Antibiotics from mangroves?

Researchers at the Universiti Teknologi MARA (UiTM) in Malaysia have conducted a study on the mangrove ecosystem to search for actinomycetes bacteria. The mangrove ecosystem is known as a highly productive habitat for isolating actinomycetes, which has the potential of producing biologically active secondary metabolites.The UiTM study focused on eight different mangrove sites in Malaysia, which were chosen at random to isolate and screen actinomycetes from soil samples. A total of 53 possible marine actinomycetes were isolated and it was found that a three percent concentration of sodium chloride was sufficient to support the growth of marine actinomycetes.Among the isolated filamentous bacteria, five isolates showed antimicrobial activity from direct culture broth against at least one of the test organisms. Meanwhile, four extracts of ethyl acetate showed activity against Gram-positive test organisms. The results revealed that marine actinomycetes is a potential source for producing antibiotics.Story Source:The above story is based on materials provided by Universiti Teknologi MARA (UiTM). Note: Materials may be edited for content and length.

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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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Genes increase the stress of social disadvantage for some children

Genes amplify the stress of harsh environments for some children, and magnify the advantage of supportive environments for other children, according to a study that’s one of the first to document how genes interacting with social environments affect biomarkers of stress.”Our findings suggest that an individual’s genetic architecture moderates the magnitude of the response to external stimuli — but it is the environment that determines the direction” says Colter Mitchell, lead author of the paper and a researcher at the University of Michigan Institute for Social Research (ISR).The study, published today in the Proceedings of the National Academy of Sciences, uses telomere length as a marker of stress. Found at the ends of chromosomes, telomeres generally shorten with age, and when individuals are exposed to disease and chronic stress, including the stress of living in a disadvantaged environment.For the study, Mitchell and colleagues used telomere samples from a group of 40 nine-year-old boys from two very different environments – one nurturing and the other harsh. Those in the nurturing environment came from stable families, with nurturing parenting, good maternal mental health, and positive socioeconomic conditions, while those in the harsh environment experienced high levels of poverty, harsh parenting, poor maternal mental health, and high family instability.For those children with heightened sensitivity in the serotonergic and dopaminergic genetic pathways compared to other children, telomere length was shortest in a disadvantaged environment, and longest in a supportive environment.Story Source:The above story is based on materials provided by University of Michigan. Note: Materials may be edited for content and length.

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Gastro outbreaks hit elderly hardest

Frail elderly people living in residential care facilities are at increased risk of severe illness or death from outbreaks of viral gastroenteritis.This is the finding from a study led by Craig Davis from Department of Health Queensland, published in the April issue of the Australian and New Zealand Journal of Public Health.”Importantly, prompt notification of outbreaks to public health units led to a much shorter duration of the outbreak,” Mr Davis said.”Notification of outbreaks to public health units should occur within 24 hours of any outbreak so that diagnostic testing and control measures can begin as soon as possible.”A number of viruses may cause outbreaks, but norovirus is by far the most common.”It typically causes vomiting, watery diarrhea, nausea and abdominal cramps with symptoms such as fatigue, myalgia, headache, chills and fever. There is no specific treatment and no vaccine for norovirus. Gastro outbreaks cause a considerable burden in residential care facilities, including disruptions relating to staff absenteeism due to illness, closure of common areas to residents, cancellation of events and increased attention required to infection control.Story Source:The above story is based on materials provided by Wiley. Note: Materials may be edited for content and length.

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Time out: Spanking babies is surprisingly common, U.S. study finds

