We work harder when we are happy, new study shows

Happiness makes people more productive at work, according to the latest research from the University of Warwick. Economists carried out a number of experiments to test the idea that happy employees work harder. In the laboratory, they found happiness made people around 12% more productive.Professor Andrew Oswald, Dr Eugenio Proto and Dr Daniel Sgroi from the Department of Economics at the University of Warwick led the research.This is the first causal evidence using randomized trials and piece-rate working. The study, to be published in the Journal of Labor Economics, included four different experiments with more than 700 participants.During the experiments a number of the participants were either shown a comedy movie clip or treated to free chocolate, drinks and fruit. Others were questioned about recent family tragedies, such as bereavements, to assess whether lower levels of happiness were later associated with lower levels of productivity.Professor Oswald said: “Companies like Google have invested more in employee support and employee satisfaction has risen as a result. For Google, it rose by 37%, they know what they are talking about. Under scientifically controlled conditions, making workers happier really pays off.”Dr Sgroi added: “The driving force seems to be that happier workers use the time they have more effectively, increasing the pace at which they can work without sacrificing quality.”Dr Proto said the research had implications for employers and promotion policies.He said: “We have shown that happier subjects are more productive, the same pattern appears in four different experiments. This research will provide some guidance for management in all kinds of organizations, they should strive to make their workplaces emotionally healthy for their workforce.”The report can be found online at: http://www2.warwick.ac.uk/fac/soc/economics/staff/academic/proto/workingpapers/happinessproductivity.pdfStory Source:The above story is based on materials provided by University of Warwick. Note: Materials may be edited for content and length.

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Ivy is 11 months old!

Eric, Ivy and I just arrived in Seattle last night to visit my sister and to go to the AWP conference, while my mom watches the other kids. It’s the first time we’ve left our children and gone somewhere together. I’m looking forward to good food, warmer (if wetter) weather, lots of fun sight-seeing, and best of all one-on-one time with Ivy during the day. Thanks to all my blog readers who sent in suggestions of things to do! She does this funny scrunchy thing with her face when she smiles Having only one child is SO EASY in comparison to four. Only one little person to get dressed and feed and clean up after and buckle into carseats/strollers and get in and …

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Weather changes may be linked with stroke hospitalization, death

Stroke hospitalization and death rates may rise and fall with changes in environmental temperature and dew point, according to research presented at the American Stroke Association’s International Stroke Conference 2014.”Weather is not something people would typically associate with stroke risk; however, we’ve found weather conditions are among the multiple factors that are associated with stroke hospitalizations,” said Judith H. Lichtman, Ph.D., M.P.H., study author and an associate professor in Epidemiology at the Yale School of Public Health in New Haven, Conn.Researchers identified a nationwide sample of 134,510 people, 18 years and older, admitted to hospitals in 2009-10 for ischemic stroke (caused by a blood clot that blocks blood flow in or leading to the brain). They then obtained temperature and dew point data during that period.They found:Larger daily temperature changes and higher average dew point (indicating higher air moisture) were associated with higher stroke hospitalization rates. Lower average annual temperatures were associated with stroke hospitalizations and death. With each 1F increase in average temperature, there was a 0.86 percent decrease in the odds of stroke hospitalization and a 1.1 percent decrease in the odds of dying in the hospital after stroke. Increases in daily temperature fluctuation and average dew point were associated with increased odds of stroke hospitalization, but not with dying in the hospital. “This study suggests that meteorological factors such as daily fluctuations in temperature and increased humidity may be stressors that increase stroke hospitalizations,” Lichtman said. “People at risk for stroke may want to avoid being exposed to significant temperature changes and high dew point and, as always, be prepared to act quickly if they or someone they know experiences stroke signs and symptoms.”Future research is needed to better understand the cause and effect of changes in weather conditions, as well as to explore potential mechanisms for this association.”Stroke risk factors that can be changed, treated or controlled include: high blood pressure; cigarette smoking; diabetes; carotid or other artery disease; peripheral artery disease; atrial fibrillation; other heart disease; sickle cell disease; high blood cholesterol; poor diet; physical inactivity; obesity; and excessive alcohol consumption.Stroke signs and symptoms are facial drooping, arm weakness, speech difficulty, sudden numbness or weakness of the leg, arm or face, sudden confusion or trouble understanding, sudden trouble seeing in one or both eyes, sudden trouble walking, dizziness, loss of balance or coordination, and sudden severe headache with no known cause.Co-authors are: Erica C. Leifheit-Limson, Ph.D., and Larry B. Goldstein, M.D.The study was funded by the Yale School of Public Health.Story Source:The above story is based on materials provided by American Heart Association. …

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Whole diet approach to lower cardiovascular risk has more evidence than low-fat diets

