Culture

ITHACA, N.Y. - Astronomers have uncovered a new way of searching for life in the cosmos. Harsh ultraviolet radiation flares from red suns, once thought to destroy surface life on planets, might help uncover hidden biospheres. Their radiation could trigger a protective glow from life on exoplanets called biofluorescence, according to new Cornell University research.

"Biofluorescent Worlds II: Biological Fluorescence Induced by Stellar UV Flares, a New Temporal Biosignature," was published in Monthly Notices of the Royal Astronomical Society.

"This is a completely novel way to search for life in the universe. Just imagine an alien world glowing softly in a powerful telescope," said lead author Jack O'Malley-James, a researcher at Cornell's Carl Sagan Institute.

"On Earth, there are some undersea coral that use biofluorescence to render the sun's harmful ultraviolet radiation into harmless visible wavelengths, creating a beautiful radiance. Maybe such life forms can exist on other worlds too, leaving us a telltale sign to spot them," said co-author Lisa Kaltenegger, associate professor of astronomy and director of the Carl Sagan Institute

Astronomers generally agree that a large fraction of exoplanets - planets beyond our solar system - reside in the habitable zone of M-type stars, the most plentiful kinds of stars in the universe. M-type stars frequently flare, and when those ultraviolet flares strike their planets, biofluorescence could paint these worlds in beautiful colors. The next generation of Earth- or space-based telescopes can detect the glowing exoplanets, if they exist in the cosmos.

Ultraviolet rays can get absorbed into longer, safer wavelengths through a process called "photoprotective biofluorescence," and that mechanism leaves a specific sign for which astronomers can search.

"Such biofluorescence could expose hidden biospheres on new worlds through their temporary glow, when a flare from a star hits the planet," said Kaltenegger.

The astronomers used emission characteristics of common coral fluorescent pigments from Earth to create model spectra and colors for planets orbiting active M stars to mimic the strength of the signal and whether it could be detected for life.

In 2016, astronomers found a rocky exoplanet named Proxima b - a potentially habitable world orbiting the active M star Proxima Centauri, Earth's closest star beyond the sun - that might qualify as a target. Proxima b is also one of the most optimal far-future travel destinations.

"These biotic kinds of exoplanets are very good targets in our search for exoplanets, and these luminescent wonders are among our best bets for finding life on exoplanets," O'Malley-James said.

Large, land-based telescopes that are being developed now for 10 to 20 years into the future may be able to spot this glow.

"It is a great target for the next generation of big telescopes, which can catch enough light from small planets to analyze it for signs of life, like the Extremely Large Telescope in Chile," Kaltenegger said.

Unlike people, crocodiles do not clean their teeth to slow down wear and tear. Instead, they get rid of them and replace them with new copies.

Having one of the most powerful bites in the animal kingdom, crocodiles must be able to bite hard to eat their food such as turtles, wildebeest and other large prey. Now, researchers at the University of Missouri have found that crocodiles -- and even their plant-eating ancestors -- had thin tooth enamel, a trait that is in stark contrast to humans and other hard-biting species. These findings could suggest new approaches for dealing with people's teeth.

"Once we unlock genetically how crocodiles and other non-mammals do this, maybe new teeth can be bioengineered for people," said Brianne Schmiegelow, a former undergraduate student at MU and current dental student at University of Missouri-Kansas City. "Instead of using fillers such as crowns, people could instead 'grow' new teeth when they need to replace their worn out chompers."

The team used a three-dimensional x-ray scanner to measure the thickness of tooth enamel in crocodiles. They found regardless of tooth position -- incisor, canine, molar -- age or diet, crocodiles do not have thick tooth enamel. With this new information, the team also studied published data on dinosaur teeth and found that the data nearly matched what they were seeing in crocodiles. For instance, a Tyrannosaurus rex has the same enamel thickness as a crocodile and can also bite extremely hard.

"Crocodiles bite really hard, so we were curious if they have teeth that correspondingly withstand those forces -- tough teeth to match a tough bite," said Kaleb Sellers, a postdoctoral fellow in the School of Medicine at the University of Missouri and lead researcher on the study. "We found that they don't have tough teeth, and we think it's because they replace their teeth like most other non-mammal animals. That made us wonder if other animals -- even prehistoric -- had similar issues."