The same hands that parents use to lovingly feed, clothe and bathe their babies are also commonly used to spank their bundles of joy.A new University of Michigan study found that 30 percent of 1-year-old children were spanked at least once in the past month by their mother, father or both parents.A long-time topic of debate, spanking children is a common practice among U.S. parents. Previous research has focused on disciplining children as young as age 3, in part, because spanking is common among children of this age. Studies have shown that spanking is related to children’s greater aggression, depression and other negative behavior.But the latest findings show that spanking is used on children who are so young that, in some cases, they haven’t even taken their first step.Researchers examined 2,788 families who participated in a longitudinal study of new births in urban areas. The study indicated that spanking by the child’s mother, father or mother’s current partner when the child was a year old was linked to child protective services’ involvement between ages 1 and 5. During that time, 10 percent of the families received at least one visit by CPS.U-M social work professors Shawna Lee and Andrew Grogan-Kaylor say that spanking babies is particularly misguided and potentially harmful, and may set off a cascade of inappropriate parental behavior. Their research is a snapshot of a larger problem: many people lack parenting skills that include alternatives to spanking.”Intervention to reduce or eliminate spanking has the potential to contribute to the well-being of families and children who are at-risk of becoming involved with the (social services) system,” Lee said.Perinatal well-baby clinical visits and home visitations after the child’s birth are opportunities for pediatricians, nurses and social workers to talk to parents about alternatives to spanking babies and toddlers, the researchers say.Story Source:The above story is based on materials provided by University of Michigan. Note: Materials may be edited for content and length.

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Drinking water linked to infections in many countries

Brisbane’s water supply has been found to contain disease carrying bugs which can be directly linked to infections in some patients, according to a new study by QUT.Dr Rachel Thomson, who has completed her PhD through QUT’s Faculty of Health, said certain species of nontuberculous mycobacteria were present in Brisbane’s water distribution system.”We know that certain species of nontuberculous mycobacteria can cause disease and infection in humans, especially in some at-risk groups, but not all exposure to mycobacteria is harmful,” she said.”We also know this is not isolated to Brisbane, with water supplies in many countries being a risk. What my study has been able to do is directly link the strains of bugs found in Brisbane’s water supply with the strains of bugs found in human infections, indicating that the water may be the source of the infection. Mycobacterial infections usually present as a persistent cough with symptoms similar to tuberculosis and include fatigue, night sweats and weight loss.”Dr Thomson said the number of mycobacterial disease cases in Queensland was steadily increasing, with an estimated 200 new cases diagnosed each year.”Mycobacterial infections are most common in people with underlying lung disease such as people with emphysema and cystic fibrosis, as well as those with immune suppression conditions like HIV or those taking chemotherapy-type medications,” she said.”But what is concerning is we are also seeing a growing number of middle-aged women getting the disease; they tend to be slender and slightly above average height, and who for all intents and purposes are fit and healthy.”It has been termed Lady Windermere syndrome because we are seeing it in women who tend to quietly and politely cough ineffectively, thereby not coughing up the bacteria.”Dr Thomson said in Queensland in people aged over 65, mycobacterial infection was more common than type 1 diabetes.”The other big concern is treatment. People who contract the infection usually have to take three different types of antibiotics over a 12 to 18 month period, sometimes even longer, and there can be side effects,” she said.”Certain strains of the disease are also notoriously difficult to treat and carry a high risk of morbidity and mortality, and there has been a recent suggestion that infection with one species may be transmitted between patients.”Dr Thomson’s study also looked at whether household water exposure through aerosols by activities like showering could lead to infection.”We found that nontuberculous mycobacteria could be aerosolised during showering to a respirable particle size and therefore potentially inhaled deep into the lungs,” Dr Thomson said.”The combined findings of strain comparisons of city wide and patient home sampling indicate that patients are at risk of infection from exposure to Brisbane’s water and showers.”Dr Thomson said the easiest way to kill water-borne mycobacteria was by boiling water, although her study suggested additional water chlorination through the water treatment process may also help. To reduce aerosolised mycobacteria, bathing rather than showering is recommended.She said reducing the temperature of home hot water systems contributed to increased household exposure to these mycobacteria.The four specific species of mycobacteria Dr Thomson found in Brisbane water that have been linked to human disease include Mycobacterium abscessus, Mycobacterium avium, Mycobacterium lentiflavum, and Mycobacterium kansasii.Story Source:The above story is based on materials provided by Queensland University of Technology. Note: Materials may be edited for content and length.

