Tuesday, July 07, 2020

Sensory neurons outside the brain drive autistic social behaviors, Penn study suggests

Fly model points to potential new therapeutic target for autism spectrum disorders

UNIVERSITY OF PENNSYLVANIA SCHOOL OF MEDICINE

PHILADELPHIA-- A new study from Penn Medicine lends further evidence the social behaviors tied to autism spectrum disorders (ASD) emerge from abnormal function of sensory neurons outside the brain. It's an important finding, published today in the journal Cell Reports, because peripheral sensory systems--which determine how we perceive the environment around us --makes for more accessible therapeutic targets to treat ASD-related symptoms, rather than the central brain itself.

In the fruit fly Drosophila-- a powerful model for studying neurobiology-- the researchers showed that loss of a protein known as neurofibromin 1 caused adult male flies to have social impairments. Those deficits, the researchers also showed, traced back to a primary disruption in a small group of peripheral neurons controlling external stimuli, like smell and touch, that communicate to the brain.

"These data raise the exciting possibility that the root of the problem doesn't begin with errors in the brain itself. It's the disrupted flow of information from the periphery to the brain we should be taking a closer look at," said senior author Matthew Kayser, MD, PhD, an assistant professor in the department of Psychiatry in the Perelman School of Medicine at the University of Pennsylvania. "The findings should help guide the field toward sensory processing therapeutic targets that, if effective, could be transformative for patients suffering from these disorders."

In humans, a loss of neurofibromin 1 is associated with neurofibromatosis type 1 (NF1), a neurodevelopmental disorder with high rates of ASD, but how that loss leads to social deficits is unknown. Past studies have also shown a link between the peripheral sensory system and social deficits; however, this is the first study to implicate neurofibromin's function.

Up to 50 percent of children with NF1 fall on the autism spectrum, and are 13 times more likely to exhibit highly elevated ASD symptoms, including social and communicative disabilities, increased isolation and bullying, difficulties on social tasks, and sensitivities to sound or light. Those symptoms are all tied to difficulties with processing sensory information. Face and gaze processing, for example, makes a social gesture like eye contact exceedingly difficult.

The team, led by Penn postdoctoral scientist Emilia Moscato, PhD, used genetically manipulated flies to show that a loss of neurofibromin led to diminished social courtship behavior and errors in gustatory sensory neurons called ppk23, which are known to coordinate such behaviors. These behavioral deficits stem from an ongoing role for neurofibromin in coordinating social functions in adults, as opposed to guiding development of social behavioral neural circuits.

More specifically, in vivo monitoring of neural activity in the mutant flies showed decreased sensory neuron activation in response to specific pheromonal cues, which then disrupted proper function of downstream brain neurons that direct social decisions. The disruption also led to persistent changes in behavior of the flies beyond the social interaction itself, suggesting a brief sensory error can have long-lasting consequences on behavior.

Next, the researchers aim to better understand how this mutation translates to disruption in brain activity and ultimately behaviors associated with ASD and NF1. They also hope to test different drugs in animal models to identify novel compounds that can restore social behaviors.

"Sensory processing is a readily testable entry-point into social behavioral dysfunction," Kayser said, "so findings from these experiments have potential to rapidly impact the clinical setting."

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Newer solar power equipment ages better than older units

By using fixed effects regression techniques, researchers studied photovoltaic performance degradation over time.

AMERICAN INSTITUTE OF PHYSICS

WASHINGTON, July 7, 2020 -- Utility-scale photovoltaics, ground-mounted projects larger than 5 megawatts of alternating current, are the largest sector of the overall solar market within the U.S. and the fastest-growing form of renewable power generation.

This fleet of utility-scale photovoltaic projects is relatively young and hasn't been operating long enough to establish a lengthy history of operational field service. The first utility-scale photovoltaic projects in the U.S. came online in 2007, and most projects have been operating for only a few years.

In the Journal of Renewable and Sustainable Energy, from AIP Publishing, Mark Bolinger and colleagues from the U.S. Department of Energy's Lawrence Berkeley National Laboratory and the National Renewable Energy Laboratory assess the performance of a fleet of 411 utility-scale photovoltaic projects built within the U.S. from 2007 through 2016.

This fleet produced more than half of all of the solar electricity generated within the U.S. in 2017.