Researchers said the next step is to study tooth replacement and the timing of teeth growth in crocodiles and other animals such as dinosaurs -- even looking into the possibility of genetic causes.

"Enamel takes a long time to build, so it's not something animals will do 'off-the-cuff,' so to speak," said Casey Holliday, an associate professor of anatomy in the MU School of Medicine. "It presents us with an interesting puzzle. If ancient crocodiles were chewing plants, did their new teeth already have the correct architecture -- dimples and facets -- to allow for this chewing? The findings here have paved the way for exploring this mystery with future research."

While oral cannabidiol (CBD) capsules were approved by the U.S. Food and Drug Administration (FDA) for use in patients with seizures in 2018, very little was known about the effect of food on CBD absorption.

A University of Minnesota study, published in Epilepsia, examined whether eating high-fat foods after taking CBD increased the body's absorption of CBD. The study tested whether fasting or a high fat meal has an effect when cannabidiol oral capsules were taken by patients.

To find out what effect a fatty meal would have on CBD absorption, the research group measured CBD concentrations in epilepsy patients at the MINCEP Epilepsy Care clinic who were taking 99 percent pure CBD capsules. Concentrations from patients who took CBD on an empty stomach and a standardized fatty breakfast (i.e. breakfast burrito) were compared.

"The type of food can make a large difference in the amount of CBD that gets absorbed into the body. Although fatty foods can increase the absorption of CBD, it can also increase the variability as not all meals contain the same amount of fat," said Angela Birnbaum, a professor in the College of Pharmacy and study co-author.

"Increases in the amount of the CBD dose being absorbed into the body can also lead to lower medication costs," said Ilo Leppik, study co-author, a professor in the College of Pharmacy and an adjunct professor at the Medical School.

The study found:

CBD exposure is vastly increased when CBD is taken with high fatty foods;

when compared to fasting, taking CBD with food increased the amount of CBD in the body by four-times and the maximum amount recorded in the participants' blood by 14-times;

no cognitive differences were identified, which is consistent with previous studies.

"For epilepsy patients, a goal is to maintain consistent blood concentrations of drug," said Birnbaum. "This study shows that CBD concentrations could vary significantly if patients take it differently, sometimes with or without food. Variations in blood concentrations could leave a patient more susceptible to seizures."

A study published today in the journal Cell Reports sheds new light on how the CD2AP gene may enhance Alzheimer's disease susceptibility. Integrating experiments in fruit flies, mice and human brains, a multi-institutional team led by researchers at Baylor College of Medicine found that the CD2AP gene is involved in synaptic transmission, the process by which neurons communicate. Digging deeper, the researchers discovered that CD2AP affects neuronal communication by regulating the levels of key regulatory proteins present at neuron terminals (synapses).

Dr. Joshua Shulman, associate professor of neurology at Baylor and corresponding author of the work, explains that they first worked with the laboratory fruit fly to test the effect of deleting the gene in the brain. The team deleted the fly equivalent of the human CD2AP gene, called cindr, and observed evidence of defective synapse structure and function. They also found that certain proteins accumulated more in the synapses of mutant flies. Among the accumulated proteins were several that regulate neural communication. To connect these findings with Alzheimer's disease, Shulman and his colleagues also studied a mouse in which the CD2AP gene was deleted and discovered brain changes similar to those they had found in flies. Finally, in order to establish relevance for humans, they examined a collection of more than 800 brain autopsies. Shulman and colleagues found that low CD2AP levels significantly correlated with abnormal turnover of synaptic proteins, and this relationship was enhanced in the setting of Alzheimer's disease.

BLOOMINGTON, Ind. -- College students who participate in fun, peer-directed activities that openly and honestly address mental illness are significantly less likely to stigmatize people with these conditions, according to a new study led by researchers at Indiana University.

The work, published online in the Journal of the American Academy of Child and Adolescent Psychiatry, is the first study to systematically survey a single graduating class over the course of their college careers on attitudes toward people with mental illness in conjunction with a sustained campaign on the topic. The study was led by Bernice Pescosolido, IU Distinguished Professor of Sociology and director of the Indiana Consortium for Mental Health Services Research.

Specifically, the study examined the effectiveness of U Bring Change to Mind, a part of Bring Change to Mind, a national nonprofit focused on reducing the stigma associated with mental illness led by actress Glenn Close, whose sister and nephew live with mental illness. The researchers measured shifts in student attitudes over time though surveys in their freshman and junior years.

