Experiences at every stage of life contribute to cognitive abilities in old age

Early life experiences, such as childhood socioeconomic status and literacy, may have greater influence on the risk of cognitive impairment late in life than such demographic characteristics as race and ethnicity, a large study by researchers with the UC Davis Alzheimer’s Disease Center and the University of Victoria, Canada, has found.”Declining cognitive function in older adults is a major personal and public health concern,” said Bruce Reed professor of neurology and associate director of the UC Davis Alzheimer’s Disease Center.”But not all people lose cognitive function, and understanding the remarkable variability in cognitive trajectories as people age is of critical importance for prevention, treatment and planning to promote successful cognitive aging and minimize problems associated with cognitive decline.”The study, “Life Experiences and Demographic Influences on Cognitive Function in Older Adults,” is published online in Neuropsychology, a journal of the American Psychological Association. It is one of the first comprehensive examinations of the multiple influences of varied demographic factors early in life and their relationship to cognitive aging.The research was conducted in a group of over 300 diverse men and women who spoke either English or Spanish. They were recruited from senior citizen social, recreational and residential centers, as well as churches and health-care settings. At the time of recruitment, all study participants were 60 or older, and had no major psychiatric illnesses or life threatening medical illnesses. Participants were Caucasian, African-American or Hispanic.The extensive testing included multidisciplinary diagnostic evaluations through the UC Davis Alzheimer’s Disease Center in either English or Spanish, which permitted comparisons across a diverse cohort of participants.Consistent with previous research, the study found that non-Latino Caucasians scored 20 to 25 percent higher on tests of semantic memory (general knowledge) and 13 to 15 percent higher on tests of executive functioning compared to the other ethnic groups. However, ethnic differences in executive functioning disappeared and differences in semantic memory were reduced by 20 to 30 percent when group differences in childhood socioeconomic status, adult literacy and extent of physical activity during adulthood were considered.”This study is unusual in that it examines how many different life experiences affect cognitive decline in late life,” said Dan Mungas, professor of neurology and associate director of the UC Davis Alzheimer’s Disease Research Center.”It shows that variables like ethnicity and years of education that influence cognitive test scores in a single evaluation are not associated with rate of cognitive decline, but that specific life experiences like level of reading attainment and intellectually stimulating activities are predictive of the rate of late-life cognitive decline. This suggests that intellectual stimulation throughout the life span can reduce cognitive decline in old age.”Regardless of ethnicity, advanced age and apolipoprotein-E (APOE genotype) were associated with increased cognitive decline over an average of four years that participants were followed. APOE is the largest known genetic risk factor for late-onset Alzheimer’s. Less decline was experienced by persons who reported more engagement in recreational activities in late life and who maintained their levels of activity engagement from middle age to old age. Single-word reading — the ability to decode a word on sight, which often is considered an indication of quality of educational experience — was also associated with less cognitive decline, a finding that was true for both English and Spanish readers, irrespective of their race or ethnicity. …

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Dynamics behind Arctic ecosystems revealed

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

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Strictly limiting hours surgical residents can work has not improved patient safety

Strictly limiting the number of hours surgical residents can work has not improved patient outcomes but may have increased complications for some patients and led to higher failure rates on certification exams, a research paper concludes.Traditionally, doctors in the residency phase of their training spent very long hours in a hospital — often around-the-clock — so they could see a wide variety and high volume of patients. In the last 10 years, health authorities started limiting those hours in the hopes of improving patient safety and the education and well-being of doctors.In 2003, the Accreditation Council for Graduate Medical Education in the United States limited residents’ hours to 80 per week. In 2011, the council prohibited first-year residents from working 24 shifts.In Canada, on-call shifts were limited to 16 hours in Quebec after a provincial arbitrator ruled that in 2011 that a 24-hour on-call shift posed a danger to residents’ health and violated the Charter of Rights. Last year a National Steering Committee on Resident Duty Hours said the status quo was unacceptable and that shifts of 24 hours or longer without sleep should be avoided. It urged all provinces and health care institutions to develop comprehensive strategies to minimize fatigue and fatigue-related risks during residency.Dr. Najma Ahmad, a trauma surgeon at St. Michael’s Hospital who was a member of the national group, published a paper today in the Annals of Surgery that found the too-restricted hours may work for some residents, but not for surgical residents.”A one-size fits all approach to resident duty hours may not be appropriate for all specialties,” said Dr. Ahmed, noting that the American College of Surgeons Division of education has stated that mastery in surgery requires “extensive and immersive experiences.”She said the emphasis should be on reducing the amount of non-educational work residents do and to find ways to manage fatigue such as making sure they get enough uninterrupted sleep. Dr. Ahmed, who is also director of the University of Toronto’s General Surgery Program, conducted a meta-analysis of 135 articles on the impact of resident duty hours on clinical and educational outcomes in surgery.”In surgery, recent changes in hours for residents are not consistently associated with improved resident well-being and may have negative impacts on patient outcomes and performance on certification exams,” she said.Dr. …

