Mortality risks of being overweight or obese are underestimated

New research by Andrew Stokes, a doctoral student in demography and sociology in the School of Arts and Sciences at the University of Pennsylvania, suggests that many obesity studies substantially underestimate the mortality risks associated with excess weight in the United States. His study, “Using Maximum Weight to Redefine Body Mass Index Categories in Studies of The Mortality Risks of Obesity,” was published in the March issue of the open-access journal Population Health Metrics.”The scholarly community is divided over a large meta-analysis that found that overweight is the optimal BMI category and that there are no increased risks associated with obese class 1,” Stokes said.Normal weight is indicated by a BMI of 18.5-24.9 kg/m2, overweight is indicated by a BMI of 25.0-29.9 kg/m2, obese class 1 is a BMI of 30.0-34.9 kg/m2 and obese class 2 is a BMI of 35.0 kg/m2 and above.Skeptics of the meta-analysis argue that the findings are likely driven by biases, especially by illness-induced weight loss.”Using BMI at the time of the survey to assess the mortality risks of overweight and obesity is problematic, especially in older populations, because slimness can be a marker of illness,” Stokes said.Researchers have attempted to address this bias by eliminating ill people from their samples; however, according to Stokes, such measures are inadequate because information on illness is ascertained by self-reporting and not everyone with an illness has been diagnosed.Stokes used individuals’ highest BMI in life to predict mortality rates. He said that in the previous literature, the normal weight category combines data from low-risk, stable-weight individuals with high-risk individuals who have experienced weight loss. Use of weight histories makes it possible to separate the two groups and redefine the reference category as people who were a consistently normal weight throughout their lives.Stokes conducted the analyses using data from the National Health and Nutrition Examination Surveys of 1988-1994 and 1999-2004 linked to the National Death Index through 2006 on U.S. adults ages 50-84 who never smoked.He found that the percentage of mortality attributable to overweight and obesity in this group was 33 percent when assessed using maximum BMI. The comparable figure obtained using BMI at the time of survey was substantially smaller at 5 percent.”The source of the discrepancy became clear when I started looking more closely at peoples’ weight histories,” Stokes said.Stokes said that a considerable fraction of individuals classified as normal weight using BMI at time of survey were formerly overweight or obese. This group had substantially elevated mortality rates compared to individuals that were consistently normal weight throughout their lives, suggesting that for many of them the weight loss was related to an illness.He concluded that the findings provide simple and compelling evidence that the prior literature underestimates the impact of obesity on levels of mortality in the U.S. But Stokes said that his results need corroboration in future studies because maximum BMI was calculated from peoples’ recollection of their maximum weight, which may be subject to recall error. He said that his analysis should be replicated using longitudinal data with contemporaneous measures of height and weight across the lifecycle.Story Source:The above story is based on materials provided by University of Pennsylvania. Note: Materials may be edited for content and length.

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Fish biomass in the ocean may be 10 times higher than estimated: Stock of mesopelagic fish changes from 1,000 to 10,000 million tons

