Tech

Researchers at the National Institutes of Health have developed a breath test that measures how well patients with methylmalonic acidemia (MMA) respond to receiving liver or combined liver and kidney transplantation. Researchers also used the test to assess the severity of the disease in people and help determine if they would benefit from surgical or experimental genomic therapies that target the liver. The study results were published in Genetics in Medicine. Scientists at the National Human Genome Research Institute (NHGRI) led the project team, with collaborators from the National Institute of Diabetes and Digestive and Kidney Diseases and the National Institute of Mental Health.

MMA is a rare genomic disease that impairs the body's ability to metabolize certain proteins and fats. This causes toxic substances to build up, which may result in kidney disease, pancreatitis, movement disorders, intellectual impairments, complications in many organs, and, in severe cases, death. One in 80,000 children born in the United States are diagnosed with MMA during newborn screenings. Currently, MMA is incurable, but people with MMA manage their symptoms through dietary restrictions and vitamin supplements. In extreme cases, patients receive liver or combined liver and kidney transplants, which help restore normal levels of metabolic proteins.

"Vast fluctuations in metabolic substances in the bodies of patients make it difficult for us to tell if treatments like genome editing and transplants are likely to be successful," said Charles P. Venditti, M.D., Ph.D., senior author and senior investigator in the NHGRI Medical Genomics and Metabolic Genetics Branch. "Instead of looking at levels, we decided to measure metabolism itself."

One form of MMA is caused by mutations in the methylmalonyl-CoA mutase gene (MMUT), which encodes for the MMUT protein. People with this form of MMA have a deficiency in the MMUT protein, which plays a pivotal part in metabolism. The protein is involved in the biological steps that help break down food, fats, cholesterol and amino acids.

MMUT helps break down food into a chemical byproduct called propionate, which is followed by an integral process involved in metabolism called oxidation. Through oxidation, a healthy body converts propionate into energy and carbon dioxide, which is exhaled, but that process is faulty for people with MMA.

Because MMUT protein function is compromised in people with MMA, Venditti and his team chose to assess how well the MMUT protein helped break down propionate in both patients who did and not did not receive treatment. The researchers believed this would act as a proxy for how much oxidation was happening in a patient's body.

"We wanted to measure exhaled carbon dioxide because we planned to use a breath test to track oxidation of propionate in a non-invasive way," said Irini Manoli, M.D., Ph.D., co-author and associate investigator in the NHGRI Medical Genomics and Metabolic Genetics Branch. "The trick was to somehow 'mark' the carbon dioxide so we could see which patients are unable to oxidize propionate because of a faulty MMUT protein."

Usually, the carbon dioxide we exhale as a result of propionate breaking down in the body contains a lighter, more common form of carbon, carbon 12. But because carbon dioxide that contains carbon 12 is released by several metabolic processes in the human body, simply measuring carbon dioxide exhaled by MMA patients would not show how well MMUT helped oxidize propionate.

To detect if the MMUT protein was functioning properly, researchers gave patients a dose of the heavier, less abundant version of carbon -- carbon 13 -- via a commercially available food additive.

The team recruited 57 study participants, including 19 MMA patients who had received transplants (liver, kidney or both) and 16 healthy volunteers. Researchers gave participants a dose of the food additive containing carbon 13 via a drink or through a feeding tube, and then collected their breath samples after a two-minute wait.

The researchers measured how much of the exhaled carbon dioxide contained the usual carbon 12 compared to added carbon 13. As hypothesized, MMA patients who did not receive any treatment had lower levels of carbon 13 than healthy volunteers. By contrast, MMA patients with liver transplants had higher levels of carbon 13, similar to the healthy volunteers. This result indicated that the MMUT protein was helping oxidize the carbon 13 molecules by bonding with inhaled oxygen molecules.

Higher levels of carbon 13 oxidation also correlated with better clinical outcomes, such as improved cognition and slower decline in kidney function.

Currently, the test is only available for use at the NIH Clinical Center; however, the researchers hope it will soon be broadly adopted for clinical and research use.

"Our next goal is to see if this specialized breath test can detect an increase in carbon 13 propionate oxidation after gene, mRNA or genome editing therapies," Venditti said. "This way, we can also use this test to measure how effective these treatments are in restoring MMUT function."

PULLMAN, Wash. - The ability to control your own behavior, known as executive function, might not exist all in your head. A new theory proposes that it develops with many influences from outside the mind.

The theory, detailed in Perspectives on Psychological Science, draws on dynamic systems theory which originated in mathematics and physics and has been used to describe complex organizing phenomena like cloud formation and flying patterns of birds. Now, a research team led by Washington State University human development assistant professor Sammy Perone is applying it to executive function, which has been shown to play a role in everything from children's readiness for school to their social relationships. Its development is also tied to long-term outcomes for adulthood.

"We propose that executive function is really about using cues from the environment to guide your behavior," said Perone. "As humans we use our experience and norms to decide what's the appropriate path to take, so to encourage executive function development, we want to help children build those connections between cues and appropriate behaviors."

In a classroom, these cues might include things such as decorations on the wall, verbal instructions or the way tables are set up. Eliminating environmental distractions may also help children control their behavior like having sharpened pencils on hand or resolving a tottering desk chair. In addition, physical things normally thought of as peripheral, like whether a child has adequate sleep or enough to eat, also influence executive function, Perone said.

Previously, the dominant view held that executive function was three distinct neurocognitive processes: working memory, inhibitory control, which is the ability to stop yourself from doing something, and cognitive flexibility, which allows you to transition from one activity to the next. This perspective has been called into question, Perone said.