A study published in The American Journal of Medicine reveals that a whole diet approach, which focuses on increased intake of fruits, vegetables, nuts, and fish, has more evidence for reducing cardiovascular risk than strategies that focus exclusively on reduced dietary fat.This new study explains that while strictly low-fat diets have the ability to lower cholesterol, they are not as conclusive in reducing cardiac deaths. By analyzing major diet and heart disease studies conducted over the last several decades, investigators found that participants directed to adopt a whole diet approach instead of limiting fat intake had a greater reduction in cardiovascular death and non-fatal myocardial infarction.Early investigations of the relationship between food and heart disease linked high levels of serum cholesterol to increased intake of saturated fat, and subsequently, an increased rate of coronary heart disease. This led to the American Heart Association’s recommendation to limit fat intake to less than 30% of daily calories, saturated fat to 10%, and cholesterol to less than 300 mg per day.”Nearly all clinical trials in the 1960s, 70s and 80s compared usual diets to those characterized by low total fat, low saturated fat, low dietary cholesterol, and increased polyunsaturated fats,” says study co-author James E. Dalen, MD, MPH, Weil Foundation, and University of Arizona College of Medicine. “These diets did reduce cholesterol levels. However they did not reduce the incidence of myocardial infarction or coronary heart disease deaths.”Carefully analyzing studies and trials from 1957 to the present, investigators found that the whole diet approach, and specifically Mediterranean-style diets, are effective in preventing heart disease, even though they may not lower total serum or LDL cholesterol. The Mediterranean-style diet is low in animal products and saturated fat, and encourages intake of monounsaturated fats found in nuts and olive oil. In particular, the diet emphasizes consumption of vegetables, fruit, legumes, whole grains, and fish.”The potency of combining individual cardioprotective foods is substantial — and perhaps even stronger than many of the medications and procedures that have been the focus of modern cardiology,” explains co-author Stephen Devries, MD, FACC, Gaples Institute for Integrative Cardiology (Deerfield, IL) and Division of Cardiology, Northwestern University (Chicago, IL). “Results from trials emphasizing dietary fat reduction were a disappointment, prompting subsequent studies incorporating a whole diet approach with a more nuanced recommendation for fat intake.”Based on the data from several influential studies, which are reviewed in the article, Dalen and Devries concluded that emphasizing certain food groups, while encouraging people to decrease others, is more cardioprotective and overall better at preventing heart disease than a blanket low-fat diet. Encouraging the consumption of olive oil over butter and cream, while increasing the amount of vegetables, fruits, whole grains, nuts, and fish promises to be more effective.”The last fifty years of epidemiology and clinical trials have established a clear link between diet, atherosclerosis, and cardiovascular events,” concludes Dr. …

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Delaying climate policy would triple short-term mitigation costs

Sep. 12, 2013 — Higher costs would in turn increase the threshold for decision-makers to start the transition to a low-carbon economy. Thus, to keep climate targets within reach it seems to be most relevant to not further postpone mitigation, the researchers conclude.”The transitional economic repercussions that would result if the switch towards a climate-friendly economy is delayed, are comparable to the costs of the financial crisis the world just experienced,” lead-author Gunnar Luderer says. The later climate policy implementation starts, the faster — hence the more expensive — emissions have to be reduced if states world-wide want to achieve the internationally agreed target of limiting global warming to 2 degrees above pre-industrial levels. A binding global agreement to implement the emissions reductions required to reach this target is currently still under negotiation, while global emissions have continued to rise.”For the first time, our study quantifies the short-term costs of tiptoeing when confronted with the climate challenge,” Luderer says. “Economists tend to look at how things balance out in the long-term, but decision-makers understandably worry about additional burdens for the people and businesses they are responsible for right now. So increased short-term costs due to delaying climate policy might deter decision-makers from starting the transformation. The initial costs of climate policies thus can be more relevant than the total costs.”Future energy price increases could be limitedThe researchers investigated a number of cost dimensions, including climate policy effects on energy prices. If emissions reductions are delayed beyond 2030, global energy price levels are likely to increase by 80 percent in the short term. Such price increases are of particular concern because of the burden they put on the world’s poor. …

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Can you predict complications with back surgery? Preoperative factors increase risk