"This is really the first program to target stigma that's been scientifically vetted from its inception," said Pescosolido, whose team worked closely in collaboration with university leaders to implement a four-year anti-stigma campaign at IU. "This pre- and post-analysis is very unique. Moreover, the results show these efforts really did change campus climate … not only regarding attitudes but also behaviors."

The need to address mental illness on college campuses is great and continues to grow, Pescosolido said. According to a 2018 report based on data from nearly 200 college campuses, the percentage of students seeking mental health treatment between 2007 and 2017 rose from 19 to 34 percent, and the percentage of those with mental illness diagnoses rose from 22 to 36 percent. Because counseling services must focus their efforts on the most serious cases due to limited resources, Pescosolido said a need remains for other efforts that instead focus on improving the general campus climate around mental health.

Overall, the IU study found significant reductions in stigma in 11 to 14 percent of students, with the most change reported by those who participated in four or more activities sponsored by U Bring Change to Mind. This included serious events, such as a suicide awareness walk, and lighter activities, such as a scavenger hunt and escape room. These changes included reductions in prejudice toward people with mental illness -- both in college and in general -- as well as reduced likelihood of distancing themselves socially from people with mental illnesses.

To put these numbers in context, the study's authors said this represents a rate of change nearly five times greater than that produced by a national-level campaign to reduce stigma in the U.K. over the course of 10 years.

"When you look at most interventions, the numbers are very small," Pescosolido said. "This study suggests that students really are at the right moment in their lives for this sort of intervention to make a difference."

The study also suggests that a "tipping point" is needed to drive change since shifts in attitude were strongest in students who attended four or more events. Students who attended one to three events showed relatively small changes in stigmatization toward mental illness.

In addition, the IU study outlines how the U Bring Change to Mind model differs from other campaigns through a focus on open activities with honest discussion of mental illness. The concept draws upon Pescosolido and colleagues' previous work on reducing mental illness stigma, which found that efforts focusing on the scientific understanding of mental illness as "a disease like any other" did not lower stigma.

"Those messages didn't seem to affect whether or not people actually reject or include people with mental illness," Pescosolido said. "We wanted to create a program based on research that started from a new place -- one that draws from Bring Change to Mind's idea of ending stigma through starting a conversation."

The five key principles of this approach are: targeting a receptive population, such as college students, at a critical time of change; providing group leaders with needed resources to design relevant messages and organize activities "by students, for students"; avoiding past, ineffective approaches; levering existing resources; and "building in change" to evolve the program over time.

Based on the results, Pescosolido and her team at IU are designing a national and international rollout of the program. Toward this goal, they are seeking partners to assist with logistics so other universities can launch similar efforts or inform existing programs.

"We believe this is the right time for these efforts both because this generation is much more open than past generations -- including their thinking about mental health -- and because college is when people are really forming critical attitudes that will follow them the rest of their lives," Pescosolido said. "This is the moment when we can really make a difference."

Additional IU authors on the paper are Brea Perry, professor of sociology, and Anne Krendl, associate professor of psychology.

IU Research

Indiana University's world-class researchers have driven innovation and creative initiatives that matter for nearly 200 years. From curing testicular cancer to collaborating with NASA to search for life on Mars, IU has earned its reputation as a world-class research institution. Supported by $604 million last year from 868 partners, IU researchers are building collaborations and uncovering new solutions that improve lives in Indiana and around the globe.

Journal

Journal of the American Academy of Child & Adolescent Psychiatry

DOI

10.1016/j.jaac.2019.06.016

A low-cost intervention aimed at fostering a growth mindset in students gave the students more confidence in their entrepreneurship abilities and helped them persist when challenges arose.

"The finding is valuable because efficacy, or confidence in one's abilities, and perseverance are powerful motivators and are critical for career development in entrepreneurship," says Jeff Pollack, second author of a paper on the work and an associate professor of entrepreneurship at North Carolina State University.

"Growth mindsets - the belief that human attributes are malleable - help students to flourish," says Jeni Burnette, lead author of the paper and an associate professor of psychology at NC State. "For this study, we focused on fostering a growth mindset of entrepreneurship - the idea that everyone can improve their entrepreneurship ability."

For the study, researchers worked with 238 undergraduate students. One group of 120 students received three growth mindset video modules focused on the idea that, with time, effort and energy, individuals can improve their entrepreneurship ability. A control group of 118 students watched three video modules that focused on misconceptions about entrepreneurship.

