Deforestation may have far greater consequences for climate change in some soils than in others, according to new research led by Yale University scientists — a finding that could provide critical insights into which ecosystems must be managed with extra care because they are vulnerable to biodiversity loss and which ecosystems are more resilient to widespread tree removal.In a comprehensive analysis of soil collected from 11 distinct U.S. regions, from Hawaii to northern Alaska, researchers found that the extent to which deforestation disturbs underground microbial communities that regulate the loss of carbon into the atmosphere depends almost exclusively on the texture of the soil. The results were published in the journal Global Change Biology.”We were astonished that biodiversity changes were so strongly affected by soil texture and that it was such an overriding factor,” said Thomas Crowther, a postdoctoral fellow at the Yale School of Forestry & Environmental Studies and lead author of the study. “Texture overrode the effects of all the other variables that we thought might be important, including temperature, moisture, nutrient concentrations, and soil pH.”The study is a collaboration among Yale researchers and colleagues at the University of Boulder, Colorado and the University of Kentucky.A serious consequence of deforestation is extensive loss of carbon from the soil, a process regulated by subterranean microbial diversity. Drastic changes to the microbial community are expected to allow more CO2 to escape into the atmosphere, with the potential to exaggerate global warming.Specifically, the researchers found that deforestation dramatically alters microbial communities in sandy soils, but has minimal effects in muddy, clay-like soils, even after extensive tree removal.According to the researchers, particles in fine, clay-like soil seem to have a larger surface area to bind nutrients and water. This capacity might buffer soil microbes against the disturbance of forest removal, they said. In contrast, sandy soils have larger particles with less surface area, retaining fewer nutrients and less organic matter.”If you disrupt the community in a sandy soil, all of the nutrients the microbes rely on for food are leached away: they’re lost into the atmosphere, lost into rivers, lost through rain,” Crowther said. “But in clay-like soil, you can cut down the forest and the nutrients remain trapped tightly in the muddy clay.”The researchers also examined how the effects of deforestation on microbial biodiversity change over time. Contrary to their expectations, they found no correlation, even over the course of 200 years.”The effects are consistent, no matter how long ago deforestation happened,” Crowther said. “In a clay soil, you cut down the forest and the nutrients are retained for long periods of time and the community doesn’t change. …Read more
The distress caused by social stimuli (e.g., losing a friend, experiencing an injustice or more in general when a social bond is threatened) activates brain circuits related to physical pain: as observed in a study conducted by SISSA, this also applies when we experience this type of pain vicariously as an empathic response (when we see somebody else experiencing it).We would like to do without pain and yet without it we wouldn’t be able to survive. Pain signals dangerous stimuli (internal or external) and guides our behaviour. Its ultimate goal is to prioritize escape, recovery and healing. That’s why we feel it and why we’re also good at detecting it in others. Pain in fact protects not only the individual but also his social bonds. The brain contains circuits related to the more physical aspects of pain and others related to affective aspects. As observed in a study just published by Giorgia Silani, Giovanni Novembre and Marco Zanon of the International School for Advanced Studies (SISSA) of Trieste, social pain activates some brain circuits of physical pain whether we feel it personally or when we experience it vicariously as an empathic response to other people’s pain.The study by Silani and colleagues is innovative since it adopted a more realistic experimental procedure than used in the past and compared behaviours and the results of functional magnetic resonance imaging in the same subjects, during tests involving both physical and social pain. “Classic experiments used a stylized procedure in which social exclusion situations were simulated by cartoons. We suspected that this simplification was excessive and likely to lead to systematic biases in data collection, so we used real people in videos.”The subjects took part in the experimental sessions simulating a ball tossing game, where one of the players was deliberately excluded by the others (condition of social pain). The player could be the subject herself or her assigned confederate. …Read more
Heidelberg researchers have been delving into the basic regulatory mechanisms of stem cell differentiation. Using the Drosophila melanogaster fruit fly as a model organism, the team led by Prof. Dr. Ingrid Lohmann at Heidelberg University’s Centre for Organismal Studies was able to show how a special developmental gene from the Hox family influences germline stem cells. These cells are responsible for sperm formation. The scientists, working in the “Maintenance and Differentiation of Stem Cells in Development and Disease” Collaborative Research Centre (CRC 873), found that impairment of Hox gene function resulted in prematurely aged sperms.As “immature” somatic cells, stem cells can mature into different types of cells, thus making them responsible for the development of all the tissues and organs in the body. They are also able to repair damaged adult cells. “Advancements in medical research have shown that stem cells can be used to treat certain diseases. To fulfil the promise of stem cell therapy, it is important to discover the function of the respective stem cells and understand how they interact with their environment, that is, the surrounding cells and tissues,” explains Prof. Lohmann, who heads the Developmental Biology research group at the Centre for Organismal Studies (COS).This microenvironment, which stabilises and regulates stem cell activity, is called a stem cell niche. …Read more
