Culture

States with stricter firearms laws reported lower suicide and homicide rates, according to a Rutgers study.

The study, conducted by the New Jersey Gun Violence Research Center, the Rutgers School of Public Health, the Rutgers University-Newark Department of Psychology, the Rutgers School of Criminal Justice, the Rutgers New Jersey Medical School and the Rutgers-Newark Department of Social Work, was published in the Journal of Public Health and examined the association between firearm laws and suicide and homicide rates.

Firearm violence is a major public health concern in the United States, with firearm suicide and homicide accounting for the majority of gun deaths. In 2017, 66,683 people died by suicide and homicide with a majority of the deaths resulting from a firearm: 48 percent for suicide and 74 percent for homicide.

Using the State Firearm Law Database, the Rutgers researchers compared suicide and homicide rates across the United States from 1991 to 2017 with the number of firearm laws in each state. The study found that even with several factors, such as unemployment and overall gun ownership rates, taken into account, the total number of firearm laws in a state was a significant predictor of suicide and homicide rates.

"As states' strictness increased, their suicide and homicide rates decreased," said lead author John F. Gunn III, a postdoctoral researcher at the Rutgers School of Public Health and New Jersey Gun Violence Research Center.

The researchers, who were the first to focus on the impact of the total number of firearms regulations in each state, utilized a general index of states' overall approach to firearms regulation by aggregating the total number of gun laws. This index broadly defined states as restrictive or lenient towards firearms.

"With close to 40, 000 deaths annually from firearm violence, regulations that can limit access to firearms appear to reduce state-level mortality," says senior study author Bernadette Hohl, an assistant professor at Rutgers School of Public Health. "Evidence-based implementation of firearm regulations across the whole of the United States has the potential to significantly reduce the toll of firearm violence."

Previous research supports associations between state suicide and homicide rates and specific gun laws, such as waiting periods and universal background checks, with most work finding that the presence of specific firearm laws is associated with reductions in gun mortality.

Future research is required to continue to holistically examine the relationship between firearm laws and suicide and homicide rates. "Assessing the implications of law changes, regulation enforcement and if there is a correlation with violent crime decline will be necessary," Gunn said.

Days after the 4 August 2020 massive explosion at the port of Beirut in Lebanon, researchers were on the ground mapping the impacts of the explosion in the port and surrounding city.

The goal was to document and preserve data on structural and façade damage before rebuilding, said University of California, Los Angeles civil and environmental engineer Jonathan Stewart, who spoke about the effort at the Seismological Society of America (SSA)'s 2021 Annual Meeting.

The effort also provided an opportunity to compare NASA Jet Propulsion Laboratory satellite surveys of the blast effects with data collected from the ground surveys. Stewart and his colleagues concluded that satellite-based Damage Proxy Maps were effective at identifying severely damaged buildings and undamaged buildings, but were less effective for assessing intermediate levels of structural or façade damage.

"The main take away is that the Damage Proxy Maps can definitely distinguish severe damage from lack of damage" for both structural and façade assessments, Stewart said, "but they are not as good at finer tuning."

"If what you're interested in is a fairly detailed picture of what has happened, it's not able to replace a person who actually knows what they're doing looking at the structure, particularly from the inside," he added.

The reconnaissance of the Beirut blast was organized through the National Science Foundation-sponsored Geotechnical Extreme Events Reconnaissance Association (GEER). In addition to Stewart and his colleagues at the American University of Beirut, the team included members from the University of Illinois and the University of Calabria in Italy. The information analyzed by the GEER team can help engineers learn more about how to build safely against similarly destructive events, including earthquakes, in the future.

Their findings, detailed in a GEER report, also "make some recommendations about how you can optimize human resources when doing these inspections," Stewart said.

On that August day, a fire at the port detonated an estimated 2.75 kilotons TNT equivalent of ammonium nitrate and fuel, an event about the size of a magnitude 3.3 earthquake. Within days, engineers at the American University of Beirut "had set up a hotline where people could call in who were concerned with the stability of damaged structures," Stewart said.

Professors and students made visits to inspect and assess the stability of these structures and others, but the in-person visits were scaled back in September due to COVID-19. After that, the researchers depended on street view surveys, using GoPro 360-degree cameras mounted on cars driven around the city.

The damage was ranked using scales adapted from those used for post-earthquake events, said Stewart. For instance, structural damage was ranked on a scale that began with minor damage to non-load bearing elements up to the complete collapse of a structure. Façade damage was ranked using a scale that begins with cracked windows and extends to complete blowout of windows and doors.

The spatial patterns of damage from an explosion differ from those seen in an earthquake. Site conditions such as underlying soil matter much more when it comes to the structural impact of an earthquake, while explosion damage depends "on how much are you feeling that blast," Stewart explained. "With an explosion, the damage decreases with distance and with the number of buildings between you and the blast that can deflect its effects."

Stewart isn't an expert in explosion seismology, but he has experience in assessing structural damage after earthquakes from his work in post-earthquake zones with GEER. He reached out to a colleague at the American University in Beirut after the disaster to offer his help in collecting observations that could be useful to future researchers and engineers.

"We felt that it was important to gather perishable data that we anticipate will be useful to people who study blast effects in an urban setting, and to learn something from this disaster to improve our resilience to future such disasters," he said.

Research has identified critical factors that enable dangerous bacteria to spread disease by surviving on surfaces in hospitals and kitchens.

The study into the mechanisms which enable the opportunistic human pathogen Pseudomonas aeruginosa to survive on surfaces, could lead to new ways of targeting harmful bacteria.

To survive outside their host, pathogenic bacteria must withstand various environmental stresses. One mechanism is the sugar molecule, trehalose, which is associated with a range of external stresses, particularly osmotic shock - sudden changes to the salt concentration surrounding cells.

Researchers at the John Innes Centre analysed how trehalose is metabolised by P. aeruginosa to define its role in protection against external stresses.

Combining analytical biochemistry and reverse genetics - using mutated bacteria lacking key functions - they show that trehalose metabolism in P. aeruginosa is connected to biosynthesis of the carbon storage molecule glycogen.

Experiments showed that disruption of either trehalose or glycogen pathways significantly reduced the ability of P. aeruginosa to survive on man-made surfaces such as kitchen or hospital counters.

The study found that while both trehalose and glycogen are important for stress tolerance in P. aeruginosa they counter distinct stresses: trehalose helps the bacteria to survive in conditions of elevated salt; glycogen contributes to survival in dry (desiccated) environments.

The findings raise the possibility of targeting the trehalose and glycogen pathways to limit pathogen survival on man-made surfaces.

"We have shown how a dangerous human pathogen Pseudomonas aeruginosa responds to environmental challenges, such as salt stress or drying out. Disrupting the production of certain stress-tolerance sugars in this bug significantly reduces its ability to survive on kitchen and hospital worksurfaces," said corresponding author of the study Dr Jacob Malone.