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Preventing Head Blight in Barley, Wheat: Biochemical Pathways Hold Key to Resistance

Pale, shriveled heads of grain spell trouble for wheat and barley farmers — they’re the telltale signs of fusarium head blight. The fungal disease, commonly known as scab, not only dramatically shrinks yields but produces toxins that make the grain dangerous for human or animal consumption.From 1991 to 1996, head blight caused $2.6 billion in losses to the U.S. wheat crop. At its peak, the fungus destroyed the entire malting barley crop in the Red River and Ohio River Valleys, according to molecular biologist Yang Yen, an Agricultural Experiment Station researcher and professor at South Dakota State University.Two decades later the U.S. Department of Agriculture still ranks head blight as “the worst plant disease to hit the U.S. since the rust epidemics in the 1950s.” Wheat and barley farmers have lost more than $3 billion since 1990 from blight outbreaks.Despite major research funding — including the U.S. Wheat and Barley Scab Initiative, scientists admit that efforts to control this devastating disease have met with limited success.”This is an extraordinary disease that requires extraordinary means to combat it,” says Yen, who began working on head blight in 1997.Using advanced genetic and molecular technologies, Yen has begun tracing the biochemical pathways that make wheat susceptible or resistant to head blight. Three graduate students and two postdoctoral scientists have worked on this research over the last 16 years.Multiple hosts and pathogensHead blight can be caused by multiple pathogens, and these pathogens can attack multiple hosts including grasses and corn, Yen explains. This makes the disease tougher to combat.Researchers are working to develop resistant types of grain, alter tillage practices and apply fungicides to fight the disease.”This disease is not new,” Yen says. It was first reported in England in 1884 and in North America in 1890. …

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Deep ocean current may slow due to climate change

Far beneath the surface of the ocean, deep currents act as conveyer belts, channeling heat, carbon, oxygen and nutrients around the globe.A new study by the University of Pennsylvania’s Irina Marinov and Raffaele Bernardello and colleagues from McGill University has found that recent climate change may be acting to slow down one of these conveyer belts, with potentially serious consequences for the future of the planet’s climate.”Our observations are showing us that there is less formation of these deep waters near Antarctica,” Marinov said. “This is worrisome because, if this is the case, we’re likely going to see less uptake of human produced, or anthropogenic, heat and carbon dioxide by the ocean, making this a positive feedback loop for climate change.”Marinov is an assistant professor in Penn’s School of Arts and Sciences’ Department of Earth and Environmental Science, while Bernardello was a postdoctoral investigator in the same department and has just moved to the National Oceanography Centre in the United Kingdom. They collaborated with Casimir de Lavergne, Jaime B. Palter and Eric D. Galbraith of McGill University on the study, which was published in Nature Climate Change.Oceanographers have noticed that Antarctic Bottom Waters, a massive current of cold, salty and dense water that flows 2,000 meters under the ocean’s surface from near the Antarctic coast toward the equator has been shrinking in recent decades. This is cause for concern, as the current is believed to “hide” heat and carbon from the atmosphere. The Southern Ocean takes up approximately 60 percent of the anthropogenic heat produced on Earth and 40 to 50 percent of the anthropogenic carbon dioxide.”The Southern Ocean is emerging as being very, very important for regulating climate,” Marinov said.Along with colleagues, Marinov used models to discern whether the shrinking of the Antarctic Bottom Waters could be attributed to anthropogenic climate change.They looked to an unusual phenomenon that had been observed from satellite images taken between 1974 and 1976. The images revealed a large ice-free area within the Weddell Sea. Called a polynya, this opening in the sea ice forms when warm water of North Atlantic origin is pushed up toward the Southern Ocean’s surface. In a separate process, brine released during the sea-ice formation process produces a reservoir of cold, salty waters at the surface of the Weddell Sea. …

