Culture

An international team anchored by the Event Horizon Telescope (EHT) Collaboration, which is known for capturing the first image of a black hole in the galaxy Messier 87, has now imaged the heart of the nearby radio galaxy Centaurus A in unprecedented detail. The astronomers pinpoint the location of the central supermassive black hole and reveal how a gigantic jet is being born. Most remarkably, only the outer edges of the jet seem to emit radiation, which challenges our theoretical models of jets. This work, led by Michael Janssen from the Max Planck Institute for Radio Astronomy in Bonn and Radboud University Nijmegen is published in Nature Astronomy on July 19th.

At radio wavelengths, Centaurus A emerges as one of the largest and brightest objects in the night sky. After it was identified as one of the first known extragalactic radio sources in 1949, Centaurus A has been studied extensively across the entire electromagnetic spectrum by a variety of radio, infrared, optical, X-ray, and gamma-ray observatories. At the center of Centaurus A lies a black hole with the mass of 55 million suns, which is right between the mass scales of the Messier 87 black hole (six and a half billion suns) and the one in the center of our own galaxy (about four million suns).

In a new paper in Nature Astronomy, data from the 2017 EHT observations have been analyzed to image Centaurus A in unprecedented detail. "This allows us for the first time to see and study an extragalactic radio jet on scales smaller than the distance light travels in one day. We see up close and personally how a monstrously gigantic jet launched by a supermassive black hole is being born", says astronomer Michael Janssen.

Compared to all previous high-resolution observations, the jet launched in Centaurus A is imaged at a tenfold higher frequency and sixteen times sharper resolution. With the resolving power of the EHT, we can now link the vast scales of the source, which are as big as 16 times the angular diameter of the Moon on the sky, to their origin near the black hole in a region of merely the width of an apple on the Moon when projected on the sky. That is a magnification factor of one billion.

Understanding jets

Supermassive black holes residing in the center of galaxies like Centaurus A are feeding off gas and dust that is attracted by their enormous gravitational pull. This process releases massive amounts of energy and the galaxy is said to become 'active'. Most matter lying close to the edge of the black hole falls in. However, some of the surrounding particles escape moments before capture and are blown far out into space: Jets - one of the most mysterious and energetic features of galaxies - are born.

Astronomers have relied on different models of how matter behaves near the black hole to better understand this process. But they still do not know exactly how jets are launched from its central region and how they can extend over scales that are larger than their host galaxies without dispersing out. The EHT aims to resolve this mystery.

The new image shows that the jet launched by Centaurus A is brighter at the edges compared to the center. This phenomenon is known from other jets, but has never been seen so pronouncedly before. "Now we are able to rule out theoretical jet models that are unable to reproduce this edge-brightening. It's a striking feature that will help us better understand jets produced by black holes", says Matthias Kadler, TANAMI leader and professor for astrophysics at the University of Würzburg in Germany.

The oil industry, pharmaceutical companies and bioreactor manufacturers all face one common enemy: bubbles. Bubbles can form during the manufacturing or transport of various liquids, and their formation and rupture can cause significant issues in product quality.

Inspired by these issues and the puzzling physics behind bubbles, an international scientific collaboration was born. Stanford University chemical engineer Gerald Fuller along with his PhD students Aadithya Kannan and Vinny Chandran Suja, as well as visiting PhD student Daniele Tammaro from the University of Naples, teamed up to study how different kinds of bubbles pop.

The researchers were particularly interested in bubbles with proteins embedded on their surfaces, which is a common occurrence in the pharmaceutical industry and in bioreactors used for cell culture. In an unanticipated result, the researchers discovered that the protein bubbles they were studying opened up like flowers when popped with a needle. Their findings are detailed in a study published in the journal of the Proceedings of the National Academy of Sciences on July 19.

"What really strikes me is that even after all these years of research, bubble physics keeps surprising us with unexpectedly beautiful phenomena," Suja said.

Bursting the bubble

Bubbles can pop in a variety of ways, depending on their physical and chemical properties. One important property is called viscoelasticity.

"Most materials that surround us are actually not perfectly liquid like water or olive oil. They're not perfectly elastic either, like a pencil eraser. They're somewhere in between," explained Fuller, who is the Fletcher Jones II Professor in the School of Engineering and co-led the study with Professor Pier Luca Maffettone from the University of Naples.

This "in-between" state is called viscoelasticity, and the researchers found that, unlike conventional soap bubbles, viscoelastic bubbles that have both liquid- and solid-like properties deform and pop in shapes that mimic a blooming flower.

But as Tammaro notes, "With our eyes it's not possible to see how the hole opens up when a bubble pops, so we just see a bubble that vanishes."

So the researchers used high-speed cameras operating at 20,000 frames per second, over 300 times faster than a human eye, to capture and study the phenomenon.

"While working on my thesis on bubble coalescence in biologic drug formulations, I decided to look at bubble rupture through a high-speed camera that we had in our lab," Kannan said. "When we did that, we saw that this bubble, which had proteins at its surface, actually exhibited a very different mechanism of rupture compared to what we traditionally expect."

In the lab, the researchers soaked a metal ring in a solution of proteins with viscoelastic properties. They then carefully inflated bubbles on this ring using a highly controlled flow of air. Once the bubbles were large enough, they made contact with a suspended needle and popped.

As the video shows, when the bubbles reach the needle, the surface peels away like petals. This peeling happens because the viscoelastic properties at the surface allow the solution to have more solid-like characteristics than common soap bubbles. Kannan likened this special bubble bursting to a popping balloon, which also peels away like a flower.

Investigating bubble physics

Once the flowering phenomenon had been sufficiently observed, the researchers began to develop analytical models of the popping. Using current knowledge of bubble dynamics and mathematical models, the team presented a set of promising computational reproductions of the bubble flowering in their paper.

By studying bubble formation and bursting, the team hopes to eventually learn how to reduce bubble generation and popping in real-world applications. They predict that their findings will have applications in fields from medicine and vaccine production to oil transportation.

"It is really important to see how generalizable this is, and how the flowering is different for other systems," Kannan concluded.

