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URBANA, Ill. - Bacterial leaf streak, a foliar disease in corn, has only been in the United States for a handful of years, but Tiffany Jamann says it's a major problem in the Western Corn Belt.

"We don't have hard numbers yet, but this pathogen in other systems can cause up to 20% yield losses," says Jamann, an assistant professor in the Department of Crop Sciences at the University of Illinois and co-author of a new study in the journal Crop Science. "There's no effective chemical control. Fungicides don't work, as it's a bacterial disease. That's why host resistance is going to be critical, just as it is for controlling other bacterial diseases of corn, such as Goss's wilt and blight."

The disease-causing bacteria squirm in through open pores - stomata - on the leaf surface, then set up shop between veins to form long greyish streaks. Although no one has determined precisely what's happening inside the plant, Jamann says the necrotic lesions are disrupting the photosynthetic capacity of the leaf. And that hurts yield.

To make matters worse, bacterial leaf streak looks similar to a fungal disease of corn, gray leaf spot. Farmers may confuse the two diseases and spray fungicide, which is not only ineffective, it's an unnecessary cost.

Currently, there is no chemical control agent for bacterial leaf streak, and no completely resistant corn hybrids exist. But, in the Crop Science study, Jamann and her collaborators make a promising discovery that could lead to resistant lines in the future.

By inoculating 26 diverse corn lines with the disease and selecting promising lines for further analysis, they found corn varieties with moderate resistance and genetic regions associated with increased levels of resistance.

"Although we didn't identify any large-effect resistance genes, the study is the first report of host resistance to bacterial leaf streak that has ever been published," Jamann notes.

The team also looked for relationships between resistance to bacterial leaf streak and three other foliar diseases of maize, for which host resistance is better understood. The hope was that the same genes would also have an effect for bacterial leaf streak, but the relationships were not clear-cut.

"We find that the genetic architecture of resistance is complex, with lots of regions of the genome contributing to resistance," Jamann says.

Although the researchers didn't identify a "smoking gun," the information provided in the study should still be useful to breeders in the process of developing new hybrids with resistance to bacterial leaf streak. And that's key.

"Management practices can only go so far in reducing losses due to this disease. You can't always control the conditions to avoid disease spread," Jamann says. "Ultimately host resistance is going to be critical."

Back in 2015, an interdisciplinary group of research scientists made their case during a business pitch competition: They want to create a subscription-based service, much like 23andMe, through which people could send in samples for detailed analyses. The researchers would crunch that big data fast, using a speedy algorithm, and would send the consumer a detailed report.

But rather than ancestry testing via cheek swab, the team sought to determine the plethora of diverse bacterial species that reside inside an individual's gut in their ultimate aim to improve public health.

Hiroki Morizono, Ph.D., a member of that team, contributed detailed knowledge of Bacteroides, a key organism amid the diverse array of bacterial species that co-exist with humans, living inside our guts. These symbiotic bacteria convert the food we eat into elements that ensure their well-being as well as ours.

"Trillions of bacteria live in the gut. Bacteroides is one of the major bacterial species," says Morizono, a principal investigator in the Center for Genetic Medicine Research at Children's National in Washington, D.C. "In our guts they are usually good citizens. But if they enter our bloodstream, they turn evil; they're in the wrong place. If you have a bacteroides infection, the mortality rate is 19%, and they resist most antibiotic treatments."

The starting point for their project - as well as step one for better characterizing the relationship between gut bacteria and human disease - is taking an accurate census count of bacteria residing there.

In a paper published Sept. 11, 2019, in PLOS ONE, a multi-institutional research team led by George Washington University (GW) faculty did just that, finding 157 different types of organisms (eight phyla, 18 classes, 23 orders, 38 families, 59 genera and 109 species) living inside the guts of healthy volunteers.

The study participants were recruited through flyers on the GW Foggy Bottom campus and via emails. They jotted down what they ate and drank daily, including the brand, type and portion size. They complemented that food journal by providing fecal samples from which DNA was extracted. Fifty fecal metagenomics samples randomly selected from the Human Microbiome Project Phase I research were used for comparison purposes.

"The gut microbiome inherently is really, really cool. In the process of gathering this data, we are building a knowledge base. In this paper, we're saying that by looking at healthy people, we should be able to establish a baseline about what a normal, healthy gut microbiome should look like and how things may change under different conditions," Morizono adds.

And they picked a really, really cool name for their bacteria abundance profile: GutFeelingKB.

"KB is knowledge base. Our idea, it's a gut feeling. It's a bad joke," he admits. "Drosophila researchers have the best names for their genes. No other biology group can compete. We, at least, tried."

Next, the team will continue to collect samples to build out their bacteria baseline, associate it with clinical data, and then will start looking at the health implications for patients.

"One thing we could use this for is to understand how the bacterial population in the gut changes after antibiotic treatment. It's like watching a forest regrow after a massive fire," he says. "With probiotics, can we do things to encourage the right bacteria to grow?"

Its size and surface gravity are much larger than Earth's, and its radiation environment may be hostile, but a distant planet called K2-18b has captured the interest of scientists all over the world. For the first time, researchers have detected water vapor signatures in the atmosphere of a planet beyond our solar system that resides in the "habitable zone," the region around a star in which liquid water could potentially pool on the surface of a rocky planet.

Astronomers at the Center for Space Exochemistry Data at the University College London in the United Kingdom used data from NASA's Hubble Space Telescope to find water vapor in the atmosphere of K2-18b, an exoplanet around a small red dwarf star about 110 light-years away in the constellation Leo. If confirmed by further studies, this will be the only exoplanet known to have both water in its atmosphere and temperatures that could sustain liquid water on a rocky surface. Liquid water would only be possible if the planet turns out to be terrestrial in nature, rather than resembling a small version of Neptune.