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Canadian drinking-age laws have significant effect on deaths among young males

A recent study by a University of Northern British Columbia-based scientist associated with the UBC Faculty of Medicine and UNBC’s Northern Medical Program demonstrates that Canada’s drinking-age laws have a significant effect on youth mortality.The study was published in the international journal Drug and Alcohol Dependence. In it, Dr. Russell Callaghan writes that when compared to Canadian males slightly younger than the minimum legal drinking age, young men who are just older than the drinking age have significant and abrupt increases in mortality, especially from injuries and motor vehicle accidents.”This evidence demonstrates that drinking-age legislation has a significant effect on reducing mortality among youth, especially young males,” says Dr. Callaghan.Currently, the minimum legal drinking age is 18 years of age in Alberta, Manitoba, and Qubec, and 19 years in the rest of the country. Using national Canadian death data from 1980 to 2009, researchers examined the causes of deaths of individuals who died between 16 and 22 years of age. They found that immediately following the minimum legal drinking age, male deaths due to injuries rose sharply by 10 to 16 per cent, and male deaths due to motor vehicle accidents increased suddenly by 13 to 15 per cent.Increases in mortality appeared immediately following the legislated drinking age for 18-year-old females, but these jumps were relatively small.According to the research, increasing the drinking age to 19 years of age in Alberta, Manitoba, and Qubec would prevent seven deaths of 18-year-old men each year. Raising the drinking age to 21 years across the country would prevent 32 annual deaths of male youth 18 to 20 years of age.”Many provinces, including British Columbia, are undertaking alcohol-policy reforms,” adds Dr. Callaghan. “Our research shows that there are substantial social harms associated with youth drinking. These adverse consequences need to be carefully considered when we develop new provincial alcohol policies. …

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Land cover change over five years across North America revealed

A new set of maps featured in the CEC’s North American Environmental Atlas depicts land cover changes in North America’s forests, prairies, deserts and cities, using satellite images from 2005 and 2010. These changes can be attributed to forest fires, insect infestation, urban sprawl and other natural or human-caused events. Produced by the North American Land Change Monitoring System (NALCMS), a trinational collaborative effort facilitated by the CEC, these maps and accompanying data can be used to address issues such as climate change, carbon sequestration, biodiversity loss, and changes in ecosystem structure and function.This project, which seeks to address land cover change at a North American scale, was initiated at the 2006 Land Cover Summit, in Washington, DC. Since then, specialists from government agencies in Canada, Mexico and the United States have worked together to harmonize their land cover classification systems into 19 classes that provide a uniform view of the continent at a consistent 250-meter scale.To view examples of significant land cover changes in British Colombia, California, and Cancun, slide the green bars on the maps, found at: www.cec.org/nalcms.To view the full 2005-2010 land cover change map, visit www.cec.org/atlas and click on “Terrestrial Ecosystems” on the left. Under “Land Cover,” click on the plus sign next to “2005-2010 land cover change” to add the map layer to North America. Then zoom in and take a look at all the purple patches — these are the areas of North America where land cover has changed over the five-year period.North American Land Change Monitoring SystemNALCMS is a joint project between Natural Resources Canada/Canada Centre for Mapping and Earth Observation (NRCan/CCMEO), the United States Geological Survey (USGS), and three Mexican organizations: the National Institute of Statistics and Geography (Instituto Nacional de Estadstica y Geografa — Inegi), the National Commission for the Knowledge and Use of Biodiversity (Comisin Nacional para el Conocimiento y Uso de la Biodiversidad — Conabio), and the National Forestry Commission of Mexico (Comisin Nacional Forestal — Conafor), supported by the Commission for Environmental Cooperation (CEC).The North American Environmental AtlasThe North American Environmental Atlas brings together maps, data and interactive map layers that can be used to identify priority areas to conserve biodiversity, track cross-border transfers of pollutants, monitor CO2 emissions across major transportation routes and predict the spread of invasive species. Land Cover 2010 and Land Cover Change 2005-2010 are the latest in a series of maps that harmonize geographic information across North America’s political boundaries to depict significant environmental issues at a continental scale.Story Source:The above story is based on materials provided by Commission for Environmental Cooperation. Note: Materials may be edited for content and length.