New research has found marine seismic surveys used in oil and gas exploration are not impacting the abundance or behaviour of commercially valuable fishes in the tropical shelf environment in north-western Australia.

The research is the first of its kind to use dedicated seismic vessels to measure the impacts of the survey's noise in an ocean environment, with the eight-month experiment conducted within a 2500 square kilometre fishery management zone near the Pilbara coast.

It involved using multiple acoustic sensors, tagging 387 red emperor fish and deploying more than 600 underwater cameras to track and measure fish behaviour before and after firing seismic air guns into the ocean.

Australian Institute of Marine Science (AIMS) Principal Researcher and project leader Dr Mark Meekan said the large-scale experiment measured the short-term and long-term effects of seismic airguns on the community of commercially important species in the region, such as red emperor (Lutjanus sebae).

"What makes this research unique and robust is we used an actual seismic vessel in a real ocean environment and some of the most advanced technologies to track and measure possible impacts," he said.

"Commercial fishers are concerned seismic survey noise could change the abundance and behaviour of key fish species - this research directly sought to determine if commercially valuable fish leave the area or hide when exposed to the seismic noise.

"The results reveal there were no short-term or long-term effects on the abundance, behaviour and movement of bottom-living fishes.

"This suggests seismic surveys have little impact on commercially valuable fish species in this environment."

AIMS acoustic scientist and co-author Dr Miles Parsons said Baited Remote Underwater Video Systems (BRUVS) were deployed to document the movements, feeding patterns and abundance of the entire benthic fish community.

Red emperor fish - an important target of fisheries - were tagged and tracked via an array of acoustic telemetry receivers to understand their movements.

"It was surprising to find no changes in the key behaviours we were assessing after the fish were exposed to seismic blasts," he said.

This research fills in a key knowledge gap in the effect of seismic exploration on fisheries in the area, which is necessary for managers, marine industries, and policy makers to make informed decisions about its sustainable use.

"The magnitude and extent of this study also means the results provide valuable knowledge on potential impacts in other environments, not just in Australia, but internationally."

The research experiment is part of the North West Shoals to Shore Research Program. The program also investigates impacts on pearl oysters, with this study still in progress.

The struggle to get your child to go to sleep and stay asleep is something most parents can relate to. Once the bedtime battle is over and the kids have finally nodded off, many parents tune out as well.

But University of South Australia researcher Professor Kurt Lushington is calling for parents to check on their small snoozers before switching off.

He says knowing the quality of a child's sleep is important, as it could be an indicator of sleep-disordered breathing - an under-reported medical condition that can affect a child's health and wellbeing.

"During sleep, the muscles keeping the upper airway stiff relax, and as a consequence, the airway narrows, which can cause snoring, snorting or in severe cases, the complete obstruction of the airway," Prof Lushington says.

"This is known as sleep-disordered breathing, which can lead to a number of problems for children including daytime sleepiness, fatigue, irritability, hyperactivity and poor attention - and potentially worsens school performance.

"The long-term effects are not well understood but research suggests sleep-disordered breathing could also impair cardiovascular and metabolic health.

"Sleep-disordered breathing is significantly undiagnosed in the community. Parents can play an important role in the diagnostic process by looking out for the common symptoms, which include heavy breathing, snoring, gasping, or snorting, and stopping breathing altogether - and then share that information with their child's doctor."

In a new study of 1639 children in South Australia, Prof Lushington and colleagues surveyed parents to gauge whether they saw sleep-disordered breathing symptoms as a sleep problem. The findings suggest many parents do hold concerns about their children's sleeping habits, but it doesn't translate to them seeking medical help.

Almost all parents of children with sleep-disordered symptoms viewed apnoea as a problem while nearly two-thirds saw snorting, gasping, and being fearful their child would stop breathing as a problem.

Roughly half of parents considered snoring a problem and only one third viewed breathing heavily but not snoring as an issue.

Prof Lushington says the results are surprising given that most parents don't bring up these concerns with their child's medical professionals.

"Parents don't tend to discuss their child's sleep difficulties at medical consultations - in Australia, it's estimated only four per cent of parents will bring this up with their doctor," he says.

"The good news from our study is that we found that many parents are already recognising that there is a sleep problem. Prior to this, we had hypothesised that the under-reporting of symptoms suggestive of sleep-disordered breathing, or of sleep problems in general, at medical consultation could be because of the lack of parents' awareness of a problem existing.

"While there does need to be more education for parents on symptoms of sleep-disordered breathing - particularly around snoring or heavy breathing being a potential cause for concern, there are clearly other barriers to parents bringing up sleep problems in medical consultations.

"To address this, we suggest medical practitioners need to purposely include questions about sleep at consultations to prompt parents to discuss any symptoms they may have observed in their children at night.

"If parents check in to see how well their children are sleeping at night and doctors routinely check in with parents to discuss children's sleeping habits, we might be able to catch sleep-disordered breathing earlier and take steps to treat it before it affects a child's behaviour and health."

The current treatment for sleep-disordered breathing in children is adenotonsillectomy - the removal of adenoid and tonsils - which is known to improve children's quality of life and sleep.

The research was published in the paper 'Sleep disordered breathing in children: which symptoms do parents consider a problem?' in the Sleep Medicine.

Your child's sleep - tips for checking in:

Familiarise yourself with guidelines advising how much sleep children need at different ages to function well during the day.

If your child is getting enough sleep according to the guidelines but experiences daytime problems with sleepiness, fatigue, irritability, hyperactivity, or poor attention, this could be a sign of sleep-disordered breathing.

If you notice your child snores, struggles to breath at night, has long pauses between breaths greater than 20 seconds, or gasps at night - it's time to bring up the symptoms with your child's GP or paediatrician.

Educate yourself on what normative sleep is to make sure everyone in your household is getting a good night's sleep - the Sleep Health Foundation is a great starting point with a number of fact sheets freely available online.

The July issues of two of the American Psychiatric Association journals, The American Journal of Psychiatry and Psychiatric Services are available online.

