Dynamics behind Arctic ecosystems revealed

Species such as the musk ox, Arctic fox and lemming live in the harsh, cold and deserted tundra environment. However, they have often been in the spotlight when researchers have studied the impact of a warmer climate on the countryside in the north. Until now, the focus has been concentrated on individual species, but an international team of biologists has now published an important study of entire food-web dynamics in the journal Nature Climate Change. Field studies covering three continents show that temperature has an unexpectedly important effect on food-web structure, while the relationship between predator and prey is crucial for the food-web dynamics and thereby the entire ecosystem.Temperature is decisive’We have gathered data on all animals and plants characterising the arctic tundra in seven different areas. This has allowed us to generate a picture of how food chains vary over a very large geographical (and, with it, climatic) gradient. Therefore, and for the first time, we can offer an explanation of the factors governing the tundra as an ecosystem,’ says Niels Martin Schmidt from Aarhus University, Denmark, one of the researchers behind the study. The researchers have evidenced that temperature is of decisive importance for which elements form part of the food chain, thus permitting them to predict how climate changes may impact whole food chains — and not just the conditions for the individual species.The largest avoids being eatenTemperature regulates which organisms interact with each other in the far north arctic nature. However, the present study also shows that predation, i.e. the interactions between predators and prey, is the factor regulating the energy flows in ecosystems and, with that, the function of the ecosystem.’Our results show that predators are the most important items of the tundra food chains, except in the High Arctic. The intensity varies with the body size of the herbivores (plant eaters) of the chains. …

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Animals losing migratory routes? Devasting consequences of scarcity of ‘knowledgeable elders’

Small changes in a population may lead to dramatic consequences, like the disappearance of the migratory route of a species. A study carried out in collaboration with the SISSA has created a model of the behaviour of a group of individuals on the move (like a school of fish, a herd of sheep or a flock of birds, etc.) which, by changing a few simple parameters, reproduces the collective behaviour patterns observed in the wild. The model shows that small quantitative changes in the number of knowledgeable individuals and availability of food can lead to radical qualitative changes in the group’s behaviour.Until the ’50s, bluefin tuna fishing was a thriving industry in Norway, second only to sardine fishing. Every year, bluefin tuna used to migrate from the eastern Mediterranean up to the Norwegian coasts. Suddenly, however, over no more than 4-5 years, the tuna never went back to Norway. In an attempt to solve this problem, Giancarlo De Luca from SISSA (the International School for Advanced Studies of Trieste) together with an international team of researchers (from the Centre for Theoretical Physics — ICTP — of Trieste and the Technical University of Denmark) started to devise a model based on an “adaptive stochastic network.” The physicists wanted to simulate, simplifying it, the collective behaviour of animal groups. Their findings, published in the journal Interface, show that the number of “informed individuals” in a group, sociality and the strength of the decision of the informed individuals are “critical” variables, such that even minimal fluctuations in these variables can result in catastrophic changes to the system.”We started out by taking inspiration from the phenomenon that affected the bluefin tuna, but in actual fact we then developed a general model that can be applied to many situations of groups “on the move,” explains De Luca.The collective behaviour of a group can be treated as an “emerging property,” that is, the result of the self-organization of each individual’s behaviour. “The majority of individuals in a group may not possess adequate knowledge, for example, about where to find rich feeding grounds” explains De Luca. “However, for the group to function, it is enough that only a minority of individuals possess that information. The others, the ones who don’t, will obey simple social rules, for example by following their neighbours.”The tendency to comply with the norm, the number of knowledgeable individuals and the determination with which they follow their preferred route (which the researchers interpreted as being directly related to the appeal, or abundance, of the resource) are critical variables. …

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Our memory for sounds is significantly worse than our memory for visual or tactile things

Remember that sound bite you heard on the radio this morning? The grocery items your spouse asked you to pick up? Chances are, you won’t.Researchers at the University of Iowa have found that when it comes to memory, we don’t remember things we hear nearly as well as things we see or touch.”As it turns out, there is merit to the Chinese proverb ‘I hear, and I forget; I see, and I remember,” says lead author of the study and UI graduate student, James Bigelow.”We tend to think that the parts of our brain wired for memory are integrated. But our findings indicate our brain may use separate pathways to process information. Even more, our study suggests the brain may process auditory information differently than visual and tactile information, and alternative strategies — such as increased mental repetition — may be needed when trying to improve memory,” says Amy Poremba, associate professor in the UI Department of Psychology and corresponding author on the paper, published this week in the journal PLoS One.Bigelow and Poremba discovered that when more than 100 UI undergraduate students were exposed to a variety of sounds, visuals and things that could be felt, the students were least apt to remember the sounds they had heard.In an experiment testing short term-memory, participants were asked to listen to pure tones they heard through headphones, look at various shades of red squares, and feel low-intensity vibrations by gripping an aluminum bar. Each set of tones, squares and vibrations was separated by time delays ranging from one to 32 seconds.Although students’ memory declined across the board when time delays grew longer, the decline was much greater for sounds, and began as early as four to eight seconds after being exposed to them.While this seems like a short time span, it’s akin to forgetting a phone number that wasn’t written down, notes Poremba. “If someone gives you a number, and you dial it right away, you are usually fine. But do anything in between, and the odds are you will have forgotten it,” she says.In a second experiment, Bigelow and Poremba tested participants’ memory using things they might encounter on an everyday basis. Students listened to audio recordings of dogs barking, watched silent videos of a basketball game, and, touched and held common objects blocked from view, such as a coffee mug. The researchers found that between an hour and a week later, students were worse at remembering the sounds they had heard, but their memory for visual scenes and tactile objects was about the same.Both experiments suggest that the way your mind processes and stores sound may be different from the way it process and stores other types of memories. …