An unexpected finding was how the bacteria operates different pathways for different stresses, said Dr Malone: "Conventional wisdom says that trehalose was responsible for both phenotypes, but we have shown that trehalose only protects against osmo-stress and glycogen is needed to protect against desiccation. We were also surprised to see such a marked drop in surface survival when we disrupted the pathways in the bugs."

The next step for the research is to understand how trehalose and glycogen metabolic pathways are regulated in P. aeruginosa and closely related species. The group also wants to understand how glycogen accumulation allows the bacteria to survive in dry environments and provide more explanation of how and when different parts of the pathways are turned on and off.

P. aeruginosa is a significant pathogen in animals as well as humans. In humans it primarily affects immunocompromised individuals, where it is a major cause of pneumonia and hospital-acquired infections. Chronic P. aeruginosa infections occur in 80% of adult cystic fibrosis patients, where it is the primary cause of morbidity and mortality.

EUGENE, Ore. -- April 22, 2021 -- Product marketers should be clear in their messaging to avoid customer skepticism that makes them feel duped, according to University of Oregon research.

At issue in a new study, published in the Journal of Business Research, was a social-cognitive construct called theory of mind, which considers how well people assess the mental states and apparent goals of others.

Developmental psychologists link it to an ability to show empathy. In business, the study, led by former UO doctoral student Elizabeth Minton, showed it also can influence a person's recognition of being persuaded. And that affects a person's evaluation and willingness to buy a product, she found.

"There has been some research on adult theory of mind, particularly in understanding sales communications," said co-author T. Bettina Cornwell, head of the Department of Marketing and a Philip H. Knight Chair at the UO. "However, there hasn't been a lot of attention to variations of how it plays out."

In young children, Cornwell said, theory of mind is easily seen. For them, she said, their parent's minds and aspirations are their minds, too. If a child wants a doll for a birthday, then mom does, too. Later a child separates that thinking, realizing that mom may instead prefer perfume or dinner out.

In the project, Minton, now an associate professor of marketing at the University of Wyoming, designed four experiments in collaboration with Cornwell and Hong Yuan, the Richard P. Booth Associate Professor and Research Scholar of marketing and director of the UO's Business Research Institute.

"We wanted to know when the recognition of persuasion becomes particularly important," Minton said. "At what point will a person be misled?"

The first experiment involved a pool of 61 online participants who considered a visual with a character describing "a soap that smells good and is gentle on your hands." A second condition had the additional text, "You HAVE to buy it." Result found that no matter the text in the advertisement, higher theory of mind increased skepticism and, in turn, attitudes toward the product and purchase intentions declined.

Next, 238 subjects were recruited from the customer database of a real company that produces a stevia leaf cocoa syrup. All saw the same general text about the sweetener but across three ads the accompanying visuals changed. One ad had no additional visuals or text, one showed an outline of a girl on a bicycle with a persuasive message, and the last with an added bubble containing persuasive words spoken by the girl.

Again, the pattern of results showed that across the advertising types, theory of mind increased advertising skepticism and, in turn, attitude, purchase intentions and willingness to pay for the product declined.

A third experiment dealt with transparency. An online group of 200 adults saw an advertisement for a limited time offer to get seven packets of seed butter for free but with shipping costs of $10.99. About half of the participants saw the price information on the same page (high transparency) and the rest on a second page (low transparency).

Same-page high transparency produced little skepticism. The delayed low transparency presentation, however, significantly raised flags of skepticism and reduced the subjects' attitudes, purchase intentions and willingness to pay.

"This clearly showed us a sense of transparency that people appreciated," Yuan said. "It tells us that we, as advertisers and marketers, probably need to focus on transparency."

The final experiment, with 215 undergraduate students, considered possible boundaries to how theory of mind influences advertising skepticism as found in the first three studies. Participants viewed one advertisement that was either a private-use item (socks) or a public use item (a graphic T-shirt) with varied text and visuals.

The logic is that because theory of mind is a social processing capability, the researchers said, it might be emphasized in a situation where the product is publicly seen and noticeable.

Skepticism, as in previous experiments, remained high in participants with high levels of theory of mind, but the private-versus-public nature had strong effects. Those showing higher skepticism reported higher valuations for the private products, while participants with lower levels of skepticism showed higher valuation for the public products.

"These findings continue to provide evidence for the importance of understanding theory of mind's influence on response to potential persuasion episodes and the interaction with a product's private versus public nature," the researchers suggest.

The study, Minton said, opens a public policy question about advertising being allowed to potentially persuade people who haven't developed a strong theory of mind.

"It's probably not advantageous for marketers to promote a product in a way that has low transparency and makes a consumer have to work hard to understand the offer," Cornwell said.

"One, consumers who don't have high theory of mind may be duped then frustrated while those who have high theory of mind, and thus more skepticism, will be irritated by the way the offer is presented and be less willing to buy," she said. "Neither of the outcomes is good."

PROVIDENCE, R.I. [Brown University] -- As NASA's Perseverance rover begins its search for ancient life on the surface of Mars, a new study suggests that the Martian subsurface might be a good place to look for possible present-day life on the Red Planet.

The study, published in the journal Astrobiology, looked at the chemical composition of Martian meteorites -- rocks blasted off of the surface of Mars that eventually landed on Earth. The analysis determined that those rocks, if in consistent contact with water, would produce the chemical energy needed to support microbial communities similar to those that survive in the unlit depths of the Earth. Because these meteorites may be representative of vast swaths of the Martian crust, the findings suggest that much of the Mars subsurface could be habitable.

"The big implication here for subsurface exploration science is that wherever you have groundwater on Mars, there's a good chance that you have enough chemical energy to support subsurface microbial life," said Jesse Tarnas, a postdoctoral researcher at NASA's Jet Propulsion Laboratory who led the study while completing his Ph.D. at Brown University. "We don't know whether life ever got started beneath the surface of Mars, but if it did, we think there would be ample energy there to sustain it right up to today."

In recent decades, scientists have discovered that Earth's depths are home to a vast biome that exists largely separated from the world above. Lacking sunlight, these creatures survive using the byproducts of chemical reactions produced when rocks come into contact with water.

One of those reactions is radiolysis, which occurs when radioactive elements within rocks react with water trapped in pore and fracture space. The reaction breaks water molecules into their constituent elements, hydrogen and oxygen. The liberated hydrogen is dissolved in the remaining groundwater, while minerals like pyrite (fool's gold) soak up free oxygen to form sulfate minerals. Microbes can ingest the dissolved hydrogen as fuel and use the oxygen preserved in the sulfates to "burn" that fuel.

In places like Canada's Kidd Creek Mine, these "sulfate-reducing" microbes have been found living more than a mile underground, in water that hasn't seen the light of day in more than a billion years. Tarnas has been working with a team co-led by Brown University professor Jack Mustard and Professor Barbara Sherwood Lollar of the University of Toronto to better understand these underground systems, with an eye toward looking for similar habitats on Mars and elsewhere in the solar system. The project, called Earth 4-D: Subsurface Science and Exploration, is supported by the Canadian Institute for Advances Research.