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Continuous handling of receipts linked to higher urine BPA levels

Study participants who handled receipts printed on thermal paper continuously for 2 hours without gloves had an increase in urine bisphenol A (BPA) concentrations compared to when they wore gloves, according to a study in the February 26 issue of JAMA.Human exposure to bisphenol A (BPA) has been associated with adverse health outcomes, including reproductive function in adults and neurodevelopment in children exposed shortly before or after birth. “Exposure to BPA is primarily through dietary ingestion, including consumption of canned foods. A less-studied source of exposure is thermal receipt paper, handled daily by many people at supermarkets, ATM machines, gas stations, and other settings,” according to background information in the article. Thermal paper has a coating that is sensitive to heat, which is used in the process of printing on the paper, and has been shown to be transferred to skin with handling.Shelley Ehrlich, M.D., Sc.D., M.P.H., of Cincinnati Children’s Hospital Medical Center, and colleagues conducted a study to examine the effect of handling thermal receipts on urine BPA levels. The authors recruited 24 volunteers who provided urine samples before and after handling (with or without gloves) of receipts printed on thermal paper for a continuous two hours. BPA was detected in 83 percent (n = 20) of urine samples at the beginning of the study and in 100 percent of samples after handling receipts without gloves. The researchers observed an increase in urinary BPA concentrations after continuously handling receipts for 2 hours without gloves, but no significant increase when the participants used gloves.The clinical implications of the height of the peak level and of chronic exposure are unknown, but may be particularly relevant to populations with occupational exposure such as cashiers, who handle receipts 40 or more hours per week, the authors write. “A larger study is needed to confirm our findings and evaluate the clinical implications.”Story Source:The above story is based on materials provided by The JAMA Network Journals. Note: Materials may be edited for content and length.

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Hormone released after exercise can ‘predict’ biological age

Scientists from Aston University (UK) have discovered a potential molecular link between Irisin, a recently identified hormone released from muscle after bouts of exercise, and the aging process.Irisin, which is naturally present in humans, is capable of reprograming the body’s fat cells to burn energy instead of storing it. This increases the metabolic rate and is thought to have potential anti-obesity effects.The research team led by Dr James Brown have proven a significant link exists between Irisin levels in the blood and a biological marker of aging called telomere length. Telomeres are small regions found at the end of chromosomes that shorten as cells within the body replicate. Short telomere length has been linked to many age-related diseases including cancer, heart disease and Alzheimer’s disease.Using a population of healthy, non-obese individuals, the team has shown those individuals who had higher levels of Irisin were found to have longer telomeres. The finding provides a potential molecular link between keeping active and healthy aging with those having higher Irisin levels more ‘biological young’ than those with lower levels of the hormone.Dr James Brown from Aston’s Research Centre for Healthy Ageing, said: “Exercise is known to have wide ranging benefits, from cardiovascular protection to weight loss. Recent research has suggested that exercise can protect people from both physical and mental decline with aging. Our latest findings now provide a potential molecular link between keeping active and a healthy aging process.”Irisin itself is secreted from muscle in response to exercise and is capable of reprograming the body’s fat cells to burn energy instead of storing it. This increases the metabolic rate and is thought to have potential weight loss effects, which in turn could help with conditions such as type-2 diabetes.Story Source:The above story is based on materials provided by Aston University. Note: Materials may be edited for content and length.

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Beauty and bacteria: Slim, attractive men have less nasal bacteria than heavy men

Do attractive traits tell us anything about a person’s reproductive health? New research in the American Journal of Human Biology reveals a link between Body Mass Index (BMI) and the amount of bacteria colonizing noses. The results show that heavier men harbor more potentially pathogenic species of bacteria in their nose, compared with slimmer, more traditionally attractive men.”According to an evolutionary point of view, traits related to attractiveness are supposed to be honest signals of biological quality,” said Dr. Boguslaw Pawlowski. “We analyzed whether nasal and throat colonization with potentially pathogenic bacteria is related to body height and BMI in both sexes.”103 healthy females and 90 healthy males participated in the study. Heights and weights were self-reported, while waist and hip circumferences were measured. Six potentially pathogenic bacteria were isolated and identified from nasal and throat swabs. The results showed that ‘colonized’ men were found to have a higher BMI than non-colonized males, although no differences were found in females.”To our knowledge, this is the first attempt to study body morphology traits related to physical attractiveness in relation to bacterial colonization in young people,” said Pawlowski. “The results confirmed our hypothesis, but only for BMI in males.”Story Source:The above story is based on materials provided by Wiley. Note: Materials may be edited for content and length.