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Selenium, vitamin E supplements can increase risk of prostate cancer in some men

A multi-center study led by Fred Hutchinson Cancer Research Center has found that high-dose supplementation with both the trace element selenium and vitamin E increase the risk of high-grade prostate cancer. But importantly, this risk depends upon a man’s selenium status before taking the supplements.These findings, published in Journal of the National Cancer Institute, are based on data from the Selenium and Vitamin E Cancer Prevention Trial, or SELECT, a rigorously executed, randomized and placebo-controlled trial conducted by the SWOG cancer research cooperative group that involved more than 35,000 men. The study sought to determine whether taking high-dose vitamin E (400 IU/day) and/or selenium (200 mcg/day) supplements could protect men from prostate cancer.The trial, which began in 2001 and was designed to last 12 years, stopped early, in 2008, because it found no protective effect from selenium and there was a suggestion that vitamin E increased risk. While use of the study supplements stopped, men were still followed and after an additional two years the men who took vitamin E had a statistically significant 17 percent increased risk of prostate cancer.Selenium supplementation increased cancer in men with high selenium status at baselineWhen the study started, there was some evidence that selenium supplementation would not benefit men who already had an adequate intake of the nutrient. For that reason, researchers measured the concentration of selenium in participants’ toenails and planned to test whether selenium supplementation would benefit only the subset of men with low selenium status at baseline. Instead, they found that taking selenium supplements increased the risk of high-grade cancer by 91 percent among men with high selenium status at baseline. When selenium supplements were taken by men who had high selenium status to begin with, the levels of selenium became toxic.Taking vitamin E increased cancer risk in men with low selenium status at baselineThe study also found that only a subgroup of men was at increased risk of prostate cancer from taking vitamin E. Among men with low selenium status at baseline, vitamin E supplementation increased their total risk of prostate cancer by 63 percent and increased the risk of high-grade cancer by 111 percent. This explained one of the original SELECT findings, which was that only men who received vitamin E plus a placebo pill, and not those who received both vitamin E and selenium, had an increased prostate cancer risk. Selenium, whether from dietary sources or supplements, protected men from the harmful effects of vitamin E.”Many people think that dietary supplements are helpful or at the least innocuous. …

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Huntington disease prevention trial shows creatine safe, slows progression

The first clinical trial of a drug intended to delay the onset of symptoms of Huntington disease (HD) reveals that high-dose treatment with the nutritional supplement creatine was safe and well tolerated by most study participants. In addition, neuroimaging showed a treatment-associated slowing of regional brain atrophy, evidence that creatine might slow the progression of presymptomatic HD. The Massachusetts General Hospital (MGH) study also utilized a novel design that allowed participants — all of whom were at genetic risk for the neurodegenerative disorder — to enroll without having to learn whether or not they carried the mutation that causes HD.”More than 90 percent of those in the United States who know they are at risk for HD because of their family history have abstained from genetic testing, often because they fear discrimination or don’t want to face the stress and anxiety of knowing they are destined to develop such a devastating disease,” says H. Diana Rosas, MD, of the MassGeneral Institute for Neurodegenerative Disease (MGH-MIND), lead and corresponding author of the paper that will appear in the March 11 issue of Neurology and has been released online. “Many of these individuals would still like to help find treatments, and this trial design allows them to participate while respecting their autonomy, their right not to know their personal genetic information.”Among the ways that the mutated form of the huntingtin protein damages brain cells is by interfering with cellular energy production, leading to a depletion of ATP, the molecule that powers most biological processes. Known to help restore ATP and maintain cellular energy, creatine is being investigated to treat a number of neurological conditions — including Parkinson disease, amyotrophic lateral sclerosis and spinal cord injury. Studies in mouse models of HD showed that creatine raises brain ATP levels and protects against neurodegeneration. Previous clinical trials of creatine in symptomatic HD patients have been limited in scale, involved daily doses of 10 grams or less, and did not provide evidence of potential efficacy. Based on the results of a pilot study at MGH that evaluated doses as high as 40 grams, participants in the current study received doses of up to 30 grams daily.The phase II PRECREST trial enrolled 64 adult participants — 19 who knew they carried the mutated form of the HD gene and 45 with a 50 percent risk of having inherited the HD mutation. Genetic testing, results of which were made available only to the study statistician and not to study staff or participants, confirmed the genetic status of those who had previously been tested and revealed an additional 26 presymptomatic carriers of the mutated gene, for a total of 47 participants with presymptomatic HD and 17 controls.For the first 6 months of the trial, participants were randomized into two groups, regardless of gene status. …