The study found that the growth mindset intervention did not directly or indirectly affect the classroom performance of students.

However, in post-intervention surveys, the researchers found that students who received the growth mindset intervention, relative to the control, reported greater entrepreneurial self-efficacy, such as confidence in their ability to identify new business opportunities and create new products. The growth mindset intervention also fostered greater persistence. Specifically, students reported continuing to pursue an entrepreneurial idea as part of a class project, even after encountering a challenge.

Additionally, self-efficacy correlated with an increased likelihood that students would consider entrepreneurship as a field of study and as a possible career.

Effects of the intervention did not depend on the student's gender or previous experience in the entrepreneurship field.

"This low-cost approach can be easily integrated into the classroom and is a promising tool for increasing students' motivation in entrepreneurship above and beyond simply learning about the field," Burnette says.

St. Paul, MN (August, 2019)--Tarnished plant bug is one of the most harmful pests of cotton in the mid-Atlantic states of Virginia and North Carolina. To learn more about this threat, Sally Taylor and Seth Dorman, of Virginia Tech Tidewater Agricultural Research and Extension Center (AREC), scouted and studied cotton fields from 2016 to 2018. They present their findings in the webcast "Tarnished Plant Bug Management Strategies for Mid-Atlantic Cotton."

Taylor and Dorman encourage growers to avoid planting cotton beside other hosts of tarnished plant bug, including wheat and corn, and emphasize weed management to eliminate the proximity of other hosts. Taylor and Dorman also report that cotton planted later in the year and certain varieties of cotton, such as mid- to full-maturing and smooth-leaf varieties, require more intensive management.

Taylor and Dorman conclude that scouting and using thresholds are the most effective strategies for managing tarnished plant bug. They also recommend strategies for insecticide use and resistance management.

This webcast complements "Tarnished Plant Bug in North Carolina and Virginia," which gives a more general overview of the pest's relationship with cotton.

Both webcasts are available through the "Focus on Cotton" resource on the Plant Management Network. This resource contains more than 75 webcasts, along with presentations from six conferences, on a broad range of aspects of cotton crop management: agronomic practices, diseases, harvest and ginning, insects, irrigation, nematodes, precision agriculture, soil health and crop fertility, and weeds. These webcasts are available to readers open access (without a subscription).

The "Focus on Cotton" homepage also provides access to "Cotton Cultivated," a new resource from Cotton Incorporated that helps users quickly find the most current cotton production information available. These and other resources are freely available courtesy of Cotton Incorporated at http://www.plantmanagementnetwork.org/foco.

Mice scurry around while foraging for food, but genetics may be the unseen hand controlling these meandering movements. Researchers at University of Utah Health are using machine learning to draw links between genetic controls that shape incremental steps of instinctive and learned behaviors. The results are available online in Cell Reports on August 13.

"Patterns of complex behavior, like searching for food, are composed of sequences that feel random, spontaneous and free," said Christopher Gregg, Ph.D., assistant professor in Neurobiology and Anatomy at U of U Health and senior author of the study. "Using machine learning, we are finding discrete sequences that are reproduced more frequently than you would expect by chance and these sequences are rooted in biology."

The research team is venturing into the new territory of behavioral sequencing.

"We are trying to understand the architecture of complex behavior and how genetics shape these patterns," said Gregg.

The research supports the idea that complex behavior is composed of a collection of finite 'building blocks' the authors call behavioral modules, and that genetics are controlling the progression of these building blocks to form different behavioral patterns.

The research team evaluated 190 mice with differences in their genetics and age as they moved from their home into a uniquely created 'arena' to evaluate the set of behavioral sequences expressed while foraging for food. In the search for food, mice exhibit behaviors that require many neural systems to control seeking-behaviors, anxiety, reward, preservation, hunger, satiety, attention, navigation and memory. The new methods revealed that different genetic and age effects influence different sequences.

"Most species have a home range and their behaviors are structured around this home range," Gregg said. "We were able to identify reproduceable behavioral sequences and use this information to understand the complex patterns over time."

The team separated round trips from home to a food source and back into a series of more than 5,600 mouse actions. Layered within these actions are additional information, such as gait pattern, velocity, distance traveled and locations visited. Using machine learning, they evaluated this information and identified 71 reproduceable behavioral sequences that are the underlying building blocks for more complex behavior patterns.