Sep. 3, 2013 — For older adults undergoing surgery for spinal stenosis, some simple indicators of poor preoperative health predict a high risk of major medical complications, reports a study in the September 1 issue of Spine. The journal is published by Lippincott Williams & Wilkins, a part of Wolters Kluwer Health.In combination, these risk factors may help in identifying patients at increased risk of heart attack and other serious events after spinal stenosis surgery, according to the report by Dr Richard A. Deyo and colleagues of Oregon Health and Science University, Portland. They write, “These factors may help in selecting patients and planning procedures, improving patient safety.”Information on Risk Factors for Major Medical ComplicationsThe researchers analyzed data on more than 12,000 patients undergoing surgery for spinal stenosis in the lower (lumbar) spine at Veterans Affairs (VA) medical centers between 1998 and 2009. Patients with spinal stenosis have narrowing of the spinal canal, causing back pain, leg pain, and other symptoms. It is the most common reason for spine surgery in older adults.The analysis focused on identifying risk factors for major medical complications such as myocardial infarction, stroke, pneumonia, and sepsis. The overall rate of such major medical complications was 2.1 percent, along with a 0.6 percent risk of death within 90 days. By comparison, the rate of surgical wound-related complications was 3.2 percent.Risk of major medical complications increased steadily with age: from less than one percent for patients under 50 to four percent for those aged 80 or older. In contrast, the risk of wound complications was similar across age groups.A key risk factor for was the American Society of Anesthesiologists (ASA) class — a standard score for assessing patients’ fitness for surgery. …

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Save my limbs

Sep. 3, 2013 — When trying to unclog a drain, plumbers will insert a device from the top and guide it down to push through whatever is causing the blockage. Endovascular surgeons use the same technique when trying to open up the vessels of patients with peripheral artery disease (PAD). However, sometimes the vessels become so hardened that it’s impossible to push through. A new technique called retrograde access now gives surgeons an additional path from below.”There are three arteries that branch off into smaller arteries and supply blood to the legs and feet,” said Dr. Hosam El-Sayed, an endovascular surgeon with Houston Methodist DeBakey Heart & Vascular Center. “Over time, plaque develops in the walls of the arteries and completely blocks blood from flowing to the lower extremities. These patients can develop severe conditions such as non-healing sores or gangrene and could eventually face amputation.”Retrograde access is a delicate procedure that allows surgeons to go through arteries in the foot and work their way upward. El-Sayed says this procedure is not for everyone with PAD, only those complex patients with heavily-calcified arteries. It’s seen in many people with severe diabetes. …

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Women less likely to die after TAVI than men

Sep. 2, 2013 — Women are 25% less likely to die one year after TAVI than men, according to research presented at the ESC Congress today by Dr Mohammad Sherif from Germany. The findings suggest that TAVI might be the preferred treatment option for elderly women with symptomatic severe aortic stenosis.Dr Sherif said: “Earlier studies on the impact of gender on outcome after transcatheter aortic valve implantation (TAVI) have had conflicting results. A Canadian study reported in 641 consecutive patients that female sex is associated with a better long-term and short-term survival after TAVI.1 An Italian study of 305 high risk patients found no gender differences in composite safety and efficacy endpoints at 30 days and one year after TAVI.”2The current analysis examined gender differences in outcomes for 1432 consecutive patients from 27 centers who were enrolled in the German TAVI registry between January 2009 and June 2010. Women comprised 57.8% of the cohort. At baseline the average age of women was 83 years vs 80 years for men. Women had aortic valve gradients at baseline of 52 mmHg vs 45 mmHg for men (severe aortic stenosis is defined as gradients exceeding 40 mmHg).At baseline men had more prior myocardial infarction (22% vs 11.5%, p<0.001); more extensive coronary artery disease (36% vs 16%, p<0.001); more history of open-heart surgery (33% vs 14%, p<0.001); more peripheral vascular disease (37% vs 26%, p<0.001); and more COPD (28% vs 21%, p<0.001).</p>During the TAVI procedure, 25.2% of women had vascular complications (including iliac artery dissection, and bleeding from the puncture site requiring blood transfusion) compared to 17.2% of men (p<0.001).</p>At 30 days follow-up mortality was 7.6% for women versus 8.6% for men (p=0.55); however by one year the all cause mortality was 17.3% for women vs 23.6% for men (p<0.01). Dr Sherif said: “Our results show that mortality at 30 days was the nearly same for women and men. Women’s higher survival rate at one year could be explained by their longer life expectancy and lower rates of comorbidity in comparison to men.”</p>The investigators did a multivariate analysis to adjust for the effect of differences between women and men in demographic, procedural, and clinical variables on one year mortality. Figure 1 shows women’s survival advantage at 12 months. …

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Fractions gain traction with real-life models