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‘Friendly’ robots could allow for more realistic human-android relationships

Two ‘friendly’ robots, including a 3D-printed humanistic android, are helping scientists to understand how more realistic long-term relationships might be developed between humans and androids.ERWIN (Emotional Robot with Intelligent Network) is the brainchild of Dr John Murray, from the School of Computer Science, University of Lincoln, UK. It is now being used as part of a PhD study to find out how some of the human-like thought biases in robot characteristics affect the human-robot relationship.It is hoped the research will not only help scientists to understand and develop better, more realistic relationships between humans and ‘companion’ robots, but that it could also help to inform how relationships are formed by children with autism, Asperger syndrome or attachment disorder.PhD student Mriganka Biswas said: “Cognitive biases make humans what they are, fashioning characteristics and personality, complete with errors and imperfections. Therefore, introducing cognitive biases in a robot’s characteristics makes the robot imperfect by nature, but also more human-like.”Based on human interactions and relationships, we will introduce ‘characteristics’ and ‘personalities’ to the robot. If we can explain how human-to-human long-term relationships begin and develop, then it would be easier to plan the human-robot relationship.”When two people interact for the first time, if the two different personalities attract each other, a relationship forms. But, in the case of conventional human-robot interaction, after gathering information about the robot, the robot’s lack of identifiable characteristics and personality prevents any relationship bond developing.ERWIN has the ability to express five basic emotions while interacting with a human.Mriganka said: “Robots are increasingly being used in different fields, such as rescuing people from debris, in medical surgeries, elderly support and as an aid for people who have autism.”For the latter two especially, robots need to be friendly and relatively more sympathetic and emotive to its users. A companion robot needs to be friendly and have the ability to recognize users’ emotions and needs, and to act accordingly. So, for each category the robot needs to form a ‘long-term’ relationship with its users, which is possible by continuous interactions and the robot having its own personality and characteristics.”Scientists will be collating data from the robot’s interactions with humans, while also employing a 3D-printed humanoid robot and Keepon — a small yellow robot designed to study social development by interacting with children.Its simple appearance and behaviour are intended to help children, particularly those with developmental disorders such as autism, to understand its attentive and emotive actions.The ‘non-emotive’ Keepon will be used in the research project to study the different reactions people have to it compared to the emotive ERWIN. The aim is to discover which is most effective in engaging with participants, and whether those interactions are long or short-term.Story Source:The above story is based on materials provided by University of Lincoln. Note: Materials may be edited for content and length.

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Are invasive plants a problem in Europe? Controversial views among invasion biologists

Some introduced (i.e. non-native) plants become abundant, threaten species richness and the well-functioning of ecosystems, the economy, or health (plant invasion). Environmental policies that attempt to restrict the expansion of non-native species are based on a consensus among scientific experts that invasions are a serious environmental problem. An example of a problematic non-native species in many parts of the world is Fallopia japonica, the Japanese knotweed that negatively affects river ecosystems.A consensus among experts on the severity of plant invasions seems evident in many scientific and outreach publications. However, instead of consensus, a new study by an interdisciplinary research team at ETH Zurich (Switzerland) of psychologists and plant biologists found a wide range of different opinions among scientific experts about how to describe invasive plant species, and how severe their effects on the environment are. The study is published in the latest issue of the open access journal NeoBiota.The researchers conducted 26 face-to-face interviews with a representative sample of German-speaking scientists working on plant invasions, or more generally on environmental change, in Europe. The interviews revealed that individual understandings of scientific concepts, uncertainties, and value-based attitudes towards invasive plants and their management diverged widely among these experts.”Particularly, ambiguous definitions of the terms non-native and invasive (two key notions in invasion science) are a strong source of misunderstandings among scientists,” said lead author Franziska Humair, a doctoral student at ETH Zurich. Some of the study participants used a biological definition to discriminate native from non-native species (“species from a different biogeographic region”), while others referred to culture (“species not familiar to local people”). “Based on each definition, a different set of species is considered non-native in a particular country,” Ms Humair said. Equally, different experts considered different impacts by invasive species on ecosystems and their functioning for humans (ecosystem services) to be relevant. …

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As the temperature drops, risk of fracture rises