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Breast cancer drug found in bodybuilding supplement

In a letter to The BMJ this week, researchers explain that, for more than 30 years, bodybuilders have taken tamoxifen to prevent and treat gynaecomastia (breast swelling) caused by use of anabolic steroids.Usually, tamoxifen is sourced from the illicit market, they say. However, bodybuilding discussion forums have speculated that a dietary supplement called Esto Suppress contains tamoxifen because the label listed one of its chemical names.The researchers purchased four samples at different times between late 2011 and early 2012 and analysed their contents. Tamoxifen was found in three out of the four samples at different concentrations (3.8 mg, 0.9 mg and 3 mg).The product label suggested a dosage of two capsules a day, which in the case of sample 1 may have provided 7.6 mg of tamoxifen (10-20 mg is used clinically for treating gynaecomastia).It is not known whether the Esto Suppress currently being sold still contains tamoxifen, but since the 2000s a growing number of off-the-shelf “food,” “herbal,” or “dietary” “supplements” — aimed at gym goers and people wanting to lose weight or enhance their sex lives — have contained pharmacologically active substances, explain the authors.These include anabolic steroids, erectogenics (to stimulate erections), stimulants, appetite suppressants, and anxiolytics (to treat anxiety).Often the substances are not listed on the labelling, and products may be marketed as “natural,” exploiting the belief that they are safer and healthier options, they add. In other cases, such as with Esto Suppress, only an obscure reference is made to the substance, such as a chemical name.They warn that most users “will be unaware that they are taking these substances” and urge healthcare professionals to ask their patients about their use of “supplements” and report suspected adverse reactions.Story Source:The above story is based on materials provided by BMJ-British Medical Journal. Note: Materials may be edited for content and length.

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Large-scale studies to evaluate testosterone therapy risks

According to a statement issued today by the Endocrine Society, the risks and benefits of testosterone therapy for older men with declining levels of the hormone need to be fully evaluated.The statement comes in response to recent studies that have raised concerns about the safety of testosterone therapy in older men with a history of heart disease. Two retrospective analyses and one randomized trial supported by the Veterans Health Care System, and the National Institutes of Health found a higher rate of cardiovascular events in men who received testosterone and had preexisting heart problems. The U.S. Food and Drug Administration has announced it plans to evaluate the safety of testosterone therapy.Testosterone is approved for the treatment of hypogonadism due to known diseases of the testes, pituitary and hypothalamus. Although the use of testosterone therapy is increasing, the treatment has not been approved for the treatment of age-related symptoms or the age-related decline of testosterone levels.Important safety data are expected from the NIA’s ongoing randomized trial examining testosterone in about 800 older men with unequivocally low testosterone levels and accompanying symptoms, including sexual and physical dysfunction. The trial’s structure and careful monitoring of cardiovascular events will help provide important safety information.The Society calls for the development of more large-scale randomized controlled trials to determine the true risks and benefits of testosterone therapy in older men.In the statement, the Society recommends that middle-aged and older men who are considering testosterone supplementation for age-related declines should be informed of the potential cardiovascular risks. The Society also believes that it may be prudent not to administer testosterone therapy to men who have had a cardiovascular event (such as myocardial infarction, stroke or acute coronary syndrome) in the preceding six months.In cases where men are being treated for hypogonadism as a result of known diseases of the testes, pituitary and hypothalamus, however, patients should consult their health care providers before making any changes to their medication regimen. The Society believes testosterone is generally safe and beneficial when used to treat young, hypogonadal men with these conditions.Story Source:The above story is based on materials provided by The Endocrine Society. Note: Materials may be edited for content and length.