The transition from one 'building block' to the next implies a mechanistic relationship that yields specific foraging behaviors that minimize predation risk, energy expenditure and caloric intake. In addition, the algorithm was able to identify spontaneous responses that are unique to specific mice.

Gregg believes this approach is sensitive enough to pick up a mutation in the copy of one gene. To prove this point, his team focused on foraging behaviors in mice with a mutation in an imprinted gene, Magel2, which is linked to autism. For example, when the mother's copy is turned off, the father's copy is turned on. In this scenario, it was widely believed that the mother's copy was silent and did not affect the offspring. Not so.

"What was exciting to us was we were able to detect significant effects on behavior from a single mutation in only the mother's gene copy," Gregg said.

At this time, the study has only explored the building blocks of foraging behavior in lab mice. Gregg believes the methodology could be applied to understand the basis of other complex behavior patterns and learn the specific genomic elements that shape behaviors leading to disease in humans, including obesity, addiction, fear, anxiety and psychiatric disorders.

"By deconstructing really complex, seemingly spontaneous behaviors, we were able to detect things that weren't observable in other studies," Gregg said. "If there is a mutation that causes disease in people we hope to use this method to map it to specific modules [aka behavior building blocks] to learn how genes contribute to shaping particular behavior patterns."

Bottom Line: Patterns of high blood pressure in midlife that extend to late life or high blood pressure in midlife followed by low blood pressure later in life was associated with increased risk for dementia compared to having normal blood pressure. This observational study included nearly 4,800 participants who had blood pressure measurements taken over 24 years at five visits plus a detailed neurocognitive evaluation during the fifth and a sixth visit, where dementia was assessed. There were 516 new cases of dementia diagnosed between the fifth and sixth visits. Study authors report that compared with maintaining normal blood pressure, an increased risk of dementia was associated with hypertension (greater than 140/90 mm Hg or use of antihypertensive medication) in midlife (age 54 to 63) that was sustained to late life and a pattern of hypertension in midlife and low blood pressure (less than 90/60 mm Hg) later life. Midlife hypertension followed by late-life low blood pressure also was associated with increased risk of mild cognitive impairment. Limitations of the study include that the findings may have been biased because of the increased likelihood that participants with higher blood pressure and poorer cognition during midlife dropped out of the study. Also, study participants were from Washington County, Maryland; Forsyth County, North Carolina; Jackson, Mississippi; and Minneapolis, so the results may not be generalizable to other areas.

Authors: Keenan A. Walker, Ph.D., Johns Hopkins University School of Medicine, Baltimore, and coauthors

(doi:10.1001/jama.2019.10575)

Editor's Note: The article includes conflict of interest and funding/support disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

Bottom Line: Consuming more gluten during the first five years of life was associated with increased risk of celiac disease and celiac disease autoimmunity (the presence of antibodies in the blood) among genetically predisposed children. It remains unclear whether the amount of gluten consumed can trigger celiac disease. This observational study included 6,605 children born between 2004 and 2010 in Finland, Germany, Sweden and the United States who had a genetic predisposition for celiac disease. Gluten intake was estimated from food records collected at ages 6, 9, and 12 months and then biannually until the age of 5. Of the 6,605 children, 18% developed celiac disease autoimmunity and 7% developed celiac disease. The incidence of both outcomes peaked at 2 to 3 years old. The authors report that for every 1-gram per day increase in gluten consumption there was an associated higher risk of celiac disease and celiac disease autoimmunity. If gluten intake was one gram per day higher than the average at age 2 (corresponding to a half slice of white bread), the absolute risk differences for celiac disease autoimmunity and celiac disease were 6% and 7% higher, respectively, by age 3. A limitation of the study is the uncertainty of the accuracy of the reported gluten intake. The authors suggest a randomized clinical trial be done of different amounts of gluten during early childhood in genetically at-risk children.

Authors: Daniel Agardh, M.D., Ph.D., Lund University, Malmo, Sweden and coauthors

(doi:10.1001/jama.2019.10329)

Editor's Note: The article includes conflict of interest and funding/support disclosures. Please see the article for additional information, including other authors, author contributions and affiliations, financial disclosures, funding and support, etc.

A vast region of Africa affected by drought and changing land use emits as much carbon dioxide each year as 200 million cars, research suggests.