Given the high level of activity of its red dwarf star, K2-18b may be more hostile to life as we know it than Earth, as it is likely to be exposed to more high-energy radiation. The planet, discovered by NASA's Kepler Space Telescope in 2015, also has a mass eight times greater than Earth's. That means the surface gravity on this planet would be significantly higher than on our planet.

The team used archive data from 2016 and 2017 captured by Hubble and developed open-source algorithms to analyze the host star's light filtered through K2-18b's atmosphere. The results revealed the molecular signature of water vapor, and also suggest the presence of hydrogen and helium in the planet's atmosphere.

The authors of the paper, published in Nature Astronomy, believe that other molecules, including nitrogen and methane, may be present but they remain undetectable with current observations. Further studies are required to estimate cloud coverage and the percentage of atmospheric water present. A paper from a different team of scientists using Hubble observations has been submitted to the Astronomical Journal.

K2-18b is one of hundreds of "super-Earths" -- exoplanets with masses between those of Earth and Neptune -- found by Kepler. NASA's TESS mission is expected to detect hundreds more super-Earths in the coming years. The next generation of space telescopes, including the James Webb Space Telescope, will be able to characterize exoplanet atmospheres in more detail.

The Hubble Space Telescope is a project of international cooperation between ESA (the European Space Agency) and NASA.

An evolution revolution has begun after scientists extracted genetic information from a 1.77 million-year-old rhino tooth - the largest genetic data set this old to ever be confidently recorded.

Researchers identified an almost complete set of proteins, a proteome, in the dental enamel of the now-extinct rhino and the resulting genetic information is one million years older than the oldest DNA sequenced from a 700,000-year-old horse.

The findings by scientists from the Faculty of Health and Medical Sciences, University of Copenhagen, and St John's College, University of Cambridge, are published today in Nature. They mark a breakthrough in the field of ancient molecular studies and could solve some of the biggest mysteries of ancient animal and human biology by allowing scientists to accurately reconstruct evolution from further back in time than ever before.

'For 20 years ancient DNA has been used to resolve questions about the evolution of extinct species, adaptation and human migration but it has limitations. For the first time we have retrieved ancient genetic information which allows us to reconstruct evolution way beyond the usual time limit of DNA preservation', Professor Enrico Cappellini, Associate Professor in Palaeoproteomics at the Globe Institute, University of Copenhagen, and first author on the paper, says.

'This new analysis of ancient proteins from dental enamel will start an exciting new chapter in the study of molecular evolution.'

For example, the reliance on DNA analysis allowed to genetically track the processes of evolution behind the origins of our species that occurred approximately in the last 400,000 years. However, considering the lineages leading to our species and to the chimp (the living species closest to us) branched apart approximately six to seven million years ago, it means that we currently have no genetic information from more than 90% of the path of evolution that led to us.

Accordingly, we still don't know what exactly is the genetic relation between us and, for example, Homo erectus - the oldest known species of humans to have had modern human-like body proportions -, or between us and the Australopithecus group of species, which includes the iconic fossil commonly referred to as Lucy.

Ancient protein sequencing, based on a ground-breaking technology called mass spectrometry, has now been able to retrieve genetic information from a 1.77 million year old Stephanorhinus - an extinct rhinoceros which lived in Eurasia during the Pleistocene. The researchers extracted protein remains of dental enamel from a fossil tooth, which was discovered in Dmanisi, Georgia, and used mass spectrometry to sequence the ancient proteins and retrieve genetic information previously unobtainable using DNA sequencing.

Tooth enamel is the hardest material present in mammal body. In this study researchers discovered that the set of proteins it contains lasts longer than DNA and is genetically more informative than collagen, the only other ancient protein so far retrieved in fossils older than one million year.

Ultimately, mass spectrometry-based ancient protein sequencing expands the possibilities of retrieving reliable and rich genetic information from mammal fossils to those which are millions, rather than just thousands, of years old.

'With the new, protein-sequencing based method the possibilities of genetic information have been stretched beyond ancient DNA', Professor and co-corresponding author, Jesper Velgaard Olsen from the Novo Nordisk Foundation Center for Protein Research explains.

'Basically, this approach can tell us not only the species and the gender of an ancient fossil, but we can also draw an evolutionary line - all from a single tooth', he says.
'Dental enamel is extremely abundant and it is highly durable, which is why a high proportion of fossil records are teeth', Enrico Cappellini adds.

'We have been able to find a way to retrieve genetic information that is more informative and reliable than any other source of comparable age before, and it's from a material that is abundant in the fossil records so the potential of the application of this approach is extensive.'

The sequencing of the ancient proteome from the Dmanisi Stephanorhinus fossil has led the researchers to integrate it in the evolutionary tree including other extinct and extant rhinoceros species and to define its genetic relation with them, lead author on the paper Professor Eske Willerslev explains. Eske Willerslev holds positions at St John's College, University of Cambridge, and is director of The Lundbeck Foundation Centre for GeoGenetics at the University of Copenhagen.

'There are extinct species of early humans that we haven't been able to get any DNA from - species like Homo Erectus. The remains we have are too old and too poorly preserved for the DNA to survive', he says.

'This research is a game-changer that opens up a lot of opportunities for further evolutionary studies in terms of humans as well as mammals. It will revolutionise the methods of investigating evolution based on molecular markers and it will open a complete new field of ancient molecular studies.'