With a stock estimated at 1,000 million tons so far, mesopelagic fish dominate the total biomass of fish in the ocean. However, a team of researchers with the participation of the Spanish National Research Council (CSIC) has found that their abundance could be at least 10 times higher. The results, published in Nature Communications journal, are based on the acoustic observations conducted during the circumnavigation of the Malaspina Expedition.Mesopelagic fishes, such as lantern fishes (Myctophidae) and cyclothonids (Gonostomatidae), live in the twilight zone of the ocean, between 200 and 1,000 meters deep. They are the most numerous vertebrates of the biosphere, but also the great unknowns of the open ocean, since there are gaps in the knowledge of their biology, ecology, adaptation and global biomass.During the 32,000 nautical miles traveled during the circumnavigation, the researchers of the Malaspina Expedition (a project led by CSIC researcher Carlos Duarte) took measurements between 40N and 40S, from 200 to 1,000 meters deep, during the day.Duarte states: “Malaspina has provided us the unique opportunity to assess the stock of mesopelagic fish in the ocean. Until now we only had the data provided by trawling. It has recently been discovered that these fishes are able to detect the nets and run, which turns trawling into a biased tool when it comes to count its biomass.”Transport of organic carbonXabier Irigoyen, researcher from AZTI-Tecnalia and KAUST (Saudi Arabia) and head of this research, states: “The fact that the biomass of mesopelagic fish (and therefore also the total biomass of fishes) is at least 10 times higher than previously thought, has significant implications in the understanding of carbon fluxes in the ocean and the operation of which, so far, we considered ocean deserts.”Mesopelagic fish come up at night to the upper layers of the ocean to feed, whereas they go back down during the day in order to avoid being detected by their predators. This behaviour speeds up the transport of organic matter into the ocean, the engine of the biological pump that removes CO2 from the atmosphere, because instead of slowly sinking from the surface, it is rapidly transported to 500 and 700 meters deep and released in the form of feces.Irigoyen adds: “Mesopelagic fish accelerate the flux for actively transporting organic matter from the upper layers of the water column, where most of the organic carbon coming from the flow of sedimentary particles is lost. Their role in the biogeochemical cycles of ocean ecosystems and global ocean has to be reconsidered, as it is likely that they are breathing between 1% and 10% of the primary production in deep waters.”According to researchers, the excretion of material from the surface could partly explain the unexpected microbial respiration registered in these deep layers of the ocean. Mesopelagic fishes would act therefore as a link between plankton and top predators, and they would have a key role in reducing the oxygen from the depths of the open ocean.Story Source:The above story is based on materials provided by Spanish National Research Council (CSIC). Note: Materials may be edited for content and length.

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Fish biomass in the ocean is ten times higher than estimated: Stock of mesopelagic fish changes from 1,000 to 10,000 million tons

With a stock estimated at 1,000 million tons so far, mesopelagic fish dominate the total biomass of fish in the ocean. However, a team of researchers with the participation of the Spanish National Research Council (CSIC) has found that their abundance could be at least 10 times higher. The results, published in Nature Communications journal, are based on the acoustic observations conducted during the circumnavigation of the Malaspina Expedition.Mesopelagic fishes, such as lantern fishes (Myctophidae) and cyclothonids (Gonostomatidae), live in the twilight zone of the ocean, between 200 and 1,000 meters deep. They are the most numerous vertebrates of the biosphere, but also the great unknowns of the open ocean, since there are gaps in the knowledge of their biology, ecology, adaptation and global biomass.During the 32,000 nautical miles traveled during the circumnavigation, the researchers of the Malaspina Expedition (a project led by CSIC researcher Carlos Duarte) took measurements between 40N and 40S, from 200 to 1,000 meters deep, during the day.Duarte states: “Malaspina has provided us the unique opportunity to assess the stock of mesopelagic fish in the ocean. Until now we only had the data provided by trawling. It has recently been discovered that these fishes are able to detect the nets and run, which turns trawling into a biased tool when it comes to count its biomass.”Transport of organic carbonXabier Irigoyen, researcher from AZTI-Tecnalia and KAUST (Saudi Arabia) and head of this research, states: “The fact that the biomass of mesopelagic fish (and therefore also the total biomass of fishes) is at least 10 times higher than previously thought, has significant implications in the understanding of carbon fluxes in the ocean and the operation of which, so far, we considered ocean deserts.”Mesopelagic fish come up at night to the upper layers of the ocean to feed, whereas they go back down during the day in order to avoid being detected by their predators. This behaviour speeds up the transport of organic matter into the ocean, the engine of the biological pump that removes CO2 from the atmosphere, because instead of slowly sinking from the surface, it is rapidly transported to 500 and 700 meters deep and released in the form of feces.Irigoyen adds: “Mesopelagic fish accelerate the flux for actively transporting organic matter from the upper layers of the water column, where most of the organic carbon coming from the flow of sedimentary particles is lost. Their role in the biogeochemical cycles of ocean ecosystems and global ocean has to be reconsidered, as it is likely that they are breathing between 1% and 10% of the primary production in deep waters.”According to researchers, the excretion of material from the surface could partly explain the unexpected microbial respiration registered in these deep layers of the ocean. Mesopelagic fishes would act therefore as a link between plankton and top predators, and they would have a key role in reducing the oxygen from the depths of the open ocean.Story Source:The above story is based on materials provided by Spanish National Research Council (CSIC). 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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Breakthrough Mesothelioma Case