The American Journal of Psychiatry is the most widely read psychiatric journal in the world. Its July issue offers a collection of articles discussing the impacts of structural racism, socioeconomic deprivation and stigmatization on mental health. This includes the article From Womb to Neighborhood: A Racial Analysis of Social Determinants of Psychosis in the United States, which was featured at the APA Annual Meeting in May. Among other highlights:

Dismantling Structural Racism in Psychiatry: A Path to Mental Health Equity

Modification of Heritability for Educational Attainment and Fluid Intelligence by Socioeconomic Deprivation

Sustained Effect of a Brief Video in Reducing Public Stigma Toward Individuals With Psychosis

Association Between Benzodiazepine or Z-Drug Prescriptions and Drug-Related Poisonings Among Patients Receiving Buprenorphine Maintenance

"I am very excited about this issue of the Journal as it presents papers that are fundamental to understanding how structural racism negatively impacts our patients and the field of psychiatry," said American Journal of Psychiatry Editor-in-Chief Ned H. Kalin, M.D. "Our Editors and Editorial Board are committed to using the Journal to combat the effects of structural racism, social injustices, and other inequities on mental health and well-being and this is an important step in that direction."

Psychiatric Services, established in 1950, features research reports on issues related to the delivery of mental health services, especially for people with serious mental illness in community-based treatment programs. Its July issue features:

The Role of Board-Certified Psychiatric Pharmacists in Expanding Access to Care and Improving Patient Outcomes

Community Inclusion and Social Determinants: From Opportunity to Health

Integrating Videoconferencing Into Treatment for Obsessive-Compulsive Disorder: Practical Strategies With Case Examples

Addiction Medicine Practice-Based Research Network (AMNet): Building Partnerships

Defining and Addressing Gaps in Care for Obsessive-Compulsive Disorder in the United States

"In addition to addressing the emerging role of pharmacists in psychiatric care, July's issue of Psychiatric Services presents research on opportunities and gaps in the treatment of OCD and evidence that stigma responds to brief video interventions," said Psychiatric Services Editor Lisa B. Dixon, M.D., M.P.H. "Part of our mission is to provide evidence-based practices to transform mental health service delivery, and these studies are very much in line with that goal."

BIRMINGHAM, Ala. - An experimental drug reported in Nature Communications suggests that a "path is clearly achievable" to treat currently untreatable cases of cystic fibrosis disease caused by nonsense mutations. This includes about 11 percent of cystic fibrosis patients, as well as patients with other genetic diseases, including Duchenne muscular dystrophy, β-thalassemia and numerous types of cancers, that are also caused by nonsense mutations.

The drug is a small molecule with a novel mechanism of action, say David Bedwell, Ph.D., and Steven Rowe, M.D., MSPH, co-senior authors. Bedwell is professor and chair of the University of Alabama at Birmingham Department of Biochemistry and Molecular Genetics, and Rowe is a professor in the UAB Department of Medicine.

To understand how a nonsense mutation causes disease -- and how the experimental drug works to suppress the mutation -- requires a close look at the biological machinery that makes proteins inside a cell.

A protein is a chain of hundreds of amino acids that then folds to its proper shape and moves to its proper place to perform its function. The chain is made, link by link, by ribosomes that read a sequence for the protein carried on messenger RNA. That sequence instructs which of the 20 different amino acids to add at each link, one by one.

In the disease cystic fibrosis, mutations affect the protein CFTR that functions at the surface of lung cells to regulate the flow of water to the mucus. A malfunctioning or absent CFTR creates very sticky mucus that allows infections in the lungs. A gene mutation that changes one of the nucleotide bases on the messenger RNA may cause an incorrect amino acid to be placed in the protein chain, altering its function. The nonsense premature termination codons that Bedwell and Rowe study cause a different problem -- the mutation forces the ribosome to stop protein synthesis in mid-course, yielding an incomplete protein. It also causes nonsense-mediated mRNA decay.

Thus, Bedwell, Rowe and colleagues wanted to find small-molecule compounds that would make the ribosome skip through the nonsense premature stop mutation, permitting the ribosome to continue full synthesis of the protein. They hoped to find readthrough agents that have a novel mechanism and function better than current ones, such as aminoglycoside antibiotics, which have poor efficacy.

The researchers used rat cells that carried a modified gene from a deep-sea shrimp to test hundreds of thousands of compounds. The gene encodes NanoLuc luciferase, but with a modification to place a premature termination codon in mid-gene. A small molecule that causes the ribosome to readthrough the premature stop would produce intact luciferase, making the cells glow with bright luminescence.

This reporter gene allowed a team at Southern Research to test 771,345 compounds, using high-throughput screening. Of the 180 compounds showing readthrough activity, the small molecule SRI-37240 was the most active.

Researchers found that SRI-37240 restored the function of human CFTR genes with premature termination codon mutations, as tested in rat cell cultures. It significantly increased the amount of CFTR protein and slightly increased the amount of CFTR messenger RNA. An aminoglycoside called G418 is known to aid readthrough of the premature codon mutations, and researchers found that SRI-37240 and G418 acted synergistically to restore CFTR function.

They found that SRI-37240 induces a prolonged pause at stop codons of messenger RNA and inhibits termination of protein synthesis at premature termination codons without stimulating readthrough at the normal termination codons found at the end protein-encoding sequence on the messenger RNA.

Medicinal chemists synthesized 40 derivatives of SRI-37240, and one, SRI-41315, was more potent and showed better physiochemical features. In human cell lines with the NanoLuc reporter gene, SRI-41315 showed much greater readthrough efficiency than SRI-37240, and SRI-41315 acted synergistically with G418.

Ribosome complexes include ribosomal proteins and other proteins that function as termination factors, translation factors and nonsense-mediated mRNA decay factors. The researchers looked at the abundance of seven of those proteins and found that SRI-41315 dramatically reduced a single termination factor called eRF1, through a proteasome degradation-dependent pathway. This novel mechanism has not been previously seen for a pharmacological agent.

To predict clinical efficacy for cystic fibrosis, researchers tested primary human bronchial epithelial cells that had endogenous CFTR premature termination codons. Neither SRI-37240 nor SRI-41315 alone increased CFTR function, but SRI-41315 together with G418 showed a significant increase in function.