For this new study, the researchers wanted to see if the ingredients for radiolysis-driven habitats could exist on Mars. They drew on data from NASA's Curiosity rover and other orbiting spacecraft, as well as compositional data from a suite of Martian meteorites, which are representative of different parts of the planet's crust.

The researchers were looking for the ingredients for radiolysis: radioactive elements like thorium, uranium and potassium; sulfide minerals that could be converted to sulfate; and rock units with adequate pore space to trap water. The study found that in several different types of Martian meteorites, all the ingredients are present in adequate abundances to support Earth-like habitats. This was particularly true for regolith breccias -- meteorites sourced from crustal rocks more than 3.6 billion years old -- which were found to have the highest potential for life support. Unlike Earth, Mars lacks a plate tectonics system that constantly recycle crustal rocks. So these ancient terrains remain largely undisturbed.

The researchers say the findings help make the case for an exploration program that looks for signs of present-day life in the Martian subsurface. Prior research has found evidence of an active groundwater system on Mars in the past, the researchers say, and there's reason to believe that groundwater exists today. One recent study, for example, raised the possibility of an underground lake lurking under the planet's southern ice cap. This new research suggests that wherever there's groundwater, there's energy for life.

Tarnas and Mustard say that while there are certainly technical challenges involved in subsurface exploration, they aren't as insurmountable as people may think. A drilling operation wouldn't require "a Texas-sized oil rig," Mustard said, and recent advances in small drill probes could soon put the Martian depths within reach.

"The subsurface is one of the frontiers in Mars exploration," Mustard said. "We've investigated the atmosphere, mapped the surface with different wavelengths of light and landed on the surface in half-a-dozen places, and that work continues to tell us so much about the planet's past. But if we want to think about the possibility of present-day life, the subsurface is absolutely going to be where the action is."

Researchers have found that a natural molecule can effectively block the binding of a subset of human antibodies to SARS-CoV-2. The discovery may help explain why some COVID-19 patients can become severely ill despite having high levels of antibodies against the virus.

In their research, published in Science Advances today (22 April 2021), teams from the Francis Crick Institute, in collaboration with researchers at Imperial College London, Kings College London and UCL (University College London), found that biliverdin and bilirubin, natural molecules present in the body, can suppress the binding of antibodies to the coronavirus spike.

As vaccines are rolled out globally, understanding immunity to SARS-CoV-2 and also how the virus evades antibodies is critically important. However, there are still many unknowns. The ability of the immune system to control the infection and the quality of the antibody response are highly variable, and not well correlated, between individuals.

The Crick researchers were involved in the development of tests that see if a person has been exposed to the virus. The scientists discovered that the SARS-CoV-2 spike protein strongly binds to biliverdin, a molecule which was giving these proteins an unusual green colouration.

Working with teams at Imperial College London, UCL and Kings College London, they found that this natural molecule reduced antibody binding to the spike. They used blood sera and antibodies from people who were previously infected with SARS-CoV-2 and found that biliverdin could suppress the binding of human antibodies to the spike by as much as 30-50%, with some antibodies becoming ineffective at neutralising the virus.

Such a significant impact was completely unexpected, as biliverdin only binds to a very small patch on the virus' surface. To find out the mechanism at work, the team at the Crick used cryo-electron microscopy and X-ray crystallography to look in detail at the interactions between the spike, the antibodies and biliverdin. They found that biliverdin attaches to the spike N-terminal domain and stabilises it so that the spike is not able to open up and expose parts of its structure. This means that some antibodies are not able to access their target sites and so cannot bind to and neutralise the virus.

Annachiara Rosa, first author and postdoctoral training fellow in the Chromatin structure and mobile DNA Laboratory at the Crick, says: "When SARS-CoV-2 infects a patient's lungs it damages blood vessels and causes a rise in the number immune cells. Both of these effects may contribute to increasing the levels of biliverdin and bilirubin in the surrounding tissues. And with more of these molecules available, the virus has more opportunity to hide from certain antibodies. This is a really striking process, as the virus may be benefiting from a side-effect of the damage it has already caused."

Peter Cherepanov, author and a group leader of the Chromatin structure and mobile DNA Laboratory at the Crick, says: "In the first months of the pandemic, we were extremely busy churning out viral antigens for SARS-CoV-2 tests. It was a race, as these tests were urgently needed. When we finally found the time to study our green proteins, we expected a mundane answer. Instead, we were astonished to discover a new trick the virus uses to avoid antibody recognition. This is a result of a collaborative effort of several amazing teams working at the Crick and three partner universities, led purely by scientific curiosity."

The researchers will continue this work from various angles, including measuring the levels of biliverdin and other haem metabolites in patients with COVID-19 and also exploring if it is possible to hijack the binding site used by biliverdin to potentially find new ways to target the virus.

A new study by Simon Fraser University historical ecologists finds that Indigenous-managed forests--cared for as "forest gardens"--contain more biologically and functionally diverse species than surrounding conifer-dominated forests and create important habitat for animals and pollinators. The findings are published today in Ecology and Society.

According to researchers, ancient forests were once tended by Ts'msyen and Coast Salish peoples living along the north and south Pacific coast. These forest gardens continue to grow at remote archaeological villages on Canada's northwest coast and are composed of native fruit and nut trees and shrubs such as crabapple, hazelnut, cranberry, wild plum, and wild cherries. Important medicinal plants and root foods like wild ginger and wild rice root grow in the understory layers.

"These plants never grow together in the wild," says Chelsey Geralda Armstrong, an SFU Indigenous Studies assistant professor and the study lead researcher. "It seemed obvious that people put them there to grow all in one spot - like a garden. Elders and knowledge holders talk about perennial management all the time."

"It's no surprise these forest gardens continue to grow at archaeological village sites that haven't yet been too severely disrupted by settler-colonial land-use."

Ts'msyen and Coast Salish peoples' management practices challenge the assumption that humans tend to overturn or exhaust the ecosystems they inhabit. This research highlights how Indigenous peoples not only improved the inhabited landscape, but were also keystone builders, facilitating the creation of habitat in some cases. The findings provide strong evidence that Indigenous management practices are tied to ecosystem health and resilience.

"Human activities are often considered detrimental to biodiversity, and indeed, industrial land management has had devastating consequences for biodiversity," says Jesse Miller, study co-author, ecologist and lecturer at Stanford University. "Our research, however, shows that human activities can also have substantial benefits for biodiversity and ecosystem function. Our findings highlight that there continues to be an important role for human activities in restoring and managing ecosystems in the present and future."

Forest gardens are a common management regime identified in Indigenous communities around the world, especially in tropical regions. Armstrong says the study is the first time forest gardens have been studied in North America -- showing how important Indigenous peoples are in the maintenance and defence of some of the most functionally diverse ecosystems on the Northwest Coast.

"The forest gardens of Kitselas Canyon are a testament to the long-standing practice of Kitselas people shaping the landscape through stewardship and management," says Chris Apps, director, Kitselas Lands & Resources Department. "Studies such as this reconnect the community with historic resources and support integration of traditional approaches with contemporary land-use management while promoting exciting initiatives for food sovereignty and cultural reflection."