On February 13, 2012, the Italian court announced a verdict that may have an impact on people and families around the world who are dealing with mesothelioma. Billionaires Stephan Schidheiny and Jean-Louis de Cartier, key shareholders in the company Eternit, a producer of fiber-reinforced cement, were each sentenced to sixteen years in prison for the failure to comply with safety regulations in their factories’ uses of asbestos. This class action law suit is being touted as the most significant suit yet, because criminal charges were actually placed on the owners who benefited from the profits of the negligent factories.Invented in the late 19th century, fiber-reinforced cement products, generally containing a mixture of cement and asbestos, has been favored in construction for it’s relatively light weight …

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Ivy is 6 months old!

Ivy has been (figuratively) running from one milestone to another. She started commando-style crawling right after she turned 5 months old. Just this week she crawled for real. She has started to twist from a crawl into a sideways supported sit. She has otherwise skipped the sitting phrase altogether. Because sitting is for babies. And this morning, Eric found her standing up, cruising along the open dishwasher. He turned away for a moment, and she pulled the dishrack off and on top of herself. Slow down little Ivy! You have plenty of time to learn how to walk and run. Just be a baby for a little longer. She’s all over the house, getting into the houseplants, stuffing every scrap of paper she can find into her …

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Get touchy feely with plants

Sep. 12, 2013 — Forget talking to plants to help them grow, gently rubbing them with your fingers can make them less susceptible to disease, a paper in the open access journal BMC Plant Biology reveals.Gently rubbing the leaves of thale cress plants (Arabidsopsis thaliana) between thumb and forefinger activates an innate defense mechanism, Floriane L’Haridon and colleagues report. Within minutes, biochemical changes occur, causing the plant to become more resistant to Botrytis cinerea, the fungus that causes grey mould.Rubbing the leaves is a form of mechanical stress. Plants frequently have to deal with mechanical stress, be it caused by rain, wind, animals or even other plants. Trees growing on windy shorelines, for example, sometimes respond by developing shorter, thicker trunks.But plants also respond to more delicate forms of mechanical stress, such as touch. Some responses are obvious — the snapping shut of a Venus fly trap, the folding leaflets of a touched touch-me-not plant (Mimosa pudica) — whilst some are more discrete. Plants also launch an arsenal of ‘invisible’ responses to mechanical stress, including changes at the molecular and biochemical level.Rubbing the thale cress leaves triggered a host of internal changes. Genes related to mechanical stress were activated. Levels of reactive oxygen species increased. And the protective outer layer of the leaf became more permeable, presumably to aid the escape of various biologically active molecules that were detected and which are thought to contribute to the observed immune response. …

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Improving the lives of allergy sufferers

Sep. 10, 2013 — Allergen immunotherapy improves the quality of life of people who are allergic to grass pollen and house dust mites, reveals a study in the open access World Allergy Journal. With less time taken off work, the therapy yields economic as well as patient benefits.Around a quarter of adults in Europe suffer from respiratory allergies. Symptoms can include asthma and / or rhino-conjunctivitis, inflammation of the inner nasal lining which causes a runny, stuffy nose. Treatment is usually with drugs, such as antihistamines, which manage the symptoms.Allergen immunotherapy, however, seeks to treat the underlying cause. Subcutaneous immunotherapy, the type used in this study, involves regular injections with increasing doses of a specific allergen vaccine, then less frequent ‘top-up’ injections over several years.Karin D Petersen and colleagues observed 248 allergy patients prospectively as they received the treatment for one year. As expected, disease severity lessened, but critically, this translated to significant improvements in quality of life. Sufferers experienced fewer symptom-filled days — 145 instead of 189 days per year — and took fewer sick days from work — 1.2 instead of 3.7.This is likely to have knock-on effects for patients, employers and society, the team say. One US study found that allergic rhino-conjunctivitis causes an annual at-work productivity loss of around $2.5 billion. A separate study showed employees with allergic rhino-conjunctivitis suffer a productivity loss of around $593 per year.But the real burden is personal, an element that is difficult to measure using traditional methods. …