After correcting for variations in weather and curtailment, the group found, on average, the first-year performance of these systems was largely as expected, and that newer projects have degraded at a slower rate than older ones. This suggests photovoltaics technology has improved over time. Interestingly, they also confirmed that projects in hotter climates tend to degrade faster than those in cooler climates.

"A large and rapidly growing market that lacks a lengthy operating history means that investors are fronting a lot of money -- $6.5 billion for projects built within the U.S. in 2018 alone -- based on as-yet untested assumptions about the long-term performance of these projects," said Bolinger.

Photovoltaic cells degrade in efficiency and performance over time due to a variety of factors.

"Most photovoltaic module manufacturers warrant that their modules' performance won't degrade by more than a certain percentage, for example, losing 0.5% per year, during a 25-year period," he said. "But module degradation is only part of the story, because the other components of a utility-scale photovoltaic system -- the inverter, tracking system, fuses, wiring -- can also negatively affect output."

Many existing studies so far have explored module-level degradation, but the total system-level performance and degradation is what truly affects the bottom line.

"To our knowledge, our study is the first use of fixed effects regression techniques to analyze photovoltaic performance degradation," Bolinger said. "Unlike other approaches commonly used, fixed effects regression is compatible with low-frequency generation data."

Because low-frequency generation data tends to be publicly available, in contrast to high-frequency data, which is often proprietary, this new approach is more accessible to researchers and enables large-sample or even fleetwide analyses.

"But the flip side is that lower-frequency data often results in greater uncertainty around degradation estimates," Bolinger said. "By focusing on system-level rather than module-level performance, our approach provides a more holistic and realistic estimate of long-term investment risk."

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The article, "System-level performance and degradation of 21 GWDC of utility-scale PV plants in the United States," is authored by Mark Bolinger, Will Gorman, Dev Millstein and Dirk Jordan. It will appear in the Journal of Renewable and Sustainable Energy on July 7, 2020 (DOI: 10.1063/5.0004710). After that date, it can be accessed at https://aip.scitation.org/doi/10.1063/5.0004710.

ABOUT THE JOURNAL

Journal of Renewable and Sustainable Energy is an interdisciplinary journal that publishes across all areas of renewable and sustainable energy relevant to the physical science and engineering communities. Topics covered include solar, wind, biofuels and more, as well as renewable energy integration, energy meteorology and climatology, and renewable resourcing and forecasting. See https://aip.scitation.org/journal/rse.

Among older adults, statin use tied to decreased risk of death

In a retrospective analysis of US veterans 75 years or older, researchers found those who were prescribed statins had a 25 percent lower risk of death than their counterparts

BRIGHAM AND WOMEN'S HOSPITAL

"Based on these data, age is not a reason to not prescribe statins," said lead and corresponding author Ariela Orkaby, MD, MPH, a physician scientist at VA Boston Health Care System and in the Division of Aging at the Brigham . "Statins are commonly studied and prescribed for middle-aged adults but understudied in people over age 75. One of the most remarkable things about our results is that we found the benefit of statins held true regardless of whether a person was older or younger or had a condition such as dementia."

Orkaby and colleagues looked at data on veterans who used VA services between 2002 and 2012, were 75 years or older, and had not previously had a heart attack, stroke or other cardiovascular event. Of the more than 300,000 eligible veterans, the team identified more than 57,000 who began taking statins during this time. Using propensity scoring, the authors compared individuals who began taking statins to those who had the same likelihood of being prescribed a statin based on clinical characteristics but did not receive a prescription for the drug.

Overall, taking statins was significantly associated with lower risk of death from a cardiovascular event or death from any cause. And the benefits remained for veterans at advanced age, including those who were 90 years or older. Lower death rates extended to those with other conditions such as dementia -- individuals who have been excluded from previous studies. In secondary analyses, the team found that starting a statin was also significantly associated with a lower risk of cardiovascular events such as heart attacks and strokes. Orkaby notes that it was particularly intriguing to see a marked decline in rate of strokes among the study's black participants.

"There are many interesting leads to follow up on," said Orkaby, "but it's important to keep in mind that this is not a randomized, clinical trial. Instead, it's a retrospective analysis using real world data that helps us explore where the truth lies."