In 2005, an ultramarathon runner ran continuously 560 kilometers (350 miles) in 80 hours, without sleeping or stopping. This distance was roughly 324,000 times the runner's body length. Yet this extreme feat pales in comparison to the relative distances that fruit flies can travel in a single flight, according to new research from Caltech.

Caltech scientists have now discovered that fruit flies can fly up to 15 kilometers (about 9 miles) in a single journey--6 million times their body length, or the equivalent of over 10,000 kilometers for the average human. In comparison to body length, this is further than many migratory species of birds can fly in a day. To discover this, the team conducted experiments in a dry lakebed in California's Mojave Desert, releasing flies and luring them into traps containing fermenting juice in order to determine their top speeds.

The research was conducted in the laboratory of Michael Dickinson, Esther M. and Abe M. Zarem Professor of Bioengineering and Aeronautics and executive officer for biology and biological engineering. A paper describing the study appears in the journal Proceedings of the National Academy of Sciences on April 20.

The work was motivated by a longstanding paradox that was identified in the 1940s by Theodosius Dobzhansky and other pioneers of population genetics who studied Drosophila species across the Southwest United States. Dobzhansky and others found that fly populations separated by thousands of kilometers appeared much more genetically similar than could be easily explained by their estimates of how far the tiny flies could actually travel. Indeed, when biologists would release flies outdoors, the insects would often simply buzz around in circles over short distances, like they do in our kitchens.

Did flies behave differently when out in the wild, in search of food? In the 1970s and '80s, a group of population geneticists attempted to address this paradox by coating hundreds of thousands of flies in fluorescent powder and releasing them one evening in Death Valley. Remarkably, the group detected a few fluorescent flies in buckets of rotting bananas up to 15 kilometers away the next day.

"These simple experiments raised so many questions," says Dickinson. "How long did it take them to fly there? Were they just blown by the wind? Was it an accident? I have read that paper many times and found it very inspiring. No one had tried to repeat the experiment in a way that would make it possible to measure whether the flies were carried by the wind, how fast they were flying, and how far they can really go."

To measure how flies disperse and interact with the wind, the team designed "release and recapture" experiments. Led by former postdoctoral scholar Kate Leitch, the team made several trips to Coyote Lake, a dry lakebed 140 miles from Caltech in the Mojave Desert, with hundreds of thousands of the common lab fruit fly, Drosophila melanogaster, in tow.

The aim was to release the flies, lure them into traps at set locations, and measure how long it took the insects to fly there. To do this, the team set up 10 "odor traps" in a circular ring, each located along a one-kilometer radius around the release site. Each trap contained a tantalizing cocktail of fermenting apple juice and champagne yeast, a combination that produces carbon dioxide and ethanol, which are irresistible to a fruit fly. The traps also each had a camera, and were constructed with one-way valves so that the flies could crawl into the trap toward the cocktail but not back out. In addition, the researchers set up a weather station to measure the wind speed and direction at the release site throughout each experiment; this would indicate how the flies' flight was affected by the wind.

So as not to interfere with their flight performance, the team did not coat the flies with identifiers like fluorescent powder. So how did they know they were catching their own fruit flies? Before the release, the team first placed the traps and checked them over time, and found that although D. melanogaster are found at date farms within the Mojave, they are extremely rare at Coyote Lake.

The flies released by the team had been originally collected at a fruit stand and then were raised in the lab, but they were not genetically modified in any way. The team performed the experiments after receiving permits from the Bureau of Land Management.

At experiment time, the team drove the buckets of flies to the center of the circle of traps. The buckets contained plenty of sugar, so that the insects would be fully energized for their flight; however, they contained no protein, giving the flies a strong drive to search for protein-rich food. The team estimated that the flies would not be able to smell the traps from the center of the ring, forcing them to disperse and search.

At a precise time, a team member at the center of the circle opened up the buckets simultaneously and quickly released the flies.

"The person who stayed at the center of the ring to open the lids off of all the buckets witnessed quite a spectacle," says Leitch. "It was beautiful. There were so many flies--so many that you were overwhelmed by the whirring drone. A few of them would land on you, often crawling in your mouth, ears, and nose."

The team repeated these experiments under various wind conditions.

It took about 16 minutes for the first fruit flies to cover one kilometer to reach the traps, corresponding to a speed of approximately 1 meter per second. The team interpreted this speed as a lower limit (perhaps these first flies had buzzed around in circles a bit after release or did not fly in a perfectly straight line). Previous studies from the lab showed that a fully fed fruit fly has the energy to fly continuously for up to three hours; extrapolating, the team concluded that D. melanogaster can fly roughly 12 to 15 kilometers in a single flight, even into a gentle breeze, and will go further if aided by a tailwind. This distance is approximately 6 million times the average body length of a fruit fly (2.5 millimeters, or one tenth of an inch). As an analogy, this would be like the average human covering just over 10,000 kilometers in a single journey--roughly the distance from the North Pole to the equator.

"The dispersal capability of these little fruit flies has been vastly underestimated. They can travel as far or farther than most migratory birds in a single flight. These flies are the standard laboratory model organism, but they are almost never studied outside of the laboratory and so we had little idea what their flight capabilities were," Dickinson says.

In 2018, the Dickinson laboratory discovered that fruit flies use the sun as a landmark in order to fly in a straight line in search of food; flying aimlessly in circles could be deadly, so there is an evolutionary benefit to being able to navigate efficiently. After completing the release experiments described in this study, the team proposed a model that suggests that each fly chooses a direction at random, uses the sun to fly straight in that direction, and carefully regulates its forward speed while allowing itself to be blown sideways by the wind. This enables it to cover as much distance as possible and increases the probability that it will encounter a plume of odor from a food source. The team compared their model with traditional models of random insect dispersal and found that their model could explain the results of the desert releases more accurately because of the flies' propensity to maintain a constant heading once released.

Even though D. melanogaster has been co-evolving with humans, this work shows that the fly brain still contains ancient behavioral modules. Dickinson explains: "For any animal, if you find yourself in the middle of nowhere and there's no food, what do you do? Do you just hop around and hope you find some fruit? Or do you say--'Okay, I'm going to pick a direction and go as far as I can in that direction and hope for the best.' These experiments suggest that that's what the flies do."

The research has broader implications for the field of movement ecology, which studies how populations move around the world, essentially shifting biomass for other animals to eat. In fact, during their early pre-release experiments to check for local populations of Drosophila, the team several times caught an invasive species of fly, the spotted-wing Drosophila (Drosophila suzukii), which causes significant agricultural damage across the West Coast.

"We set up these traps in the middle of nowhere, not the Central Valley where there would be fields of food, and still we find these agricultural pests cruising through," says Dickinson. "It's kind of scary to see how far these introduced species can travel using simple navigational strategies."