There have been some few patients who have survived far beyond the usual one year prognosis for most mesothelioma victims and a handful that have even been cured, with no trace of the aggressive cancer several years after treatment (though recurrence is always possible).Many medical experts are baffled by this observation and for most of the time they are yet to find a real scientific basis to explain why some mesothelioma patients survive and others do not.There seems to be one common factor amongst those that have survived the disease for longer times – the immune system. Studies of those who have either survived or been cured of the disease reveal that most of these patients participated in some sort of therapy that enhanced their immune …Read more
Oct. 16, 2013 — Animal populations can have a far more significant impact on carbon storage and exchange in regional ecosystems than is typically recognized by global carbon models, according to a new paper authored by researchers at the Yale School of Forestry & Environmental Studies (F&ES).In fact, in some regions the magnitude of carbon uptake or release due to the effects of specific animal species or groups of animals — such as the pine beetles devouring forests in western North America — can rival the impact of fossil fuel emissions for the same region, according to the paper published in the journal Ecosystems.While models typically take into account how plants and microbes affect the carbon cycle, they often underestimate how much animals can indirectly alter the absorption, release, or transport of carbon within an ecosystem, says Oswald Schmitz, the Oastler Professor of Population and Community Ecology at F&ES and lead author of the paper. Historically, the role of animals has been largely underplayed since animal species are not distributed globally and because the total biomass of animals is vastly lower than the plants that they rely upon, and therefore contribute little carbon in the way of respiration.”What these sorts of analyses have not paid attention to is what we call the indirect multiplier effects,” Schmitz says. “And these indirect effects can be quite huge — and disproportionate to the biomass of the species that are instigating the change.”In the paper, “Animating the Carbon Cycle,” a team of 15 authors from 12 universities, research organizations and government agencies cites numerous cases where animals have triggered profound impacts on the carbon cycle at local and regional levels.In one case, an unprecedented loss of trees triggered by the pine beetle outbreak in western North America has decreased the net carbon balance on a scale comparable to British Columbia’s current fossil fuel emissions.And in East Africa, scientists found that a decline in wildebeest populations in the Serengeti-Mara grassland-savanna system decades ago allowed organic matter to accumulate, which eventually led to about 80 percent of the ecosystem to burn annually, releasing carbon from the plants and the soil, before populations recovered in recent years.”These are examples where the animals’ largest effects are not direct ones,” Schmitz says. “But because of their presence they mitigate or mediate ecosystem processes that then can have these ramifying effects.””We hope this article will inspire scientists and managers to include animals when thinking of local and regional carbon budgets,” said Peter Raymond, a professor of ecosystem ecology at the Yale School of Forestry & Environmental Studies.According to the authors, a more proper assessment of such phenomena could provide insights into management schemes that could help mitigate the threat of climate change.For example, in the Arctic, where about 500 gigatons of carbon is stored in permafrost, large grazing mammals like caribou and muskoxen can help maintain the grasslands that have a high albedo and thus reflect more solar energy. In addition, by trampling the ground these herds can actually help reduce the rate of permafrost thaw, researchers say.”It’s almost an argument for rewilding places to make sure that the natural balance of predators and prey are there,” Schmitz says. “We’re not saying that managing animals will offset these carbon emissions. What we’re trying to say is the numbers are of a scale where it is worthwhile to start thinking about how animals could be managed to accomplish that.”Read more
Oct. 15, 2013 — Evaluation of diagnostic studies is often a challenge in diseases that are not defined by a specific test. Assessment of the accuracy of diagnostic tests is essential because they may be used to define who is considered to have a disease and receive treatment for it. However, measuring the accuracy of a diagnostic test requires an accurate gold standard, which defines which patients truly have and do not have the disease. Studies of diseases not defined by a specific test often rely on expert panels to establish the gold standard. In a systematic review and analysis of the diagnostic literature using expert panels to define the gold standard for a given disease, Loes Bertens and colleagues from University Medical Center Utrecht determined how expert panels were used in such studies and how well their process was described and reliability assessed.Share This:The authors evaluated 81 diagnostic studies published up to May 31, 2012, including studies of diagnostic tests for psychiatric disorders (30 of 81 papers, 37%), half of which pertained to dementia, cardiovascular diseases (17 papers, 21%), and respiratory disorders (10 papers, 12%). They found that reporting was often incomplete, with 83% of studies missing at least some important information about the expert panel. In 75% of studies the panel consisted of three or fewer members, and panel members were blinded to the results of the test results being evaluated in only 31% of studies. Blinding is important because knowledge of the index text results could influence the panelists’ decision as to whether the patient had the disease. Reproducibility of the decision process was assessed in only 21% of studies.The authors state, “Complete and accurate reporting is a prerequisite for judging potential bias in a study and for allowing readers to apply the same study methods. …Read more