Record-setting winter weather in the U.S. has led to lots of road condition advisories, but could there also be a slip and fall alert?By analyzing various conditions — like snow, wind speed, temperature — into a ‘Slipperiness Score,’ a University of Michigan Health System study helps identify what days are the most risky for slip and fall injuries.The study, published in February’s Plastic and Reconstructive Surgery Journal, focuses on Medicare patients, all over age 65, but authors note, the risk of falling exists for anyone during harsh winter weather.”Although the concept that slippery footing increases your risk of falling isn’t new, what we’ve been able to show is that these dangerous conditions result in more fractures in this already vulnerable population of adults,” says lead study author Aviram Giladi, M.D., a resident in the U-M Department of Surgery’s Division of Plastic Surgery.The study findings include:Based on a scale, ranging from 0 to 7, on a day with a score above 4 the risk of sustaining a wrist fracture increased by 21 percent. On the most slippery days, that additional risk went up to nearly 40 percent. In the winter, over 1,000 additional wrist fractures occurred among adults age 65 and older compared to other seasons. Nearly 90,000 Medicare enrollees sustain wrist fractures each year, frequently from falls while standing and usually outdoors. The fractures can be quite limiting, and lead to a loss of independence for older patients. Medicare spends more than $240 million a year treating the injuries.”Understanding the risk of these injuries can help inform prevention and preparation efforts, especially on days where the weather is bound to result in more slippery conditions,” says senior study author Kevin C. Chung, M.D., professor of plastic surgery and orthopedic surgery and the Charles B. G. de Nancrede Professor of Surgery. …

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Doctors likely to accept new Medicaid patients as coverage expands

Oct. 16, 2013 — The upcoming expansion of Medicaid under the Affordable Care Act (ACA) won’t lead physicians to reduce the number of new Medicaid patients they accept, suggests a study in the November issue of Medical Care, published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.However, doctors may be less likely to accept those patients who remain uninsured, according to an analysis of historical data by Lindsay M. Sabik, PhD, and Sabina Ohri Gandhi, PhD, of Virginia Commonwealth University, Richmond. They write, “Our results suggest that after increases in Medicaid coverage within a market, access may be limited for the remaining patients.”Doctors Likely to Continue Accepting Medicaid Patients After ExpansionAs part of the ACA, Medicaid coverage will expand substantially beginning in 2014, with the goal of improving the health of people who were previously uninsured. Whether that goal is achieved will partly depend on how doctors respond to changes in their local market — and how those decisions affect low-income individuals who rely on “safety-net” care.Drs Sabik and Gandhi analyzed data from a long-term, nationwide study of changes in the health care system (the Community Tracking Study Physician Survey). Physician survey responses from the mid-1990s to the mid-2000s were analyzed to assess how market-level changes in Medicaid coverage affected doctors’ acceptance of new patients: both patients covered by Medicaid and uninsured patients who were unable to pay.For most of the period studied, Medicaid coverage rates increased while uninsurance rates trended lower. Both rates varied between different markets. About 70 percent of physicians surveyed were in solo or group medical practice.The data suggested that changes in Medicaid coverage did not significantly affect doctors’ acceptance of new Medicaid patients. “[P]hysicians who were already accepting (or not accepting) Medicaid patients before changes in Medicaid coverage rates continue to do so,” Drs Sabik and Gandhi write.On average, new Medicaid patients were accepted by about 72 percent of office-based and 90 percent of facility-based doctors (those who work at hospitals or other facilities). These rates remained about the same after changes in Medicaid coverage.But May Not Accept Patients Who Remain UninsuredHowever, when Medicaid coverage rates increased, physicians became less likely to accept new uninsured patients. …

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African-Americans at higher risk for health problems from insufficient sleep

Sep. 9, 2013 — Blacks are more likely than whites to sleep less than seven hours a night and the black-white sleep disparity is greatest in professional occupations, according to a new study from Harvard School of Public Health (HSPH). “Short sleep” has been linked with increased risk of health problems, including obesity, high blood pressure, diabetes, heart disease, and death. The researchers also found that black professionals had the highest prevalence of short sleep and white professionals had the lowest prevalence.The study appears online September 9, 2013 in the American Journal of Epidemiology.”With increasing numbers of blacks entering professional and management roles in numerous industries, it is important to investigate and address the social factors contributing to the short sleep disparities in blacks compared with whites in general, and particularly in professional settings,” said lead author Chandra Jackson, Yerby postdoctoral research fellow in the Department of Nutrition at HSPH.The researchers analyzed eight years of data, from 2004-2011, from nearly 137,000 U.S. adults who participated in the National Health Interview Survey. Workers from the U.S. Census Bureau interviewed survey participants about their health, lifestyles, jobs, and socioeconomic status. Based on self-reports, 30% of the respondents were considered “short sleepers,” sleeping less than 7 hours a night; 31% were “optimal sleepers,” sleeping about 7 hours a night; and 39% were “long sleepers,” sleeping more than 7 hours a night.After adjusting for various factors, including age, demographic factors, health behaviors such as smoking and alcohol consumption, physical activity, medical conditions, and socioeconomic status, the researchers found that black workers in general — and black professionals in particular — were more likely to experience short sleep than whites. Among black respondents, 37% were short sleepers; among whites, 28%.In all industries combined, blacks working in professional or management positions were more likely to experience short sleep than their white counterparts (42% vs. 26%). …