Using the Atacama Large Millimeter/submillimeter Array (ALMA), astronomers found a rotating baby galaxy 1/100th the size of the Milky Way at a time when the Universe was only seven percent of its present age. Thanks to assistance by the gravitational lens effect, the team was able to explore for the first time the nature of small and dark "normal galaxies" in the early Universe, representative of the main population of the first galaxies, which greatly advances our understanding of the initial phase of galaxy evolution.

"Many of the galaxies that existed in the early Universe were so small that their brightness is well below the limit of the current largest telescopes on Earth and in Space, making difficult to study their properties and internal structure," says Nicolas Laporte, a Kavli Senior Fellow at the University of Cambridge. "However, the light coming from the galaxy named RXCJ0600-z6, was highly magnified by gravitational lensing, making it an ideal target for studying the properties and structure of a typical baby galaxies."

Gravitational lensing is a natural phenomenon in which light emitted from a distant object is bent by the gravity of a massive body such as a galaxy or a galaxy cluster located in the foreground. The name "gravitational lensing" is derived from the fact that the gravity of the massive object acts like a lens. When we look through a gravitational lens, the light of distant objects is intensified and their shapes are stretched. In other words, it is a "natural telescope" floating in space.

The ALMA Lensing Cluster Survey (ALCS) team used ALMA to search for a large number of galaxies in the early Universe that are enlarged by gravitational lensing. Combining the power of ALMA, with the help of the natural telescopes, the researchers are able to uncover and study fainter galaxies.

Why is it crucial to explore the faintest galaxies in the early Universe? Theory and simulations predict that the majority of galaxies formed few hundred millions years after the Big-Bang are small, and thus faint. Although several galaxies in the early Universe have been previously observed, those studied were limited to the most massive objects, and therefore the less representative galaxies, in the early Universe, because of telescopes capabilities. The only way to understand the standard formation of the first galaxies, and obtain a complete picture of galaxy formation, is to focus on the fainter and more numerous galaxies.

The ALCS team performed a large-scale observation program that took 95 hours, which is a very long time for ALMA observations, to observe the central regions of 33 galaxy clusters that could cause gravitational lensing. One of these clusters, called RXCJ0600-2007, is located in the direction of the constellation of Lepus, and has a mass 1000 trillion times that of the Sun. The team discovered a single distant galaxy that is being affected by the gravitational lens created by this natural telescope. ALMA detected the light from carbon ions and stardust in the galaxy and, together with data taken with the Gemini telescope, determined that the galaxy is seen as it was about 900 million years after the Big Bang (12.9 billion years ago). Further analysis of these data suggested that a part of this source is seen 160 times brighter than it is intrinsically.

By precisely measuring the mass distribution of the cluster of galaxies, it is possible to "undo" the gravitational lensing effect and restore the original appearance of the magnified object. By combining data from Hubble Space Telescope and the European Southern Observatory's Very Large Telescope with a theoretical model, the team succeeded in reconstructing the actual shape of the distant galaxy RXCJ0600-z6. The total mass of this galaxy is about 2 to 3 billion times that of the Sun, which is about 1/100th of the size of our own Milky Way Galaxy.

What astonished the team is that RXCJ0600-z6 is rotating. Traditionally, gas in the young galaxies was thought to have random, chaotic motion. Only recently has ALMA discovered several rotating young galaxies that have challenged the traditional theoretical framework, but these were several orders of magnitude brighter (larger) than RXCJ0600-z6.

"Our study demonstrates, for the first time, that we can directly measure the internal motion of such faint (less massive) galaxies in the early Universe and compare it with the theoretical predictions", says Kotaro Kohno, a professor at the University of Tokyo and the leader of the ALCS team.

"The fact that RXCJ0600-z6 has a very high magnification factor also raises expectations for future research," explains Seiji Fujimoto, a DAWN fellow at the Niels Bohr Institute. "This galaxy has been selected, among hundreds, to be observed by the James Webb Space Telescope (JWST), the next generation space telescope to be launched this autumn. Through joint observations using ALMA and JWST, we will unveil the properties of gas and stars in a baby galaxy and its internal motions. When the Thirty Meter Telescope and the Extremely Large Telescope are completed, they may be able to detect clusters of stars in the galaxy, and possibly even resolve individual stars. There is an example of gravitational lensing that has been used to observe a single star 9.5 billion light-years away, and this research has the potential to extend this to less than a billion years after the birth of the Universe."

These observation results were presented in Seiji Fujimoto et al. "ALMA Lensing Cluster Survey: Bright [CII] 158 μm Lines from a Multiply Imaged Sub-L* Galaxy at z = 6.0719" in the Astrophysical Journal on April 22, 2021, and Nicolas Laporte et al. "ALMA Lensing Cluster Survey: a strongly lensed multiply imaged dusty system at z > 6" in the Monthly Notices of the Royal Astronomical Society on April 22, 2021.

When it comes to friendships and rivalries, male dolphins know who the good team players are. New findings, published in Nature Communications by University of Bristol researchers, reveal that male dolphins form a social concept of team membership based on cooperative investment in the team.

The Bristol researchers, with colleagues from the University of Zurich and University of Massachusetts, used 30 years of observational data from a dolphin population in Shark Bay, Western Australia, and sound playback experiments to assess how male dolphins responded to the calls of other males from their alliance network.

Dr Stephanie King, Senior Lecturer from Bristol's School of Biological Sciences who led the research, said: "Social animals can possess sophisticated ways of classifying relationships with members of the same species. In our own society, we use social knowledge to classify individuals into meaningful groups, like sports teams and political allies. Bottlenose dolphins form the most complex alliances outside humans, and we wanted to know how they classify these relationships."

Dr Simon Allen, Research Fellow at Bristol's School of Biological Sciences, who contributed to the study, added: "We flew drones above dolphin groups, recording their behaviour during the sound playbacks, tracking their movements underwater and revealing novel insights into how dolphins respond to the calls of other males in their network of allies."

Males responded strongly to all of the allies that had consistently helped them out in the past, even if they weren't currently close friends. On the other hand, they didn't respond strongly to males who hadn't consistently helped them out in the past, even if they were friends. What this shows is that these dolphins form social concepts of 'team membership', categorizing allies according to a shared cooperative history.

Dr King said: "Such concepts develop through experience and likely played a role in the cooperative behaviour of early humans. Our results show that cooperation-based concepts are not unique to humans, but also occur in other animal societies with extensive cooperation between non-kin."

The week of Thanksgiving last year, a postcard arrived in mailboxes in Christiansburg. A link to a survey was on the back. On the front, there was a picture that was, by then, very familiar to the residents of a town that made history in 2019 as the first place in the U.S. to have a residential drone delivery service: a yellow-winged drone with a small cardboard box tucked underneath it.

The survey's 20 questions were designed to measure how Christiansburg's 22,000 residents felt about drone delivery -- the first time that this question had ever been posed to a community that had actually experienced the service. The survey was developed and conducted by researchers from the Virginia Tech Mid-Atlantic Aviation Partnership (MAAP), a federally designated drone test site, and Lee Vinsel, an assistant professor of science, technology, and society in the College of Liberal Arts and Human Sciences.