The study focused only on veterans, a predominantly white and male population, which may limit its generalizability, but the study's size made it possible to glean statistically meaningful information on underrepresented groups. During the study's timeframe, the most commonly prescribed statin was simvastatin, but currently, higher-dose and higher-intensity statins have become more frequently prescribed. While statins are generally well tolerated, many people report aches and pains as a side effect, which may lead some to stop taking the drug. The current study did not evaluate whether patients discontinued statin use.

Two randomized, clinical trials of statins among older adults are now underway with results from one of the studies expected later this year. Orkaby and colleagues plan to follow up on their study by exploring the effects of statin dosing and examining outcomes for sub-populations included in their analysis.

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This research was supported by the VA (CSR&D CDA-2 award IK2-CX001800), National Institute on Aging (R03-AG060169), and VA Merit Award I01 CX001025. Support for

VA/Centers for Medicare & Medicaid Services data is provided by the Department of Veterans Affairs, VA Health Services Research and Development Service, VA Information Resource Center (project numbers SDR 02-237 and 98-004). Co-author Luc Djousse, MD, ScD, reported receiving grants from Merck.

Paper cited: Orkaby AR et al. "Association of Statin Use With All-Cause and Cardiovascular Mortality in US Veterans 75 Years and Older" JAMA DOI:10.1001/jama.2020.7848

Brigham Health, a global leader in creating a healthier world, consists of Brigham and Women's Hospital, Brigham and Women's Faulkner Hospital, the Brigham and Women's Physicians Organization and many related facilities and programs. With more than 1,000 inpatient beds, approximately 60,000 inpatient stays and 1.7 million outpatient encounters annually, Brigham Health's 1,200 physicians provide expert care in virtually every medical and surgical specialty to patients locally, regionally and around the world. An international leader in basic, clinical and translational research, Brigham Health has nearly 5,000 scientists, including physician-investigators, renowned biomedical researchers and faculty supported by over $700 million in funding. The Brigham's medical preeminence dates back to 1832, and now, with 19,000 employees, that rich history is the foundation for its commitment to research, innovation, and community. Boston-based Brigham and Women's Hospital is a teaching affiliate of Harvard Medical School and dedicated to educating and training the next generation of health care professionals. For more information, resources, and to follow us on social media, please visit brighamandwomens.org.

Mental health benefits of parks dimmed by safety concerns

NYU LANGONE HEALTH / NYU SCHOOL OF MEDICINE

Researchers at NYU Grossman School of Medicine found that New Yorkers are more likely to exercise in a park if they believe they live very close to it. In turn, they feel less anxious and less depressed the more often they exercise there -- but only if they are not concerned about being safe.

"Living near a park may not be enough to improve your physical and mental well-being through exercise," says study lead author Stephanie Orstad, PhD, a research assistant professor in the Department of Medicine at NYU Langone Health. "If we want to make the most of the abundant health benefits parks offer, then we need to make them not only accessible, but also safe for everyone."

Many past studies have linked the availability of urban green spaces to lower stress levels, weight, and risk of heart disease, the study authors say. Other work has shown that living closer to a park leads to fewer days of anxiety and depression.

The new study, publishing online July 7 in the International Journal of Environmental Research and Public Health, is the latest to suggest that safety concerns could interfere with mental health advantages that park proximity offers New Yorkers, Orstad says.

For the investigation, the researchers analyzed responses from more than 3,800 New Yorkers who completed the city's 2010-2011 Physical Activity and Transit Survey. The assessment tracked the participants' mental health, as well as how long they estimated it would take them to walk from home to the nearest park. The survey also asked participants to estimate how often they used the park to exercise or play sports.

Nearly twice as many people said they exercised in the nearest park "sometimes," or "often" if they lived less than a five-minute walk away, compared with people who estimated living more than 30 minutes away, the researchers say. In addition, people who described themselves as "frequent" park exercisers reported having one fewer day of mental health issues a month compared to people who said they "rarely" or "never" were active in their local park.

However, the closeness of a local park made no difference in park use for those who worried about crime in the area. According to Orstad, improving cleanliness and lighting along paths, offering more park-based programs, and fostering a sense of community could help make parks feel safer. She emphasized that the coronavirus pandemic has highlighted the importance of such communal programs because parks are one of the few remaining places where people can get out of their homes, be active, and connect (from a distance) with their neighbors.