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Aerobic fitness boosts learning, memory in 9-10-year-old children

Sep. 11, 2013 — Physical fitness can boost learning and memory in children, particularly when initial learning on a task is more challenging, according to research published September 11 in the open access journal PLOS ONE by Lauren Raine and colleagues from the University of Illinois at Urbana-Champaign.Share This:Forty-eight children aged nine to ten were asked to memorize names and locations on a fictitious map, either only by studying the information or being tested on the material as they studied. Half the children were in the top 30% of their age group on a test measuring aerobic fitness, while the other half scored in the lowest 30 percent. When asked to recollect the information studied, children who were fitter performed better than those who were not as fit.The difference between the high-fitness and low-fitness groups was also stronger when the initial learning was performed by studying alone than when testing and study were interspersed. Previous studies have suggested that combining testing and study improves later recall in children, and is less challenging than studying alone. Based on these results, the authors suggest that fitness levels may influence learning differently when the study method used is more challenging, and that higher levels of aerobic fitness can benefit learning and memory in school-age children. They conclude, “Future research should focus on the manner in which these factors impact the neural processes of children during learning.”In addition, the study suggests these findings may be important from an educational policy perspective. As the authors state, “Reducing or eliminating physical education in schools, as is often done in tight financial times, may not be the best way to ensure educational success among our young people.”Share this story on Facebook, Twitter, and Google:Other social bookmarking and sharing tools:|Story Source: The above story is based on materials provided by Public Library of Science. Note: Materials may be edited for content and length. For further information, please contact the source cited above. …

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Ashtray availability, signage may determine success of smoke-free legislation

Sep. 4, 2013 — Signs banning smoking may not have as much of an impact on secondhand smoke concentrations as the presence of ashtrays or ashtray equivalents, according to research published September 4 in the open access journal PLOS ONE by Constantine Vardavas from the Harvard School of Public Health and colleagues from other institutions.Share This:The authors measured the success of a non-enforced, nationwide smoke-free legislation in Greece by testing levels of secondhand smoke before the ban and for two years afterward. Following the 2010 legislation, secondhand smoke concentrations dropped immediately, but gradually increased again in subsequent measurements. However, all measurements after the ban remained significantly lower than levels of secondhand smoke measured before the legislation.They found that outdoor or indoor signs that banned smoking did not correlate with levels of secondhand smoke in areas where signs were posted. However, the presence of ashtrays, or ashtray equivalents, such as candleholders, was strongly associated with a higher concentration of secondhand smoke. Based on their results, the authors conclude “While the public may be supportive of smoke-free legislation, adherence may decline rapidly if enforcement is limited or non-existent. Moreover, enforcement agencies should also focus on the comprehensive removal of ashtray equivalents that could act as a cue for smoking within a venue.”Share this story on Facebook, Twitter, and Google:Other social bookmarking and sharing tools:|Story Source: The above story is based on materials provided by Public Library of Science. Note: Materials may be edited for content and length. For further information, please contact the source cited above. Journal Reference:Constantine I. …

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Air pollution worsened by climate change set to be more potent killer in the 21st century

Sep. 4, 2013 — This century, climate change is expected to induce changes in air pollution, exposure to which could increase annual premature deaths by more than 100,000 adults worldwide. Based on the findings from a modelling study published in Springer’s journal Climatic Change, lead author Dr. Yuanyuan Fang, formerly at Princeton University and now at the Carnegie Institute for Science at Stanford, urges, in the face of future climate change, stronger emission controls to avoid worsening air pollution and the associated exacerbation of health problems, especially in more populated regions of the world.Fang and her colleagues ran various present and future simulations using the Geophysical Fluid Dynamics Laboratory Atmospheric Model version 3 (AM3), one of the first fully coupled global chemistry-climate models to integrate atmospheric dynamics, chemistry and physics. An earlier version of this model was ranked among the best in the Intergovernmental Panel on Climate Change Fourth Assessment Report (IPCC AR4). The research team examined the impact of climate change on surface air quality, and how this influences global health statistics. Under a moderate climate change scenario, the simulated global surface temperature and precipitation increased by 2.7⁰C and 6 percent respectively, consistent with findings from the recent IPCC AR4 report.Climate change is believed to harm human health in a variety of ways, including through adverse changes in food production, heat stress, sea level rise, increased storm intensity, flooding and droughts, and increased incidence of vector-borne diseases. In addition, climate change indirectly impacts health by influencing concentrations of air pollutants, such as surface ozone and fine particulate matter (smaller than 2.5 micrometers in diameter), including sulphate, nitrate, fine dust particles and black carbon. These pollutants are linked with increased risks of lung cancer and respiratory, cardiopulmonary, cardiovascular and all-cause deaths.This study shows that climate change will exacerbate air pollution and associated health risks globally and especially over heavily populated and polluted regions of East Asia, South Asia and North America. The increased health risks are mainly driven by an increase in fine particulate matter under climate change. …