Observations from two satellites have consistently shown emissions over northern tropical Africa of between 1 and 1.5 billion tonnes of carbon each year.

The data suggest stored carbon has been released from degraded soils - those subject to prolonged or repeated drought or land use change - in western Ethiopia and western tropical Africa, but scientists say further study is needed to provide a definitive explanation for the emissions.

Their findings improve understanding of greenhouse gas sources and aid efforts to meet the terms of the Paris Agreement, which aims to limit average global temperature rise below 2C.

The carbon source might have gone undiscovered with land-based surveys alone, according to a team led by researchers from the University of Edinburgh.

Researchers examined data gathered by two NASA satellite missions - Japanese Greenhouse Gases Observing SATellite (GOSAT) and the Orbiting Carbon Observatory (OCO-2).

They compared readings with three atmospheric models showing changes in vegetation, and a host of other measurements of ground water, fire and levels of photosynthesis.

The study is the result of a decade of work, involving hundreds of dedicated engineers and scientists, and billions of dollars of investment by space agencies.

Professor Paul Palmer, of the University of Edinburgh's School of GeoSciences, who led the study, said: "The tropics are home to one-third of Earth's three billion trees and their stored carbon, and yet we are only scratching the surface of understanding how they are responding to changes in climate. We anticipate that satellite data will continue to improve that situation."

New Haven, Conn. - To understand the most ordinary matter in the universe -- and the extraordinary things that happen to it -- a Yale-led team of astronomers took a deep dive into the cosmic fog.

They learned intriguing new details about the dynamics of baryons, the collection of subatomic particles (including protons and neutrons) that accounts for much of the visible matter in the universe. Most baryons reside in the intergalactic medium (IGM), which is the space in-between galaxies where matter is neither bound to nor tugged upon by surrounding systems.

In a new study, Yale postdoctoral associate Nir Mandelker and professor Frank C. van den Bosch report on the most detailed simulation ever of a large patch of the IGM. For the first time, they were able to see how cold, dense gas clouds in the IGM organize themselves and react within much larger "sheets" or "pancakes" of matter in the vastness of space.

The findings appear in the Astrophysical Journal Letters.

Researchers have tried for years to piece together the structures and properties of the IGM -- in part to test the standard model of Big Bang cosmology, which predicts that 80%-90% of baryons are in the IGM, but also to investigate the IGM's crucial role as the universe's fuel source.

"The reason galaxies are able to form stars continuously is because fresh gas flows into galaxies from the IGM," said Mandelker, lead author of the study. "It is clear that galaxies would run out of gas in very short order if they didn't accrete fresh gas from the IGM."

Yet detecting the IGM's gas has been supremely difficult. Unlike galaxies, which shine brightly in starlight, gas in the IGM is almost never luminous enough to detect directly. Instead, it has to be studied indirectly, through the absorption of background light. Such absorption studies allow researchers to learn about the density and chemical composition of gas clouds; in particular, they're able to find out if star formation in nearby galaxies has polluted the gas with metals (elements heavier than helium).

With its new simulation, the Yale team learned quite a lot -- including new properties of those aforementioned sheets of baryons.

"These are flattened distributions of matter, known as 'pancakes,' that extend across many millions of light years across," said van den Bosch. "We found that rather than being smoothly distributed, the gas in these pancakes shatters into what resembles a 'cosmic fog' made up of tiny, discrete clouds of relatively cold and dense gas."

Such dense clouds of gas had been thought to form only in areas of space close to galaxies, where the gas is naturally denser. But the new simulation shows that they also can condense out of the low-density IGM. The researchers said the phenomenon occurs naturally, as the result of an instability triggered by the efficient cooling of the gas.

Another aspect of this cosmic fog, based on the Yale simulation, is that it is pristine; it is too far away from any galaxy to be polluted with metals. According to Mandelker, this is significant because it explains recent, puzzling observations of dense, metal-free clouds at large distances from galaxies. Astronomers could not explain this phenomenon, but the new simulation suggests their presence may simply be the outcome of a natural process.

"Our work highlights the importance of properly resolving the properties of gas in the IGM, which is often neglected in favor of better resolving the central galaxies," Mandelker said. "It has been very difficult to understand how the gas in the IGM could possibly become so dense and optically thick, especially when previous generations of cosmological simulations did not reveal any such dense gas in the IGM."