"If these different cognitive processes are what makes up executive function, you would think you could just train those processes, and then, you can then use them everywhere," he said. "Turns out, that doesn't work, and that's been shown over and over again. People think and behave in an environment, so we can't just train executive function by say doing computer exercises on working memory."

The new theory builds on the work of cognitive scientist Sabine Doebel who called for a redefinition of executive function in 2020 as the "development of skills in using control in the service of behavior." Perone and his co-authors from University of Kansas and University of Tennessee expand on that new definition by bringing in dynamics systems theory to help explain how humans use a variety of external factors to organize their behavior.

"We need to think more about executive function as it operates--as goal-directed behavior in the real world," Perone said. "When you take that perspective, all of the sudden, it becomes much more practical to childcare providers and parents, because that's where kids are thinking and behaving and developing."

Developing new materials and novel processes has continued to change the world. The M3I3 Initiative at KAIST has led to new insights into advancing materials development by implementing breakthroughs in materials imaging that have created a paradigm shift in the discovery of materials. The Initiative features the multiscale modeling and imaging of structure and property relationships and materials hierarchies combined with the latest material-processing data.

The research team led by Professor Seungbum Hong analyzed the materials research projects reported by leading global institutes and research groups, and derived a quantitative model using machine learning with a scientific interpretation. This process embodies the research goal of the M3I3: Materials and Molecular Modeling, Imaging, Informatics and Integration.

The researchers discussed the role of multiscale materials and molecular imaging combined with machine learning and also presented a future outlook for developments and the major challenges of M3I3. By building this model, the research team envisions creating desired sets of properties for materials and obtaining the optimum processing recipes to synthesize them.

"The development of various microscopy and diffraction tools with the ability to map the structure, property, and performance of materials at multiscale levels and in real time enabled us to think that materials imaging could radically accelerate materials discovery and development," says Professor Hong.

"We plan to build an M3I3 repository of searchable structural and property maps using FAIR (Findable, Accessible, Interoperable, and Reusable) principles to standardize best practices as well as streamline the training of early career researchers."

One of the examples that shows the power of structure-property imaging at the nanoscale is the development of future materials for emerging nonvolatile memory devices. Specifically, the research team focused on microscopy using photons, electrons, and physical probes on the multiscale structural hierarchy, as well as structure-property relationships to enhance the performance of memory devices.

"M3I3 is an algorithm for performing the reverse engineering of future materials. Reverse engineering starts by analyzing the structure and composition of cutting-edge materials or products. Once the research team determines the performance of our targeted future materials, we need to know the candidate structures and compositions for producing the future materials."

The research team has built a data-driven experimental design based on traditional NCM (nickel, cobalt, and manganese) cathode materials. With this, the research team expanded their future direction for achieving even higher discharge capacity, which can be realized via Li-rich cathodes.

However, one of the major challenges was the limitation of available data that describes the Li-rich cathode properties. To mitigate this problem, the researchers proposed two solutions: First, they should build a machine-learning-guided data generator for data augmentation. Second, they would use a machine-learning method based on 'transfer learning.' Since the NCM cathode database shares a common feature with a Li-rich cathode, one could consider repurposing the NCM trained model for assisting the Li-rich prediction. With the pretrained model and transfer learning, the team expects to achieve outstanding predictions for Li-rich cathodes even with the small data set.

With advances in experimental imaging and the availability of well-resolved information and big data, along with significant advances in high-performance computing and a worldwide thrust toward a general, collaborative, integrative, and on-demand research platform, there is a clear confluence in the required capabilities of advancing the M3I3 Initiative.

Professor Hong said, "Once we succeed in using the inverse "property?structure?processing" solver to develop cathode, anode, electrolyte, and membrane materials for high energy density Li-ion batteries, we will expand our scope of materials to battery/fuel cells, aerospace, automobiles, food, medicine, and cosmetic materials."

Buck Institute researchers have discovered and are developing a novel, non-invasive biomarker test that can be used to measure and track performance of senolytics: a class of drugs that selectively eliminate senescent cells. The discovery is expected to play a major role in efforts to develop treatments that would battle a myriad of chronic age-related conditions that range from arthritis to lung disease to Alzheimer's disease and glaucoma. This biomarker is a unique signaling lipid metabolite, normally exclusively intracellular, but is released when senescent cells are forced to die. This metabolite is detectible in blood and urine, making non-invasive testing possible. With a growing list of senolytic drugs in development, detecting this metabolite via a companion test could verify performance of senolytic candidates.

"The list of age-related diseases definitively linked to cellular senescence keeps growing, as does the number of biotech companies racing to develop drugs to eliminate senescent cells," said Buck professor Judith Campisi, PhD, senior scientist on the study. "While the field has never been more promising, the lack of a simple biomarker to measure and track efficacy of these treatments has been a hindrance to progress. We are excited to bring this new biomarker to the field and look forward to it being used in the clinic."

Understanding senescence and identifying lipids as a new and potent component of the SASP

During cellular senescence, stressed or damaged cells permanently stop dividing, a putative mechanism to safeguard against cancer. Senescent cells are not dead - they spew out a stew of bioactive molecules that promote wound healing and chronic inflammation, the latter playing a major role in many age-related diseases as the cells accumulate over time. This bioactive stew is known as the SASP (senescence-associated secretory phenotype); its composition, and deleterious effects have been well-studied.