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Australian tarantula venom contains novel insecticide against agricultural pests

Sep. 11, 2013 — Spider venoms are usually toxic when injected into prey, but a new protein discovered in the venom of Australian tarantulas can also kill prey insects that consume the venom orally. The protein is strongly insecticidal to the cotton bollworm, an important agricultural pest, according to research published September 11 in the open access journal PLOS ONE by Glenn King and Maggie Hardy from the Institute of Molecular Bioscience at the University of Queensland, Australia, and colleagues from other institutions.Share This:The small protein, named orally active insecticidal peptide-1 (OAIP-1), was found to be highly toxic to insects that consumed it, with potency similar to that of the synthetic insecticide imidacloprid. Cotton bollworm, a pest that attacks crop plants, was more sensitive to OAIP-1 than termites and mealworms, which attack stored grains.These and other insect pests reduce global crop yields by 10-14% annually and damage 9-20% of stored food crops, and several species are resistant to available insecticides. Isolated peptides from the venom of spiders or other venomous insectivorous animals, such as centipedes and scorpions, may have the potential to serve as bioinsecticides. Alternately, the authors suggest the genes encoding these peptides could be used to engineer insect-resistant plants or enhance the efficacy of microbes that attack insect pests. King elaborates, “The breakthrough discovery that spider toxins can have oral activity has implications not only for their use as bioinsecticides, but also for spider-venom peptides that are being considered for therapeutic use.”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:Margaret C. …

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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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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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Fresh fuel reignites Asperger’s debate

July 30, 2013 — Children with Asperger’s Syndrome have different electroencephalography (EEG) patterns to children with autism, reveals a study in the open access journal BMC Medicine With distinct neurophysiology, the study pours fresh fuel on the on-going debate about how Asperger’s should be classified.People with Asperger’s syndrome experience social difficulties, and display restricted and repetitive behavioural patterns and interests. Until recently, the condition was classified as a disorder in its own right, distinct from the Autism Spectrum Disorder (ASD), which manifests some overlapping symptoms. But the most recent edition of the mental health manual, the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), published earlier this year, reversed the decision, lumping Asperger’s in with ASD.Frank H. Duffy and colleagues at the Departments of Neurology and Psychaitry of Boston Children’s Hospital studied electrical recordings from the scalps of children with Asperger’s and children with ASD. They looked at EEG-derived measures of brain connectivity, and found that, although the disorders were closely related, there were clear neurophysiological differences between the groups.The results show that Asperger’s and ASD can be discriminated on the basis of electrical activity in the brain. Asperger’s is a normally distributed entity that fits within the higher functioning end of the ASD. Just as dyslexia is now recognized as the low end of the reading ability distribution curve, so, the authors suggest, Asperger’s syndrome could be usefully defined as a distinct entity within the higher functioning end of the autism distribution curve. However, the authors caution that, with study numbers low, the results need replicating in larger numbers before any firm conclusions can be drawn.In the meantime, the stakes are high. Merging the diagnosis of Asperger’s into ASD, effectively removes the disorder as condition in its own right. Families and advocates are concerned that some people could lose their diagnosis, leading to repercussions at clinical, educational, emotional and financial levels.