Aug. 27, 2013 — If 3 is greater than 2, then ⅓ must be bigger than ½ ­ — right? Wrong. As thousands of students head back to school next week, many will use exactly that kind of thinking when faced with fractions for the first time. New research from Concordia University shows that for children to understand math, teachers must constantly make the connection between abstract numbers and real world examples.Helena Osana, associate professor in Concordia’s Department of Education, and PhD candidate Nicole Pitsolantis put this theory to the test in a classroom of fifth and sixth graders. Their findings — published in the professional journal Teaching Children Mathematics, as well as in the British Journal of Educational Psychology — show students understand math much more clearly when teachers use pictures and concrete models to demonstrate what fractions actually mean.Those connections are even stronger when the model is personally meaningful to the students. Write out ‘¾’ on the blackboard and the concept is not so clear. Show kids ¾ of a shoelace or talk about running ⅓of the way to school and suddenly they get it.Although teachers already use models when talking about fractions — for instance, to show a picture of a pie with slices eaten — they often put them away too quickly. To prove that the constant use of models made a bigger impact, Osana and Pitsolantis tried teaching with models for only part of the lesson and then the entire lesson.They found that students showed much greater understanding when the models were continually present. “Our study shows teachers should not only include pictures and models while teaching fractions, but also have them side by side throughout the class while continually making clear connections between the concepts and the models,” says Osana.The lessons produced by this research have the potential to go beyond the classroom. …

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Higher intake of fruits and vegetables may reduce the risk of bladder cancer in women

Aug. 23, 2013 — University of Hawaii Cancer Center Researcher Song-Yi Park, PhD, along with her colleagues, recently discovered that a greater consumption of fruits and vegetables may lower the risk of invasive bladder cancer in women.Share This:The investigation was conducted as part of the Multiethnic Cohort (MEC) Study, established in 1993 to assess the relationships among dietary, lifestyle, genetic factors, and cancer risk. Park and her fellow researcher’s analyzed data collected from 185,885 older adults over a period of 12.5 years, of which 581 invasive bladder cancer cases were diagnosed (152 women and 429 men).After adjusting for variables related to cancer risk (age, etc.) the researchers found that women who consumed the most fruits and vegetables had the lowest bladder cancer risk. For instance, women consuming the most yellow-orange vegetables were 52% less likely to have bladder cancer than women consuming the least yellow-orange vegetables. The data also suggested that women with the highest intake of vitamins A, C, and E had the lowest risk of bladder cancer. No associations between fruit and vegetable intake and invasive bladder cancer were found in men.”Our study supports the fruit and vegetable recommendation for cancer prevention, said Park. “However, further investigation is needed to understand and explain why the reduced cancer risk with higher consumption of fruits and vegetables was confined to only women.”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 University of Hawaii Cancer Center, via EurekAlert!, a service of AAAS. Note: Materials may be edited for content and length. For further information, please contact the source cited above. Journal Reference:S.-Y. …

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Nervous system disease: A new outlet for an old drug?

Aug. 15, 2013 — A sixty-year old drug designed to treat vitamin B1 deficiency helps ease the symptoms of a chronic, progress nervous system disease, a clinical trial published in the open access journal BMC Medicine reveals. A large-scale, randomised controlled trial is now needed to help reveal the drugs true potential.The disease goes by the lengthy moniker of human T lymphotropic virus type I (HTLV-I)-associated myelopathy/tropical spastic paraparesis or ‘HAM/TSP’ for short. It’s developed by a subset of people infected with the sexually-transmitted retrovirus HTLV-1, which infects up to 20 million people worldwide, mainly in equatorial regions. The result is a chronic, progressive demyelinating disease of the lower extremities, leading to muscle weakness, spasms, paraplegia and urinary problems.Twenty-four HAM/TSP patients, who had had the disease for up to 50 years, took the drug — prosultiamine — daily as part of the open-label study. Twelve weeks later, most of the patients were more mobile — they walked more quickly and were faster at going down stairs. Bladder capacity increased and bladder problems lessened, Tatsufumi Nakamura and colleagues report.The condition is currently managed with drugs that alter the immune response, such as corticosteroids and interferon-alpha. But their efficacy is contested, and they manage symptoms rather than cure the disease. Prosultiamine, on the other hand, reduced levels of the HTLV-1 provirus in the patients’ blood, a sign that the drug may be altering the underlying pathology rather than just managing symptoms.Results from an earlier trial suggested the drug may prove useful therapeutically, but treatment lasted just 2 weeks. Here, the drug produced favourable results with no serious adverse side effects after 3 months of treatment.Prosultiamine is already used in the clinic to treat a couple of brain disorders induced by vitamin B1 deficiency. …

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Eavesdropping plants prepare to be attacked