"Investing in park safety offers a practical way of improving physical and mental health in different communities in the city, especially in areas where there are stigmas associated with seeking help," says senior study author Melanie Jay, MD, MS, an associate professor in the Department of Medicine and Population Health at NYU Langone. "It takes advantage of resources that may already exist in the neighborhood."

Next, the research team plans to investigate ways to improve a community's perceptions of its neighborhood park to increase opportunities for exercise and mental health.

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Funding for the study and its publication was provided by the NYU Langone Comprehensive Program on Obesity.

In addition to Orstad and Jay, other NYU Langone investigators involved in the study are Kristin Szuhany, PhD; and Lorna Thorpe, PhD. Other researcher support was provided by Kosuke Tamura, PhD, at the National Institutes of Health.

New study sparks fresh call for seagrass preservation

An increase in carbon dioxide emissions equivalent to 5 million cars a year has been caused by the loss of seagrass meadows around the Australian coastline since the 1950s.

EDITH COWAN UNIVERSITY

IMAGE: KNOWN AS 'BLUE CARBON', SEAGRASS MEADOWS HAVE BEEN ESTIMATED TO STORE CO2 IN THEIR SOILS ABOUT 30 TIMES FASTER THAN MOST TERRESTRIAL FORESTS. view more

CREDIT: CENTRE FOR MARINE ECOSYSTEMS RESEARCH AT EDITH COWAN UNIVERSITY

An increase in carbon dioxide emissions equivalent to 5 million cars a year has been caused by the loss of seagrass meadows around the Australian coastline since the 1950s.

The stark finding was made possible by new modelling done by marine scientists at the Centre for Marine Ecosystems Research at Edith Cowan University (ECU) in Western Australia.

PhD student Cristian Salinas calculated that around 161,150 hectares of seagrass have been lost from Australian coasts since the 1950s, resulting in a 2 per cent increase in annual carbon dioxide emissions from land-use change.

The figures derive from Mr Salinas's research into the current carbon stocks of Cockburn Sound off the coast of Western Australia.

Cockburn Sound lost around 23 sqkm of seagrass between the 1960s and 1990s due to nutrient overflow caused by urban, port and industrial development.

Mr Salinas said the finding is significant because seagrass meadows play such a vital role in mitigating the impacts of climate change.

"Known as 'Blue Carbon', seagrass meadows have been estimated to store CO2 in their soils about 30 times faster than most terrestrial forests," he said.

"Seagrass meadows have been under constant threat in Australia through coastal development and nutrient run off since the 1960s. On top of that climate change is causing marine heatwaves that are catastrophic to the seagrasses.

"This study serves as a stark reminder of how important these environments are."

Mr Salinas said the study provided a clear baseline for carbon emissions from seagrass losses in Australia and warned of the need to preserve and restore the meadows. The inclusion of seagrass into the Australian Emission Reduction Fund could contribute to achieve this goal, he said.

Carbon flushed away

The ECU researchers assessed how environmental factors such as water depth, hydrodynamic energy, soil accumulation rates and soil grain size related to changes in soil carbon storage following seagrass loss.

Results showed that the degradation and loss of seagrass alone was not enough to cause the carbon loss from the soil -- hydrodynamic energy from waves, tides and currents also played a significant role.

"Without seagrass acting as a buffer, the hydrodynamic energy from the ocean releases the carbon by moving the seabed sand around," Mr Salinas Zapata said.

Researchers found hydrodynamic energy from water movement was much higher in the shallow water and associated low levels of carbon were recorded in these bare areas.

However, seagrass meadows established in shallow waters were found to have significantly more carbon stored compared to those growing in deeper areas.

"This means that nearshore meadows are particularly important to preserve," Mr Salinas said.

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Fighting E. coli with E. coli

New gut-in-a-dish study shows how a beneficial strain may protect against pathogens

AMERICAN SOCIETY FOR MICROBIOLOGY

Washington, DC - July 7, 2020 - According to findings published this week in mBio, Nissle, a strain of Escherichia coli, is harmless to intestinal tissue and may protect the gut from enterohemorrhagic E. coli, a pathogen that produces Shiga toxin.