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Experimental compound reverses down syndrome-like learning deficits in mice

Sep. 4, 2013 — Researchers at Johns Hopkins and the National Institutes of Health have identified a compound that dramatically bolsters learning and memory when given to mice with a Down syndrome-like condition on the day of birth. As they report in the Sept. 4 issue of Science Translational Medicine, the single-dose treatment appears to enable the cerebellum of the rodents’ brains to grow to a normal size.The scientists caution that use of the compound, a small molecule known as a sonic hedgehog pathway agonist, has not been proven safe to try in people with Down syndrome, but say their experiments hold promise for developing drugs like it.”Most people with Down syndrome have a cerebellum that’s about 60 percent of the normal size,” says Roger Reeves, Ph.D., a professor in the McKusick-Nathans Institute of Genetic Medicine at the Johns Hopkins University School of Medicine. “We treated the Down syndrome-like mice with a compound we thought might normalize the cerebellum’s growth, and it worked beautifully. What we didn’t expect were the effects on learning and memory, which are generally controlled by the hippocampus, not the cerebellum.”Reeves has devoted his career to studying Down syndrome, a condition that occurs when people have three, rather than the usual two, copies of chromosome 21. As a result of this “trisomy,” people with Down syndrome have extra copies of the more than 300 genes housed on that chromosome, which leads to intellectual disabilities, distinctive facial features and sometimes heart problems and other health effects. Since the condition involves so many genes, developing treatments for it is a formidable challenge, Reeves says.For the current experiments, Reeves and his colleagues used mice that were genetically engineered to have extra copies of about half of the genes found on human chromosome 21. The mice have many characteristics similar to those of people with Down syndrome, including relatively small cerebellums and difficulty learning and remembering how to navigate through a familiar space. (In the case of the mice, this was tested by tracking how readily the animals located a platform while swimming in a so-called water maze.) Based on previous experiments on how Down syndrome affects brain development, the researchers tried supercharging a biochemical chain of events known as the sonic hedgehog pathway that triggers growth and development. …

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Terror bird’s beak was worse than its bite: ‘Terror bird’ was probably a herbivore

Aug. 29, 2013 — It’s a fiercely debated question amongst palaeontologists: was the giant ‘terror bird’, which lived in Europe between 55 to 40 million years ago, really a terrifying predator or just a gentle herbivore?New research presented at the Goldschmidt conference in Florence today (Thursday 29th August) may finally provide an answer. A team of German researchers has studied fossilised remains of terror birds from a former open-cast brown coal mine in the Geiseltal (Saxony-Anhalt, Germany) and their findings indicate the creature was most likely not a meat eater.The terror bird — also known as Gastornis — was a flightless bird up to two metres in height with an enormous, ferocious beak. Based upon its size and ominous appearance, scientists have long assumed that it was a ruthless carnivore.”The terror bird was thought to have used its huge beak to grab and break the neck of its prey, which is supported by biomechanical modelling of its bite force,” says Dr Thomas Tütken, from the University of Bonn. “It lived after the dinosaurs became extinct and at a time when mammals were at an early stage of evolution and relatively small; thus, the terror bird was though to have been a top predator at that time on land.”Recent research has cast some doubt on its diet, however. Palaeontologists in the United States found footprints believed to belong to the American cousin of Gastornis, and these do not show the imprints of sharp claws, used to grapple prey, that might be expected of a raptor. Also, the bird’s sheer size and inability to move fast has made some believe it couldn’t have predated on early mammals — though others claim it might have ambushed them. But, without conclusive findings either way, the dietary inclinations of Gastornis remain a mystery.Dr Tütken and his colleagues Dr Meinolf Hellmund, Dr Stephen Galer and Petra Held have taken a new geochemical approach to determine the diet of Gastornis. By analysing the calcium isotope composition in fossilised bones, they have been able to identify what proportion of a creature’s diet was plant or animal and, on that basis, their position in the food chain of the local ecosystem. This depends on the calcium isotopic composition becoming “lighter” as it passes through the food chain. …

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Learning how to migrate: Young whoopers stay the course when they follow a wise old bird