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Water-rich gem points to vast ‘oceans’ beneath Earth’s surface, study suggests

A University of Alberta diamond scientist has found the first terrestrial sample of a water-rich gem that yields new evidence about the existence of large volumes of water deep within Earth.An international team of scientists led by Graham Pearson, Canada Excellence Research Chair in Arctic Resources at the U of A, has discovered the first-ever sample of a mineral called ringwoodite. Analysis of the mineral shows it contains a significant amount of water — 1.5 per cent of its weight — a finding that confirms scientific theories about vast volumes of water trapped 410 to 660 kilometres beneath Earth’s surface, between the upper and lower mantle.”This sample really provides extremely strong confirmation that there are local wet spots deep in the Earth in this area,” said Pearson, a professor in the Faculty of Science, whose findings were published March 13 in Nature. “That particular zone in the Earth, the transition zone, might have as much water as all the world’s oceans put together.”Ringwoodite is a form of the mineral peridot, believed to exist in large quantities under high pressures in the transition zone. Ringwoodite has been found in meteorites but, until now, no terrestrial sample has ever been unearthed because scientists haven’t been able to conduct fieldwork at extreme depths.Pearson’s sample was found in 2008 in the Juina area of Mato Grosso, Brazil, where artisan miners unearthed the host diamond from shallow river gravels. The diamond had been brought to the Earth’s surface by a volcanic rock known as kimberlite — the most deeply derived of all volcanic rocks.The discovery that almost wasn’tPearson said the discovery was almost accidental in that his team had been looking for another mineral when they purchased a three-millimetre-wide, dirty-looking, commercially worthless brown diamond. The ringwoodite itself is invisible to the naked eye, buried beneath the surface, so it was fortunate that it was found by Pearson’s graduate student, John McNeill, in 2009.”It’s so small, this inclusion, it’s extremely difficult to find, never mind work on,” Pearson said, “so it was a bit of a piece of luck, this discovery, as are many scientific discoveries.”The sample underwent years of analysis using Raman and infrared spectroscopy and X-ray diffraction before it was officially confirmed as ringwoodite. The critical water measurements were performed at Pearson’s Arctic Resources Geochemistry Laboratory at the U of A. The laboratory forms part of the world-renowned Canadian Centre for Isotopic Microanalysis, also home to the world’s largest academic diamond research group.The study is a great example of a modern international collaboration with some of the top leaders from various fields, including the Geoscience Institute at Goethe University, University of Padova, Durham University, University of Vienna, Trigon GeoServices and Ghent University.For Pearson, one of the world’s leading authorities in the study of deep Earth diamond host rocks, the discovery ranks among the most significant of his career, confirming about 50 years of theoretical and experimental work by geophysicists, seismologists and other scientists trying to understand the makeup of the Earth’s interior.Scientists have been deeply divided about the composition of the transition zone and whether it is full of water or desert-dry. Knowing water exists beneath the crust has implications for the study of volcanism and plate tectonics, affecting how rock melts, cools and shifts below the crust.”One of the reasons the Earth is such a dynamic planet is the presence of some water in its interior,” Pearson said. “Water changes everything about the way a planet works.”Story Source:The above story is based on materials provided by University of Alberta. …

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Can the blind ‘hear; colors, shapes? Yes, show researchers