E. coli has gotten a bad rap because a few pathogenic strains can cause severe, even life-threatening, symptoms. But for more than a century, the commensal strain Nissle has been used as a probiotic and, more recently, to treat intestinal disorders including ulcerative colitis.

Researchers at the University of Cincinnati wanted to understand whether Nissle could also protect intestinal tissue against EHEC and other pathogens. They studied the probiotic's protective effects using human intestinal organoids, or HIOs, which are experimental models of real tissue derived from stem cells.

The researchers first injected the HIOs with Nissle and observed that the bacterium was harmless: It did not damage the epithelial barrier, formed by the protective outer layer of the organoid. Next, in separate experiments, they injected HIOs with enterohemorrhagic E. coli or EHEC. This pathogen produces Shiga toxin, which sickens millions and kills thousands of people--mainly children--every year. The EHEC quickly broke down the epithelial barrier in the HIOs.

Then, the researchers pre-treated HIOs with Nissle and, 12 hours later, injected them with EHEC. This is where the Nissle proved to be protective: Even though the EHEC proliferated in the organoid tissue, it did not destroy the epithelial barrier. During the same time, the Nissle population declined rapidly in the tissue. The researchers observed the same effects when they injected pre-treated HIOs with uropathogenic E. coli, the strain responsible for the majority of urinary tract infections.

"Basically, the Nissle was killed by the pathogenic bacteria, but it made the intestine able to withstand damage better," said molecular geneticist Alison Weiss, Ph.D., who worked on the study together with Suman Pradhan, Ph.D., a research associate in Weiss's lab.

The results suggest Nissle may confer benefits not by inhibiting the pathogenic strains directly, but instead by harnessing defense mechanisms in the cell itself, and that the probiotic may help prevent severe EHEC infections. However, the results also suggest that Nissle can be vulnerable to phages from the Shiga toxin, which would limit the probiotic's usefulness as a therapeutic. Weiss cautioned that more studies are needed to better understand the complex interactions of bacterial species in a real-world setting.

Weiss's research focuses on bacteria that produce the Shiga toxin, like EHEC. "It's really bad," she said. "My whole career, I've been interested in preventing pediatric pathogens. Once these kids get EHEC, all you can do is give them fluids and support them. There's nothing else we can do."

Weiss is excited by the potential of using HIOs as a model for better understanding intestinal conditions. "They're a huge breakthrough," she said. "A lot of intestinal pathogens are species-specific, and organoids are really good for looking at early events."

Organoids offer at least one other major advantage over mice, she added. "Mice are awful. They pee and bite and scratch," she said. "The little organoids don't complain at all."

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The American Society for Microbiology is one of the largest professional societies dedicated to the life sciences and is composed of 30,000 scientists and health practitioners. ASM's mission is to promote and advance the microbial sciences.

ASM advances the microbial sciences through conferences, publications, certifications and educational opportunities. It enhances laboratory capacity around the globe through training and resources. It provides a network for scientists in academia, industry and clinical settings. Additionally, ASM promotes a deeper understanding of the microbial sciences to diverse audiences.

From Health Affairs: Child mortality lower when women hold office in Brazil

HEALTH AFFAIRS

Philipp Hessel from the Alberto Lleras Camargo School of Government at the University of the Andes and coauthors analyzed the association between woman political empowerment and child mortality rates in Brazil for 2000-15, finding that higher representation of women at local, state, and federal levels of decision making leads to reductions in child mortality. Researchers found that electing either 10-19 percent or 20 percent or more women to the federal Chamber of Deputies leads to a reduction in child mortality of 0.038 percentage points and 0.072 percentage points, respectively. At the state level, electing 20% or more women to the respective state legislature reduces child mortality by .038 percentage points. Localities with female leadership also reported higher-than-average participation in social programs that expand primary care, and electing a female mayor was associated with a 0.042 percentage points increase in conditional cash benefits coverage to vulnerable families. This research suggests that electing female leaders decreases under-five mortality--a key focus of the United Nations Sustainable Development Goals--by emphasizing social service offerings and increasing enrollment in existing governmental public health efforts.

Also in the issue:

Tackling Social Determinants Of Health Around The Globe, an interview with Professor Sir Michael Marmot by Health Affairs Editor-in-Chief Alan Weil. A renowned thinker, leader, researcher, and author on health equity in England and across the world, Marmot has led research groups on health equity for more than forty years.