This work, performed in human cell culture and mice, shows that senescent cells also synthesize a large array of oxylipins, bioactive metabolites derived from the oxygenation of polyunsaturated fatty acids. "Lipid components of the SASP have been vastly understudied,” says lead scientist Christopher Wiley, PhD, a former assistant research professor at the Buck, now at the Jean Mayer USDA Human Nutrition Research Center on Aging at Tufts University, Boston. "The biosynthesis of these signaling lipids promotes segments of the SASP and reinforces the permanent growth arrest of senescent cells. This work provides a new way of understanding and studying senescence-driven pathology," he said. Oxylipins are implicated in many inflammatory conditions including cardiovascular disease and pain response. Many commonly used drugs, such as aspirin and ibuprofen, act by preventing oxylipin synthesis.

The biomarker is exclusive to senescent cells and may be of interest in cancer research

Wiley says senescent cells change their fatty acid metabolism and they do it in such a way that free polyunsaturated fatty acids accumulate inside the arrested cells where they are used to manufacture oxylipins. Researchers identified one of these fatty acids, 15-deoxy-delta-12, 14-prostaglandin J2 (dihomo-15d-PGJ2), as unique to senescent cells; it accumulates inside senescent cells and is released when the cells die. In this study, mice were given chemotherapy which induces widespread senescence, followed by a senolytic drug. The biomarker was only detected in the blood and urine of mice treated with both chemotherapy and the senolytic, but not with either on its own, confirming specificity for senolysis.

Researchers also showed that dihomo-15d-PGJ2 had a functional role in senescence. Inhibiting its synthesis allowed a subset of cells to escape senescence and continue dividing, and had a less inflammatory SASP profile. Addition of dihomo-15d-PGJ2 to non-senescent cell drove them into senescence by activating RAS, a cancer-promoting gene that is also known to cause senescence.

"We hope that identifying and including these bioactive lipids as part of the SASP will encourage researchers working in a broad range of fields to take a new look at cellular senescence," said Campisi. "The fact that one of these lipids ends up being a simple non-invasive biomarker for tracking the efficacy of treatments is a huge plus for those of us working to stem the ravages of age-related disease."

Aquaculture--the farming of fish, shellfish, and other aquatic animals for food--has reached unprecedented levels of growth in recent years, but largely without consideration of its impact on individual animals, finds a new analysis by a team of researchers.

"The scale of modern aquaculture is immense and still growing," says Becca Franks, a research scientist at New York University's Department of Environmental Studies and the lead author of the paper, which appears in the journal Science Advances. "Yet we know so little about the animals that we are putting into mass production, and the negative consequences of aquaculture's expansion on individual animals will just continue to accumulate."

The study is the first to systematically examine the scientific knowledge about animal welfare for the 408 aquatic animal species being farmed around the world--animals that include salmon, carp, and shrimp. The researchers found that specialized scientific studies about animal welfare--generally defined as an animal's ability to cope with its environment--were available for just 84 species. The remaining 324 species, which represent the majority of aquaculture production, had no information available.

Animal welfare legislation is not new, but in recent years, governments have adopted laws aimed at enhancing enforcement and extending animal protections.

With traditional fishing on the decline, aquaculture has been touted as both a solution to food insecurity and as a means to reduce pressure on species in seas and oceans. However, the growth of aquaculture, or aquafarming, hasn't diminished stress on wild populations. Meanwhile, as recently as 2018, 250 to 408 billion individual animals from more than 400 species were farmed in aquaculture--or about 20 times the number of species farmed in animal agriculture on land--according to the United Nations' Food and Agriculture Organization.

The expansion of aquaculture raises concerns that the industry is moving ahead without sufficient knowledge of the animal life it is growing. The absence of this information signals risk because its operations and decisions are not scientifically based, the researchers note, and can lead to poor living conditions and suffering for the individual animals involved.

To explore this matter, the team, which also included Jennifer Jacquet, an associate professor in NYU's Department of Environmental Studies, and Chris Ewell, an NYU undergraduate at the time of the study, sought to determine what research literature existed on the more than 400 species being farmed in 2018.

Their results showed that only 25 species, or about 7 percent of animals being farmed in aquaculture, had five or more publications on these animals' welfare. By contrast, 231 species had no welfare publications while 59 had only one to four such publications. The remaining 93 did not have species-level taxonomic information, meaning it lacked sufficiently detailed findings on these species.

"While the presence of animal welfare knowledge does not ensure well-being, the absence of such information is troubling," says Franks. "In sum, our research reveals that modern aquaculture poses unparalleled animal welfare threats in terms of the global scope and the number of individual animal lives affected."

The authors emphasize that some aquatic animal species, such as bivalves, which include oysters and clams, may present fewer welfare concerns to begin with and may be a more promising avenue for production.

"Although aquaculture has been around for thousands of years, its current expansion is unprecedented and is posing great risks, but, because it is so new, we can choose a different path forward," Franks says.

SAN FRANCISCO, CA (April 2, 2021) -- In recent years, advancements in DNA sequencing have exposed a large amount of hidden diversity in reef-building corals: species that appear identical to one another but are genetically distinct. Typically ignored as they are invisible to the naked eye, a team of researchers at the California Academy of Sciences and The University of Queensland, along with over a dozen international collaborators, is taking a more holistic approach to understand these hidden species by investigating overlooked ecological differences that have wide-ranging implications for the vulnerability and resilience of reef-building corals. The team hopes that their findings, published today in Current Biology, will lead to a more nuanced consideration of coral diversity, that incorporates more aspects than appearance alone, to drive more strategic conservation planning.