This rearranging of the evolutionary lineage of a single species may seem like a small adjustment but identifying changes in numerous extinct mammals and humans could lead to massive shifts in our understanding of the way animal life has evolved. The team of scientists are already implementing the findings in their current research.

The discovery could enable scientists across the globe to collect the genetic data of ancient fossils and to build a bigger, more accurate picture of the evolution of hundreds of species including our own.

"We eat first with our eyes."

This comment has been attributed to Marcus Gavius Apicius, a 1st Century Roman gourmand. Two thousand years later, academic research backs up Apicius' statement, as a team of marketing professors at the Fowler College of Business at San Diego State University (SDSU) have studied the sensory impact of food and the evolution of healthy eating.

SDSU associate professor, Dr. Morgan Poor, who has studied the impact of food on the senses knows firsthand how just an image of food can have a sensory and emotional effect on individuals. "Seeing a photo of a hamburger, for example, can stimulate other sensory images, causing individuals to imagine the taste or smell of that hamburger," she noted.

World Wide Health Crisis

Unfortunately, the pleasing aesthetics and easy access to unhealthy foods (such as hamburgers), along with limited access to healthy foods, may be leading to a worldwide health crisis. In fact, statistics released by the World Health Organization (WHO) show that 39 percent of all adults in the world are overweight and 13 percent are obese meaning they have a body mass index (BMI) of 30 or more. The organization also noted that global obesity rates have nearly tripled since 1975.

Making Healthy Food Attractive is Key

One solution to obesity may involve focusing on the pleasure of eating which could be used a tool to promote healthy food choices. Research conducted by SDSU marketing professors Dr. Paula Peter, Dr. Iana Castro, and Dr. Sunaina Chugani, and recently published in the Journal of Business Research (print edition available July 2019), determined that associating healthy food with pleasurable experiences and emotions led to greater interest in purchasing or eating it.

The researchers cited a successful marketing campaign by Bolthouse Farms to reverse the sales decline of their brand of baby carrots. The campaign did not emphasize the carrots' healthy qualities, but embraced the sensory pleasure derived from eating them. For example, the neon orange color, crispy texture and crinkly sound of the packaging mimicked some of the characteristics of certain "junk foods" and led to an increase in product sales of 10 to 12 percent.

Breaking down Barriers to Healthy Foods

In the same research, the professors also noted that the two primary barriers to building pleasurable experiences around healthy foods are time and money. Time is needed to seek out the necessary ingredients to assemble a healthy meal or find a restaurant that serves good tasting, healthy food, where money is needed to purchase the restaurant meals or the ingredients (as well as the knives, pans and other tools) to create the end product. Based on numerous studies, the professors concluded that money, more so than distance to the food or lack of time, is the primary barrier to healthy food access.

Castro has done extensive research on access to healthy foods (including fresh produce) for people living in lower income and ethnically-diverse neighborhoods. Residents of underserved communities do not always have access to supermarkets and may rely on smaller food stores, liquor stores or corner stores to meet their food needs. These smaller stores are limited in the amount of healthy foods they can offer. However, distributors require minimum order quantities to cover their delivery costs and, in many cases, these minimum order requirements exceed store needs.

In an article that was co-authored by Castro that is forthcoming in Translational Behavioral Medicine*, researchers studied whether stores that accept food assistance payments are able to meet the minimum stocking requirements set by United States Department of Agriculture. While the stocking requirements are meant to increase the amount of healthy food items available in smaller stores, the research suggests that stores are struggling to meet the requirements.

Taking Action

Castro decided she wanted to do more than just study food access challenges in underserved communities - she wanted to find a way to give community residents access to fresh produce while providing SDSU students a learning experience that increased their involvement in tackling pressing issues that impacted the local community.

Castro co-founded BrightSide Produce, a produce distribution service operated by SDSU students, to address the challenges faced by small stores in underserved communities. BrightSide Produce initially launched in June 2017 with five stores in National City, California, but word spread that the produce was popular with customers and profitable for the store owners. As of September 2019, BrightSide Produce was delivering fresh produce to 13 stores in National City, with plans to expand into the City of San Diego by the end of the year.

Respect for the Insect

What's next for academics, cooks and scientists wanting to find healthy, low-fat food sources that are also easily sustainable? Professor Peter is finding evidence to suggest a new food source may be coming to American menus soon:

Bugs.

While eating bugs (entomophagy) may be trending in epicurean circles, they would certainly lack eye appeal to most people and would seem to fly in the face of some of Peter's earlier research emphasizing the aesthetic attributes of healthy foods. However, given the popularity of edible bugs in other cultures, beauty may be in the eye of the beholder.

"Insects such as ants, grasshoppers, crickets and various kinds of larvae have been used as a low-fat source of protein in many parts of the world (especially in Asia), but have found little traction in the Western Hemisphere, especially the U.S.," said Peter. "While many people in Western culture find the practice of eating insects to be repugnant, they are actually high in protein and iron, as well as an inexpensive and sustainable food source."

Will American chefs and lovers of healthy foods be able to make bugs look good enough to eat? Stay tuned - Professor Peter is researching that now.

There's a whole world behind the scenes at natural history museums that most people never see. Museum collections house millions upon millions of dinosaur bones, pickled sharks, dried leaves, and every other part of the natural world you can think of--more than could ever be put on display. Instead, these specimens are used in research by scientists trying to understand how different kinds of life evolved and how we can protect them. And a new study in PLOS ONE delves into how scientists are using digital records of all these specimens.