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Women fare worse than men following stroke

The good news: More people survive stroke now than 10 years ago due to improved treatment and prevention. The bad news: Women who survive stroke have a worse quality of life than men, according to a study published in the Feb. 7 online issue of the journal Neurology.Researchers at Wake Forest Baptist Medical Center compared the quality of life in men and women who had a stroke or transient ischemic attack (TIA). A total of 1,370 patients ages 56 to 77 from the AVAIL registry – a national, multicenter, longitudinal registry of ischemic stroke and TIA patients – were included in the study.The patients’ quality of life was measured at three months and one year after a stroke or TIA using a formula that assesses mobility, self-care, everyday activities, depression/anxiety and pain.“We found that women had a worse quality of life than men up to 12 months following a stroke, even after considering differences in important sociodemographic variables, stroke severity and disability,” said Cheryl Bushnell, M.D., associate professor of neurology at Wake Forest Baptist and senior author of the study.“As more people survive strokes, physicians and other healthcare providers should pay attention to quality of life issues and work to develop better interventions, even gender-specific screening tools, to improve these patients’ lives.”The study findings showed that at three months, women were more likely than men to report problems with mobility, pain/discomfort and anxiety and depression, but the difference was greatest in those over age 75. At one year, women still had lower quality of life scores overall than men but the magnitude of those differences had diminished, Bushnell said.“The reason we do these types of studies is to be able to add different variables sequentially to determine what accounts for these gender differences,” Bushnell said. “We found that age, race and marital status accounted for the biggest differences between men and women at three months, with marital status being the most important. Even though the women in the study were older than the men, our study showed that age really had very little effect on quality of life.”The results suggest that further research on mobility, pain or discomfort and anxiety/depression may provide a clearer understanding for how to improve the lives of women after stroke, Bushnell added.The next step for the Wake Forest Baptist team will be to look at the trajectory of cognitive decline in men and women before and after stroke, she said.Story Source:The above story is based on materials provided by Wake Forest Baptist Medical Center. Note: Materials may be edited for content and length.

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Source of chlamydia reinfections may be GI tract

The current standard of care treatment for chlamydia sometimes fails to eradicate the disease, according to a review published ahead of print in Infection and Immunity, and the culprit may be in the gut.Chlamydia trachomatis not only infects the reproductive tract, but abides persistently — though benignly — in the gastrointestinal tract. There it remains even after eradication from the genitals by the antibiotic, azithromycin, says first author Roger Rank, of the Arkansas Children’s Research Institute, Little Rock. And that reservoir is likely a source of the all-too-common reinfections that follow treatment.The source of the reinfections has long been a conundrum. Some are blamed on continued intercourse with an infected partner. This is not surprising since chlamydia is usually asymptomatic in men.Chlamydiae have long been assumed often to persist within the genital tract in a non-replicating form, but Rank says there is no evidence for this. “While all agree that chlamydiae may persist in a patient for long periods of time, and that recurrent infections do develop, there has been no agreement on how and where and in what form chlamydiae persist,” says Rank.In a recent study, coauthor and Arkansas colleague Laxmi Yeruva showed in mice that azithormycin eradicated the genital infection, but not the GI infection.Rank showed further — also in mice — that chlamydial infection of the GI does not elicit an inflammatory response, and never resolves, unlike in the genital tract.”However, we found that GI infection does produce a strong immune response that can actually be effective against a genital infection, but that is unable to cure the GI infection,” says Rank.While chlamydial persistence in the GI tract has largely escaped notice of late, it was documented in the veterinary literature in numerous animals as early as the 1950s, says Rank. His reading of that early literature was a major factor motivating his and Yeruva’s studies, and this review, Rank says.Chlamydia trachomatis is the most common cause of sexually transmitted disease in the world. In the US, approximately 1.4 million cases occur annually, according to the Centers for Disease Control and Prevention. Adolescents are most affected, and 6.8 percent of sexually active females ages 14-19 become infected annually.Story Source:The above story is based on materials provided by American Society for Microbiology. Note: Materials may be edited for content and length.