"We know we are greatly underestimating the true number of coral species because of this hidden diversity," says lead author and Academy Curator Pim Bongaerts. "In our study, we provide one of the first clear examples of how coral species that look identical can be very different in terms of their ecology and physiology, from when they reproduce to what depths they prefer. This means that our current framework for classifying reef-building corals based primarily on morphology is limiting our ability to understand and protect them."

By conducting one of the most extensive genomic studies of a coral species to date, which involved obtaining DNA samples from more than 1,400 individuals, the researchers began their study by discovering that the "serpent coral" (Pachyseris speciosa)--one of the most widespread corals across the Indo-Pacific--is actually four different species that evolved millions of years ago. To their surprise, these species were indistinguishable from each other, even at a microscopic level, sparking the researchers to take it a step further and look for ecological differences that may have been missed when they were thought to be one species.

Using remotely-operated vehicles and specialized deep diving gear, the researchers investigated corals from shallow depths down to 80 meters beneath the surface--into the vastly understudied mesophotic zone of coral reefs. They discovered that although individuals from each species could be found over the entire range of depths, they had distinct depths where they were most abundant, with corresponding differences in physiological traits such as protein content that affect their ability to survive and thrive at their preferred depths.

"Knowing what corals thrive where and at which depths is crucial for reef conservation," says study co-author at The University of Queensland Professor Ove Hoegh-Guldberg. "Most marine protected areas only protect shallow reefs, which means that hidden species at mesophotic depths are being overlooked by current conservation strategies. We need to give this gap in protection some further thought."

Besides the physiological and depth differences, the research team also developed a rapid DNA test to be able to identify these species in the field and monitor their reproduction. They discovered that there were differences between the species in the timing of broadcast spawning--the mechanism whereby environmental cues trigger an entire population of corals to synchronously release their gametes. This staggered spawning may provide an explanation for the lack of interbreeding between the species (a common occurrence for many corals) despite living side-by-side on the reef.

"For years we have asked ourselves about the relevance of this hidden diversity, wondering if we are missing something important," says Academy researcher and study co-author Alejandra Hernández-Agreda. "By using all of the tools at our disposal to analyze not just the morphology, but all these other aspects of these species as well, we now show how this hidden diversity can mask major differences in these species that could translate to their ability to cope with the rapidly changing conditions of our world's oceans."

Ultimately, the researchers hope that their findings reveal the importance of taking a holistic approach to understanding these hidden species that appear identical, but may be harboring key differences that impact global conservation efforts.

"At a moment when reefs around the world are experiencing rapid degradation," Bongaerts says, "it is critical to start capturing this hidden diversity--not only of species, but of how they live and function--to improve our understanding and ability to protect these fragile ecosystems."

UNIVERSITY PARK, Pa. -- Like moths to a flame, spotted lanternflies are visually drawn toward and seemingly captivated by vertical objects such as utility poles, a behavior that could be valuable in predicting where the pests might be heading, according to entomologists in Penn State's College of Agricultural Sciences.

Research from the laboratory of Tom Baker, recently published in the Journal of Insect Behavior, is laying the foundation for future strategies to monitor and possibly trap the invasive insect from Asia, which first was found in North America in Berks County, Pennsylvania, in 2014. The planthopper now is confirmed in 34 Pennsylvania counties and several surrounding states.

These findings show that telephone poles attract flight-dispersing spotted lanternflies, which are visually drawn to turn and land on the poles when they are less than about 10 feet away. They remain on the pole for many minutes, even hours, while crawling up toward the top to try to take flight again.

However, a large proportion of those launching themselves from the pole are drawn back to the pole, which serves as a sort of "visual magnet" from which the insects cannot escape for a while. The pole thus attracts and retains a large proportion of the lanternflies that are drawn to it.

"The spotted lanternfly feeds on more than 70 plant species, making it a great concern to U.S. tree-fruit and grape growers, as well as to the forest products industry," said Baker, distinguished professor of entomology and chemical ecology.

"Understanding the how and why of its flight capabilities and its attraction to stimuli from the environment can help us better exploit these behaviors to assess, and possibly thwart, future threats from this pest."

This latest study is an offshoot of experiments on the insect's flight behaviors and dispersal patterns led by Baker and his colleagues Andrew Myrick, assistant research professor of entomology, and Michael Wolfin, postdoctoral research associate.

Their flight-dispersal research efforts began during late summer and early fall in September and October of 2017 and 2018 at a fruit farm near Oley and at Dorney Park in Allentown. Both locations had been severely affected by spotted lanternfly infestations.

Baker's team had found that, in the lanternflies' apparent quest to find new sources of food to complete their development and then mate, they will fly onto and crawl to the top of the nearest vertical surfaces -- including inanimate objects such as buildings and telephone poles and host and nonhost plants -- and launch themselves into the wind.

Because lanternflies cannot generate much lift, only thrust, their normal flight paths conform to gradually descending, straight-line trajectories in which they are able to traverse usually only 30 to 150 feet over the ground before landing.

Baker reported that their landing sites are indiscriminate with respect to species of trees, bushes and inanimate objects. "The lanternflies' forced landings on the ground due to insufficient lift are indiscriminate, too," he said.

An exception to the typical low-to-the-ground flights occurs on days with high temperatures and rising air currents, allowing the low-flying lanternflies to be lifted to higher altitudes, with the now high-flying adults being transported downwind for perhaps thousands of yards.

It is on such occasional late-summer days during the past few years when huge swarms have been deposited by the tens of thousands -- much to the alarm of the human population -- in shopping center parking lots, gas stations, and industrial and residential areas within heavily infested regions, Baker pointed out.