What if you could “hear” colors? Or shapes? These features are normally perceived visually, but using sensory substitution devices (SSDs) they can now be conveyed to the brain noninvasively through other senses.At the Center for Human Perception and Cognition, headed by Prof. Amir Amedi of the Edmond and Lily Safra Center for Brain Sciences and the Institute for Medical Research Israel-Canada at the Hebrew University of Jerusalem Faculty of Medicine, the blind and visually impaired are being offered tools, via training with SSDs, to receive environmental visual information and interact with it in ways otherwise unimaginable. The work of Prof. Amedi and his colleagues is patented by Yissum, the Hebrew University’s Technology Transfer CompanySSDs are non-invasive sensory aids that provide visual information to the blind via their existing senses. For example, using a visual-to-auditory SSD in a clinical or everyday setting, users wear a miniature camera connected to a small computer (or smart phone) and stereo headphones. The images are converted into “soundscapes,” using a predictable algorithm, allowing the user to listen to and then interpret the visual information coming from the camera.With the EyeMusic SSD (available free at the Apple App store at http://tinyurl.com/oe8d4p4), one hears pleasant musical notes to convey information about colors, shapes and location of objects in the world.Using this SSD equipment and a unique training program, the blind are able to achieve various complex. visual-linked abilities. In recent articles in Restorative Neurology and Neuroscience and Scientific Reports, blind and blindfolded-sighted users of the EyeMusic were shown to correctly perceive and interact with objects, such as recognizing different shapes and colors or reaching for a beverage (A live demonstration can be seen at http://youtu.be/r6bz1pOEJWg).In another use of EyeMusic, it was shown that other fast and accurate movements can be guided by the EyeMusic and visuo-motor learning. …

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Macro-portrait of future bird and wetland scenarios under climate change

Using a mountain of satellite photographic data and decades of waterfowl counts, a Texas Tech University biologist said she and others have found a correlation with the amount of waterfowl and the amount of wetlands available across the plains from Canada to Texas.More wetlands meaning more waterfowl may sound like a no-brainer, but researchers were able to land at conclusion using macrosystems ecology said Nancy McIntyre, a professor of biological sciences and curator of birds at the Natural Science Research Laboratory.The research appeared in a special edition of the peer-reviewed journal, Frontiers in Ecology and the Environment, dedicated to macrosystems ecology.”The novelty of what we’re doing is in taking the weather data from the past to be able to say certain types of precipitation conditions led to X amount of available wetlands, which was associated with Y number of birds,” McIntyre said. “If future climate scenarios say we should get fewer but more extreme precipitation events, then we can estimate how many wetlands and birds will be around in the future, so long as no more wetlands are converted into farm use or turned into neighborhoods. That’s work in progress. It sounds straightforward, but it has never been done because of the complexity and the massive amount of data used here.”Macrosystems ecology is a new and emerging science using large amounts of information that are analyzed by faster and smarter computers to not only create greater understanding of how habitats interact, but also make better predictions about how these systems may react in the face of global climate change, she said.”A change in the number of wetlands available can cascade in to the variety and numbers of birds, as well as amphibians, dragonflies and a number of other animals,” McIntyre said. “In the United States, we’ve lost about 50 percent of the nation’s original wetlands in the past 200 years. The losses are particularly bad in the Great Plains, where about 98 percent of the wetlands have disappeared since 1986. With climate change on the horizon, we’re trying to understand how these wetlands and the animals that use them interact.”The research was part of a $1.6 million grant from the National Science Foundation. McIntyre and others looked at freshwater wetlands across the Great Plains from the prairie potholes carved by glacial activity in the north, through the Rainwater Basin of Nebraska down to the playa lakes of the South Plains.”They call it the duck factory of the world,” McIntyre said. “Most of the ducks breed up there and overwinter down here. But there are about 300 species of regularly occurring, breeding land birds in the Great Plains, many of which use these wetlands.”Researchers studied photos from satellites that passed over the same area of land every 16 days, she said. …

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Cancer Researchers Discover Pre-Leukemic Stem Cell at Root of AML, Relapse