When digitized, information about what each museum specimen is and where it's from becomes part of a repository called a biodiversity database. In these databases, data on individual organisms, entire populations, and whole ecosystems is now free and accessible. Scientists are beginning to explore hundreds of years' worth of information on organisms and ecosystems simply by going online. "It's an interesting time for biodiversity data and scientific data more broadly," says Joan Damerow, a post-doctoral researcher at the Field Museum and the paper's first author. "The field is growing and people are becoming more aware of the importance of making data free to everyone."

With decades of data available for an animal or plant species, scientists can track what has changed over time and tell a story about a species. A group of researchers, led by Field Museum scientists and researchers from the Florida Museum of Natural History and the Universidad de Navarra, decided to determine exactly how these extensive libraries were being used by scientists to tell stories about animals, ecosystems, and other topics. "In the last 10 years, there has been a massive effort by global institutions to digitize decades' worth of data," says Rüdiger Bieler, curator of invertebrates at the Field Museum. "While a single shell or insect in a collection may not tell a story, these libraries of data create new opportunities to study what is happening to populations of animals over time."

Using keywords that indicated the use of a biodiversity database, the researchers examined the full text of hundreds of published papers. "We wanted to look in depth at specifics in the text, including how people are citing databases, how they're taking data errors into account, and what subjects they are studying." says Damerow, lead author. "We found that there's no efficient or automated way to sort through the text of hundreds of papers at this stage?we had to do it manually."

The researchers were able to see which digital records got the most use. Out of all groups of organisms, biodiversity databases are most commonly used to study plants. Plants are a broad and diverse group, so it may simply take much more research, and many more papers, to classify them and study their populations.

On the other hand, the researchers found that not as many scientists published papers using data from insects. A much smaller proportion of insect specimens have been digitized, compared to plants and vertebrates. That might be because of bugs' small sizes and the vast number of them in museum collections--they're often pinned or preserved by the thousands in jars of alcohol, making it daunting to convert each individual specimen's physical label into a digital record that can be searched on a database. Insect population health can be an indicator of ecosystem health, so digitizing and analyzing insect data is important for ecological and conservation research. "It was interesting to me to confirm that vertebrates have more existing online records than invertebrates," says Petra Sierwald, an associate curator of insects, arachnids, and myriapods at the Field Museum and one of the paper's authors. "Because this showed we still have far to go with invertebrate digitization, it renewed my enthusiasm for digitizing insect specimens."

Damerow and her colleagues found that scientists most often use biodiversity databases to find out where different species are found, how many species are present in a region, and how organisms are related to each other. This kind of information helps scientists track species populations, migration patterns, and the spread of disease--crucial information for conservation and public health research. For instance, scientists can see if animals that normally live in cold regions are retreating farther north to deal with climate change.

As the mechanisms to accurately record and explore information improve and become standardized, the ability to make hypotheses and predictions about what has happened or will happen to animal and plant populations will become even more powerful.

"With the biodiversity loss in many ecosystems right now, it's critical to document where and with what abundance different species exist in an environment," says Damerow. "The biodiversity crisis is making it more urgent that we have a place where information on these ecosystems is easily accessible. As species' populations decline, we need efficient methods that help focus conservation efforts and resources."

An initial baseline healthy gut microbiome database and abundance profile is described in a study published September 11, 2019 in the open-access journal PLOS ONE by Charles Hadley King from George Washington University Medical Center, USA, and colleagues.

Though research interest in the human gut microbiome's importance to overall health continues to grow, there's currently no comprehensive gut microbiome reference list available to researchers and patients. In this study, King and colleagues begin to catalog the organismal makeup of healthy human gut microbiomes, and developed a prototype reporting template for clinicians to relay results to patients.

To compile their database, the authors genetically sequenced 48 fecal samples from sixteen healthy participants recruited from George Washington University campus in Washington, D.C., in addition to using 50 fecal metagenomic samples downloaded from the Human Microbiome Project from individuals screened as "healthy".

After parsing all samples' genomic and metagenomic sequences using a novel software-based workflow, King and colleagues compiled an initial database of confirmed microbes and their relative abundance across all samples, the GutFeelingKB, using NCBI's comprehensive and publicly available genetic information to provide metadata on the organisms described.

The GutFeelingKB describes 157 organisms (155 bacterial and two archaeal organisms) across 60 distinct genera. The largest phylum of bacteria represented was Firmicutes (40 percent of all organisms on the list), which in turn was made up of 20 percent Clostridia, 19 percent Bacterioidia, 17 percent Bifidobacteriales, 14 percent Enterobacterales, and 14 percent Lactobacillales bacteria--classes of bacteria also found in yogurt and other probiotic foods. The authors also note that 84 organisms were common to all of the samples, potentially indicating that these may be core species for the human gut.

This study only recruited sixteen participants, a small sample. But while further studies might continue to identify additional organisms present in healthy guts from around the world, GutFeelingKB is an important first step. The database could act as a starting point for comparative analysis of samples and the development of future patient microbiome treatments.

The authors add: "Our goal is to map the healthy gut microbiome so that we and other researchers can use our data to develop disease specific prediction models."

ITHACA, N.Y. - A new synthetic material that creates a linked sensory network similar to a biological nervous system could enable soft robots to sense how they interact with their environment and adjust their actions accordingly.

The stretchable optical lace material was developed by Ph.D. student Patricia Xu through the Organics Robotics Lab at Cornell University.

"We want to have a way to measure stresses and strains for highly deformable objects, and we want to do it using the hardware itself, not vision," said lab director Rob Shepherd, associate professor of mechanical and aerospace engineering and the paper's senior author. "A good way to think about it is from a biological perspective. A blind person can still feel because they have sensors in their fingers that deform when their finger deforms. Robots don't have that right now."