However, he said that the pest's typical, low-to-ground flight coupled with its visual attraction to tall vertical objects may provide an effective and inexpensive way to monitor and even trap the insect.

"Telephone poles, which are plentiful and visible from the roadway, could be used by field scouts to document the presence or absence of spotted lanternfly by driving along and examining the poles at designated intervals," said Baker, who also suggested the possible use of poles as "attract-and-kill stations" to protect designated areas.

Despite the importance of these natural flight-dispersal abilities, a method of travel for the lanternflies that citizens should be very concerned about is human transport of adults and egg masses via trains, trucks and recreational vehicles, noted Baker.

"People who are traveling through, or residing in, an area affected by spotted lanternfly should check their vehicles and items they are transporting before leaving to ensure they are not carrying these unwanted hitchhikers to new locations," he said.

Acomprehensive review published in the journal Psychological Science re-examines previous work that claimed to show a direct link between early screen time and attention problems in children. Although other studies do not reflect these findings, the earlier research continues to be widely reported by the media.

"The findings from the original study, upon further scrutiny, are not borne out. We found that there is still no evidence that TV, by itself, causes ADHD or any kind of attention problems in young children," said Wallace E. Dixon, Jr., a professor of psychology and department head at East Tennessee State University and coauthor of the study. "Our research also tells us that it's important to be skeptical of earth-shattering findings that come in the form of 'something that everybody is doing harms our children.' Extraordinary claims require extraordinary evidence.

"What excites us about the research is that we can ease up on blaming parents or making them feel guilty for letting their children watch television when they are very young," said Dixon.

The newly reported research involved looking at the same data as the 2004 study and using multiverse analyses--a technique that involves asking a research question hundreds of different ways to determine if the answers are similar each time. This method was used to create 848 analyses to find out if early TV viewing causes later attention problems. A vast majority of results showed no link between the two. The few that did, the authors believe, reflect some oddities in the data set that are not likely to represent the real world.

HOUSTON - (April 2, 2021) - Understanding what drives food choices can help high-volume food service operations like universities reduce waste, according to a new study.

Researchers have concluded that food waste in places like university cafeterias is driven by how much people put on their plates, how familiar they are with what's on the menu and how much they like - or don't like - what they're served.

Food waste has been studied often in households, but not so often in institutional settings like university dining commons. What drives food choices in these "all-you-care-to-eat" facilities is different because diners don't perceive personal financial penalty if they leave food on their plates.

Published in the journal Foods, "Food Choice and Waste in University Dining Commons -- A Menus of Change University Research Collaborative Study" was conducted by a team of experts from Rice University; the University of California, Davis; Stanford University; Lebanon Valley College; the University of California, Santa Barbara; and the University of California, Berkeley.

Co-author Eleanor Putnam-Farr, assistant marketing professor at Rice's Jones Graduate School of Business, is available to discuss the findings and potential impact with news media.

The researchers conducted student surveys during the 2019 spring and fall semesters to study foods types, diner confidence and diner satisfaction. They used photos taken by diners themselves before and after eating to measure how much food was taken and how much of it went to waste. "Diners were intercepted at their dining halls and asked if they wanted to participate in a study about food choices and satisfaction, but the objective of investigating food waste behavior was not disclosed," the authors wrote.

The study found the amount of food wasted didn't significantly differ among types of food. Instead, researchers discovered waste was related to the amount of food diners put on their plates, how satisfied they were with their meals and how often they went to the dining commons. If students were satisfied with their food, they tended waste less of it. And diners who visited the commons most often -- making them more familiar with the menus and more confident in their choices -- tended to waste less.

Mixed dishes, like sandwiches or stir-fry, took up a greater percentage of the surface area on surveyed plates than animal proteins or grains and starches. Those three types of food took up a greater area of the plates than fruits, vegetables or plant proteins. The amount of food wasted, however, did not significantly differ among the various food categories.

The mixed dishes and animal proteins that took up greater portions of the plate tended to be pre-plated by the commons staff or have a suggested serving size. The study's results showed that greater amounts of food taken by diners correlated with the item being pre-plated or served by others.

The authors recommend future research on the topic uses their multicampus approach -- which enabled them to study food choice among a large and diverse group -- to better understand what causes food waste and find out if it can be reduced by interventions such as posting signs that encourage healthier choices.

Wearing a face mask can protect yourself and others from Covid-19, but the type of material and how many fabric layers used can significantly affect exposure risk, finds a study from the Georgia Institute of Technology.

The study measured the filtration efficiency of submicron particles passing through a variety of different materials. For comparison, a human hair is about 50 microns in diameter while 1 millimeter is 1,000 microns in size.

"A submicron particle can stay in the air for hours and days, depending on the ventilation, so if you have a room that is not ventilated or poorly ventilated then these small particles can stay there for a very long period of time," said Nga Lee (Sally) Ng, associate professor and Tanner Faculty Fellow in the School of Chemical and Biomolecular Engineering and the School of Earth and Atmospheric Sciences.

The study was conducted during spring 2020, when the pandemic triggered a global shutdown of most institutions. Communities faced massive shortages of personal protective equipment, prompting many people to make their own homemade masks. Georgia Tech quickly set up the study since it already had "a great system for testing filtration efficiency using existing instruments in the lab," Ng recalled.

The study's findings were used to shape homemade face mask recommendations here last April, with the comprehensive study findings published on March 22 in the journal Aerosol Science and Technology.