Cancer researchers led by stem cell scientist Dr. John Dick have discovered a pre-leukemic stem cell that may be the first step in initiating disease and also the culprit that evades therapy and triggers relapse in patients with acute myeloid leukemia (AML).The research, published online today in Nature is a significant leap in understanding the steps that a normal cell has to go through as it turns into AML, says Dr. Dick, and sets the stage to advance personalized cancer medicine by potentially identifying individuals who might benefit from targeting the pre-leukemic stem cell. AML is an aggressive blood cancer that the new research shows starts in stem cells in the bone marrow. Dr. Dick, a Senior Scientist at Princess Margaret Cancer Centre, University Health Network (UHN), and Professor in the Department of Molecular Genetics, University of Toronto, pioneered the cancer stem cell field by first identifying leukemia stem cells (1994) and colon cancer stem cells (2007).”Our discovery lays the groundwork to detect and target the pre-leukemic stem cell and thereby potentially stop the disease at a very early stage when it may be more amenable to treatment,” says Dr. Dick, who holds a Canada Research Chair in Stem Cell Biology and is also Director of the Cancer Stem Cell Program at the Ontario Institute for Cancer Research (OICR).”Now we have a potential tool for earlier diagnosis that may allow early intervention before the development of full AML. We can also monitor remission and initiate therapy to target the pre-leukemic stem cell to prevent relapse,” he says.The findings show that in about 25% of AML patients, a mutation in the gene DNMT3a causes pre-leukemic stem cells to develop that function like normal blood stem cells but grow abnormally. These cells survive chemotherapy and can be found in the bone marrow at remission, forming a reservoir of cells that may eventually acquire additional mutations, leading to relapse.The discovery of pre-leukemic stem cells came out of a large Leukemia Disease Team that Dr. Dick assembled and included oncologists who collected samples for the Princess Margaret Cancer Centre Biobank and genome scientists at the OICR who developed sophisticated targeted sequencing methodology. …

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Predicting cardiovascular events in sleep apnea

Obstructive sleep apnea (OSA) generally is associated with increased risk for cardiovascular (CV) disease. OSA is usually measured using the apnea-hypopnea index (AHI), the number of times that breathing pauses or severely slows per hour of sleep. However, sleep studies using to diagnose OSA produce a number of other measures.Whether those measures are associated with CV disease, and whether they predict CV disease as well or better than AHI, is not known. Tetyana Kendzerska (University of Toronto) and colleagues conducted a large cohort study of 10,149 participants referred for suspected OSA who underwent diagnostic polysomnography at the sleep laboratory at St Michael’s Hospital (Toronto, Canada) between 1994 and 2010. The patients were followed up through provincial health administrative data (Ontario, Canada) until May 2011 for CV disease (myocardial infarction, stroke, congestive heart failure, revascularization procedures) and death from any cause, analyzed as a composite outcome.A total of 1,172 (11.5%) of the 10,149 participants experienced the composite CV disease outcome. The researchers found that, after adjusting for potentially confounding factors, time spent with oxygen saturation < 90%, sleep time, number of awakenings, periodic leg movements, heart rate, and daytime sleepiness were all associated with the composite outcome, with the total sleep time spent with oxygen saturation below 90% being the strongest association (9 minutes vs. 0 minutes: hazard ratio=1.5, 95% confidence interval, 1.25-1.79). The size of increased relative risk ranged from 5% to 50%, after controlling for known CV risk factors. Furthermore, when the authors examined the outcomes individually, the OSA risk factors were associated with increased risk for all-cause mortality, hospitalization for congestive heart failure, and stroke, but not for acute myocardial infarction.AHI was associated with the composite outcome when analyzed by itself. However, after the other OSA-related factors were added to the model, AHI was no longer a significant predictor of the composite outcome.The authors also developed a nomogram to predict the CVD risk of individuals based on their sleep study scores. …

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Piezoelectrics and butterflies: Now scientists know more about how the materials actually work

Piezoelectrics — materials that can change mechanical stress to electricity and back again — are everywhere in modern life. Computer hard drives. Loud speakers. Medical ultrasound. Sonar. Though piezoelectrics are a widely used technology, there are major gaps in our understanding of how they work. Now researchers at the National Institute of Standards and Technology (NIST) and Canada’s Simon Fraser University believe they’ve learned why one of the main classes of these materials, known as relaxors, behaves in distinctly different ways from the rest and exhibit the largest piezoelectric effect. And the discovery comes in the shape of a butterfly.The team examined two of the most commonly used piezoelectric compounds — the ferroelectric PZT and the relaxor PMN — which look very similar on a microscopic scale. Both are crystalline materials composed of cube-shaped unit cells (the basic building blocks of all crystals) that contain one lead atom and three oxygen atoms. The essential difference is found at the centers of the cells: in PZT these are randomly occupied by either one zirconium atom or one titanium atom, both of which have the same electric charge, but in PMN one finds either niobium or manganese, which have very different electric charges. …