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Health Affairs is the leading peer-reviewed journal at the intersection of health, health care, and policy. Published monthly by Project HOPE, the journal is available in print and online. Late-breaking content is also found through healthaffairs.org, Health Affairs Today, and Health Affairs Sunday Update.

Stay Up To Date With Health Affairs' COVID-19 Resource Center: We've gathered blogs and journal articles, along with relevant content from our journal archive: lessons from previous pandemics, including school closures during the Spanish flu; public health preparedness; and communicating risk.

Project HOPE is a global health and humanitarian relief organization that places power in the hands of local health care workers to save lives across the globe. Project HOPE has published Health Affairs since 1981.

Nutrients in microalgae: An environmentally friendly alternative to fish

MARTIN-LUTHER-UNIVERSITÄT HALLE-WITTENBERG

Microalgae could provide an alternative source of healthy omega-3 fatty acids for humans while also being more environmentally friendly to produce than popular fish species. This is the result of a new study by scientists from Martin Luther University Halle-Wittenberg (MLU). The study was recently published in the Journal of Applied Phycology and offers an initial indication of the environmental effects of producing microalgae in Germany.

Microalgae have been the focus of several decades of research - initially as a raw material for alternative fuels, but more recently as a source of nutrients in the human diet. They are mainly produced in open ponds in Asia; however, these ponds are at risk of potential contamination. Also, some species of algae are easier to cultivate in closed systems, so-called photobioreactors. "We wanted to figure out whether microalgae produced in photobioreactors in Germany could provide a more environmentally friendly source of essential nutrients than fish," says Susann Schade from the Institute of Agricultural and Nutritional Sciences at MLU. Up to now, photobioreactors had usually only been compared to pond cultivation and they often scored worse due to their higher environmental impacts. "However, little research has been done on the precise extent of the environmental impacts of algae produced for human consumption, especially under climatic conditions such as those found in Germany," adds Schade.

For their study, the researchers developed a model to determine location-specific environmental impacts. "One of the things we did was to compare the carbon footprint of nutrients from microalgae and fish. We also analysed how much both food sources increase the acidification and eutrophication in water bodies," explains Dr Toni Meier, head of the Innovation Office nutriCARD at MLU. The researchers were able to show that microalgae farming has a similar impact on the environment as fish production. "However, if we compare the environmental effects in relation to the amount of omega-3 fatty acids produced, fish from aquaculture comes off far worse," says Schade. One advantage of algae cultivation is its low land consumption; even infertile soils can be used. In contrast, both open ponds and the cultivation of feed for aquaculture require very large areas of land. In particular, fish species that are popular in Germany, such as salmon and pangasius, are primarily produced through aquaculture and therefore put the environment under a considerable amount of pressure. However, even fishing wild Alaska pollack had poorer values than microalgae for all environmental indicators.

"Microalgae should not and cannot completely replace fish as a food source. But if microalgae could be established as a common food, it would be another excellent environmentally friendly source of long-chain omega-3 fatty acids," explains Meier. Several algae are already used as a food supplement in powder or tablet form and as an additive to foods such as pasta or cereals. It would be a way to reduce the current gap in the global supply of omega-3 fatty acids. At the same time, it would provide considerable relief to the world's oceans.

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The study was funded by the Federal Ministry of Education and Research (BMBF) as part of the joint project "Novel microalgae species as a sustainable source of bioactive nutrients in human nutrition" (NovAL). In addition to MLU, the Anhalt University of Applied Sciences, the University of Leipzig and the Friedrich Schiller University Jena are involved in the research alliance.

Our animal inheritance: Humans perk up their ears, too, when they hear interesting sounds

SAARLAND UNIVERSITY

Many animals, including dogs, cats and various species of monkeys, will move their ears to better focus their attention on a novel sound. That humans also have this capability was not known until now. A research team based in Saarland has demonstrated for the first time that we make minute, unconscious movements of our ears that are directed towards the sound want to focus our attention on. The team discovered this ability by measuring electrical signals in the muscles of the vestigial motor system in the human ear. The results have now been published in the journal eLife.