Aug. 28, 2013 — Studies show that migraine is more common among people with lower incomes. This relationship is examined in a study published in the August 28, 2013, online issue of Neurology®, the medical journal of the American Academy of Neurology, looking at whether developing migraines limits people’s educational and career achievements, leading to a lower income status, or whether problems related to low income such as stressful life events and poor access to health care increase the likelihood of developing migraines.Contrary to the theory that social stressors increase the rate of migraine in low-income people, the researchers found that the remission rate when migraines stop occurring for a time or for good was the same regardless of income. “If the stresses of low income were the sole determinant, we would expect low-income people to be less likely to stop having migraines,” said study author Walter F. Stewart, PhD, with Sutter Health, a not-for-profit health system in Northern California. “It’s possible that the start of the disease may have a different cause than the stopping of the disease.”For the study, 162,705 people age 12 and older provided information on whether they had migraine symptoms, the age symptoms started and household income. Low income was defined as less than $22,500 per year for the household and high income as $60,000 per year or more.The study confirmed that the percentage of people with migraine is higher among those in lower income groups. For example, for women age 25-34, 20 percent of those from high-income households had migraine, compared to 29 percent of those with middle income and 37 percent of those with low income. For men in that age range, 5 percent in high-income households had migraine, compared to 8 percent in middle income and 13 percent in low income. The results remained the same after adjusting for factors such as race, age and sex.”New evidence from this study shows that a higher percentage of people have migraine in low income groups because more people get migraine, not because people in lower income groups have migraine for a longer period of time,” Stewart said. …Read more
Aug. 21, 2013 — Part of the risk for alcohol dependence is genetic, and the same is true for eating disorders. Now, researchers at Washington University School of Medicine in St. Louis have found it’s likely some of the same genes are involved in both.In the September issue of the Journal of Studies on Alcohol and Drugs, the researchers report that people with alcohol dependence may be more genetically susceptible to certain types of eating disorders and vice versa.”In clinical practice, it’s been observed that individuals with eating disorders also have high rates of alcohol abuse and dependence,” said Melissa A. Munn-Chernoff, PhD, the study’s first author. “Other studies have focused on the genetic connections between alcohol dependence and eating disorders, but all of those studies looked only at women. Ours was the first to include men as well.”According to Munn-Chernoff, a postdoctoral research scholar in psychiatry, that’s important because although eating disorders tend to be thought of as a female problem, they affect men, too.Studying data gathered from nearly 6,000 adult twins in Australia, Munn-Chernoff and her colleagues found that common genetic factors underlie alcoholism and certain eating-disorder symptoms, such as binge eating and purging habits that include self-induced vomiting and the abuse of laxatives.By studying twins, the researchers used statistical methods to determine the odds that certain traits result from the same genes. Those statistical insights are based on the fact that identical twins share 100 percent of their genetic makeup while fraternal twins share about half.”By comparing the findings in identical and fraternal twins, we can develop estimates of how much of the difference in particular traits is due to genes or environment,” Munn-Chernoff explained. “We found that some of the genes that influence alcohol dependence also influence binge eating in men and women.”Even with the growing awareness and more frequent diagnoses of problems such as anorexia nervosa and bulimia nervosa, rates of the full-blown forms of these disorders are relatively low, and they’re rare in populations of twins. So the researchers surveyed study subjects about whether they suffered from eating-disorder symptoms.”The symptoms can cut across multiple eating disorder diagnoses,” said Munn-Chernoff. …Read more
Aug. 2, 2013 — Scientists from the Florida campus of The Scripps Research Institute have described findings that could enable the development of more effective drugs for addiction with fewer side effects.The study, published in the August 2, 2013 issue of the Journal of Biological Chemistry, showed in a combination of cell and animal studies that one active compound maintains a strong bias towards a single biological pathway, providing insight into what future drugs could look like.The compound examined in the study, known as 6′- guanidinonaltrindole (6′-GNTI), targets the kappa opioid receptor (KOR). Located on nerve cells, KOR plays a role in the release of dopamine, a neurotransmitter that plays a key role in drug addiction. Drugs of abuse often cause the brain to release large amounts of dopamine, flooding the brain’s reward system and reinforcing the addictive cycle.”There are a number of drug discovery efforts ongoing for KOR,” said Laura Bohn, a TSRI associate professor, who led the study. “The ultimate question is how this receptor should be acted upon to achieve the best therapeutic effects. Our study identifies a marker that shows how things normally happen in live neurons — a critically important secondary test to evaluate potential compounds.”While KOR has become the focus for drug discovery efforts aimed at treating addiction and mood disorders, KOR can react to signals that originate independently from multiple biological pathways, so current drug candidates targeting KOR often produce unwanted side effects. Compounds that activate KOR can decrease the rewarding effects of abused drugs, but also induce sedation and depression.The new findings, from studies of nerve cells in the striatum (an area of the brain involved in motor activity and higher brain function), reveal a point on the KOR signaling pathway that may prove to be an important indicator of whether drug candidates can produce effects similar to the natural biological effects.”Standard screening assays can catch differences but those differences may not play out in live tissue,” Bohn noted. “Essentially, we have shown an important link between cell-based screening assays and what occurs naturally in animal models.”The first author of the study, ‘Functional Selectivity of 6′-guanidinonaltrindole (6’-GNTI) at Kappa Opioid Receptors in Striatal Neurons,” is Cullen L. Schmid of TSRI. Other authors include John M. …Read more