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First evidence of common brain code for space, time, distance

A new Dartmouth study provides the first evidence that people use the same brain circuitry to figure out space, time and social distances.The findings, which help reveal how our brains organize information and create our perspective of the world, appear in the Journal of Neuroscience.The researchers looked at whether there is an overlap, or a common mechanism, in the brain areas used to represent time, space and social distances. They used fMRI to analyze the brain patterns of participants while they viewed objects photographed at different distances, viewed photos of friends or acquaintances and read phrases referring to the immediate or more remote future.”The results showed that the same brain patterns that decide whether something is physically near to us versus far away also decide whether we are thinking about the near or distant future or seeing a friend versus an acquaintance,” said senior author Thalia Wheatley, an associate professor of Psychological and Brain Sciences. “In other words, there is a common neural code for space, time and social distance. Near, now and dear (friends) activate one pattern and far, later and acquaintance activate a different pattern.”There are interesting implications for this,” she said. “For one, it suggests why we use distance metaphors to talk about time and friendship — for example, close friends and distant relatives. These metaphors stick because they echo the very neural computations involved. Our brains use distance to understand time and social connectedness. This mapping function may have a particularly important benefit in determining whether we care enough to act: Is something happening here, now, to someone I love? Or over there, years from now, to a stranger?”Story Source:The above story is based on materials provided by Dartmouth College. Note: Materials may be edited for content and length.

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First live births with a novel simplified IVF procedure

More than 5 million IVF babies have now been born worldwide, but because of high costs IVF is largely the preserve of developed countries and is only available or affordable for less than 10% of the world population. The success and sustainability of assisted reproductive technologies will depend to a large extent on the ability to optimize these techniques in terms of availability, affordability and effectiveness.In developing countries the consequences of involuntary childlessness can create wide-ranging societal problems, especially for women. Because many families in developing countries depend entirely on children for economic survival, childlessness can often be viewed as a social and public-health issue and not only as a medical problem.Published in Reproductive BioMedicine Online, American and Belgian researchers outline the first results of a prospective study performed in Genk, Belgium. They report the results of a study in which a simple, reduced cost IVF culture system was used to replace more expensive incubator systems. The new method does not alter the need for surgical egg retrieval and embryo transfer, laboratory staffing and egg or embryo freezing.In a short prospective clinical trial, successful outcomes were obtained with the simplified method at levels that compare favorably with those reported by typical IVF programs in developed countries.Sixteen healthy babies have now been born using the new method. It is expected that laboratory costs may be reduced, however the extent of this remains to be determined.The simplified IVF method has the potential to open up a new era in the history of IVF and may not only change the accessibility of IVF in resource-poor countries, but also have implications for accessibility in developed countries too, where IVF is increasingly becoming available only to affluent couples. The trend in IVF has been to introduce new and complex instruments and tests. It is hoped that the new embryo culture method may change this philosophy.This study is part of the Walking Egg Project (www.thewalkingegg.com), an international project that aims to raise awareness surrounding involuntary childlessness in resource-poor countries. The project also aims to make infertility care in all its aspects, including assisted reproductive technologies, available and accessible for a larger proportion of the world population in both developing and developed countries.Story Source:The above story is based on materials provided by Elsevier. Note: Materials may be edited for content and length.

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‘Envy-free’ algorithm developed for settling disputes from divorce to inheritance

Whether it’s season tickets to Green Bay Packers’ games or silver place settings, divorce and inheritance have bred protracted disputes over the assignment of belongings. But, now, a trio of researchers has found a method for resolving such conflicts in an envy-free way.The paper, authored by New York University’s Steven Brams, Wilfrid Laurier University’s D. Marc Kilgour, and the University of Graz’s Christian Klamler and published this month in Notices of the American Mathematical Society, outlines a pair of algorithms that are based on the self-identified priorities of the parties.”The problem of fairly dividing a divisible good, such as cake or land, between two people probably goes back to the dawn of civilization,” write the authors.They point out that dividing indivisible goods, like the marital property in a divorce, is harder, adding, “Unlike more demanding fair-division algorithms, which ask players to give more detailed information or make more difficult comparisons, our algorithms are easy to apply and, therefore, eminently practicable.”Their work is based on principles of fairness. In the first algorithm, the two players make simultaneous or independent choices in sequence, starting with their most-preferred items and progressively descending to less-preferred items that have not already been allocated. In the second, the players submit their complete preference rankings in advance to a referee or arbitrator.This algorithm is “envy free” because each party prefers each of its items to a corresponding item of the other party. A potential conflict arises, of course, when the two parties desire the same item at the same time. For example, assume players A and B rank four items, going from left to right, as follows:A: 1 2 3 4 B: 2 3 4 1Now, if we give A item 1 and B item 2 (their most preferred), the next unallocated item on both their lists is item 3. Who should get it? The algorithm gives it to A and gives item 4 to B, which is an envy-free allocation because each player prefers its items to the other player’s:A prefers item 1 to 2 and item 3 to 4 B prefers item 2 to 3 and item 4 to 1Not only does each party prefer its pair of items to the other’s, but there is no alternative allocation that both parties would prefer, which makes it efficient. Although such an efficient, envy-free allocation is not always possible, the algorithm finds one that comes as close to this ideal as can be achieved.Story Source:The above story is based on materials provided by New York University. …