Asking children to 'perk up their ears' means asking them to listen intently. Nobody seriously thinks that kids literally move their ears the way that cats, dogs or horses do. But the fact is, they do, as researchers at the Systems Neuroscience & Neurotechnology Unit (SNNU) have now shown. The research team, led by Professor Danial Strauss, has shown that the muscles around the ear become active as soon as novel, unusual or goal-relevant sounds are perceived. 'The electrical activity of the ear muscles indicates the direction in which the subject is focusing their auditory attention,' says neuroscientist and computer scientist Strauss. 'It is very likely that humans still possess a rudimentary orientation system that tries to control the movement of the pinna (the visible outer part of the ear). Despite becoming vestigial about 25 million years ago, this system still exists as a "neural fossil" within our brains,' explains Professor Strauss. The question why pinna orienting was lost during the evolution of the primate lineage has still not been completely resolved.

The researchers were able to record the signals that control the minute, generally invisible, movements of the pinna using a technique known as surface electromyography (EMG). Sensors attached to the subject's skin detected the electrical activity of the muscles responsible for moving the pinna or altering its shape. Two types of attention were examined. To assess the reflexive attention that occurs automatically when we hear unexpected sounds, the participants in the study were exposed to novel sounds coming at random intervals from different lateral positions while they silently read a monotonous text. To test the goal-directed attention that we show when actively listening, the participants were asked to listen to a short story coming from one laterally positioned speaker, while ignoring a 'competing' story from a speaker located on the opposite side. Both experiments showed that muscle movements in the vestigial pinna-orienting system indicate the direction of the subject's auditory attention.

To better characterize these minute movements of the ear, the team also made special high-definition video recordings of the subjects during the experiments. The subtle movements of the ears were made visible by applying computer-based motion magnification techniques. Depending on the type of aural stimulus used, the researchers were able to observe different upward movements of the ear as well as differences in the strength of the rearward motion of the pinna's upper-lateral edge.

'Our results show that electromyography of the ear muscles offers a simple means of measuring auditory attention. The technique is not restricted to fundamental research, it also has potential for a number of interesting applications," explains Professor Strauss. One area of great practical relevance would be in developing better hearing aids. 'These devices would be able to amplify the sounds that the wearer is trying to hear, while suppressing the noises that they are trying to ignore. The device would function in a way that reflects the user's auditory intention.' The hearing aid would almost instantaneously register and interpret the electrical activity in the ear muscles. A miniature processor would gauge the direction the user is trying to direct their attention towards and then adjust the gain on the device's directional microphones accordingly.

The research project was conducted by researchers at the Systems Neuroscience & Neurotechnology Unit (SNNU), which is affiliated to both the Medical Faculty at Saarland University and to the School of Engineering at the University of Applied Sciences in Saarland (htw saar). External project partners were Dr. Ronny Hannemann from the hearing aid manufacturer Sivantos GmbH and Steven A. Hackley, Professor of Psychology at the University of Missouri-Columbia, who in 2015 first postulated the existence of a vestigial pinna-orienting system in humans.

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Link to publication:

Daniel J. Strauss, Farah I. Corona-Strauss, Andreas Schroeer, Philipp Flotho, Ronny Hannemann, Steven A. Hackley: 'Vestigial Auriculomotor Activity Indicates the Direction of Auditory Attention in Humans'. DOI: 10.7554/eLife.54536 (https://elifesciences.org/articles/54536)

eLife-Digest: https://elifesciences.org/digests/54536/perk-up-your-ears

The inter-institutional Systems Neuroscience & Neurotechnology Unit (SNNU) is the project lead on numerous German and international research projects at the interface of neuroscience and technology. SNNU is involved in projects whose potential uses range from medical applications to optimized human-machine interactions.

http://www.snnu.uni-saarland.de/

For cleaner air, water, and soil

INSTITUTE OF PHYSICAL CHEMISTRY OF THE POLISH ACADEMY OF SCIENCES

IMAGE: TOXIC CHEMICALS STAND NO CHANCE AGAINST A NANOSHIELD CREATED BY SCIENTISTS FROM IPC PAS. PHOTO MADE ON SITE OF THE FRONT MODLIN COMPANY. view more

CREDIT: IPC PAS, GRZEGORZ KRZYZEWSKI

The air around us is still getting more and more polluted. No wonder many scientists strive to find a way to purify it. Thanks to the work of an international team led by prof. Juan Carlos Colmenares from the Institute of Physical Chemistry, Polish Academy of Sciences, we are a big step closer to achieve this goal. They found a way to make an efficient reactive adsorbent able to purify the air from various toxic compounds, cheaply, and effectively.