Shepherd's lab previously created sensory foams that used optical fibers to detect such deformations. For the optical lace project, Xu used a flexible, porous lattice structure manufactured from 3D-printed polyurethane. She threaded its core with stretchable optical fibers containing more than a dozen mechanosensors and then attached an LED light to illuminate the fiber.

When she pressed the lattice structure at various points, the sensors were able to pinpoint changes in the photon flow.

"When the structure deforms, you have contact between the input line and the output lines, and the light jumps into these output loops in the structure, so you can tell where the contact is happening," Xu said. "The intensity of this determines the intensity of the deformation itself."

The optical lace would not be used as a skin coating for robots, Shepherd said, but would be more like the flesh itself. Robots fitted with the material would be better suited for the health care industry, specifically beginning-of-life and end-of-life care, and manufacturing.

While the optical lace does not have as much sensitivity as a human fingertip, which is jam-packed with nerve receptors, the material is more sensitive to touch than the human back. The material is washable, too, which leads to another application: Shepherd's lab has launched a startup company to commercialize Xu's sensors to make garments that can measure a person's shape and movements for augmented reality training.

In Switzerland, more than 400,000 people suffer from type 2 diabetes, a serious metabolic disorder that is constantly increasing. Obesity, by promoting the resistance to the action of insulin - one of the hormones that regulate blood sugar levels - is a major risk factor. However, insulin imbalance may not be the only cause of the onset of diabetes. Indeed, researchers at the University of Geneva (UNIGE) have highlighted another mechanism: indeed, the liver appears to have the ability to produce a significant amount of glucose outside of any hormonal signal. In patients with excess liver fat, this overproduction of glucose could lead to type 2 diabetes, regardless of hormonal circuits. These results, published by the Journal of Biological Chemistry, highlight a novel re-reading of the origin of diabetes in overweight patients.

Blood sugar levels are mainly regulated by two antagonistic hormones: insulin, which lowers blood glucose level, and glucagon, which increases it. The liver plays an essential role in regulating blood glucose levels by producing and redistributing glucose under the influence of these two hormones. Overweight people therefore face two threats: on the one hand, the risk of developing insulin resistance, which is a precursor to type 2 diabetes, and on the other hand, an accumulation of fat in liver cells, which is known as "fatty liver" syndrome. This accumulation of lipids indeed induces an alteration in the morphology and structure of mitochondria, the cells energy plants.

"Do these alterations have an effect on mitochondrial function? Is there a link between liver cell mitochondria, obesity and diabetes? To find out, we focused on a protein called OPA1 which, in its "long" form, in other words its non-degraded form, has the function of maintaining the structure of mitochondria," explains Pierre Maechler, professor at the Department of Cell Physiology and Metabolism and at the Diabetes Faculty Centre of the UNIGE Faculty of Medicine, who led this work.

No glucose production without OPA1 protein

Scientists inactivated the OPA1 function in mice to be able to analyze the exact role of mitochondria. "The liver of mice that do not have the long form of OPA1 loses its ability to produce sugar in just a few weeks," says Lingzi Li, a doctoral student in Professor Maechler's laboratory and the first author of the study. "Liver cell mitochondria then show an altered morphology, confirming their importance in sugar metabolism."

An unexpected discovery on the liver

To refine their analysis, Pierre Maechler and colleagues reintroduced a functional OPA1 protein in mice in which it had previously been deleted. "And the mitochondria have regained their normal morphology, but not their activity," the scientists say. "In this area too, shape does not dictate function! It is not enough for mitochondria to appear normal for them to function properly."

However, the greatest surprise was yet to come. "By observing controls, i.e. healthy mice in which OPA1 had been introduced in its long form, we discovered that, when equipped with these "super-mitochondria", they generated more glucose than necessary, and their liver produced sugar without any hormonal call," enthuses Pierre Maechler. This study therefore undermines the long-held belief that the production of glucose by the liver necessarily depends on external stimuli.

This is the first time that glucose production by the liver has been observed independently of an external signal, and particularly hormonal. This finding may explain the development of type 2 diabetes in patients with a "fatty liver" syndrome, apart from any apparent insulin imbalance. To confirm this, UNIGE researchers are now considering modifying the morphology of liver cell mitochondria in overweight mice to see if this overproduction of glucose can trigger abnormally high blood sugar levels and therefore diabetes

Alzheimer's disease (AD) is the most common cause of dementia but the changes in brain cell function underlying memory loss remains poorly understood. Researchers at the University of Bristol have identified that calcium channel blockers may be effective in treating memory loss.

The team's findings, published in Frontiers in Cellular Neuroscience, found treating a diseased brain cell with a blocker of the L-type channel reduced the number of calcium ions able to flow into the brain cell.

The researchers used fruit flies to study AD, using a fluorescent molecule called GCaMP6f, which reports the amount of calcium ions inside brain cells.

They found that diseased brain cells become overloaded with calcium ions, which at normal levels are important for memory formation. This overload was due to the overproduction of the gene encoding a channel, known as the L-type channel, which allows calcium ions to flow into the cell from outside. More of these channels means more calcium ions are able to flow into the cell, disrupting memory formation. Using a drug to block the L-type channel reversed the effect of disease and reduced the flow of calcium ions to a normal level.

The research team also investigated the memory of fruit flies by testing if they could remember which of two odours had previously been paired with an electric shock - similar to Pavlov's experiments with dogs.