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Incoming comet ISON appears intact to NASA’s hubble

Oct. 17, 2013 — A new image of the sunward plunging Comet ISON suggests that the comet is intact despite some predictions that the fragile icy nucleus might disintegrate as the Sun warms it. The comet will pass closest to the Sun on November 28.Share This:In this NASA Hubble Space Telescope image taken on October 9, the comet’s solid nucleus is unresolved because it is so small. If the nucleus broke apart then Hubble would have likely seen evidence for multiple fragments.Moreover, the coma or head surrounding the comet’s nucleus is symmetric and smooth. This would probably not be the case if clusters of smaller fragments were flying along. What’s more, a polar jet of dust first seen in Hubble images taken in April is no longer visible and may have turned off.This color composite image was assembled using two filters. The comet’s coma appears cyan, a greenish-blue color due to gas, while the tail is reddish due to dust streaming off the nucleus. The tail forms as dust particles are pushed away from the nucleus by the pressure of sunlight. The comet was inside Mars’ orbit and 177 million miles from Earth when photographed. Comet ISON is predicted to make its closest approach to Earth on December 26, at a distance of 39.9 million miles.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 Space Telescope Science Institute (STScI). …

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How tiny organisms make a big impact on clean water

Oct. 15, 2013 — Nearly every body of water, from a puddle or a pond to a vast ocean, contains microscopic organisms that live attached to rocks, plants, and animals. These so-called sessile suspension feeders are critical to aquatic ecosystems and play an important role in cleaning up environmental contaminants by consuming bacteria. A study published by Cell Press on October 15 in the Biophysical Journal reveals that by actively changing the angle of their bodies relative to the surfaces, these feeders overcome the physical constraints presented by underwater surfaces, maximize their access to fresh, nutrient-rich water, and filter the surrounding water.Share This:”Our findings will allow scientists to make better estimates about how much water each of these tiny organisms can filter and clean, which can help us to make better estimates about how quickly bodies of water can recover after contamination caused by oil spills and sewage leaks,” says lead study author Rachel Pepper of the University of California, Berkeley.Microscopic sessile suspension feeders, which are made up of only one or a few cells, use hair-like or whip-like appendages to draw nutrient-rich fluid toward their bodies, filtering up to 25% of the seawater in coastal areas each day. Because they live attached to surfaces, they potentially face several challenges while they feed. For example, currents encounter resistance and slow down when they flow across these surfaces, interfering with the ability of suspension feeders to efficiently extract nutrients. The way that currents interact with surfaces may also cause water to recirculate around suspension feeders after the nutrients have been consumed.To examine how the tiny organisms overcome these challenges, Pepper and her team used a combination of experiments and calculations. They observed that a protozoan called Vorticella convallaria actively changes its body orientation relative to the surface to which it is attached, in contrast to previous models, which assumed that sessile suspension feeders always feed at a perpendicular angle. The new model revealed that feeding at a parallel or other non-perpendicular angle substantially increases the amount of nutrients the organisms can extract from their surroundings by reducing both fluid resistance and the recirculation of nutrient-depleted water.”We know very little about the processes microbes use to remove and recycle contaminants,” Pepper says. “Our study shows that fluid flows at the scale of individual small organisms, when aggregated, can be important contributors to maintaining the quality of natural waters.”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 Cell Press, via EurekAlert!, a service of AAAS. …