"Most important is the material we made at the laboratory," says prof. Colmenares. "It not only adsorbs toxic vapors from the air but also, thanks to its photocatalytic properties, can break them into less toxic elements." Material made by the team consists of two quite cheap and easy to acquire compounds: titanium dioxide and graphite oxide. "We intended to make it widely available," explains the professor, and "environmentally friendly." The innovation here was to use ultrasound to make the two counterparts - one organic and one inorganic - to co-operate. The organic counterpart catches the toxic particles, and the inorganic one destroys them by photocatalysis. Ultrasonic manipulation also significantly widens the active surface and chemical heterogeneity of the new material, allowing for higher detoxification efficiency against the "bad guys" from the air. "Thanks to the ultrasound waves, we get excellent dispersion and the layer of graphite oxide sort of rests on the surface of titanium dioxide," says prof. Colmenares. Initially, researchers planned to incorporate this material as an additional filter layer for soldiers' gas masks, or into fabrics, making uniforms that would protect a soldier from toxic gaseous chemicals on the combat field. All this, providing the day, was sunny, and garment had additional LED lights activating photocatalysis. However, high absorptance can be achieved even in the dark.

However, although the invention has been tested on warfare agents, its potential applications are much broader and more peaceful.

One could, for example, make industrial suits for workers exposed to toxic vapors daily. "Just milligrams in a suit would be sufficient," says professor, "if only dispersed properly. The only downside is that potential fabrics should be artificial polymers rather than natural cotton or flax," he smiles lightly. Scientists would also have to find a way to fasten their nanomaterial to the carrier fabric more securely as clothes get washed. We know that nearly 35% of microplastic found in the environment comes from synthetic clothes and washed linen. "We would not like our nanomaterial to end in rivers and seas," says the professor. "We aim for being environmentally friendly all the way, not only at the level of destroying air toxins." Although, as shown earlier by Dimitrios A. Giannakoudakis, the first author of the current work published in the Chemical Engineering Journal and other members of the international team, by ultrasonication, the active phases can be anchored quickly and stably both on cotton and carbon textiles.

If adequately modified, the same technology could help purify not only air but also water and soil. "We have not examined these possibilities yet," says prof. Colmenares, "but it mainly depends on whether we would safely deposit our nanomaterial on possible future carriers/substrates. While purifying water from toxins, we would not like to pollute it with these oxides; we would not want nanotoxicity, although in theory neither TiO2 nor graphite oxide is toxic to humans," explains the scientist. "After all, who was not chewing on a pencil while at school?"

If we resolved this issue, we could say, "sky is the limit." New material could detoxify sewage in paper and coke industries or even neutralize highly toxic remnants of World War II, lying deep in the Baltic Sea. "For now, we aim at sewage plants," says the professor. "Photocatalysis and nanocomposites can help where microbes cannot because the environment is too toxic for them."

Photocatalysis of the soil is the greatest challenge. However, even this is imaginable with proper mixing, lighting, and a proper photocatalyst, for example, to remove herbicides or pesticides.

Cleaner air is within active reach. For cleaner water and soil, we would have to wait a little longer for an optimum solution, but scientists from IPC PAN are just starting their quest for a better, cleaner environment by sustainable approaches for us all.

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Acknowledgments: the National Science Centre in Poland within OPUS-13 project No 2017/25/B/ST8/01592 and project Miniatura 2 No 2018/02/X/ST5/03531.

The Institute of Physical Chemistry of the Polish Academy of Sciences (http://www.ichf.edu.pl/) was established in 1955 as one of the first chemical institutes of the PAS. The Institute's scientific profile is strongly related to the newest global trends in the development of physical chemistry and chemical physics. Scientific research is conducted in nine scientific departments. CHEMIPAN R&D Laboratories, operating as part of the Institute, implement, produce and commercialize specialist chemicals to be used, in particular, in agriculture and pharmaceutical industry. The Institute publishes approximately 200 original research papers annually.

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