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New tissue engineering breakthrough encourages nerve repair

July 8, 2013 — A new combination of tissue engineering techniques could reduce the need for nerve grafts, according to new research by The Open University. Regeneration of nerves is challenging when the damaged area is extensive, and surgeons currently have to take a nerve graft from elsewhere in the body, leaving a second site of damage. Nerve grafts contain aligned tissue structures and Schwann cells that support and guide neuron growth through the damaged area, encouraging function to be restored.Share This:The research, published in Biomaterials, reported a way to manufacture artificial nerve tissue with the potential to be used as an alternative to nerve grafts.Pieces of Engineered Neural Tissue (EngNT) are formed by controlling natural Schwann cell behaviour in a three-dimensional collagen gel so that the cells elongate and align, then a stabilisation process removes excess fluid to leave robust artificial tissues. These living biomaterials contain aligned Schwann cells in an aligned collagen environment, recreating key features of normal nerve tissue.Incorrect orientation of regenerating nerve cells can lead to delays in repair, scarring and poor restoration of nerve function. Much research has taken place into how support cells (Schwann cells) can be combined with materials to guide nerve regeneration. The new technology from The Open University avoids the use of synthetic materials by building neural tissue from collagen, a protein that is abundant in normal nerve tissue. Building the artificial tissue from natural proteins and directing the cellular alignment using normal cell-material interactions means the EngNT can integrate effectively at the repair site.Dr James Phillips, Lecturer in Health Sciences at The Open University, said: “We previously reported how self-alignment of Schwann cells could be achieved by using a tethered collagen hydrogel, which exploited cells’ natural ability to orientate in the appropriate direction by using their internal contraction forces. Our current research shows that cell-alignment in the hydrogel can be stabilised using plastic compression. The compression removes fluid from the gels, leaving a strong and stable aligned structure that has many features in common with nerve tissue.”The team incorporated Schwann cells within the aligned material to form artificial neural tissue that could potentially be used in peripheral nerve repair. The technique could be applied to other regenerative medicine scenarios, where a stable artificial tissue containing aligned cellular architecture would be of benefit.Share this story on Facebook, Twitter, and Google:Other social bookmarking and sharing tools:|Story Source: The above story is reprinted from materials provided by Open University. …

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Greenhouse gas likely altering ocean foodchain: Atmospheric CO2 has big consequences for tiny bacteria

July 2, 2013 — Climate change may be weeding out the bacteria that form the base of the ocean’s food chain, selecting certain strains for survival, according to a new study.In climate change, as in everything, there are winners and losers. As atmospheric carbon dioxide levels and temperature rise globally, scientists increasingly want to know which organisms will thrive and which will perish in the environment of tomorrow.The answer to this question for nitrogen-fixing cyanobacteria (bacteria that obtain energy through photosynthesis, or “blue-green algae”) turns out to have implications for every living thing in the ocean. Nitrogen-fixing is when certain special organisms like cyanobacteria convert inert — and therefore unusable — nitrogen gas from the air into a reactive form that the majority of other living beings need to survive. Without nitrogen fixers, life in the ocean could not survive for long.”Our findings show that CO2 has the potential to control the biodiversity of these keystone organisms in ocean biology, and our fossil fuel emissions are probably responsible for changing the types of nitrogen fixers that are growing in the ocean,” said David Hutchins, professor of marine environmental biology at the USC Dornsife College of Letters, Arts and Sciences and lead author of an article about this research that appeared in Nature Geoscience on June 30.”This may have all kinds of ramifications for changes in ocean food chains and productivity, even potentially for resources we harvest from the ocean such as fisheries production,” Hutchins said.Hutchins and his team studied two major groups of nitrogen-fixing cyanobacteria: Trichodesmium, which forms large floating colonies big enough to see with the naked eye and makes vast “blooms” in the open ocean, and Crocosphaera, which is also very abundant but is a single-celled, microscopic organism.Previous research showed that these two types of cyanobacteria should be some of the biggest “winners” of climate change, thriving in high CO2 levels and warmer oceans. However, those previous studies only examined one or two strains of the organisms.That’s where USC’s unique resource comes into play — the university is home to a massive culture library of strains and species of the organisms assembled by USC Associate Professor Eric Webb.Using the culture library, the team was able to show that some strains grow better at CO2 levels not seen since the start of the Industrial Revolution, while others will thrive in the future “greenhouse” Earth.”It’s not that climate change will wipe out all nitrogen fixers; we’ve shown that there’s redundancy in nature’s system. Rather, increasing atmospheric carbon dioxide changes specifically which nitrogen fixers are likely to thrive,” Hutchins said. “And we’re not entirely certain how that will change the ocean of tomorrow.”