LAWRENCE -- Climate change is a problem facing countries around the world, but media coverage of the topic differs from one nation to the next. A new study from the University of Kansas shows the way media frame climate change coverage can be predicted by several national factors, yet none tend to frame it as an immediate problem requiring national policies to address the issue.

While richer countries tend to frame climate change coverage as a political issue, poorer countries more often frame it as an international issue that the world at large needs to address.

"Media can tell people what to think about. At the same time, framing can have an effect on how people think about certain issues," said Hong Vu, assistant professor of journalism at KU and the study's lead author. "Not only can framing have an impact on how an issue is perceived but on whether and how policy is made on the issue. With big data, machine-learning techniques, we were able to analyze a large amount of media climate change coverage from 45 countries and territories from 2011 to 2015."

Vu and co-authors Yuchen Liu, graduate student at KU; and Duc Vinh Tran of Hanoi University of Science and Technology published their findings in the journal Global Environmental Change. They analyzed over 37,000 articles and considered national factors such as economic development, weather and energy consumption. They reviewed headlines from nationally circulated publications of varying political ideologies that contained the keywords "greenhouse gas," "climate change" and/or "global warming," or the local language equivalent.

The most consistent predictor of how the issue was framed was a nation's gross domestic product per capita.

"We showed that the issue is more politicized in richer countries. In poorer countries, it was framed more as an international issue," Vu said. "Which makes sense, as poorer countries don't have the resources that richer countries do to fight it."

Even when richer countries framed the issue as one they could address with their more plentiful resources, it was often also framed as a political issue and would focus on debate or argument about political approaches as opposed to proposing policy solutions. Media from richer countries also focused more on the science of climate change.

When climate change was framed as an economic issue, it was in countries that had the most severe climates and those that have experienced the most adverse consequences of climate change and natural disasters, loss of life and property, and economic effects.

In terms of social progress framing, richer countries framed the issue in terms of energy policy and use. Those that emit the most carbon dioxide framed content in terms of energy issues, while poorer countries and those that had experienced the most severe climates focused more on natural impact.

The study also used independent nation-level variables from several databases, including the World Bank, the Center for Research on the Epidemiology of Disasters, the Global Carbon Atlas Project and Freedom House, all nongovernment organizations working in development or on climate change.

The authors argue that the international relations frame being the most widely used reflects the fact that climate change is a problem every nation needs to address. Economic effects being second most popular reflects that fighting climate change will have impacts on every economy and that when natural disasters and climate change were discussed, they were nearly always brought forth in an economic sense. They also contend that richer countries framing the issue as political reflects that climate change skeptics in those nations gaining more media prominence and the efforts of multiple groups trying to politicize the issue, influence media agendas and policymaking.

The study helps add to the understanding of media influence on climate change coverage, Vu said. Future work will address questions of framing the topic, if it's done on local, national or global levels, if communicators suggest solutions, if such solutions are attributed to individuals, businesses or governments and efficacy of proposed solutions. Three decades of communications on the topic show there is not a sense of immediacy in covering the problem and influencing policy.

"As communications researchers we want to know why, if climate change entered public discussion more than 30 years ago and we've been covering it as a global problem since, why can't we slow the warming climate down," Vu said. "If we want the public to have better awareness of climate change, we need to have media imparting it in an immediate sense. By looking at how they have portrayed it, we can better understand how to improve it, and hopefully make it a priority that is reflected in policy."

A new multicenter study at Columbia University links long-term exposure to air pollution, especially ozone, to development of emphysema, a chronic lung disease.

In Brief

Long-term exposure to outdoor air pollutants, especially the pollutant ozone, accelerates the development of emphysema and age-related decline in lung function, even among people who have never smoked, according to a study published in the Journal of the American Medical Association.

The findings may help explain why emphysema is relatively common in nonsmokers.

Background

Chronic lower respiratory disease--a catchall term for emphysema, chronic obstructive pulmonary disease (COPD), chronic bronchitis, and asthma--is the fourth-leading cause of death in the U.S. and third-leading cause of death worldwide. Short-term exposure to air pollutants is a major risk factor for poor lung health. But the long-term effects of air pollutants on the lungs are not well understood.