In all, the researchers tested 33 different commercially accessible materials not limited to cloth fabrics, including single-layer woven fabrics such as cotton and woven polyester, blended fabrics, nonwoven materials, cellulose-based materials, materials commonly found and used in hospitals, and various filter materials.

"We learned there was a lot of variability in filtration performance even in the same type of material," Ng said.

"We found commercially available materials that provide acceptable levels of submicron particle rejection while still maintaining air flow resistance similar to a surgical mask," said Ryan Lively, an associate professor and John H. Woody Faculty Fellow in the School of Chemical and Biomolecular Engineering. "These materials combine fabric fiber density, a maze-like structure, and fiber surface chemistry to effectively reject submicron particles."

The best-performing materials for homemade masks were blackout drapery and sterilization wrap widely used for packing surgical instruments. Both materials are commercially available.

The researchers said people should avoid using filters such as a HEPA/MERV or vacuum bags unless they are certified to be fiberglass-free since often such filters on their own may release glass fibers that can be inhaled. Other materials to avoid for masks include loose-knitted material, batting fabric, felt, fleece, or shiny, reusable shopping bags.

Multilayered samples performed much better than single-layer samples, but people should pay attention to breathability. The two-layered and three-layered samples tested show an overall filtration efficiency of about 50% for submicron particles. Mask fit is also important since particles can easily escape through gaps at the nose or through the sides of the mask.

The analysis showed that properly fitted and multilayer masks reject 84% of particles expelled by a person when one person wears it. Two people donning these types of masks reduces particle transmission by 96%.

A final takeaway of the research was the importance of universal mask wearing.

"The best way to protect ourselves and others is to reduce exhaled particles at the source, and the source is our face," Ng said, adding, "That really gets amplified when everyone starts wearing masks."

She expressed optimism that the findings will motivate people to more widely embrace mask wearing if they are sick and need to be in public.

"Not everyone understands the importance of airborne virus transmission, and the importance of wearing a mask," she said. "I hope that the practice will continue to help reduce the release of these viral particles into the environment and help protect others."

BOSTON - New research led by investigators at Massachusetts General Hospital (MGH) provides insights on why people with red hair exhibit altered sensitivity to certain kinds of pain. The findings are published in Science Advances.

In people with red hair (as in numerous other species of animals with red fur), the pigment-producing cells of the skin--called melanocytes--contain a variant form of the melanocortin 1 receptor. This receptor sits on the cell surface, and if it becomes activated by circulating hormones called melanocortins, it causes the melanocyte to switch from generating yellow/red melanin pigment to producing brown/black melanin pigment. Earlier work by David E. Fisher, MD, PhD, director of the Mass General Cancer Center's Melanoma Program and director of MGH's Cutaneous Biology Research Center, demonstrated that the inability of red-haired individuals to tan or darken their skin pigment is traced to inactive variants of this receptor.

To investigate the mechanisms behind different pain thresholds in red-haired individuals, Fisher and his colleagues studied a strain of red-haired mice that (as in humans) contains a variant that lacks melanocortin 1 receptor function and also exhibits higher pain thresholds.

The team found that loss of melanocortin 1 receptor function in the red-haired mice caused the animals' melanocytes to secrete lower levels of a molecule called POMC (proopiomelanocortin) that is subsequently cut into different hormones including one that sensitizes to pain and one that blocks pain. The presence of these hormones maintains a balance between opioid receptors that inhibit pain and melanocortin 4 receptors that enhance perception of pain.

In red-haired mice (and therefore, possibly humans), having both hormones at low levels would seemingly cancel each other out. However, the body also produces additional, non-melanocyte-related factors that activate opioid receptors involved in blocking pain. Therefore, the net effect of lower levels of the melanocyte-related hormones is more opioid signals, which elevates the threshold for pain.

"These findings describe the mechanistic basis behind earlier evidence suggesting varied pain thresholds in different pigmentation backgrounds," says Fisher. "Understanding this mechanism provides validation of this earlier evidence and a valuable recognition for medical personnel when caring for patients whose pain sensitivities may vary."

Fisher adds that the results suggest new ways to manipulate the body's natural processes that control pain perception--for example, by designing new medications that inhibit melanocortin 4 receptors involved in sensing pain.

"Our ongoing work is focused on elucidating how additional skin-derived signals regulate pain and opioid signaling," adds co-lead author Lajos V. Kemény, MD, PhD, a research fellow in Dermatology at MGH. "Understanding these pathways in depth may lead to the identification of novel pain-modulating strategies."

Researchers in Italy have identified a pair of microRNA molecules that help maintain a population of cancerous stem cells that drive the growth of breast cancers and initiate tumor relapse after treatment. The study, which will be published April 2 in the Journal of Cell Biology (JCB), reveals that targeting these microRNAs makes cancer stem cells more susceptible to some chemotherapies and could potentially improve the prognosis of patients with aggressive forms of breast cancer.

Many tumors contain a small population of cancer stem cells that initiate tumor growth and give rise to the various cell types found in tumors. Moreover, because cancer stem cells are often resistant to radio- and chemotherapies, they can survive and promote tumor relapse and metastasis after initial rounds of treatment. In breast cancer, for example, tumors containing a relatively high number of cancer stem cells have a much poorer prognosis than tumors with fewer stem cells.

Eliminating these stem cells may therefore be crucial for the successful treatment of breast cancer and other tumor types. One class of molecule that might help cancer stem cells to persist within tumors is microRNAs. These short RNA molecules control the fate and identity of cells by regulating the levels of hundreds of longer, protein-encoding “messenger” RNAs.