This is progress, Bedwell and Rowe say, yet hurdles remain. Unfortunately, the two compounds had a deleterious effect on ion conductance mediated by the epithelial sodium channel, which limits development in their current form as a treatment for cystic fibrosis. The already known readthrough effect of aminoglycosides is also limited because these antibiotics do not restore therapeutic levels of CFTR, and they also must be given intravenously and can be toxic.

Bedwell and Rowe say it is increasingly likely that multiple distinct agents with different mechanisms of action will be required to impart a clinically impactful response. They concluded, "While further medicinal chemistry is needed to identify readthrough compounds that maximally impact CFTR function without undesirable off-target effects, the results presented here suggest this path is clearly achievable."

Scientists from the University of Graz, Kanzelhöhe Observatory, Skoltech, and the World Data Center SILSO at the Royal Observatory of Belgium, have presented the Catalogue of Hemispheric Sunspot Numbers. It will enable more accurate predictions of the solar cycle and space weather, which can affect human-made infrastructure both on Earth and in orbit. The study came out in the Astronomy & Astrophysics journal, and the catalogue is available from SILSO -- the World Data Center for the production, preservation, and dissemination of the international sunspot number.

Our Sun is a big boiling ball of gas, most of which is so hot that electrons are ripped off from atoms, creating a circulating mix of charged particles, called plasma. These moving charges endow the Sun with an enormous magnetic field, which bundles up as it rises from the solar interior and creates dark areas known as sunspots on the surface.

Sunspots are the primary sources of solar flares and coronal mass ejections, or CMEs. These are huge magnetic clouds of plasma released from the Sun at great speeds. When directed toward the Earth, they cause powerful magnetic disturbances that can damage the equipment on satellites, incapacitate telecommunications, and even cause blackouts in a city -- with devastating effects on the economy.

The appearance and disappearance of sunspots varies according to a roughly 11-year cycle. It begins with almost no sunspots. As it progresses, more and more spots emerge on the middle latitudes and migrate to the solar equator. Since the Sun's equator rotates faster than the poles, its magnetic field becomes entangled and strengthened in bundles over the course of the cycle. Eventually, the field line bundles become strong enough to get pushed out through the photosphere as loops that trap and eject plasma as CMEs.

Monitoring sunspots is therefore crucial for predicting dangerous space weather events and their effects on air travelers, astronauts, and the equipment and infrastructure -- both on Earth, in orbit, and on long-term space missions.

Initially observed by Galileo in the 17th century, sunspots are now monitored daily by about 80 observatories across the world. The World Data Center SILSO at the Royal Observatory of Belgium is the global hub for all sunspot data. Systematic data on the total count of sunspots is available starting from the 18th century. However, recent models suggest that solar activity is better understood as an interplay between the activities in the northern and the southern hemispheres considered separately. Such data is much more scarce, with the most important solar activity index -- the International Sunspot Number -- only recording sunspot counts by hemisphere since 1992.

The authors of the recent study in Astronomy & Astrophysics came up with a method to greatly extend the available data by reconstructing historical hemispheric sunspot numbers. As a result, they released a continuous catalogue of daily and monthly data of the northern and southern hemispheric sunspot numbers going back to 1874. The team showed its high correspondence to the existing hemispheric data and demonstrated that solar cycle predictions are indeed more accurate when the evolution of sunspot numbers is considered separately for the two hemispheres.

"Our Sun is an intriguing star, and its physics is both simple and complicated. We have learned from our study that we can obtain a better understanding of the long-term evolution of the Sun's activity by simply treating first the two hemispheres separately and only afterwards summing both contributions up to obtain the overall activity. The newly reconstructed data on hemispheric sunspot numbers will be available to the scientific community, and we believe they can provide an important basis to develop new, more accurate prediction schemes of solar activity," said Astrid Veronig, the lead author of the study, professor at the University of Graz, and head of the Kanzelhöhe Observatory for Solar and Environmental Research.

Skoltech graduate student and study co-author Shantanu Jain highlighted the practical utility of the new catalogue: "We believe that this new catalogue will be essential to accurately predict space weather since we now have continuous hemispheric data for a longer period to make meaningful solar cycle predictions. If we were to face extreme solar eruptions in today's age of technological dependency, it could easily knock out our power grids, satellite communications, the internet, and cause economic losses of up to trillions of dollars. An accurate prediction of space weather can help prepare ourselves and avoid such a scenario."

"For permanent technical infrastructures, for long-term issues like ozone depletion or climate, and in view of future long-duration manned space missions to the Moon or Mars, there is a growing need for mid- and long-term forecasts of the trend of solar activity over the next few months or years. As part of an emerging discipline called 'space climate,' such long-term predictions of the strength of the solar cycle can only rest on a detailed knowledge of the actual evolution of many past solar cycles. Our new extended data series is one of the key steps in the growing efforts to revisit and fully exploit legacy data collections using the modern tools of the 21st century," study co-author and the head of the World Data Center SILSO Frédéric Clette commented.

"Currently, we still do not fully understand how the solar dynamo works and how the solar magnetic field is generated during the 11-year solar cycle. All the planets of our solar system orbit around the Sun in a so-called ecliptic plane. It means that observatories on Earth or instruments on board any Earth-orbiting satellite which make images of the Sun never really see what happens on the solar poles. However, in February 2020 a groundbreaking space mission -- the Solar Orbiter -- was launched to fly very close to the Sun. It will perform gravitational maneuvers to reach out of the ecliptic and glimpse at the poles for the first time in history. The first polar pass is expected to take place in March 2025 with the spacecraft reaching an inclination of 17 degrees above the ecliptic plane and increasing to 33 degrees in July 2029. We think that the newly developed product of hemispheric sunspot numbers together with the unprecedented observations and fundamentally new knowledge from the Solar Orbiter will help us to advance solar cycle studies and space weather predictions. And whatever storms may rage, we wish everyone good weather in space," said Tatiana Podladchikova, a co-author of the paper and assistant professor at the Skoltech Space Center.