Aug. 7, 2013 — In a world full of hungry predators, prey animals must be constantly vigilant to avoid getting eaten. But plants face a particular challenge when it comes to defending themselves.”One of the things that makes plants so ecologically interesting is that they can’t run away,” says John Orrock, a zoology professor at the University of Wisconsin-Madison. “You can’t run, you can’t necessarily hide, so what can you do? Some plants make themselves less tasty.”Some do this either by boosting their production of toxic or unpleasant-tasting chemicals (think cyanide, sulfurous compounds, or acids) or through building physical defenses such as thorns or tougher leaves.But, he adds, “Defense is thought to come at a cost. If you’re investing in chemical defenses, that’s energy that you could be putting into growth or reproduction instead.”To balance those costs with survival, it may behoove a plant to be able to assess when danger is nigh and defenses are truly necessary. Previous research has shown that plants can induce defenses against herbivores in response to airborne signals from wounded neighbors.But cues from damaged neighbors may not always be useful, especially for the first plant to be attacked, Orrock says. Instead he asked whether plants — here, black mustard, a common roadside weed — can use other types of cues to anticipate a threat.In a presentation Aug. 6 at the 2013 Ecological Society of America Annual Meeting in Minneapolis, he and co-author Simon Gilroy, a UW-Madison botany professor, reported that the plants can eavesdrop on herbivore cues to mount a defensive response even before any plant is attacked.Slugs and snails are generalist herbivores that love to munch on mustard plants and can’t help but leave evidence of their presence — a trail of slime, or mucus. Where there’s slime, there’s a snail. …

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Polar ecosystems acutely vulnerable to sunlight-driven tipping points

July 31, 2013 — Slight changes in the timing of the annual loss of sea-ice in polar regions could have dire consequences for polar ecosystems, by allowing a lot more sunlight to reach the sea floor.The research by scientists at UNSW and the Australian Antarctic Division predicts that biodiversity on some areas of the polar seabed could be reduced by as much as one third within decades, as the poles warm.The study, Light-driven tipping points in polar ecosystems, will be published in the journal Global Change Biology.Dr Graeme Clark, of the UNSW School of Biological, Earth and Environmental Sciences, says the team’s research shows that polar ecosystems may be even more sensitive to climate change than previously thought.”Even a slight shift in the date of the annual sea-ice departure could cause a tipping point, leading to widespread ecosystem shifts. On the Antarctic coast this may cause unique, invertebrate-dominated communities that are adapted to the dark conditions to be replaced by algal beds, which thrive on light, significantly reducing biodiversity,” Dr Clark says.The invertebrates lost could include sponges, moss animals, sea squirts and worms. These animals perform important functions such as filtering of water and recycling of nutrients and provide a food source for fish and other creatures.”This is a prime example of the large-scale ecological impacts that humans can impose through global warming — even in places as remote as Antarctica,” says UNSW team member, Associate Professor Emma Johnston.”Our modelling shows that recent changes in ice and snow cover at the poles have already transformed the amount of light reaching large areas of the Arctic and Antarctic annually.”For the study, the team deployed light meters on the sea floor at seven sites near Casey Station in Antarctica, at depths of up to 10 metres. They used cameras to photograph the coast at midday every day for two and a half years, to determine sea-ice cover.They determined the growth rates of Antarctic algae in the lab in different light conditions, and conducted experiments in Antarctic waters to test the sensitivity of algae to available light. They also surveyed species living on sub-tidal boulders, to see how communities varied with ice cover.Tipping points are events where small changes in environmental conditions cause rapid and extensive ecological change.The amount of sunlight reaching the poles is highly dependent on the seasons because Earth’s tilt causes the sun to be above the horizon for considerably longer during summer than winter, and the lower solar angle during winter increases reflectance from the water surface.”Early melt that brings the date of sea-ice loss closer to midsummer will cause an exponential increase in the amount of sunlight reaching some areas per year,” says Dr Clark.

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Atmospheric rivers set to increase UK winter flooding