The primary finding: 87 percent of people who responded to the survey reported that they liked the idea of drone delivery. The resoundingly positive results, published in the spring issue of Issues in Science and Technology, plant a new stake in the ground for the future of a technology still at the beginning of its transition from research to retail.

Interest in drone delivery is rising. The service in Christiansburg, run by Wing, Alphabet's drone-delivery subsidiary, is the most advanced of the handful of trial services operating today. But drone technology -- and the laws that regulate it -- are maturing, and it's expected that services like these could become routine in the next few years.

Whether they're successful or not will depend in large part on how the public responds. Delivering packages to homes unfolds in the public eye to a greater extent than many other applications for drones: People may see the drone in the commercial area where it picks up its cargo, at the customer's house, and in the neighborhoods in between.

Accurate estimates of public opinion are critical for the regulatory agencies developing rules that will govern its use and state and local governments considering whether to encourage it, in addition to the companies pioneering these services and hoping to scale their businesses.

Until now, though, data has been limited, and usually not encouraging: The handful of surveys on this topic have pegged public support for drone delivery at around 50 percent in the U.S. and lower in Europe and the U.K..

But several factors suggest that those anemic results might not be definitive.

First, crucially, these surveys polled people who had almost certainly never received a delivery by drone, and were speculating about a service they were imagining rather than reporting on one they'd experienced. Second, many of the survey questions frame their questions in a way that implies risk, asking respondents to rate their level of concern about potential problems selected by the researchers in advance. Highlighting potential negative outcomes may prompt a more negative overall sentiment.

Christiansburg, then, represented a unique research opportunity.

"Gauging people's reactions to new technologies can be really difficult, including because it's so easy to bias respondents' views," Vinsel said. "We wanted to create a survey that was as neutral as possible to examine sentiments about drone delivery. And Christiansburg was a great opportunity for us because it was a unique population that had actually experienced these systems."

The survey asked respondents about standard demographic factors and their typical response to new technologies. It asked about how familiar they were with drone delivery, how they'd found out about it, and what their general attitude toward it was. Instead of asking about specific risks and benefits, the researchers asked open-ended questions about what the respondents saw as positive and negative aspects of the technology.

The survey was approved by the Virginia Tech Institutional Review Board; Wing helped fund the survey development and distribution through an existing research contract with MAAP, but the analysis was funded entirely by Virginia Tech. Adeline Guthrie, a graduate student in the statistics in the College of Science and collaborator with the Statistical Applications and Innovations Group, assisted with data analysis.

The results were resoundingly positive.

Not only did 87 percent of respondents report positive sentiment about drone delivery, 89 percent indicated either that they were likely to use the service or already had, and 49 percent reported liking the idea of drones used for package delivery more than drones used for other purposes.

All of these results are dramatically different from those of other surveys, in which positive sentiment never exceeded 51 percent and delivery was a relatively unpopular application when ranked against others.

The survey also asked respondents if their opinion had changed since the pandemic. When COVID-19 hit Virginia in March, the number of people signing up for Wing's service and ordering drone deliveries spiked. Wing partnered with additional local businesses and worked with a school librarian to deliver books.

The survey results suggested that these contributions had helped. The pandemic popped up frequently in the open-ended question about positive aspects of the technology. Fifty-eight percent of Christiansburg survey respondents said that their opinion of drone delivery had improved -- a much bigger boost than was measured in a 2020 survey from the Consumer Technology Association that polled a general population sample.

Here again, Christiansburg residents' experience with drone delivery may have contributed to the jump -- seeing a favorite coffee shop find a new way to reach customers without in-person shopping or a neighbor's child receiving a delivery of sidewalk chalk and crackers, may resonate more than an abstract appreciation for contact-free delivery.

MAAP worked with Wing to launch the drone delivery program under the federal UAS Integration Pilot Program, a drone-integration initiative that brought together state agencies, local governments, and companies to advance the rollout of drone applications that could have significant benefits for communities (the trial is continuing under the IPP successor program BEYOND). MAAP and Wing conducted months of community outreach before the service launched, talking to thousands of Christiansburg residents about what the service would look like.

"One of the goals of the IPP was to take a community-oriented approach to drone integration," said Tombo Jones, MAAP's director. "There's not a shortcut here. You need careful, methodical research to demonstrate that the system is safe and reliable. Then you can take that information out into the community, and talk to people to learn what they're looking for and what their concerns are. It's rewarding to see how positive the results of this survey are, because they show that, when it's done the right way, developing new applications for drones can have a genuinely positive impact on a community."

The team is hoping that future research will reveal more detail about how people's opinions evolve before and after they're exposed to drone delivery, the aspects of drone delivery that inspire the greatest enthusiasm or strongest skepticism, and what factors help determine how someone will feel about the technology.

"The key thing is that speculation about technologies is different than actual experiences with them," Vinsel said. "Lots of factors influence how we feel about the technologies in our lives, but something scholars have found repeatedly over for the last 60 years is that familiarity breeds acceptance. To be at an early point in the rollout of this technology and be able to study a population that has actually experienced it is pretty exciting."

Diseases continue to be a major threat to coral reef health. For example, a relatively recent outbreak termed stony coral tissue loss disease is an apparently infectious waterborne disease known to affect at least 20 stony coral species. First discovered in 2014 in Miami-Dade County, the disease has since spread throughout the majority of the Florida's Coral Reef and into multiple countries and territories in the Caribbean. Some reefs of the northern section of Florida's Coral Reef are experiencing as much as a 60 percent loss of living coral tissue area.

A new study by researchers at Florida Atlantic University's Harbor Branch Oceanographic Institute reveals how a common antibiotic used to treat bacterial infections in humans is showing promise in treating disease-affected Montastraea cavernosa coral colonies in situ. M. cavernosa, also known as the Great Star Coral, is a hard or stony coral found widely throughout the tropical western Atlantic, including several regions currently affected by stony coral tissue loss disease. Preserving M. cavernosa colonies is of particular importance due to its high abundance and role as a dominant reef builder in the northern section of Florida's Coral Reef.

The objective of the study, published in Scientific Reports, was to experimentally assess the effectiveness of two intervention treatments: chlorinated epoxy and amoxicillin combined with Core Rx/Ocean Alchemists Base 2B as compared to untreated controls. Results showed that the Base 2B plus amoxicillin treatment had a 95 percent success rate at healing individual disease lesions. However, it did not necessarily prevent treated colonies from developing new lesions over time. Chlorinated epoxy treatments were not significantly different from untreated control colonies, suggesting that chlorinated epoxy treatments are an ineffective intervention technique for stony coral tissue loss disease.

"There are three possible scenarios that may explain the appearance of new lesions in the amoxicillin treated lesions of the corals that had healed in our study," said Erin N. Shilling, M.S., first author and a recent graduate of the Marine Science and Oceanography masters degree program at FAU Harbor Branch. "It's possible that the causative agent of stony coral tissue loss disease is still present in the environment and is re-infecting quiesced colonies. It also could be that the duration and dose of this antibiotic intervention was sufficient to arrest stony coral tissue loss disease at treated lesions, but insufficient at eliminating its pathogens from other areas of the coral colony."