Aug. 29, 2013 — Scientists have studied bird migration for centuries, but it remains one of nature’s great mysteries. How do birds find their way over long distances between breeding and wintering sites? Is their migration route encoded in their genes, or is it learned?Working with records from a long-term effort to reintroduce critically endangered whooping cranes in the Eastern U.S., a University of Maryland-led research team found evidence that these long-lived birds learn their migration route from older cranes, and get better at it with age.Whooping crane groups that included a seven-year-old adult deviated 38% less from a migratory straight-line path between their Wisconsin breeding grounds and Florida wintering grounds, the researchers found. One-year-old birds that did not follow older birds veered, on average, 60 miles (97 kilometers) from a straight flight path. When the one-year-old cranes traveled with older birds, the average deviation was less than 40 miles (64 kilometers).Individual whoopers’ ability to stick to the route increased steadily each year up to about age 5, and remained roughly constant from that point on, the researchers found.Many migration studies are done in short-lived species like songbirds, or by comparing a young bird to an older bird, said UMD biologist Thomas Mueller, an expert on animal migration and the study’s lead scientist. “Here we could look over the course of the individual animals’ lifetimes, and show that learning takes place over many years.”The researchers’ findings, to be published August 30 in the journal Science, are based on data from an intensive effort to restore the endangered bird to its native range. The whooping crane (Grus americana), is North America’s largest bird, standing five feet tall, and one of its longest-lived, surviving 30 years or more in the wild. The species was near extinction in the 1940s, with fewer than 25 individuals. Today about 250 wild whoopers summer in Canada and migrate to Texas for the winter.The Whooping Crane Eastern Partnership, made up of government and non-profit experts, has been working since 2001 to establish a second population in the Eastern U.S., which now numbers more than 100 birds. …

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Hydrogen fuel from sunlight

Aug. 29, 2013 — In the search for clean, green sustainable energy sources to meet human needs for generations to come, perhaps no technology matches the ultimate potential of artificial photosynthesis. Bionic leaves that could produce energy-dense fuels from nothing more than sunlight, water and atmosphere-warming carbon dioxide, with no byproducts other than oxygen, represent an ideal alternative to fossil fuels but also pose numerous scientific challenges. A major step toward meeting at least one of these challenges has been achieved by researchers with the U.S. Department of Energy (DOE)’s Lawrence Berkeley National Laboratory (Berkeley Lab) working at the Joint Center for Artificial Photosynthesis (JCAP).”We’ve developed a method by which molecular hydrogen-producing catalysts can be interfaced with a semiconductor that absorbs visible light,” says Gary Moore, a chemist with Berkeley Lab’s Physical Biosciences Division and principal investigator for JCAP. “Our experimental results indicate that the catalyst and the light-absorber are interfaced structurally as well as functionally.”Moore is the corresponding author, along with Junko Yano and Ian Sharp, who also hold joint appointments with Berkeley Lab and JCAP, of a paper describing this research in the Journal of the American Chemical Society (JACS). The article is titled “Photofunctional Construct That Interfaces Molecular Cobalt-Based Catalysts for H2 Production to a Visible-Light-Absorbing Semiconductor.” Co-authors are Alexandra Krawicz, Jinhui Yang and Eitan Anzenberg.Earth receives more energy in one hour’s worth of sunlight than all of humanity uses in an entire year. Through the process of photosynthesis, green plants harness solar energy to split molecules of water into oxygen, hydrogen ions (protons) and free electrons. The oxygen is released as waste and the protons and electrons are used to convert carbon dioxide into the carbohydrate sugars that plants use for energy. Scientists aim to mimic the concept but improve upon the actual process.JCAP, which has a northern branch in Berkeley and a southern branch on the campus of the California Institute of Technology (Caltech), was established in 2010 by DOE as an Energy Innovation Hub. …

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Mindfulness training can help reduce teacher stress and burnout

Aug. 28, 2013 — Teachers who practice “mindfulness” are better able to reduce their own levels of stress and prevent burnout, according to a new study conducted by the Center for Investigating Healthy Minds (CIHM) at UW-Madison’s Waisman Center.The results of the study, led by Assistant Scientist Lisa Flook, were recently published in the journal Mind, Brain and Education.Mindfulness, a notion that stems from centuries-old meditative traditions and is now taught in a secular way, is a technique to heighten attention, empathy and other pro-social emotions through an awareness of thoughts, external stimuli, or bodily sensations such as breath.While teachers play a critical role in nurturing children’s well-being, progress in addressing teacher stress has been elusive. Stress and burnout among teachers is a major concern for school districts nationwide, affecting the quality of education and incurring increased costs in recruiting and sustaining teachers.For the study, a group of 18 teachers was recruited to take part in a Mindfulness-Based Stress Reduction (MBSR) course, a well-established and well-studied method of mindfulness training. The project team adapted the MBSR training to fit the particular needs and time demands of elementary school teachers. It was among the first efforts to train teachers, in addition to students, in mindfulness techniques and to examine the effects of this training in the classroom.”We wanted to offer training to teachers in a format that would be engaging and address the concerns that were specifically relevant to their role as teachers,” says Flook, who has advanced degrees in education and psychology and whose primary interest is in exploring strategies to reduce stress and promote well-being in children and adolescents.The teachers who received the training were randomly assigned and asked to practice a guided meditation at home for at least 15 minutes per day. They also learned to use specific strategies for preventing and dealing with stressors in the classroom, such as “dropping in,” a term to describe the process of bringing attention to the sensations of breath and other physical sensations, thoughts, and emotions for brief periods of time. The training also included caring practices to bring kind awareness to their experiences, especially those that are challenging.One of the goals of the study was to evaluate outcomes using measures that could be affected by mindfulness training. The researchers found that those who received the mindfulness training displayed reductions in psychological stress, improvements in classroom organization and increases in self-compassion. In comparison, the group that did not receive the training showed signs of increased stress and burnout over the course of the school year. These results provide objective evidence that MBSR techniques are beneficial to teachers.”The most important outcome that we observed is the consistent pattern of results, across a range of self-report and objective measures used in this pilot study, that indicate benefits from practicing mindfulness,” says Flook, who also leads CIHM’s “Kindness Curriculum” study involving 4-year-old preschoolers.Madison teacher Elizabeth Miller discovered that mindfulness is a meditative technique that does not require “just sitting still and trying to observe your thoughts,” which she said was difficult for her. …