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Major changes needed for coral reef survival

June 28, 2013 — To prevent coral reefs around the world from dying off, deep cuts in carbon dioxide emissions are required, says a new study from Carnegie’s Katharine Ricke and Ken Caldeira. They find that all existing coral reefs will be engulfed in inhospitable ocean chemistry conditions by the end of the century if civilization continues along its current emissions trajectory.Their work will be published July 3 by Environmental Research Letters.Coral reefs are havens for marine biodiversity and underpin the economies of many coastal communities. But they are very sensitive to changes in ocean chemistry resulting from greenhouse gas emissions, as well as to coastal pollution, warming waters, overdevelopment, and overfishing.Ricke and Caldeira, along with colleagues from Institut Pierre Simon Laplace and Stanford University, focused on the acidification of open ocean water surrounding coral reefs and how it affects a reef’s ability to survive.Coral reefs use a mineral called aragonite to make their skeletons. It is a naturally occurring form of calcium carbonate, CaCO3. When carbon dioxide, CO2, from the atmosphere is absorbed by the ocean, it forms carbonic acid (the same thing that makes soda fizz), making the ocean more acidic and decreasing the ocean’s pH. This increase in acidity makes it more difficult for many marine organisms to grow their shells and skeletons, and threatens coral reefs the world over.Using results from simulations conducted using an ensemble of sophisticated models, Ricke, Caldeira, and their co-authors calculated ocean chemical conditions that would occur under different future scenarios and determined whether these chemical conditions could sustain coral reef growth.Ricke said: “Our results show that if we continue on our current emissions path, by the end of the century there will be no water left in the ocean with the chemical properties that have supported coral reef growth in the past. We can’t say with 100% certainty that all shallow-water coral reefs will die, but it is a pretty good bet.”Deep cuts in emissions are necessary in order to save even a fraction of existing reefs, according to the team’s results. Chemical conditions that can support coral reef growth can be sustained only with very aggressive cuts in carbon dioxide emissions.”To save coral reefs, we need to transform our energy system into one that does not use the atmosphere and oceans as waste dumps for carbon dioxide pollution. The decisions we make in the next years and decades are likely to determine whether or not coral reefs survive the rest of this century,” Caldeira said.

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Biological arithmetic: Plants do sums to get through the night

June 24, 2013 — New research shows that to prevent starvation at night, plants perform accurate arithmetic division. The calculation allows them to use up their starch reserves at a constant rate so that they run out almost precisely at dawn.”This is the first concrete example in a fundamental biological process of such a sophisticated arithmetic calculation.” said mathematical modeller Professor Martin Howard from the John Innes Centre.Plants feed themselves during the day by using energy from the sun to convert carbon dioxide into sugars and starch. Once the sun has set, they must depend on a store of starch to prevent starvation.In research to be published in the open access journal eLife, scientists at the John Innes Centre show that plants make precise adjustments to their rate of starch consumption. These adjustments ensure that the starch store lasts until dawn even if the night comes unexpectedly early or the size of the starch store varies.The John Innes Centre scientists show that to adjust their starch consumption so precisely they must be performing a mathematical calculation — arithmetic division.”The capacity to perform arithmetic calculation is vital for plant growth and productivity,” said metabolic biologist Professor Alison Smith.”Understanding how plants continue to grow in the dark could help unlock new ways to boost crop yield.”During the night, mechanisms inside the leaf measure the size of the starch store and estimate the length of time until dawn. Information about time comes from an internal clock, similar to our own body clock. The size of the starch store is then divided by the length of time until dawn to set the correct rate of starch consumption, so that, by dawn, around 95% of starch is used up.”The calculations are precise so that plants prevent starvation but also make the most efficient use of their food,” said Professor Smith.”If the starch store is used too fast, plants will starve and stop growing during the night. If the store is used too slowly, some of it will be wasted.”The scientists used mathematical modelling to investigate how such a division calculation can be carried out inside a plant. They proposed that information about the size of the starch store and the time until dawn is encoded in the concentrations of two kinds of molecules (called S for starch and T for time). If the S molecules stimulate starch consumption, while the T molecules prevent this from happening, then the rate of starch consumption is set by the ratio of S molecules to T molecules, in other words S divided by T.This research is funded by the Biotechnology and Biological Sciences Research Council (BBSRC)