While healthy flies remembered well, the diseased flies, like humans, displayed impaired memory. However, if the overproduction of L-type channels was corrected in the diseased flies, their brain cells were no longer overloaded with calcium ions and their memory was just as good as healthy flies. This shows that memory loss is likely due to calcium overload because too many L-type channels are made and, if this is corrected, memory impairment is rescued.

Dr James Hodge, Associate Professor in Neuroscience in the School of Physiology, Pharmacology & Neuroscience, said: "Memory loss in Alzheimer's disease (AD) is a highly distressing and difficult to treat symptom. Targeting the early changes in brain cell function - before they begin to degenerate - may be effective in treating memory loss.

"L-type channels have been thought to have a role in AD for some time and this study shows a direct link between memory loss and L-type channel overproduction in brain cells."

In humans suffering with AD, blocking these channels may be beneficial in treating memory impairment. The findings show that further work should be carried out to determine the mechanism underlying the recovery of memory and whether or not the team's research will prove effective in humans.

Since 2012, researchers at the Division of Bedrock Geology in the Department of Geology of Tallinn University of Technology Aivo Lepland and Tõnu Martma have been engaged in the research of an international research group investigating the factors controlling methane seepages and reconstructing the chronology of past methane emissions in one of the world's most climate-sensitive regions - the Barents Sea in the Arctic.

"Methane is one of the most aggressive climate-warming greenhouse gases, while being also an important energy resource. Changes of methane concentrations in the atmosphere have a major impact on the Earth's climate. Optimal use of methane with minimal climate effects therefore requires a very good understanding of the processes of methane generation and migration. To better understand the processes and forecast future trends, the scientists analyse not only current processes, but those that occurred during the geologic evolution of the Earth, i.e. the processes related to methane circulation that have taken place over millions of years," says a member of the research group, geologist Aivo Lepland.

The respected scientific journal Science Advances published recently the article "A 160,000-year-old history of tectonically controlled methane seepage in the Arctic" co-authored by TalTech geologists in cooperation with their colleagues at the Geological Survey of Norway, British Geological Survey and the University of Tromsø and the University of Bremen, who studied the chronology and geological factors controlling methane release in the Barents Sea off Svalbard.

To study the past deep-sea methane release episodes, the scientists analysed carbonate crusts that form when methane emanating vigorously from the seafloor comes into contact with sulphate in seawater. In the course of this process small amounts of uranium contained in sea water are incorporated into the crystallizing carbonates. Uranium is a radioactive element, which decays to form thorium. By measuring the concentrations of uranium and thorium in carbonate crusts, the scientists can determine the time of crystallisation of the minerals. "Opening of the "birth certificates" of the carbonate crusts through uranium and thorium analysis makes it possible to reconstruct the chronology of past seabed methane emissions and assess their causes," says Lepland.

The samples collected from the 1,200 m deep seabed revealed three major emission episodes from the Arctic seabed in the last 160,000 years: after the end of the last ice age around 23,000 years ago, 40-50 000 years ago, and 150,000 years ago. Each methane release episode lasted 10,000 to 20,000 years. Such chronology suggests that the methane emissions are linked to the glacial cycles. The pressure caused by the weight of a couple of kilometres thick ice sheet caused tensions in seabed rocks and opening of fracture systems allowing the upward flow of gases from deep subsurface strata.

The novelty of the findings lies in the fact that it is the first time that deep-sea methane emissions have been linked to ice ages. The growing and melting of ice sheet affect the tectonic regime in the earth's crust, triggering methane release episodes, which could have had an impact on the climate. So it is a kind of a closed circle. "How much methane was emitted exactly this way and what were the climate effects, however, requires further investigation," Lepland adds.

Some creatures, such as chameleons and neon tetra fish, can alter their colors to camouflage themselves, attract a mate or intimidate predators. Scientists have tried to replicate these abilities to make artificial "smart skins," but so far the materials haven't been robust. Now, researchers reporting in ACS Nano have taken a page from the chameleon's playbook to develop a flexible smart skin that changes its color in response to heat and sunlight.

The hues of chameleon skin rely not on dyes or pigments as most colors do, but instead on arrays of tiny structures known as photonic crystals. Light reflects from these microscopic surfaces and interferes with other beams of reflected light, producing a color. The hue changes when the distance between photonic crystals varies -- for example, when a chameleon tenses or relaxes its skin. To mimic these natural abilities, scientists have embedded photonic crystals in flexible materials, such as hydrogels, and changed their colors by contracting or expanding the material like an accordion. However, these large fluctuations in size can strain the materials and cause them to buckle. Khalid Salaita and colleagues wanted to take a closer look at chameleon skin and use what they learned to design a strain-accommodating smart skin.

By watching time-lapse images of chameleon skin, the researchers noticed that only a small fraction of skin cells actually contain photonic crystal arrays, while the rest are colorless. The team reasoned that the colorless cells might help accommodate the strain when the photonic crystals contract and expand. Inspired by this observation, the researchers patterned arrays of photonic crystals in a hydrogel and then embedded these arrays in a second, non-color-changing hydrogel that acted as a supporting layer. Upon heating, the resulting material changed color but remained the same size. The smart skin also altered its hue in response to natural sunlight, similar to how a tetra fish does. The new material could someday find applications in camouflage, signaling and anti-counterfeiting, the researchers say.

Solar cells that use mixtures of organic molecules to absorb sunlight and convert it to electricity, that can be applied to curved surfaces such as the body of a car, could be a step closer thanks to a discovery that challenges conventional thinking about one of the key components of these devices.