A new study published in Accident Analysis & Prevention shows how biometric data can be used to find potentially challenging and dangerous areas of urban infrastructure before a crash occurs. Lead author Megan Ryerson led a team of researchers in the Stuart Weitzman School of Design and the School of Engineering and Applied Science in collecting and analyzing eye-tracking data from cyclists navigating Philadelphia's streets. The team found that individual-based metrics can provide a more proactive approach for designing safer roadways for bicyclists and pedestrians.

Current federal rules for installing safe transportation interventions at an unsafe crossing--such as a crosswalk with a traffic signal--require either a minimum of 90-100 pedestrians crossing this location every hour or a minimum of five pedestrians struck by a driver at that location in one year. Ryerson says that the practice of planning safety interventions reactively with a "literal human cost," has motivated her and her team to find more proactive safety metrics that don't require waiting for tragic results.

Part of the challenge, says Ryerson, is that transportation systems are designed and refined using metrics like crash or fatality data instead of data on human behavior to help understand what makes an area unsafe or what specific interventions would be the most impactful. This reactive approach also fails to capture where people might want to cross but don't because they consider it too dangerous and that, if it were safe, more people would utilize.

"Today we have technology, data science, and the capability to study safety in ways that we didn't have when the field of transportation safety was born," says Ryerson. "We don't have to be reactive in planning safe transportation systems; we can instead develop innovative, proactive ways to evaluate the safety of our infrastructure."

The team developed an approach to evaluate cognitive workload, a measure of a person's ability to perceive and process information, in cyclists. Cognitive workload studies are frequently used in other fields of transportation, such as air traffic control and driving simulations, to determine what designs or conditions enable people to process the information around them. But studies looking at cognitive workload in bicyclists and pedestrians are not as common due to a number of factors, including the difficulty of developing realistic cycling simulations.

The researchers in Ryerson's lab looked at how different infrastructure designs elicit changes in cognitive workload and stress in urban cyclists. In 2018, the team had 39 cyclists travel along a U-shaped route from JFK Boulevard and Market Street, down 15th Street to 20th Street, then returning back to 15th and Market. Riders wore Tobii eye-tracking glasses equipped with inward- and outward-facing camera and a gyroscope capable of collecting eye- and head-movement data 100 times per second.

Along with the route being one of Philadelphia's newest protected bicycle lanes at the time, and therefore a new experience for all of the study participants, it also has a dramatic change in infrastructure along the 8-10-minute route, including a mix of protected bike lanes, car-bike mixing zones, and completely unprotected areas. "We felt that, in a short segment of space, our subjects could experience a range of transportation-infrastructure designs which may elicit different stress and cogitative workload responses," Ryerson says.

One of the study's main findings is the ability to correlate locations that have disproportionately high numbers of crashes with a consistent biometric response that indicates increased cognitive workload. If a person's cognitive workload is high, Ryerson says, it doesn't necessarily mean that they will crash, but it does mean that a person is less able to process new information, like a pedestrian or a driver entering the bike lane, and react appropriately. High cognitive workload means the threat of a crash is heightened.

In addition, the researchers found that stressful areas were consistent between expert cyclists and those less experienced or confident. This has implications for current approaches to managing safety, which typically focus on pedestrian- and cyclist-education interventions. Education is still important, Ryerson says, but these results show that infrastructure design is just as important in terms of making spaces safe.

"Even if you're a more competent cyclist than I am, we still have very similar stress and workload profiles as we traverse the city," says Ryerson. "Our finding, that safety and stress are a function of the infrastructure design and not the individual, is a shift in perspective for the transportation-safety community. We can, and must, build safety into our transportation systems."

The Ryerson lab is now analyzing a separate eye-tracking dataset from cyclists traveling Spruce and Pine streets before and after the 2019-20 installation of protected bike lanes, an experiment that will allow closer study of the impacts of a design intervention.

Overall, Ryerson says, the research shows that it's possible to be more proactive about safety and that city planners could use individual-level data to identify areas where a traffic intervention might be useful--before anyone is hit by a car. "The COVID-19 pandemic encouraged so many of us to walk and bike for commuting and recreation. Sadly, it also brought an increase in crashes. We must proactively design safer streets and not wait to count more crashes and deaths. We can use the way people feel as they move through the city as a way to design safer transportation systems," she says.

Black holes with masses equivalent to millions of suns do put a brake on the birth of new stars, say astronomers. Using machine learning and three state of the art simulations to back up results from a large sky survey, the researchers resolve a 20-year long debate on the formation of stars. Joanna Piotrowska, a PhD student at the University of Cambridge, will present the new work today (Tuesday 20 July) at the virtual National Astronomy Meeting (NAM 2021).

Star formation in galaxies has long been a focal point of astronomy research. Decades of successful observations and theoretical modelling resulted in our good understanding of how gas collapses to form new stars both in and beyond our own Milky Way. However, thanks to all-sky observing programmes like the Sloan Digital Sky Survey (SDSS), astronomers realised that not all galaxies in the local Universe are actively star-forming - there exists an abundant population of "quiescent" objects which form stars at significantly lower rates.

The question of what stops star formation in galaxies remains the biggest unknown in our understanding of galaxy evolution, debated over the past 20 years. Piotrowska and her team set up an experiment to find out what might be responsible.

Using three state-of-the-art cosmological simulations - EAGLE, Illustris and IllustrisTNG - the astronomers investigated what we would expect to see in the real Universe as observed by the SDSS, when different physical processes were halting star formation in massive galaxies.

The astronomers applied a machine learning algorithm to classify galaxies into star-forming and quiescent, asking which of three parameters: the mass of the supermassive black holes found at the centre of galaxies (these monster objects have typically millions or even billions of times the mass of our Sun), the total mass of stars in the galaxy, or the mass of the dark matter halo around galaxies, best predicts how galaxies turn out.

These parameters then enabled the team to work out which physical process: energy injection by supermassive black holes, supernova explosions or shock heating of gas in massive halos is responsible for forcing galaxies into semi-retirement.

The new simulations predict the supermassive black hole mass as the most important factor in putting the brakes on star formation. Crucially, the simulation results match observations of the local Universe, adding weight to the researchers' findings.