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How research ecologists can benefit urban design projects

Oct. 11, 2013 — Ecologists conducting field research usually study areas that they hope won’t be disturbed for a while. But in an article published in the November issue of BioScience, “Mapping the Design Process for Urban Ecology Researchers,” Alexander Felson of Yale University and his colleagues describe how ecologists can perform hypothesis-driven research from the start of design through the construction and monitoring phases of major urban projects.Share This:The results from such “designed experiments” can provide site-specific data that improve how the projects are conceptualized, built and subsequently monitored.In light of the billions of dollars spent each year on urban construction, Felson and his coauthors see important potential in improving its environmental benefits and minimizing its harms. Currently, environmental consultants advising on the designs for such projects usually rely on available knowledge and principles that were originally tested in natural settings.The authors note that researchers must understand contracting, then work to establish their credentials with project designers and their clients to be awarded a recognized role in a construction project. Felson and colleagues therefore provide maps of the process for researchers’ benefit. Ecologist researchers should try to involve themselves at the earliest stages, even before designing starts, and be ready to accept priorities that are alien to typical research settings.Felson and his colleagues provide two case studies to show how it can be done.One is the construction of a “green” parking lot and associated water gardens at an environmental center in New Jersey, the other a major tree-planting project in New York City. In both cases, researchers involved themselves during the contract phases of the projects by establishing the likely value of answering research questions. Although they had to make some compromises with commercial and political imperatives, the designed experiments undertaken allowed researchers to influence the design and implementation and improve environmental benefits, while also establishing viable long-term research sites in highly urbanized areas.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 American Institute of Biological Sciences, via EurekAlert!, a service of AAAS. Note: Materials may be edited for content and length. For further information, please contact the source cited above. …

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The eyes have it: How organic mercury can interfere with vision

Sep. 11, 2013 — More than one billion people worldwide rely on fish as an important source of animal protein, states the United Nations Food and Agriculture Organization. And while fish provide slightly over 7 per cent of animal protein in North America, in Asia they represent about 23 per cent of consumption.Humans consume low levels of methylmercury by eating fish and seafood. Methylmercury compounds specifically target the central nervous system, and among the many effects of their exposure are visual disturbances, which were previously thought to be solely due to methylmercury-induced damage to the brain visual cortex. However, after combining powerful synchrotron X-rays and methylmercury-poisoned zebrafish larvae, scientists have found that methylmercury may also directly affect vision by accumulating in the retinal photoreceptors, i.e. the cells that respond to light in our eyes.Dr. Gosia Korbas, BioXAS staff scientist at the Canadian Light Source (CLS), says the results of this experiment show quite clearly that methylmercury localizes in the part of the photoreceptor cell called the outer segment, where the visual pigments that absorb light reside.”There are many reports of people affected by methylmercury claiming a constricted field of vision or abnormal colour vision,” said Korbas. “Now we know that one of the reasons for their symptoms may be that methylmercury directly targets photoreceptors in the retina.”Korbas and the team of researchers from the University of Saskatchewan including Profs. Graham George, Patrick Krone and Ingrid Pickering conducted their experiments using three X-ray fluorescence imaging beamlines (2-ID-D, 2-ID-E and 20-ID-B) at the Advanced Photon Source, Argonne National Laboratory near Chicago, US, as well as the scanning X-ray transmission beamline (STXM) at the Canadian Light Source in Saskatoon, Canada.After exposing zebrafish larvae to methylmercury chloride in water, the team was able to obtain high-resolution maps of elemental distributions, and pinpoint the localization of mercury in the outer segments of photoreceptor cells in both the retina and pineal gland of zebrafish specimens. The results of the research were published in ACS Chemical Biology under the title “Methylmercury Targets Photoreceptor Outer Segments.”Korbas said zebrafish are an excellent model for investigating the mechanisms of heavy metal toxicity in developing vertebrates. …

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