July 24, 2013 — The prolonged heat wave that has bathed the UK in sunshine over the past month has given the country an unexpected taste of summer that has seemed to be missing in recent years.However, a new study published today, 24 July, in IOP Publishing’s Environmental Research Letters, has provided warnings that will chime with those accustomed to more typical British weather.According to the study, winter flooding in the UK is set to get more severe and more frequent under the influence of climate change as a result of a change in the characteristics of atmospheric rivers (ARs).ARs are narrow regions of intense moisture flows in the lower troposphere of the atmosphere that deliver sustained and heavy rainfall to mid-latitude regions such as the UK.They are responsible for many of the largest winter floods in the mid-latitudes and can carry extremely large amounts of water: the AR responsible for flooding in the northwest of the UK in 2009 transported 4500 times more water than the average flow in the River Thames in London.The researchers, from the University of Reading and University of Iowa, found that large parts of the projected changes in AR frequency and intensity would be down to thermodynamic changes in the atmosphere, rather than the natural variability of the climate, suggesting that it is a response to anthropogenic climate change.To reach these conclusions, the researchers used simulations from five state-of-the-art climate models to investigate how the characteristics of ARs may change under future climate change scenarios.Firstly, they used the climate models to see how accurately they could simulate the ARs that occurred between 1980 and 2005. The five models did this successfully and were deemed capable of projecting how future ARs will develop under different scenarios.The models were then used to simulate future conditions under two scenarios — RCP4.5 and RCP8.5 — that represent different, yet equally plausible, scenarios for future increases in greenhouse gas concentrations in the atmosphere. They projected changes that would occur between 2074 and 2099.Each of the five models simulated an increase in AR frequency. For the RCP8.5 projections, which represents stronger increases in greenhouse gas concentrations than RCP4.5, there was a striking level of consistency in the magnitude of change in AR frequency — all models showed an approximate doubling of the number of future ARs compared to the simulations for 1980 — 2005.The models also projected an increase in intensity of the ARs, meaning an AR impacting the UK in the future is projected to deliver more moisture, potentially causing larger precipitation totals.Lead author of the research, Dr David Lavers, said: “ARs could become stronger in terms of their moisture transport. In a warming world, atmospheric water vapour content is expected to rise due to an increase in saturation water vapour pressure with air temperature. This is likely to result in increased water vapour transport.”The link between ARs and flooding is already well established, so an increase in AR frequency is likely to lead an increased number of heavy winter rainfall events and floods. More intense ARs are likely to lead to higher rainfall totals, and thus larger flood events.”

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How Mars’ atmosphere got so thin: Reports detail Curiosity clues to atmosphere’s past

July 18, 2013 — A pair of new papers report measurements of the Martian atmosphere’s composition by NASA’s Curiosity rover, providing evidence about loss of much of Mars’ original atmosphere.Curiosity’s Sample Analysis at Mars (SAM) suite of laboratory instruments inside the rover has measured the abundances of different gases and different isotopes in several samples of Martian atmosphere. Isotopes are variants of the same chemical element with different atomic weights due to having different numbers of neutrons, such as the most common carbon isotope, carbon-12, and a heavier stable isotope, carbon-13.SAM checked ratios of heavier to lighter isotopes of carbon and oxygen in the carbon dioxide that makes up most of the planet’s atmosphere. Heavy isotopes of carbon and oxygen are both enriched in today’s thin Martian atmosphere compared with the proportions in the raw material that formed Mars, as deduced from proportions in the sun and other parts of the solar system. This provides not only supportive evidence for the loss of much of the planet’s original atmosphere, but also a clue to how the loss occurred.”As atmosphere was lost, the signature of the process was embedded in the isotopic ratio,” said Paul Mahaffy of NASA Goddard Space Flight Center, Greenbelt, Md. He is the principal investigator for SAM and lead author of one of the two papers about Curiosity results in the July 19 issue of the journal Science.Other factors also suggest Mars once had a much thicker atmosphere, such as evidence of persistent presence of liquid water on the planet’s surface long ago even though the atmosphere is too scant for liquid water to persist on the surface now. The enrichment of heavier isotopes measured in the dominant carbon-dioxide gas points to a process of loss from the top of the atmosphere — favoring loss of lighter isotopes — rather than a process of the lower atmosphere interacting with the ground.Curiosity measured the same pattern in isotopes of hydrogen, as well as carbon and oxygen, consistent with a loss of a substantial fraction of Mars’ original atmosphere. Enrichment in heavier isotopes in the Martian atmosphere has previously been measured on Mars and in gas bubbles inside meteorites from Mars. Meteorite measurements indicate much of the atmospheric loss may have occurred during the first billion years of the planet’s 4.6-billion-year history. The Curiosity measurements reported this week provide more precise measurements to compare with meteorite studies and with models of atmospheric loss.The Curiosity measurements do not directly measure the current rate of atmospheric escape, but NASA’s next mission to Mars, the Mars Atmosphere and Volatile Evolution Mission (MAVEN), will do so. “The current pace of the loss is exactly what the MAVEN mission now scheduled to launch in November of this year is designed to determine,” Mahaffy said.The new reports describe analysis of Martian atmosphere samples with two different SAM instruments during the initial 16 weeks of the rover’s mission on Mars, which is now in its 50th week. …

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One More Homo Species? 3D-comparative analysis confirms status of Homo floresiensis as fossil human species