Piotrowska says: "It's really exciting to see how the simulations predict exactly what we see in the real Universe. Supermassive black holes - objects with masses equivalent to millions or even billions of Suns - really do have a big effect on their surroundings. These monster objects force their host galaxies into a kind of semi-retirement from star formation."

COLUMBUS, Ohio - Flavor is the name of the game for scientists who want to optimize food for consumption in ways that improve nutrition or combat obesity.

But there is more to flavor than the substances that meet the mouth. Olfaction, our sense of smell, is a major contributor to how we perceive aromas, especially those related to what we eat.

With hopes to capitalize on the smell factor in flavor development, researchers are exploring how the route an aroma takes to get to the olfactory system, through the nose or the back of the throat, influences our response to the scent in question.

In a new study, when participants were asked to match a known scent such as rose with one of four unknown scents, they did best when the aromas were introduced in the same way, either through sniffing them in a vial or drinking them in a solution - an expected result.

The scientists were surprised to find, however, that participants were also better at matching aromas when the reference scent - the one that they were going to try to find a match for - was not labeled with its familiar name. The less they knew about the reference aroma, the higher their chances of correctly identifying a match - a finding that suggests aroma detection involves learning, memory and cognitive strategy.

The team eventually wants to consider other factors that could influence the perception of aromas and flavors, such as genetics and our microbiomes, the communities of microbes living in our nasal passages and oral cavities.

"A better understanding of these mechanisms could give us another way to modulate flavors and to modulate food-related experiences," said Christopher Simons, associate professor of food science and technology at The Ohio State University and senior author of the study. "It's really hard to understand what people experience, and I don't have access to your brain to see exactly what you're perceiving. But if there are ways to influence that perception, maybe that's a way to get people to eat healthier."

The study is published in the September 2021 issue of the journal Physiology and Behavior.

Simons and colleagues were testing the theory known as the "duality of smell," which posits that how we perceive what we're smelling depends on which path it takes to get to the olfactory system.

The theory has been supported by tests of food flavors that we're used to putting in our mouths. In this study, the researchers used less familiar floral scents - which study participants drank in a solution to activate the sense of smell through the back of the throat and sniffed from a vial to activate the sense of smell through the nose.

The 34 participants would first either sniff or drink the reference scent, which was labeled with its common name - the choices were rose, lavender, honeysuckle or jasmine - its Latin name, or a generic label that gave no information. They then sampled the same unnamed four floral scents - either through the same sense-of-smell pathway or its opposite - with the goal of finding the match to the reference aroma.

When the routes of delivery differed, participants made more mistakes, meaning there was something about those delivery systems to the nose that altered their ability to recognize similar scents - further supporting the duality of smell hypothesis.

But the finding that no information was better than a clear scent name was unexpected - and also suggests that this is where cognitive activity comes into play.

"If I say 'rose,' there's information that will affect the way you process and smell those aromas. When there's no identifying information, what you have to do is profile - smell it and find something distinguishing about that particular aroma. That's much harder than knowing what you're looking for," Simons said.

"We think there's cognitive interference from the language centers that impacts how people do this matching and searching test. ... Fundamentally, the fact you have exactly the same stimulus that activates exactly the same receptors, and you can't make a match - that's fascinating."

Simons is interested in repeating this kind of test with unpleasant aromas to see if the theory holds up, and also hopes to conduct experiments that could reveal whether our genetic makeup or the array of microbes and enzymes in our noses and mouths hold secrets to why the duality of smell exists in the first place.

Champaign, IL, July 19, 2021 - For dairy cows, the transition period--the time between a cow giving birth and beginning to produce milk--brings the greatest possibility of health problems. The current widespread belief is that the effects of excess nonesterified fatty acids (NEFA) in the bloodstream and the ensuing hyperketonemia during this period, coupled with low levels of available calcium, are largely responsible for disorders such as mastitis, metritis, retained placenta, and poor fertility. Much attention has therefore been devoted to regulating NEFA and calcium levels in transition cows--yet all these efforts have not made the transition period less of a challenge to cows and, hence, to farmers, with approximately 75 percent of disease occurring during the first months postpartum. Dairy producers literally pay the price in terms of reduced milk production, costs of treatment, early culling of cows, reduced reproductive abilities, and animal welfare.

In a new review in the Journal of Dairy Science, a team from the Iowa State University Department of Animal Science, Ames, IA, USA, led by Lance H. Baumgard, PhD, Norman L. Jacobson Endowed Professor in Dairy Nutrition, critically reviews the current accepted understanding of cow health during the transition period to investigate the reasons for these persistent problems and suggests lines of inquiry and perspectives on dairy cow health that may prove more effective. Their findings call into question the methods and conclusions of a large body of previous research and how such work has been applied in the dairy industry.

"During the last 50 years, dairy scientists have increasingly viewed elevated circulating NEFA and ketones and hypocalcemia as pathological and causal toward negative outcomes," Baumgard observed.

The team found that this tenet is largely based on observational studies, epidemiology, correlations, and ex vivo immune cell function assays. "It is becoming increasingly evident that periparturient diseases and disorders cannot be explained by the severity of changes in these simple metabolites. Interpreting biomarkers as causal agents of metabolic disorders deviates from the purpose of epidemiological studies," Baumgard added. In their review of previous research, Baumgard and colleagues emphasized the fundamental scientific principle that "correlation does not equal causation."

Examining data both from dairy cows and across species, the team concluded that postcalving changes to energetic and calcium metabolism reflect normal biological processes. Healthy animals use these processes to maximize milk production. In other words, conditions that have been widely regarded as indicating poor health may in fact represent normal and even advantageous functions--and some of the ways in which the challenges of the transition period are addressed may actually make problems worse. Unhealthy cows (metritis, mastitis etc.) utilize similar processes to support an effective immune system. Thus, the unhealthy cow and high-producing healthy cow share similar metabolic profiles.

Baumgard and colleagues provide a basis for further investigating this perspective, with the suggestion that future research might focus on preventing immune system activation in cows, thereby reducing the negative effects of inflammation. Proceeding thus, with careful attention to scientific rigor, they hope to make progress in overcoming the transition cow health problems that remain key obstacles to profitable dairy farming and improving overall agricultural sustainability.