“We wanted to identify microRNAs required for the maintenance of normal mammary stem cells that are inherited by cancer stem cells and could represent potential therapeutic targets in breast cancer,” says Francesco Nicassio, a principal investigator and Center Coordinator of the Center for Genomic Science at the Italian Institute of Technology in Milan.

In the new study, Nicassio and colleagues, including co-senior author Pier Paolo Di Fiore, a group leader at the European Institute of Oncology and professor at the University of Milan, identified two closely related microRNAs, miR-146a and miR-146b, that are present in breast cancer stem cells as well as normal mammary stem cells. Indeed, the levels of these two microRNAs tended to be highly elevated in aggressive breast cancers that have a high number of cancer stem cells and a poor prognosis.

The researchers found that miR-146a/b are required to maintain the pool of cancer stem cells. Depleting these two microRNAs from patient-derived cancer cells reduced the ability of these cells to form new tumors when implanted into mice.

Nicassio and colleagues determined that miR-146a/b regulate hundreds of messenger RNAs, thereby controlling numerous cellular processes such as metabolism and DNA replication. Depleting miR-146a/b from cancer stem cells might alter these processes in ways that leave the cells more vulnerable to chemotherapy. Nicassio and colleagues found that reducing the levels of miR-146a/b made breast cancer stem cells over 20 times more sensitive to methotrexate, significantly improving this metabolic inhibitor’s ability to restrict tumor growth in mice.

“While the molecular details remain to be determined, our results clearly show that reducing miR-146a/b levels represents an attractive approach to overcome some forms of drug resistance in the clinical setting, unmasking a ‘hidden vulnerability’ exploitable for the development of anti-cancer stem cell therapies,” Nicassio says.

A dangerous toxin has been witnessed – for the first time – releasing into the air from pond scum, research published in the peer-reviewed journal Lake and Reservoir Management today shows.

Not only is pond scum – otherwise known as algal bloom – an unsightly formation which can occur on still water across the world, it can also prove dangerous to wildlife and humans.

For the first time, scientists have now detected the presence of the algal toxin anatoxin-a (ATX)which is also known as ‘Very Fast Death Factor’, in the air near a Massachusetts pond with large algal blooms.

ATX can cause a range of symptoms at acute doses, including loss of coordination, muscular twitching and respiratory paralysis, and has been linked to the deaths of livestock, waterfowl and dogs from drinking contaminated water.

ATX is produced by single celled organisms known as cyanobacteria, which can form harmful algal blooms – when huge amounts of cyanobacteria grow in lake surface waters. Blooms are exacerbated by fertilizer run-off entering lakes or ponds from nearby fields or improperly treated wastewater, and can stimulate growth and high water temperatures. Cyanobacteria, which also are known as blue-green algae, are actually a type of bacteria that can photosynthesize.

Cyanobacterial blooms can also lead to low oxygen conditions, further degrading water quality. This is because when the algae in these large blooms die, they sink to the lake bottom and decompose, which can use up all the oxygen in the water, killing fish and other animals. The blooms also can release toxins into the water that can prove fatal for these animals.

"ATX is one of the more dangerous cyanotoxins produced by harmful algal blooms, which are becoming more predominant in lakes and ponds worldwide due to global warming and climate change," says lead author Dr James Sutherland, at the Nantucket Land Council.

ATX had never been detected in the atmosphere before, but Sutherland and his colleagues suspected that it might become airborne under certain environmental conditions.

To test this possibility, they collected samples of airborne particles from around the edge of Capaum Pond on Nantucket Island in Massachusetts, US, from July to October 2019, when it was regularly covered with algal blooms, by sucking air through a glass fiber filter. They then used an analytical technique called liquid chromatography-tandem mass spectrometry to search for ATX in these samples, as well as in samples of water from the pond.

Not only were they able to detect ATX in the pond water, at concentrations of up to 21ng/mg, but on one occasion they also detected it in the air around the pond, at an average concentration of 0.87ng/filter, which corresponds to a potential airborne exposure of 0.16ng/m3. This detection occurred on a foggy day in September, after a windy night, when the ATX was likely blown from the surface of the water by the strong wind and then protected by the fog, allowing it to be detected.

The researchers are unsure exactly how ATX is released into the air from the pond, whether within small water droplets, attached to aerosol particles or even inside cyanobacteria blown into the air. It is also unclear what effects exposure to these trace concentrations of ATX might have on humans and wildlife, but the fact that there is exposure is clearly a cause for concern and requires further research.

Whilst this new toxin was witnessed in one specific pond, researchers warn caution for people across the world to approach still water with algal blooms. Therefore, further research is needed to test algal blooms in ponds internationally.

"People often recreate around these lakes and ponds with algal blooms without any awareness of the potential problems," said Sutherland. " Direct contact or inhalation of these cyanotoxins can present health risks for individuals, and we have reported a potential human health exposure not previously examined."

The Tibet ASγ experiment, a China-Japan joint research project on cosmic-ray observation, has discovered ultra-high-energy diffuse gamma rays from the Milky Way galaxy. The highest energy detected is estimated to be unprecedentedly high, nearly 1 Peta electronvolts (PeV, or one million billion eV).

Surprisingly, these gamma rays do not point back to known high-energy gamma-ray sources, but are spread out across the Milky Way (see Fig.1).

Scientists believe these gamma rays are produced by the nuclear interaction between cosmic rays escaping from the most powerful galactic sources ("PeVatrons") and interstellar gas in the Milky Way galaxy. This observational evidence marks an important milestone in revealing the origin of cosmic rays, which has puzzled mankind for more than a century.