July 10, 2013 — Ever since the discovery of the remains in 2003, scientists have been debating whether Homo floresiensis represents a distinct Homo species, possibly originating from a dwarfed island Homo erectus population, or a pathological modern human. The small size of its brain has been argued to result from a number of diseases, most importantly from the condition known as microcephaly.Based on the analysis of 3-D landmark data from skull surfaces, scientists from Stony Brook University New York, the Senckenberg Center for Human Evolution and Palaeoenvironment, Eberhard-Karls Universität Tübingen, and the University of Minnesota provide compelling support for the hypothesis that Homo floresiensis was a distinct Homo species.The study, titled “Homo floresiensis contextualized: a geometric morphometric comparative analysis of fossil and pathological human samples,” is published in the July 10 edition of PLOS ONE.The ancestry of the Homo floresiensis remains is much disputed. The critical questions are: Did it represent an extinct hominin species? Could it be a Homo erectus population, whose small stature was caused by island dwarfism?Or, did the LB1 skull belong to a modern human with a disorder that resulted in an abnormally small brain and skull? Proposed possible explanations include microcephaly, Laron Syndrome or endemic hypothyroidism (“cretinism”).The scientists applied the powerful methods of 3-D geometric morphometrics to compare the shape of the LB1 cranium (the skull minus the lower jaw) to many fossil humans, as well as a large sample of modern human crania suffering from microcephaly and other pathological conditions. Geometric morphometrics methods use 3D coordinates of cranial surface anatomical landmarks, computer imaging, and statistics to achieve a detailed analysis of shape.This was the most comprehensive study to date to simultaneously evaluate the two competing hypotheses about the status of Homo floresiensis.The study found that the LB1 cranium shows greater affinities to the fossil human sample than it does to pathological modern humans. Although some superficial similarities were found between fossil, LB1, and pathological modern human crania, additional features linked LB1exclusively with fossil Homo. The team could therefore refute the hypothesis of pathology.”Our findings provide the most comprehensive evidence to date linking the Homo floresiensis skull with extinct fossil human species rather than with pathological modern humans. Our study therefore refutes the hypothesis that this specimen represents a modern human with a pathological condition, such as microcephaly,” stated the scientists.

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Research in fruit flies provides new insight into Barrett’s esophagus

June 27, 2013 — Research focused on the regulation of the adult stem cells that line the gastrointestinal tract of Drosophila suggests new models for the study of Barrett’s esophagus. Barrett’s esophagus, a risk factor for esophageal cancer, is a condition in which the cells of the lower esophagus transform into stomach-like cells. In most cases this transformation has been thought to occur directly from chronic acid indigestion when stomach contents flow back up into the esophagus.A new study, published June 27, 2013 online in Cell Reports, suggests a different cause, namely a change in stem cell function, for this transformation.Researchers at the Buck Institute manipulated a signaling pathway (BMP-like Dpp) implicated in the development of Barrett’s esophagus. After manipulation, the adult stem cells that normally generate the lining of the esophagus of fruit flies morphed into the type of stem cells that generate stomach cells. “Up until this point, it’s not been clear what this signaling pathway does in stem cells of the gastrointestinal tract, or how it influences the regeneration of various types of epithelial cells in the gut of the fly,” said Heinrich Jasper, PhD, a professor at the Buck Institute for Research on Aging and senior author of the study.”Barrett’s esophagus may not be simply a mechanical response to the overabundance of gastric acid,” said Jasper. “Antacids may not be the best means of treating a condition whose development appears to be more complex. This gives us avenues to look for targets for new therapies.”Between five and ten percent of people with gastroesophageal reflux disease (GERD) develop Barrett’s esophagus, usually after the age of 55. Among that population the risk of developing an esophageal adenocarcinoma is about 0.5 percent per year. Typically before the cancer develops, precancerous cells appear in the Barrett’s tissue. Barrett’s esophagus may be present for many years before cancer develops. …

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Pneumonia revealed in a cough: Coughs give vital clues to the presence or absence of pneumonia in children

June 27, 2013 — A new method, which analyzes the sounds in a child’s cough, could soon be used in poor, remote regions to diagnose childhood pneumonia reliably. According to Udantha Abeyratne from the University of Queensland in Australia and colleagues, this simple technique of recording coughs with a microphone on the patient’s bedside table, has the potential to revolutionize the management of childhood pneumonia in remote regions around the world.Their work is published online in Springer’s journal Annals of Biomedical Engineering.Pneumonia is the leading killer of young children around the world. Since it is largely a disease of poverty, the vast majority of deaths occur in resource-poor regions such as sub-Saharan Africa, South Asia and remote areas of China. The lack of laboratory testing facilities and trained healthcare personnel in these regions mean difficulties in the timely diagnosis and adequate treatment of childhood pneumonia.At the moment, community workers in these regions use the World Health Organization’s simple clinical algorithm to diagnose pneumonia. However there are some limitations, including the high rate of false positive results which lead to over-prescription of rare antibiotic stocks.Abeyratne and team’s work identifies an easy-to-use alternative that addresses these challenges, in the form of new technology which analyzes cough sounds to diagnose pneumonia. Indeed, cough is a main symptom of pneumonia and carries vital information on the lower respiratory tract — consolidation of the lungs and secretions in particular. These markers of infection alter the acoustic properties of coughs helping to identify pneumonia-specific features.The researchers analyzed 815 cough events recorded from a total of 91 hospitalized children with and without pneumonia, at the Sardjito Hospital of Gadjah Mada University in Indonesia. Cough sounds were collected by microphones placed on nearby bedside tables. Coughs were classified as either pneumonic or non-pneumonic. The researchers used the overall clinical diagnosis provided by pediatric respiratory clinicians — aided with routine diagnostic technologies — to validate the sound analysis. …