UCC-UCM, 13 July. The Giant Galapagos tortoises which live in contact with human farming and tourism activities, or in urbanised zones, have more bacterial resistance to antibiotics than those that live in more isolated ecosystems.

This is the main conclusion of the research published in Environmental Pollution on which Universidad Complutense de Madrid participated together with the Charles Darwin Foundation (FCD), the Institute for Conservation Medicine of the Saint Louis Zoo (ICM), the Centre for Animal Health Research (INIA-CISA) and Universidad Europea de Madrid.

Ainoa Nieto, the lead author, researcher at ICM/FCD and collaborator in practical teaching and doctoral student at UCM, explains the new information provided by the study: "Human activities are facilitating the dispersal of resistance into the environment, which has already been observed in other parts of the world, but which has never been demonstrated on the Galapagos Islands."

Resistance to antibiotics is one of the major threats to public health on the planet. The WHO has estimated that by 2050 it could be leading to more deaths than cancer, diabetes or traffic accidents. The detection of these bacteria in the Galapagos archipelago for the first time turn them into environmental pollutants and the tortoises into potential "sentinels or bioindicators" of the health of ecosystems.

PCR to identify genes and bacteria

To carry out the study, samples were taken from 270 tortoises in 2018 and 2019 in two locations with different characteristics in the Galapagos Islands: the island of Santa Cruz, which has the largest human population, and the remote volcano of Alcedo on the island Isabela.

The analyses of resistance were carried out in the INIA-CISA laboratory in Madrid using a new methodology that allows the detection of resistance genes without the need to cultivate the bacteria, through PCR reactions in real time. This technique helps identify the genes and also the number of bacteria with resistant genes that are present in a sample. In total, 21 genes were analysed that codify resistance for eight of the antibiotic families most commonly used in human and animal medicine.

"We don't know the real implications that this discovery could have for the health of giant tortoises, but resistance is considered environmental pollution, and the fact that species as iconic as Galapagos tortoises are entering into contact with these resistant bacteria implies that the ecosystem in which they live is being contaminated," explains Casilda Rodríguez, a researcher at the Department of Pharmacology and Toxicology at UCM.

Finally, Ainoa Nieto recalls that antibiotics can be bought in the Galapagos without a medical prescription, for both human and veterinarian use. The authorities do not restrict their use, as happens in Spain or other countries in the world.

When it comes to transitioning from carbon-based to renewable source energy systems, Americans are on board. They're less keen, however, having these new energy infrastructures--wind turbines or solar farms--built close to their homes, which creates hurdles for policymakers. That's according to a study from University of Georgia researcher Thomas Lawrence.

Lawrence and an international team conducted surveys in the United States, Germany and Ireland to assess people's attitudes about renewable energy technologies and their willingness to have the necessary infrastructures built nearby.

"People in Germany and Ireland were more open to having renewable energy technologies closer to where they lived, perhaps because they have less space than in the U.S.," said Lawrence, professor of practice in the College of Engineering. "In the U.S., I was happily surprised to see overall support for a transition of power sources--especially to solar and wind--in the electrical grid, and it was stronger than I would have guessed."

Chilly reception for fossil fuels

Respondents in each country were asked to evaluate five energy sources--wind turbines, solar power technology, and more traditional electrical power generation using biomass, coal or natural gas as the power source. They also were asked questions about what distance from their home would be acceptable for the corresponding infrastructure and these energy sources. (The surveys were conducted using the local unit system of the three countries--miles for the U.S. and kilometers for Ireland and Germany. Five kilometers is roughly 3 miles.)

In all three countries, respondents were overwhelmingly opposed to having coal-fired or natural gas power plants located close to their residences. More than 80% chose "greater than 5 km/miles" and "reject regardless of distance" as their preferred distance for coal-fired power plants (89% in Ireland, 91% in the U.S. and 81% in Germany). More than 50% chose "greater than 5 km/miles" and "reject regardless of distance" as their preferred distance for natural gas power plants (80% in Ireland, 77% in the U.S. and 51% in Germany). They were generally more in favor of having renewable energy technologies located closer to their homes.

Respondents in Ireland and the U.S. were less willing to accept biomass power technology in their immediate vicinity, with more than 70% choosing "greater than 5 km/miles" or "reject regardless of distance" options. German respondents were somewhat more accepting, with 55% accepting biomass at distances less than 5 km/miles from their homes. According to Lawrence, the U.S. result may be because people here do not understand "biomass power," which is in essence burning biomass such as wood scraps to power a more traditional electrical generation facility.

A warmer response for renewable energy

Americans were more open to having renewable energy technologies located near their homes, compared to traditional energy technologies, with 24% agreeing to solar infrastructure and 17% agreeing to wind turbines located 0-1 km/miles from their residences. Irish respondents had higher acceptance rates for solar, with 42% agreeing to solar infrastructure 0-1 km/miles from their homes, and slightly lower rates for wind turbines, with 13% agreeing to wind turbines at the same distance. German respondents were far more open to these energy sources, with 74% agreeing to solar and 33% agreeing to wind turbines located 0-1 km/miles from their homes.

Greater acceptance of renewable energy sources in Germany is not a surprise, according to Lawrence.

"Germany has been leading the charge in transitioning away from carbon-based energy sources," he said. "Over 30% of their power right now is through wind or solar. People there are used to seeing wind farms and solar panels on rooftops."

The study, published in The Energy Journal, also examined preferences related to different national energy policy objectives: economic viability, environmental sustainability, reliability of energy supply and social acceptance.

Results revealed that social acceptance is a more significant energy policy concern for Ireland compared to either Germany or the U.S. Respondents in Ireland rank social acceptance as more important than environmental sustainability or reliability of supply. They also place more importance on those three variables compared to economic viability.

In contrast, German respondents rank all the national policy objectives examined as more important than social acceptance, though similarly, they place greater importance on environmental sustainability and reliability of supply than economic viability. Respondents from the U.S. place much lower importance on social acceptance as a national policy objective, compared to the other three policy objectives.