Cosmic rays are high-energy particles from outer space that are mainly composed of protons and nuclei, as well as small numbers of electrons/positrons and gamma rays. Cosmic rays below a few PeV are believed to be produced in our Milky Way galaxy, and a source that can accelerate cosmic rays up to PeV energy is called a PeVatron. Although supernova remnants, star-forming regions and the supermassive black hole at the galactic center are suggested to be candidate PeVatrons, none have been identified observationally yet, mainly because the majority of cosmic rays have an electric charge and will lose their original direction when propagating in the Milky Way as well as be bent by the magnetic field.

However, cosmic rays can interact with the interstellar medium near their acceleration place and produce gamma rays with roughly 10% of the energy of their parent cosmic rays. As the direction of electrically neutral gamma rays cannot be changed by the magnetic field, ultra-high-energy gamma rays (0.1-1 PeV) may tell us where the PeVatrons are in the Milky Way.

The Tibet ASγ experiment was started in 1990. After several expansions, the current air shower array consists of more than 500 radiation detectors distributed across about 65,000 square meters. In order to improve its sensitivity to gamma rays observations, new water Cherenkov-type muon detectors with a total effective area of 3400 m2 were added under the existing surface cosmic-ray detectors in 2014 (see Fig. 2).

Since gamma-rays events are muon poor and the dominant proton/nucleus events are muon rich, this feature can be used to suppress the background induced by the proton/nucleus events. Using this technique, the Tibet ASγ experiment successfully reduced proton/nucleus background events to one millionth, the most efficient one ever realized in this kind of experiment. We can therefore detect ultra-high-energy gamma rays almost free of cosmic-ray background events.

Scientists from the Tibet ASγ experiment observed gamma rays with energies between about 0.1 and 1 PeV coming from the galactic disk regions. Specifically, they found 23 ultra-high-energy cosmic gamma rays with energies above 398 TeV along the Milky Way. Of these, the highest energy observed was nearly 1 PeV, which is a new world record for gamma ray photons detected anywhere.

Surprisingly, these gamma rays do not point back to the most powerful known high-energy gamma-ray sources, but are spread out along the Milky Way! Scientists soon noticed that these gamma rays probably originated from the interaction of PeV cosmic rays and the interstellar medium after they escaped from the acceleration sources (PeVatrons). This process, known as "hadronic origin," produces gamma rays with energies roughly one-tenth that of their parent cosmic rays via the production and subsequent decay of neutral pions.

These diffuse gamma rays hint at the ubiquitous existence of powerful cosmic particle accelerators (PeVatrons) within the Milky Way. In other words, if PeVatrons exist, the cosmic rays they emit would permeate the galaxy, producing a diffuse glow of gamma rays of extreme energies. That' s just what scientists with the Tibet ASγ experiment have found. This is a long-awaited discovery for decades, providing unequivocal evidence for the existence of PeVatrons in the past and/or now in our Milky Way galaxy.

Two years ago, scientists of the Tibet ASγ experiment found extremely energetic gamma rays from the Crab Nebula, a pulsar wind nebula in the Milky Way. Those gamma rays were probably produced in a different manner, such as by high energy electrons/positrons in the nebula, a process called "leptonic origin."

Russian researchers have developed an inexpensive, safe, and reliable packed eggs surface disinfection technology. This technology helps to kill bacteria, including salmonella, on eggshells. Also, it allows growing broiler chickens with strong immunity to viral diseases. Packed eggs are disinfected with 50 nanoseconds (one billionth of a second) electron beam. Disinfection takes place in plastic containers. The description of the technology was published in Food and Bioproducts Processing.

"Disinfection of the packed eggs protects eggs from subsequent contamination during storage", said Sergey Sokovnin, a professor at Ural Federal University and Ural Branch of Russian Academy of Science. "We found out that 5 kGy is enough for disinfection. Such dose allows to disinfect container and eggshells but does not affect the physical properties of the protein, yolk, and shell, or their composition. The size of the eggs does not matter."

Disinfection does not affect the quality of meat and the volume of chicks. So, if 63% of chickens hatch from ordinary eggs, then from processed ones - 64%. But the difference is that healthy chickens emerge from the disinfected eggs.

"86% of chickens from untreated eggs show signs of chronic inflammation. In chickens from irradiated eggs, this figure reached only 4%", said Sergey Sokovnin. "At the same time, chickens from the second group had an increased immunity to Newcastle disease. This is a bird's viral disease. It means that chickens from sterilized eggs will be less sick. And it will be possible to significantly reduce the dose of antibiotics when they are growing."

The technology also saves time for industrial manufacturers. To hatch chickens from clean eggs, take about six hours less. Instead of the usual 22-24 hours, chickens appear in 16-18 hours. This is extremely important as it reduces production costs.

"The accelerator capacity is 108 million eggs per year, which is enough for a large poultry farm", said Sergey Sokovnin. "It permits irradiation up to 40 eggs per second. The cost of irradiation of plastic packaging for 10 eggs was 1.2 Eurocents. If one technological line will operate in one shift of 250 working days a year, then the investment will be returned in five years. The main costs are staff salaries, overhead costs, equipment costs".

There are no serious technical problems with the implementation of the technology. The small size of the accelerator makes it easy to integrate into existing lines for control and packaging of eggs in poultry farms. The technology, according to scientists, can also be used to disinfect the surface of eggs of other birds, as well as products with peels or another natural packaging (seeds, bananas, oranges).