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New kind of variable star discovered: Minute variations in brightness reveal whole new class of stars

June 12, 2013 — The Swiss are justly famed for their craftsmanship when creating extremely precise pieces of technology. Now a Swiss team from the Geneva Observatory has achieved extraordinary precision using a comparatively small 1.2-metre telescope for an observing programme stretching over many years. They have discovered a new class of variable stars by measuring minute variations in stellar brightness.The new results are based on regular measurements of the brightness of more than three thousand stars in the open star cluster NGC 3766* over a period of seven years. They reveal how 36 of the cluster’s stars followed an unexpected pattern — they had tiny regular variations in their brightness at the level of 0.1% of the stars’ normal brightness. These variations had periods between about two and 20 hours. The stars are somewhat hotter and brighter than the Sun, but otherwise apparently unremarkable. The new class of variable stars is yet to be given a name.This level of precision in the measurements is twice as good as that achieved by comparable studies from other telescopes — and sufficient to reveal these tiny variations for the first time.”We have reached this level of sensitivity thanks to the high quality of the observations, combined with a very careful analysis of the data,” says Nami Mowlavi, leader of the research team, “but also because we have carried out an extensive observation programme that lasted for seven years. It probably wouldn’t have been possible to get so much observing time on a bigger telescope.”Many stars are known as variable or pulsating stars, because their apparent brightness changes over time. How the brightness of these stars changes depends in complex ways on the properties of their interiors. This phenomenon has allowed the development of a whole branch of astrophysics called asteroseismology, where astronomers can “listen” to these stellar vibrations, in order to probe the physical properties of the stars and get to know more about their inner workings.”The very existence of this new class of variable stars is a challenge to astrophysicists,” says Sophie Saesen, another team member. …

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Where trash accumulates in the deep sea

June 5, 2013 — Surprisingly large amounts of discarded trash end up in the ocean. Plastic bags, aluminum cans, and fishing debris not only clutter our beaches, but accumulate in open-ocean areas such as the “Great Pacific Garbage Patch.” Now, a paper by researchers at the Monterey Bay Aquarium Research Institute (MBARI) shows that trash is also accumulating in the deep sea, particularly in Monterey Canyon.Kyra Schlining, lead author on this study, said, “We were inspired by a fisheries study off Southern California that looked at seafloor trash down to 365 meters. We were able to continue this search in deeper water — down to 4,000 meters. Our study also covered a longer time period, and included more in-situ observations of deep-sea debris than any previous study I’m aware of.”To complete this extensive study, Schlining and her coauthors combed through 18,000 hours of underwater video collected by MBARI’s remotely operated vehicles (ROVs). Over the past 22 years, technicians in MBARI’s video lab recorded virtually every object and animal that appeared in these videos. These annotations are compiled in MBARI’s Video Annotation and Reference System (VARS).For this study, video technicians searched the VARS database to find every video clip that showed debris on the seafloor. They then compiled data on all the different types of debris they saw, as well as when and where this debris was observed.In total, the researchers counted over 1,500 observations of deep-sea debris, at dive sites from Vancouver Island to the Gulf of California, and as far west as the Hawaiian Islands. In the recent paper, the researchers focused on seafloor debris in and around Monterey Bay — an area in which MBARI conducts over 200 research dives a year. In this region alone, the researchers noted over 1,150 pieces of debris on the seafloor.The largest proportion of the debris — about one third of the total — consisted of objects made of plastic. Of these objects, more than half were plastic bags. …

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Climate change may have little impact on tropical lizards: Study contradicts predictions of widespread extinction

May 17, 2013 — A new Dartmouth College study finds human-caused climate change may have little impact on many species of tropical lizards, contradicting a host of recent studies that predict their widespread extinction in a rapidly warming planet.

