, which is small but statistically significant given the study's large size, note the researchers. The ads' effect on whom individuals intended to vote for was smaller still -- a statistically insignificant 0.007 of a percentage point.

Campaigns should carefully consider efforts to tailor advertisements to specific audiences given that the evidence shows that ads' persuasive effects vary little from person to person or from commercial to commercial, the researchers concluded

The findings do not demonstrate that political advertising is always ineffective, Coppock said, noting that the study didn't analyze the influence of an entire advertising campaign.

"TV ads help candidates increase their name recognition among the public, which is extremely important," said Coppock, a resident fellow at Yale's Institution for Social Policy Studies and the Center for the Study of American Politics. "Moreover, the effects we demonstrated were small but detectable and could make the difference between winning and losing a close election."

What The Study Did: The purpose of this randomized clinical trial in France was to evaluate the effect of low-dose hydrocortisone for the treatment of ICU patients with COVID-19-related acute respiratory failure but the trial was stopped early.

Authors: Pierre-François Dequin, M.D., Ph.D., of Médecine Intensive-Réanimation in Tours, France, is the corresponding author.

To access the embargoed study: Visit our For The Media website at this link https://media.jamanetwork.com/

(doi:10.1001/jama.2020.16761)

Editor's Note: The article includes conflicts of interest and funding/support disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, conflict of interest and financial disclosures, and funding and support.