Study Details

The study, the largest and longest of its kind, looked at whether exposures to four major pollutants--ground-level ozone, fine particulate matter (PM), nitrogen oxide, and black carbon--were associated with the development of emphysema, measured by CT scan, and decline in lung function, measured by spirometry. (Ground-level ozone harms human health, but ozone high in the atmosphere ozone protects against the sun's harmful ultraviolet rays.)

The study included more than 7,000 adults (ages 45 to 84) living in Chicago, Los Angeles, Baltimore, St. Paul, New York City, and Winston-Salem, who were taking part in the Multi-Ethnic Study of Atherosclerosis Air Pollution (MESA Air) and MESA Lung studies. Participants were followed for a median of 10 years. Air pollutant levels were estimated at each participant's home address.

What the Study Found

The researchers found that exposure to each of the pollutants at the beginning of the study was independently linked to the development of emphysema during the study period. The strongest association was seen with ozone. Only ozone, at baseline and during follow-up, was associated with a decline in lung function.

Ambient concentrations of fine particulates and nitrous oxide, but not ozone, decreased significantly over the study period.

"The increase in emphysema we observed was relatively large, similar to the lung damage caused by 29 pack-years of smoking and 3 years of aging,"said R. Graham Barr, MD, DrPH, the Hamilton Southworth Professor of Medicine and Epidemiology at Columbia University Irving Medical Center and a senior author of the paper. (One pack-year is equal to smoking a pack a day for a year.)

What the Study Means

"These findings matter since ground-level ozone levels are rising, and the amount of emphysema on CT scans predicts hospitalization from and deaths due to chronic lower respiratory disease," says Barr.

"Ground-level ozone is produced when UV light reacts with pollutants from fossil fuels," adds Barr. "This process is accelerated by heatwaves, so ground-level ozone will likely continue to increase unless additional steps are taken to reduce fossil fuel emissions and curb climate change. But it's not clear what level of ozone, if any, is safe for human health."

Walter and Eliza Hall Institute researchers have identified a molecular switch that impacts immune responses to viral infections, and whether or not protective antibodies are produced.

The team also made the surprising discovery that the immune system protects against different viruses via distinct pathways. Their findings could lead to better strategies to develop vaccines for previously hard-to-prevent viruses.

The research, led by Dr Joanna Groom and PhD student Ms Amania Sheikh, was published today in the journal Cell Reports.

At a glance

Our researchers have identified that the protein T-bet determines how the immune system responds to viral infections.

The research showed that T-bet enables immune T cells to distinguish between different viral infections, controlling whether or not protective antibodies are produced.

Antibodies are an essential component of long-lived immunity to viruses, and this discovery could underpin the development of better vaccines to prevent viral diseases.

Molecular switch

Our immune system comprises a complex network of cells and signalling molecules that can produce a range of responses to infections, Ms Sheikh said. "Immune T cells are critical for coordinating specific immune responses, recruiting other cells and directing how we respond to different microbes such as bacteria, fungi or viruses," she said.

"We knew that the protein T-bet was important for the function of many immune cells, and wanted to understand its role in a subset of immune T cells that help in the formation of protective antibodies."

Antibodies are long-lived proteins that can be produced following an infection. They specifically bind to other proteins - such as those on a microbe's surface - and are important for protecting us against repeat infections by the same microbe. Vaccines work by stimulating the production of antibodies that are specific to an infectious disease, preventing the infection from establishing.

Ms Sheikh said the team discovered that T-bet was an essential switch that enabled T cells to stimulate antibody production in response to viral infections. "The level of T-bet in T cells is influenced by factors such as how a virus enters the body, and how much inflammation it triggers in its early stages. This in turn influences the immune response to the virus," she said.

Distinguishing viruses

These findings reconcile a controversy in the field about how the immune system can distinguish between different viral infections, and respond in distinct ways. "We compared the role of the T-bet switch in immune responses to two viruses, influenza and LCMV, a virus that can cause meningitis," Dr Groom said.

"These viruses are thought to activate similar immune cells, yet we demonstrated specific changes between the responses could lead to very different amounts of protective antibodies. We showed that T-bet was critical for scaling how much antibody production occurred in response to a viral infection."

The findings could underpin the development of more effective vaccines against viruses. "Most current vaccines to infectious diseases rely on robust and long-lived antibody production. If we can understand the precise triggers controlling how much antibody is produced in response to an infection, we should be able to develop vaccines that act similarly to stimulate protective antibody production," Dr Groom said.