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Reduced brain volume in kids with low birth-weight tied to academic struggles

June 10, 2013 — An analysis of recent data from magnetic resonance imaging (MRI) of 97 adolescents who were part of study begun with very low birth weight babies born in 1982-1986 in a Cleveland neonatal intensive care unit has tied smaller brain volumes to poor academic achievement.More than half of the babies that weighed less than 1.66 pounds and more than 30 percent of those less than 3.31 pounds at birth later had academic deficits. (Less than 1.66 pounds is considered extremely low birth weight; less than 3.31 pounds is labeled very low birth weight.) Lower birth weight was associated to smaller brain volumes in some of these children, and smaller brain volume, in turn, was tied to academic deficits.Researchers also found that 65.6 percent of very low birth weight and 41.2 percent of extremely preterm children had experienced academic achievement similar to normal weight peers.The research team — led by Caron A.C. Clark, a scientist in the Department of Psychology and Child and Family Center at the University of Oregon — detected an overall reduced volume of mid-brain structures, the caudate and corpus callosum, which are involved in connectivity, executive attention and motor control.The findings, based a logistic regression analyses of the MRIs done approximately five years ago, were published in the May issue of the journal Neuropsychology. The longitudinal study originally was launched in the 1980s with a grant from the National Institute of Child Health and Human Development (National Institutes of Health, grant HD 26554) to H. Gerry Taylor of Case Western University, who was the senior author and principal investigator on the new paper.”Our new study shows that pre-term births do not necessarily mean academic difficulties are ahead,” Clark said. “We had this group of children that did have academic difficulties, but there were a lot of kids in this data set who didn’t and, in fact, displayed the same trajectories as their normal birth-weight peers.”Academic progress of the 201 original participants had been assessed early in their school years, again four years later and then annually until they were almost 17 years old. “We had the opportunity to explore this very rich data set,” Clark said. “There are very few studies that follow this population of children over time, where their trajectories of growth at school are tracked. We were interested in seeing how development unfolds over time.”The findings, Clark added, provide new insights but also raise questions such as why some low-birth-weight babies develop normally and others do not? “It is very difficult to pick up which kids will need the most intensive interventions really early, which we know can be really important.”The findings also provide a snapshot of children of very low birth weights who were born in NICU 30 years ago. …

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Cheese may prevent cavities

June 5, 2013 — Consuming dairy products is vital to maintaining good overall health, and it’s especially important to bone health. But there has been little research about how dairy products affect oral health in particular. However, according to a new study published in the May/June 2013 issue of General Dentistry, the peer-reviewed clinical journal of the Academy of General Dentistry (AGD), consuming cheese and other dairy products may help protect teeth against cavities.The study sampled 68 subjects ranging in age from 12 to 15, and the authors looked at the dental plaque pH in the subjects’ mouths before and after they consumed cheese, milk, or sugar-free yogurt. A pH level lower than 5.5 puts a person at risk for tooth erosion, which is a process that wears away the enamel (or protective outside layer) of teeth. “The higher the pH level is above 5.5, the lower the chance of developing cavities,” explains Vipul Yadav, MDS, lead author of the study.The subjects were assigned into groups randomly. Researchers instructed the first group to eat cheddar cheese, the second group to drink milk, and the third group to eat sugar-free yogurt. Each group consumed their product for three minutes and then swished with water. Researchers measured the pH level of each subject’s mouth at 10, 20, and 30 minutes after consumption.The groups who consumed milk and sugar-free yogurt experienced no changes in the pH levels in their mouths. Subjects who ate cheese, however, showed a rapid increase in pH levels at each time interval, suggesting that cheese has anti-cavity properties.The study indicated that the rising pH levels from eating cheese may have occurred due to increased saliva production (the mouth’s natural way to maintain a baseline acidity level), which could be caused by the action of chewing. Additionally, various compounds found in cheese may adhere to tooth enamel and help further protect teeth from acid.”It looks like dairy does the mouth good,” says AGD spokesperson Seung-Hee Rhee, DDS, FAGD. …

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