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Anthropologists study the genesis of reciprocity in food sharing

Aug. 20, 2013 — When you share your lunch with someone less fortunate or give your friend half of your dessert, does that act of generosity flow from the milk of human kindness, or is it a subconscious strategy to assure reciprocity should you one day find yourself on the other side of the empty plate?And how do those actions among humans compare to those of our chimpanzee cousins and other nonhuman primates?Through two separate studies, UC Santa Barbara anthropologists Adrian Jaeggi and Michael Gurven found that reciprocity is similar among monkeys, apes, and humans, even when considering other factors that might otherwise predict helping behavior. However, they also found that only humans showed evidence of reciprocity in food sharing. Their research appears in the current issues of the Proceedings of the Royal Society B and of the journal Evolutionary Anthropology.”Reciprocity Explains Food Sharing in Humans and Other Primates Independent of Kin Selection and Tolerated Scrounging: A Phylogenetic Meta-Analysis,” the Proceedings of the Royal Society B article, compiles quantitative date on cooperative behavior from all existing studies in a number of primate species. “Natural Cooperators: Food Sharing in Humans and Other Primates,” the article in Evolutionary Anthropology, goes into greater detail about the origins and maintenance of cooperation among a wide range of primate species, with particular attention to the human case.”The meta-analysis clearly established that there is reciprocity in sharing both among humans and among other primates that remained significant even after controlling for other factors such as kinship, dominance relationships, and spatial proximity,” said Jaeggi, a postdoctoral student in anthropology at UCSB. “Based on our meta-analysis of existing studies, we were able to find no significant differences between humans, monkeys, and apes.”However, Jaeggi noted, humans tend to exchange food for food, while primates tend to barter food for other services, such as grooming or coalition support (e.g. assistance in dominance fights). The relative effects of reciprocity, kinship, and tolerated scrounging were similar, highlighting that all are important factors in explaining the act of sharing.”Our findings support the idea that actions that benefit another individual tend to, ultimately, also benefit the giver — either because the recipient is genetically related to the giver or will eventually return the favor,” Jaeggi said. “Of course, the giver doesn’t have to be consciously aware of the return benefits.”Through natural selection, humans have evolved to form emotional attachments to others and engage in long-term relationships within which reciprocity benefits everyone involved. “This is supported by research showing that reciprocity in many species develops over long periods of time — much more so than on an immediate tit-for-tat basis,” said Jaeggi.While the research conducted by Jaeggi and Gurven, a professor of anthropology at UCSB, identified reciprocity as an important factor in food sharing, kin selection — sharing food with genetic relatives — and tolerated scrounging are also important. …

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Belief in precognition increases sense of control over life

Aug. 7, 2013 — People given scientific evidence supporting our ability to predict the future feel a greater sense of control over their lives, according to research published August 7 in the open access journal PLOS ONE by Katharine Greenaway and colleagues from the University of Queensland, Australia.Share This:One group of study participants read a paragraph stating that researchers had found evidence supporting the existence of precognition, while another group read a related paper that refuted these findings. Both papers were published in the same issue of a scientific journal. On a subsequent survey, people who read the paper confirming our ability to predict the future agreed more strongly with statements like “I am in control of my own life,” “My life is determined by my own actions” and “I am able to live my life how I wish” than the group who read a paper denying the existence of precognition.In a second experiment, participants who were made to feel a loss of control and then asked to read the same pieces reported feeling an increased sense of control after reading about the existence of precognition, but not when they read that it did not exist. People who were made to feel more in control of their lives before reading and answering questions reported no difference in their subsequent sense of control. Based on these studies, the researchers conclude that psychic predictability can provide the psychological system with a compensatory boost in perceived control. As Greenaway explains, “Humans are predisposed towards prediction; we like to know what is going to happen in our lives. Belief in paranormal abilities like precognition can help people meet this need for predictability by making us feel as though we can control our destiny.”The study concludes, “We found that people were drawn to predictability when they experienced loss of control-even to the extent of endorsing seemingly irrational beliefs about precognition.”Share this story on Facebook, Twitter, and Google:Other social bookmarking and sharing tools:|Story Source: The above story is based on materials provided by Public Library of Science. Note: Materials may be edited for content and length. For further information, please contact the source cited above. …

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