The study was conducted approximately 2 kilometers offshore from Lauderdale-by-the-Sea in Broward County, Florida, at sites with a maximum depth of 10 meters. Both colony disease status and treated lesion status were analyzed independently so that the treatment's effectiveness at halting individual lesions could be assessed while also determining if a treatment had any impact on the colony as a whole. Colonies were monitored periodically over 11 months to assess treatment effectiveness by tracking lesion development and overall disease status.

"Success in treating stony coral tissue loss disease with antibiotics may benefit from using approaches typically successful against bacterial infections in humans, for example using a strong initial dose of antibiotics followed by a regimen of smaller supplementary doses over time," said Joshua Voss, Ph.D., senior author, an associate research professor at FAU Harbor Branch and executive director of the NOAA Cooperative Institute for Ocean Exploration, Research, and Technology. "Future research efforts should focus on assessing the potential unintended consequences of antibiotic treatments on corals, their microbial communities, and neighboring organisms. In addition, further efforts are needed to optimize dosing and delivery methods for antibiotic treatments on stony coral tissue loss disease-affected corals and scale up intervention treatments effectively."

Voss notes that many coral diseases are still poorly characterized, which has led to calls for increased research and intervention efforts to support adaptive management strategies particularly given the considerable impacts of diseases on coral reefs over the past five decades.

"Results of our experiment expand management options during coral disease outbreaks and contribute to overall knowledge regarding coral health and disease," said Voss.

This research is part of a highly coordinated collaboration through the Disease Advisory Committee (DAC) organized by the Florida Department of Environmental Protection (floridadep.gov/rcp/coral/content/stony-coral-tissue-loss-disease-response) and NOAA. Voss and Shilling are members of the DAC and part of the reconnaissance and intervention team that has collaboratively developed treatment methods, research objectives, and responses to this disease outbreak. Researchers from Nova Southeastern University, Smithsonian Marine Station and the Florida Fish and Wildlife Conservation Commission also are major partners on this team.

Ian Combs, M.S., another recent FAU graduate from Voss's lab and a co-author, helped to develop some of the coral fate-tracking techniques used in the study.

"We recommend that coral reef managers and intervention specialists, particularly those focusing on stony coral tissue loss disease, adopt 3D photogrammetric methods to ensure that data are more accurate than 2D and in-water estimates," said Combs.

Stimulus-responsive supramolecular structures have emerged as an alternative to conventional ones, owing to their applications in sensing, drug delivery, and switchable memory systems. Now, scientists at Tokyo Institute of Technology explore the hydrostatic-pressure response of "foldamers"--artificial molecules that mimic protein folding--and report a shift in their preferred conformation with changing pressure, demonstrating hydrostatic pressure-enabled dynamic control. The finding opens doors to future development of pressure-sensitive foldamers and artificial materials.

Most, if not all, biological systems are extremely complex and often rely on interactions traditional chemistry does not focus on. An entire field of research called "supramolecular chemistry" has been inspired to study exactly those interactions that govern biological processes, based on an approach relying on artificial "molecular machines" to mimic biological functions. These molecular machines are responsive to a wide range of external stimuli, such as temperature, surrounding media, excitation with light, and consequently find applications in sensing, drug delivery, molecular imaging, and switchable memory technology.

However, a particular stimulus--namely, hydrostatic pressure--has long been in fashion due to the remarkable fact that it allows a supramolecular material to be studied both in its unperturbed and pressurized state. In fact, a research group based in Japan, consisting of scientists from Tokyo Institute of Technology (Tokyo Tech), have recently shown that the optical properties and chemical processes in solutions of supramolecular materials can be precisely regulated by hydrostatic pressure.

Inspired by their findings, the group, led by Prof. Gaku Fukuhara from Tokyo Tech and Prof. Hiromitsu Maeda from Ritsumeikan University, moved on to study the effects of pressure on "foldamers"--artificial molecules that mimic proteins. Their findings were published in the journal Chemical Science (doi : 10.1039/D1SC00664A). The name "foldamer" derives from the fact that these systems can replicate proteins folding into well-defined patterns. Prof. Gaku Fukuhara explains the motivation for their study: "The solution-state behavior of foldamers under hydrostatic pressure has not been examined in detail, which poses a challenge to further advancements in supramolecular chemistry."

For a foldamer to fold into a specific conformation, it first needs to bind to a "guest" negatively charged ion that forms the racemic state (equal amount) of helical structures. The chirality (or the property of being distinct from its mirror image) of the resulting structure can then be induced by introducing an asymmetric counter positive ion, a process known as "ion pairing". The ion pairing, however, depends on the solvation conditions for the foldamer, which, in turn, can be influenced by hydrostatic pressure. Accordingly, scientists chose a fluorescent foldamer as a negative ion receptor, called a "host", and chiral ion pairs (such as chloride and bromide) as "guests" (Fig. 1) to explore the optical properties of the "host" solution under hydrostatic pressure.

The scientists began by examining the changes in fluorescence and absorption (in UV and visible) spectra for the host in various organic solvents under pressure and observed a gradual shift in the spectral band to longer wavelengths as well as an increased absorbance with rising pressure. They attributed this to the fact that the host initially adopts two conformers, one extended and one folded, and gradually shifts to an "extended-rich state" upon pressurization (Fig. 2, left). Then, after electronic excitation (hυ), two different fluorescence states were observed from these conformers (Fig. 2, right).

"Our study clearly shows that conformations in the flexible foldamer host can be dynamically controlled, in both ground and excited states, simply by changing hydrostatic pressure," comments an excited Prof. Fukuhara. "In fact, this strategy can even be extended to other foldamer and guest combinations that have difficulty sensing each other or do not show a host-guest chemistry," he adds.

The team's efforts at deciphering foldamers better certainly brings us one step closer to comprehending the complexity of proteins!

Animals use their sense of smell to navigate the world--to find food, sniff out mates and smell danger. But when a hungry animal smells food and a member of the opposite sex at the same time, what makes dinner the more attractive option? Exactly what is it about the odor of food that says, "Choose me?"

Research by investigators at Harvard Medical School illuminates the neurobiology that underlies food attraction and how hungry mice choose to pay attention to one object in their environment over another.

In their study, published March 3 in Nature, Stephen Liberles and co-author Nao Horio, identified the pathway that promotes attraction to food odors over other olfactory cues.

In a series of experiments, the investigators homed in on a signaling molecule called neuropeptide-Y (NPY), secreted by hunger-regulating neurons into a region of the brain known as the thalamus, which regulates a range of physiologic functions, including relaying sensory information to the cortex.

"It turns out that specific neurons 'listen' to hunger state through the release of a neurotransmitter called NPY in the thalamus," said Liberles, professor of cell biology in the Blavatnik Institute at HMS and an investigator at the Howard Hughes Medical Institute.

Deciding between food and romance

"In mice, both food odors and sex pheromones are attractive, but are relevant for different physiological drives," said Horio, a postdoctoral researcher in the Liberles lab. "This suggests that odors activate parallel neural circuits that are shaped by physiological need."