June 4, 2013 — A series of studies conducted by an Iowa State University research team shows that it is possible to manipulate an existing memory simply by suggesting new or different information. The key is timing and recall of that memory, said Jason Chan, an assistant professor of psychology at Iowa State.”If you reactivate a memory by retrieving it, that memory becomes susceptible to changes again. And if at that time you give people new contradictory information, that can make the original memory much harder to retrieve later,” Chan said.One of the major findings from the studies, published in the latest issue of Proceedings of the National Academy of Sciences, is the impact on declarative memory — a memory that can be consciously recalled and verbally described, such as what you did last weekend. The effects are powerful because people are retrieving memory and then incorporating new information. Chan and Jessica LaPaglia, a graduate student at Iowa State, tested the impact of new information when presented at different time intervals after the retrieval of the original memory.If it was immediate, the memory could be altered. However, there was no effect on the original memory when the information was presented 48 hours later. Chan said based on other studies, it appears there is a six-hour window before the memory is reconsolidated after recall and cannot be altered. Likewise, they found no effect if the information was presented in a different context than the original memory.”During that reconsolidation period, that’s when the memory is easy to be interfered with. Once that window closes and that memory is stable again, if you get new information it should not interfere with that original memory,” Chan said. “We found support for that idea in a number of experiments in which we varied the delay between the interfering memory or the misinformation and when people took that initial test.”Impact outside of an experimental settingFor the studies, participants watched a 40-minute episode of the TV show “24” in which a terrorist uses a hypodermic needle to attack a flight attendant. …Read more
Apr. 29, 2013 — Research into the complementary therapies evening primrose oil and borage oil shows little, if any, benefit for people with eczema compared with placebo, according to a new systematic review. The authors, who published their review in The Cochrane Library, conclude that further studies on the therapies would be difficult to justify.
Atopic eczema, also known as atopic dermatitis, is an itchy skin condition with no known cure. Usually emerging in childhood, it affects about 10 to 20% of school age children, who may suffer with tight, red, painful skin, sleepless nights and low self-esteem due to appearance, itching and scratching. For around 60% of people, the disorder will improve or clear up by adulthood. Creams, ointments, bath additives, topical steroids and antihistamines are some of the treatments prescribed to ease the condition. However, people often turn to complementary therapies such as evening primrose oil and borage oil in the belief that they will avoid side effects of conventional eczema treatments. Both evening primrose oil and borage oil contain high quantities of gamma linoleic acid, which was once thought to play a role in reducing skin inflammation in eczema.
The researchers analysed the benefits and side effects associated with evening primrose oil and borage oil in 27 studies involving a total of 1,596 people (adults and children) in 27 countries. Participants took evening primrose oil or borage oil, or a placebo, for between 3-24 weeks. Overall, the researchers found that taking evening primrose or borage oil offered no clear improvement of eczema symptoms over placebos. Commonly used placebos included olive oil and paraffin oil. There was also no improvement in quality of life with the complementary therapies, although only two studies considered this measure.
“There is no evidence that taking either evening primrose or borage oil is of benefit to eczema sufferers,” said lead researcher Joel Bamford of the University of Minnesota Medical School and Essentia Health System in Duluth, Minnesota, US. “Given the strength of the evidence in our review, we think further studies on the use of these complementary therapies to treat eczema would be hard to justify.”
Some participants in the studies experienced mild side effects such as headaches and stomach upsets or diarrhea as they also did while taking placebos. However, none of the selected studies evaluated or mentioned bleeding or anti-clotting effects, which have previously been associated with evening primrose oil. “Consumers need to be warned that oral evening primrose oil is listed as a known cause of increased bleeding for those taking Coumadin or warfarin, a very common medication,” said Bamford.Read more
As Cornell's Department of Biological and Environmental Engineering (BEE) enters its second century, a professor emeritus has chronicled its early roots in agricultural studies and its many changes over the years.Read more
Currently, only an evidence level of III supports the treatment with immunosuppressive/biological modifiers drugs: expert opinion, clinical experience or descriptive studies. We recently showed, in a multicenter, comparative prospective case …Read more