A basic organic solar cell consists of a thin film of organic semiconductors sandwiched between two electrodes which extract charges generated in the organic semiconductor layer to the external circuit. It has long been assumed that 100% of the surface of each electrode should be electrically conductive to maximise the efficiency of charge extraction.

Scientists at the University of Warwick have discovered that the electrodes in organic solar cells actually only need ?1% of their surface area to be electrically conductive to be fully effective, which opens the door to using a range of composite materials at the interface between the electrodes and the light harvesting organic semiconductor layers to improve device performance and reduce cost. The discovery, published today (11 September), is reported in Advanced Functional Materials.

The academic lead, Dr Ross Hatton from the University's Department of Chemistry, said: "It's widely assumed that if you want to optimise the performance of organic solar cells you need to maximize the area of the interface between the electrodes and the organic semiconductors. We asked whether that was really true."

The researchers developed a model electrode that they could systematically change the surface area of, and found that when as much as 99% of its surface was electrically insulating the electrode still performs as well as if 100% of the surface was conducting, provided the conducting regions aren't too far apart.

High performance organic solar cells have additional transparent layers at the interfaces between the electrodes and the light harvesting organic semiconductor layer that are essential for optimising the light distribution in the device and improving its stability, but must also be able to conduct charges to the electrodes. This is a tall order and not many materials meet all of these requirements.

Dr Dinesha Dabera, the post-doctoral researcher on this Leverhulme Trust funded project, explains:"This new finding means composites of insulators and conducting nano-particles such as carbon nanotubes, graphene fragments or metal nanoparticles, could have great potential for this purpose, offering enhanced device performance or lower cost.

"Organic solar cells are very close to being commercialised but they're not quite there yet, so anything that allows you to further reduce cost whilst also improving performance is going to help enable that."

Dr Hatton, who will be interviewed by Serena Bashal of the UK Youth Climate Coalition at the British Science Festival this week, explains: "What we've done is to demonstrate a design rule for this type of solar cell, which opens up much greater possibilities for materials choice in the device and so could help to enable their realisation commercially.''

Organic solar cells are potentially very environmentally friendly, because they contain no toxic elements and can be processed at low temperature using roll-to-roll deposition, so can have an extremely low carbon footprint and a short energy payback time.

Dr Hatton explains: "There is a fast growing need for solar cells that can be supported on flexible substrates that are lightweight and colour-tuneable. Conventional silicon solar cells are fantastic for large scale electricity generation in solar farms and on the roofs of buildings, but they are poorly matched to the needs of electric vehicles and for integration into windows on buildings, which are no longer niche applications. Organic solar cells can sit on curved surfaces, and are very lightweight and low profile.

"This discovery may help enable these new types of flexible solar cells to become a commercial reality sooner because it will give the designers of this class of solar cells more choice in the materials they can use."

A chameleon can alter the color of its skin so it either blends into the background to hide or stands out to defend its territory and attract a mate. The chameleon makes this trick look easy, using photonic crystals in its skin. Scientists, however, have struggled to make a photonic crystal "smart skin" that changes color in response to the environment, without also changing in size.

The journal ACS Nano is publishing research led by chemists at Emory University that found a solution to the problem. They developed a flexible smart skin that reacts to heat and sunlight while maintaining a near constant volume.

"Watching a chameleon change colors gave me the idea for the breakthrough," says first author Yixiao Dong, a PhD candidate in Emory's Department of Chemistry. "We've developed a new concept for a color-changing smart skin, based on observations of how nature does it."

"Scientists in the field of photonic crystals have been working for a long time to try to create color-changing smart skins for a range of potential applications, such as camouflage, chemical sensing and anti-counterfeiting tags, " adds Khalid Salaita, senior author of the paper and an Emory professor of chemistry. "While our work is still in the fundamental stages, we've established the principles for a new approach to explore and build upon."

Co-authors of the paper include Alisina Bazrafshan and Dale Combs (Emory PhD students); Kimberly Clarke (an Emory post-doctoral fellow); and Anastassia Pokutta, Fatiesa Sulejmani and Wei Sun (from Georgia Tech's Wallace H. Coulter Department of Biomedical Engineering).

Besides chameleons, many other creatures have evolved the ability to change color. The stripes on a neon tetra fish, for example, turn from deep indigo to blue-green when they swim into sunlight.

The coloration in these organisms is not based on pigments, but on tiny particles in a repeating pattern, known as photonic crystals. The periodicity in these particles causes the material to interfere with wavelengths of light. Although the particles themselves are colorless, the precise spacing between them allows certain light waves to pass through them while rejecting others. The visible colors produced change depending on factors such as lighting conditions or shifts in the distance between the particles. The iridescence of some butterfly wings and the feathers of peacocks are among many other examples of photonic crystals in nature.

If you put strawberries into a blender, Dong explains, the resulting liquid will be red because the color of the strawberries comes from pigment. If you grind up iridescent butterfly wings, however, the result will be a dull powder because the rainbow colors were not based on pigments, but on what is known as "structural color." The structure of the photonic crystal arrays is destroyed when the butterfly wings are ground up.

To mimic chameleons and create an artificial smart skin, scientists have experimented with embedding photonic crystal arrays into flexible, water-containing polymers, or hydrogels. Expanding or contracting the hydrogel changes the spacing between the arrays, resulting in a color change. The problem, however, is that the accordion-like action needed to generate a visible change in hue causes the hydrogel to significantly grow or shrink in size, leading to structural instability and buckling of the material.

"No one wants a camouflage cloak that shrinks to change color," Salaita notes.