"Respondents in all three countries were generally more in favor of having renewable energy technologies close to their homes--unlike conventional energy technologies like coal and natural gas--but 'close to my home' was different in the U.S. than Europe," Lawrence said. "Five miles was the cutoff, at least in the U.S. Once you get beyond that point, it's out of sight, out of mind. People in Germany and Ireland often don't have the luxury of five miles."

A serendipitous flythrough of the tail of a disintegrated comet has offered scientists a unique opportunity to study these remarkable structures, in new research presented today at the National Astronomy Meeting 2021.

Comet ATLAS fragmented just before its closest approach to the Sun last year, leaving its former tail trailing through space in the form of wispy clouds of dust and charged particles. The disintegration was observed by the Hubble Space Telescope in April 2020, but more recently the ESA spacecraft Solar Orbiter has flown close to the tail remnants in the course of its ongoing mission.

This lucky encounter has presented researchers with a unique opportunity to investigate the structure of an isolated cometary tail. Using combined measurements from all of Solar Orbiter's in-situ instruments, the scientists have reconstructed the encounter with ATLAS's tail. The resulting model indicates that the ambient interplanetary magnetic field carried by the solar wind 'drapes' around the comet, and surrounds a central tail region with a weaker magnetic field.

Comets are typically characterized by two separate tails; one is the well-known bright and curved dust tail, the other - typically fainter - is the ion tail. The ion tail originates from the interaction between the cometary gas and the surrounding solar wind, the hot gas of charged particles that constantly blows from the Sun and permeates the whole Solar System.

When the solar wind interacts with a solid obstacle, like a comet, its magnetic field is thought to bend and 'drape' around it. The simultaneous presence of magnetic field draping and cometary ions released by the melting of the icy nucleus then produces the characteristic second ion tail, which can extend for large distances downstream from the comet's nucleus.

Lorenzo Matteini, a solar physicist at Imperial College London and leader of the work, says: "This is quite a unique event, and an exciting opportunity for us to study the makeup and structure of comet tails in unprecedented detail. Hopefully with the Parker Solar Probe and Solar Orbiter now orbiting the Sun closer than ever before, these events may become much more common in future!"

This is the first comet tail detection occurring so close to the Sun - well inside the orbit of Venus. It is also one of the very few cases where scientists have been able to make direct measurements from a fragmented comet. Data from this encounter is expected to contribute greatly to our understanding of the interaction of comets with the solar wind and the structure and formation of their ion tails.

RESEARCH TRIANGLE PARK, N.C. -- Army-funded research identified a new material that may lead to lightweight armor, protective coatings, blast shields and other impact-resistant structures.

Researchers at the U.S. Army's Institute for Soldier Nanotechnologies at the Massachusetts Institute of Technology, Caltech and ETH Zürich found that materials formed from precisely patterned nanoscale trusses are tougher than Kevlar and steel.

In experiments, the ultralight structures, called nanoarchitectured materials, absorbed the impact of microscopic projectiles accelerated to supersonic speeds.

"Increasing protection while simultaneously decreasing the weight that soldiers carry is an overreaching theme in our research," said Dr. James Burgess, ISN program manager for the U.S. Army Combat Capabilities Development Command, known as DEVCOM, Army Research Laboratory. "This project is a really good example of such efforts where projectile energy absorption is nanostructured mechanism based."

The research, published in Nature Materials, found that the material prevented the projectiles from tearing through it.

"The same amount of mass of our material would be much more efficient at stopping a projectile than the same amount of mass of Kevlar," said Dr. Carlos Portela, assistant professor of mechanical engineering at MIT, the study's lead author.

The researchers calculate that the new material absorbs impacts more efficiently than steel, Kevlar, aluminum and other impact-resistant materials of comparable weight.

"The knowledge from this work...could provide design principles for ultra-lightweight impact resistant materials [for use in] efficient armor materials, protective coatings, and blast-resistant shields desirable in defense and space applications," said co-author Dr. Julia R. Greer, a professor of materials science, mechanics, and medical engineering at Caltech, whose lab fabricated the material.

Nanoarchitected materials are known to feature impressive properties like exceptional lightness and resilience; however, until now, the potential for additional applications has largely been untested.

"We only know about its response in a slow-deformation regime, whereas a lot of their practical use is hypothesized to be in real-world applications where nothing deforms slowly," Portela said.

To help fill this vital knowledge gap, the research team set out to study nanoarchitected materials undergoing fast deformation, such as that caused by high-velocity impacts. At Caltech, researchers first fabricated a repeating pattern known as a tetrakaidecahedron--a lattice configuration composed of microscopic struts--using two-photo lithography, a technique that uses a high-powered laser to solidify microscopic structures in photosensitive resin.

To test the tetrakaidecahedron's resilience to extreme, rapid deformation, the team performed experiments at MIT using the ISN-developed laser-induced particle impact array. This device aims an ultrafast laser through a glass slide.. As the laser passes through the slide, it generates a plasma, an immediate expansion of gas that launches the particles toward the target.

By adjusting the laser's power to control the speed of the microparticle projectiles, the researchers tested microparticle velocities within the supersonic range.

"Some experiments achieved twice the speed of sound, easily," Portela said.

Using a high-speed camera, the researchers captured videos of the microparticles impacting the nanoarchitected material. They had fabricated material of two different densities. A comparison of the two materials' impact response, found the denser one to be more resilient, and microparticles tended to embed in the material rather than tear through it.

To get a closer look, the researchers carefully sliced through the embedded microparticles and nanarchitectured target. They found that the struts below the embedded particle had crumpled and compacted in response to the impact, but the surrounding struts remained intact.

"We show the material can absorb a lot of energy because of this shock compaction mechanism of struts at the nanoscale, versus something that's fully dense and monolithic, not nanoarchitected," Portela said.

Going forward, Portela plans to explore various nanostructured configurations other than carbon, and ways to scale up the production of these nanostructures, all with the goal of designing tougher, lighter materials.

"Nanoarchitected materials truly are promising as impact-mitigating materials," Portela said. "There's a lot we don't know about them yet, and we're starting this path to answering these questions and opening the door to their widespread applications."