The findings appear in the journal Global Change Biology.

Most predictions that tropical cold-blooded animals, especially forest lizards, will be hard hit by climate change are based on global-scale measurements of environmental temperatures, which miss much of the fine-scale variation in temperature that individual animals experience on the ground, said the article’s lead author, Michael Logan, a Ph.D. student in ecology and evolutionary biology.

To address this disconnect, the Dartmouth researchers measured environmental temperatures at extremely high resolution and used those measurements to project the effects of climate change on the running abilities of four populations of lizard from the Bay Islands of Honduras. Field tests on the captured lizards, which were released unharmed, were conducted between 2008 and 2012.

Previous studies have suggested that open-habitat tropical lizard species are likely to invade forest habitat and drive forest species to extinction, but the Dartmouth research suggests that the open-habitat populations will not invade forest habitat and may actually benefit from predicted warming for many decades. Conversely, one of the forest species studied should experience reduced activity time as a result of warming, while two others are unlikely to experience a significant decline in performance.

The overall results suggest that global-scale predictions generated using low-resolution temperature data may overestimate the vulnerability of many tropical lizards to climate change.

“Whereas studies conducted to date have made uniformly bleak predictions for the survival of tropical forest lizards around the globe, our data show that four similar species, occurring in the same geographic region, differ markedly in their vulnerabilities to climate warming,” the authors wrote. “Moreover, none appear to be on the brink of extinction. Considering that these populations occur over extremely small geographic ranges, it is possible that many tropical forest lizards, which range over much wider areas, may have even greater opportunity to escape warming.”

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Why people put themselves under the knife: Plastic surgery makes people happy

Mar. 11, 2013 — In a long-term study, Prof. Dr. Jürgen Margraf, Alexander von Humboldt Professor for Clinical Psychology and Psychotherapy at the RUB, investigated the psychological effects of plastic surgery on approximately 550 patients in cooperation with colleagues from the University of Basel. Patients demonstrated more enjoyment of life, satisfaction and self-esteem after their physical appearance had been surgically altered.

The results of the world’s largest ever study on this issue are reported by the researchers in the journal Clinical Psychological Science.

The aim of the research

The researchers examined whether patients who undergo plastic surgery are systematically different from other people, what goals they set themselves before the surgery, and whether they achieve these afterwards. The researchers compared 544 first-time surgery patients with two other groups: on the one hand with 264 people who had previously wanted plastic surgery and then decided against it, and on the other hand, with around 1000 people from the general population who have never been interested in such operations. The desire for a better appearance for aesthetic reasons usually occurs in younger people with slightly above-average incomes. Women represent 87 % of all patients who opt for cosmetic surgery. Overall, there were no significant differences among the three groups studied in terms of psychological and health variables, such as mental health, life satisfaction and depressiveness.

Most patients do not expect the impossible from surgery

Using a psychological instrument, the so-called “Goal Attainment Scaling,” the researchers examined what goals the patients wanted to achieve with cosmetic surgery. Alongside open questions, ten standard goals were offered, also including two which were clearly unrealistic: “All my problems will be solved” and “I’ll be a completely new person.” Only 12 % of the respondents specified these unrealistic standard goals. In the open questions, the patients answered on the whole more realistically, expressing wishes such as to “feel better,” “eliminate blemishes” and “develop more self-confidence.”

Long-term improvements in psychological variables after surgery

The psychologists tested the patients before surgery, as well as three, six and twelve months afterwards. On average, the participants claimed to have achieved their desired goal, and to be satisfied with the results in the long-term. Compared to those who had chosen not to have plastic surgery, the patients felt healthier, were less anxious, had developed more self-esteem and found the operated body feature in particular, but also their body as a whole, more attractive. No adverse effects were observed. Thus, the researchers were able to establish a high level for the average treatment success of the cosmetic surgery, also in terms of psychological characteristics.

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