Dong was pondering the problem while watching YouTube videos of a chameleon. "I wanted to understand why a chameleon doesn't get bigger or smaller as it changes color, but remains its original size," he says.

In close-up, time-lapsed images of the chameleon changing hues, Dong noticed that the arrays of photonic crystals did not cover the entire skin but were spread out within a dark matrix. As the photonic crystals turned different colors, these patches of color remained the same distance apart. Dong hypothesized that the skin cells making up the dark matrix somehow adjusted to compensate for the shifts in the photonic crystals.

"I wondered if we could design something similar -- a composite structure of photonic crystal arrays embedded into a strain-accommodating matrix," Dong says.

The researchers used magnets to arrange patterns of photonic crystals containing iron oxide within a hydrogel. They then embedded these arrays into a second, non-color-changing hydrogel. The second, springy hydrogel was mechanically matched to the first hydrogel to compensate for shifts in distances between the photonic crystals. When heated, this strain-accommodating smart skin (SASS) changes color but maintains a near-constant size.

Dong also tested the material in sunlight, fabricating SASS films into the shape of a fish, in homage to the neon tetra, as well as into the shape of a leaf. When exposed to natural sunlight for 10 minutes, the SASS films shifted from orange to green, without changing in size.

"We've provided a general framework to guide the future design of artificial smart skins," Dong says. "There is still a long way to go for real-life applications, but it's exciting to push the field another step further."

WASHINGTON, D.C. (Sept. 10, 2019) – The Trump administration’s “public charge” rule, which would subject legal immigrants to a public charge determination if they use public health, nutrition and housing benefits for which they are eligible, represents a major threat to health, according to a “friend of the court” brief filed Sept. 10. The brief is signed by the American Public Health Association, American Academy of Nursing, and more than 60 deans and scholars from 27 schools of public health, public policy, nursing and medicine. The amicus brief has been presented to courts in multiple legal challenges to the rule now pending in federal courts in New York and California. The deans and scholars are urging the courts to block the rule from taking effect.

The rule, finalized by the U.S. Department of Homeland Security in August, allows immigration officials to designate immigrants as a “public charge” if they utilize certain “public benefits,” including many forms of Medicaid, certain types of federal housing assistance or Supplemental Nutrition Assistance Program (SNAP) benefits. Immigrants also can be labeled as a public charge if they have medical conditions requiring “extensive” health care – a term that the rule fails to define. Being designated as a public charge can disqualify immigrants from permission to enter the country or to achieve “green card” status as permanent legal residents. The amicus brief argues that the rule threatens the health of immigrants, their families, the health care safety net and entire communities in which they live. Half the U.S. population lives in communities where at least one in 10 residents is an immigrant.

“In the name of ‘self–sufficiency,’ this rule threatens dire consequences for millions of hard-working immigrants and their families and the nation’s public health,” said Lynn R. Goldman, MD, MS, MPH, the Michael and Lori Milken Dean of the George Washington University Milken Institute School of Public Health (Milken Institute SPH) and one of the amici who signed the brief. “If allowed to stand, this rule will cause immigrants to forgo services for which they are eligible and to avoid seeking necessary health care, especially preventive care. This rule will result in a spike of preventable illness and death.”

The brief argues that the Trump administration acted arbitrarily, capriciously and contrary to law when it finalized this rule, which bars lawful permanent residence to people determined likely to become so-called public charges.

Scholars state that the administration ignored or dismissed more than 266,000 comments from public health officials and others who warned that the rule was a threat to the public health.

The rule jeopardizes health care, with immigrants and their families opting to forgo critical benefits related to basic health needs, including immunizations that can keep an entire community healthy. The scholars state the rule will cause a substantial drop in enrollment in Medicaid and other essential health programs, leading to poor health outcomes and an increase in death rates.

Such a drop in Medicaid enrollment not only un-insures patients but results in falling Medicaid revenue that will affect the ability of health care safety net providers such as community health centers to serve all residents of their communities. An analysis prepared by the Geiger Gibson/RCHN Community Health Foundation Research Collaborative, concludes that as a result of declining Medicaid revenue, health centers across the nation could serve between 136,000 and 407,000 fewer patients annually. The brief further points out that patients may simply cease to obtain care they need, insured or otherwise, since having a medical condition that requires care can jeopardize the ability to remain in the U.S. Immigrants simply may forgo care for themselves and their families entirely, fearing the consequences.

The scholars also argue that the rule’s impact on the Medicaid program will lead to higher death rates, not just among immigrants but U.S. citizens as well. In a declaration filed in the U.S. District Court for the Northern District of California, Leighton Ku, PhD, a professor of health policy and management at Milken Institute SPH, concluded the “public charge” rule will cause between one and three million members of immigrant families, including U.S. citizens, to disenroll from or forgo Medicaid benefits each year, even if eligible. The loss would substantially reduce the ability of many racial and ethnic minority groups, especially Hispanic and Asian families, to afford health care and would lead to serious health problems. As a result, Ku states, there could be as many as 1,300 to 4,000 excess premature deaths per year.

The brief, which can be accessed here, was filed in the U.S. District Court for the Southern District of New York on Sept. 10. The deans and scholars, American Public Health Association, representing 25,000 public health professionals, and American Academy of Nursing, representing 2,600 nursing professionals, were represented by Ted Waters, Phillip A. Escoriaza and Christopher J. Frisina, of Feldesman Tucker Leifer Fidell, LLP of Washington, D.C.

The brief was produced with support from the Robert Wood Johnson Foundation (RWJF). The public health scholars who signed the brief did so in their individual capacities; views expressed are their own and do not represent affiliated universities or RWJF.