To pinpoint the pathway that enables a mouse to make need-based decisions, Horio constructed an experiment. To start, she placed mice in an enclosure with two odor ports: one that emitted the smell of mouse chow and the other exuding pheromones from a mouse of the opposite sex. Horio noted the length of time a mouse spent lingering over each port, with longer time indicating the animal's preference.

Fed mice with full tummies found food odors and pheromones similarly attractive, but hungry mice displayed a strong preference for food odors, the scientists observed. Fed mice that had been previously exposed to a potential mate showed a distinct preference for the sex pheromones, whereas hungry mice did not. Why did hunger change the choice?

Illuminating the chemistry of food attraction

Neurons in the hypothalamus, a tiny almond-shaped gland buried deep in the brain, emit a molecule known as agouti-related peptide (AGRP). These neurons are known to trigger the drive for food. To study the effect of AGRP-secreting neurons, the researchers used a technique known as optogenetics, which allows scientists to switch neurons on and off by using light. The experiments showed that even in fed animals, AGRP neuronal activation propelled mice to investigate food odors as though they were famished.

AGRP neurons have branches that spread far and wide, so the researchers wondered which areas of the brain were being stimulated. Further experiments demonstrated that multiple AGRP neuron terminals throughout the brain were activated, but only terminals located in a region known as the paraventricular thalamus changed food odor preference. When they did, mice that were not hungry became attracted to food. Conversely, silencing AGRP projections in this area of the thalamus decreased food-odor attraction in hungry mice.

"This observation led us to believe that the persistent stimulation of AGRP neurons that occurs during fasting enhances food-odor attraction by continually signaling downstream neurons," Liberles said.

The final obstacle was to identify whether any of the three principal neurotransmitters released by AGRP neurons--AGRP, NPY, and GABA--were required for hunger-dependent odor attraction, and if so, which one.

To find out, Liberles and Horio repeated the experiments with three groups of mice--each one genetically modified to lack one of these neurotransmitters.

Hungry mice lacking AGRP and GABA remained attracted to food odor. However, hungry animals that lacked NPY were no longer more attracted to food odors than they were to pheromones. NPY knockout mice, whether their bellies were full or not, retained a lower level of attraction to food odors comparable to their attraction to pheromones. Furthermore, mice lacking a specific NPY receptor, NPY5R, also lost hunger-dependent attraction to food odor.

Moreover, after being exposed to a mate, mice lacking NPY were more attracted to pheromones than food, a finding suggesting that mechanisms other than NPY are involved in tickling the olfactory response to pheromones, Liberles said.

The state of hunger, the study suggests, initiates a complex signaling cascade that, by rendering food aromas appetizing, drives animals to seek nourishment and make food a more attractive option than other alternatives. The experiments demonstrate that the unifying signals in this cascade are NPY and its receptor NPY5R. Moving forward, future research will investigate how NPY acts on some olfactory circuits but not others and how animals learn to associate foods with certain odors.

"It seems likely that different neurotransmitters function as spotlights for other behavioral drives, with the thalamus serving as a switchboard that gives preferential attention to sensory inputs on the basis of physiological need," Liberles said.

STUDY SHOWS VACCINES MAY PROTECT AGAINST NEW COVID-19 STRAINS ... AND MAYBE THE COMMON COLD

A new study by Johns Hopkins Medicine researchers provides evidence that CD4+ T lymphocytes -- immune system cells also known as helper T cells -- produced by people who have received either of the two messenger RNA (mRNA) vaccines for COVID-19 caused by the original SARS-CoV-2 strain also will recognize the mutant variants of the coronavirus that are rapidly becoming the dominant types worldwide.

The researchers say this suggests that T cell responses elicited or enhanced by the vaccines should be able to control the current SARS-CoV-2 variants without needing to be updated or modified. They also found that the same T cells may provide some protection from another member of the coronavirus family that is responsible for one type of the common cold.

The findings were reported April 6, 2021, in the Journal of Clinical Investigation.

CD4+ T cells get their "helper" nickname because they assist another type of immune cell, the B lymphocyte (B cell), in responding to surface proteins -- antigens -- on cells infected by invaders that include viruses such as SARS-CoV-2. Activated by the CD4+ T cells, immature B cells become either plasma cells that produce antibodies to mark infected cells for disposal from the body or memory cells that "remember" the antigen's biochemistry for a faster response to future infections.

In the case of SARS-CoV-2, the antigen is the protein making up the spikes that protrude from the surface of the virus. The mRNA vaccines -- known by their manufacturer's names, Pfizer-BioNTech and Moderna -- provide genetic instructions to a vaccinated person's immune system to recognize the spike protein and start production of antibodies against SARS-CoV-2.

CD4+ T cells also send out chemical messengers that attract another type of T cell -- known as the CD8+ T cell (or "killer T cell") -- so that the virus-infected cells can be removed.

To conduct their helper T cell study, the researchers evaluated blood samples from 30 healthy health care workers and laboratory donors who had not previously tested positive for SARS-CoV-2 -- both before and after two doses of a COVID-19 mRNA vaccine. The participants, 12 women and 18 men, ranged in age from 20 to 59.

CD4+ T cells extracted from the blood samples were analyzed for their responses to various components (protein fragments known as peptides) from the original strain SARS-CoV-2 spike protein and three common cold coronaviruses.

The researchers discovered that vaccine recipients -- as expected -- had broad T cell responses to the original strain SARS-CoV-2 spike peptides.

"We identified 23 distinct T cell-targeted peptides, of which only four appear affected by the mutations that created the variant coronaviruses first seen in the United Kingdom and South Africa," says study senior author Joel Blankson, M.D., Ph.D., professor of medicine at the Johns Hopkins University School of Medicine. "That means the other 19 peptides are the same in the original SARS-CoV-2 and the newer strains, so the mRNA vaccines should induce T cells that respond well to the variants."

Blankson says this is important because previous studies showed that antibodies don't recognize the SARS-CoV-2 variants as well as the CD4+ T cells.

"So the T cells may help prevent the variant viruses from causing severe COVID-19 disease even if antibodies don't stop them from infecting a person," he explains.

When the researchers looked at the vaccine-induced T cell response to the spike proteins of three common cold coronaviruses, they saw a three-fold increase for one, HCoV-NL63, but not the other two.

"Further studies are needed to determine why this occurred," says Blankson. "We suspect that HCoV-NL63 may have more epitopes [peptides that elicit an immune response] in common with SARS-CoV-2 than the other common cold coronaviruses."

In a recent and related study, Blankson and Johns Hopkins Medicine colleagues looked at blood from convalescent patients who had recovered from a SARS-CoV-2 infection and identified the unique receptors on memory CD4+ T cell that recognize the spike proteins of both the original strain of SARS-CoV-2 and four common cold coronaviruses.

Blankson says that characterizing these T cell receptors may be helpful in guiding development of future vaccines for a variety of coronaviruses.

Blankson is available for interviews.