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Nine steps to save waterways and fisheries identified by researchers

The key to clean water and sustainable fisheries is to follow nine guiding principles of water management, says a team of Canadian biologists.Fish habitats need ecosystems that are rich in food with places to hide from predators and lay eggs, according to the framework published today in the journal Environmental Reviews.Humans have put key freshwater ecosystems at risk because of land development and the loss of the vegetation along rivers and streams, says John Richardson, a professor in the Dept. of Forest and Conservation Sciences at the University of British Columbia, one of 15 freshwater biologists who created the framework to help protect fish and ecosystems into the future.”Fish are strongly impacted when nutrients, sediments or pollutants are added to their habitat. We cannot protect fish without maintaining a healthy freshwater ecosystem,” says Richardson, who led the policy section on protecting fish habitats. Other policy sections addressed areas such as climate change and biodiversity.Connecting waterways are also critical for healthy ecosystems, says Richardson. “If fish can’t get to breeding or rearing areas because of dams, culverts, water intakes or other changes to their habitats, then the population will not survive,” he says.With more pressure on Canada’s freshwater ecosystems, Richardson and his colleagues wanted to create a framework of evidence-based principles that managers, policy makers and others could easily use in their work. “It’s a made in Canada solution, but the principles could be applied anywhere in the world,” he says.BACKGROUNDERHealthy freshwater ecosystems are shrinking and reports suggest that the animals that depend on them are becoming endangered or extinct at higher rates than marine or terrestrial species, says Richardson. Humans also depend on these ecosystems for basic resources like clean drinking water and food as well as economic activity from the natural resource sector, tourism and more.The components of a successful management plan include:Protect and restore habitats for fisheries Protect biodiversity as it enhances resilience and productivity Identify threats to ecosystem productivity Identify all contributions made by aquatic ecosystems Implement ecosystem based-management of natural resources while acknowledging the impact of humans Adopt a precautionary approach to management as we face uncertainty Embrace adaptive management — environments continue to change so research needs to be ongoing for scientific evidence-based decision making Define metrics that will indicate whether management plans are successful or failing Engage and consult with stakeholders Ensure that decision-makers have the capacity, legislation and authority to implement policies and management plans. These recommendations are based on nine principles of ecology:Acknowledge the physical and chemical limits of an ecosystem Population dynamics are at work and there needs to be a minimum number of fish for the population to survive Habitat quantity and quality are needed for fish productivity Connecting habitats is essential for movement of fish and their resources The success of freshwater species is influenced by the watershed Biodiversity enhances ecosystem resilience and productivity Global climate change affects local populations of fish Human impacts to the habitat affect future generations of fish Evolution is important to species survival Story Source:The above story is based on materials provided by University of British Columbia. Note: Materials may be edited for content and length.

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World Nations Deny Dangers of Chrysotile Asbestos

Seven nations won out against 143 others in the debate over whether chrysotile asbestos should be added to the United Nation’s Prior Informed Consent (PIC) list of hazardous substances in the Rotterdam Convention. India, Kazakhstan, Kyrgyzstan, Russia, Ukraine, Vietnam, and Zimbabwe all objected to the addition at the sixth meeting of the Rotterdam Convention which took place April 28 – May 10,2013, in Geneva Switzerland. It comes as no surprise that the countries which objected to the listing are home to a booming asbestos industry. Russia alone mines an estimated 1,000,000 tons of asbestos annually and is the supplier for half of the world’s chrysotile production.In September of 2012, Canada, which was the sole objector to the addition at the 2011 conference, announced it would no longer object to the listing. Russia, …

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Brain scans show unusual activity in retired American football players

Oct. 17, 2013 — A new study has discovered profound abnormalities in brain activity in a group of retired American football players.Although the former players in the study were not diagnosed with any neurological condition, brain imaging tests revealed unusual activity that correlated with how many times they had left the field with a head injury during their careers.Previous research has found that former American football players experience higher rates of neurodegenerative diseases such as Alzheimer’s and Parkinson’s disease. The new findings, published in Scientific Reports, suggest that players also face a risk of subtle neurological deficits that don’t show up on normal clinical tests.The study involved 13 former National Football League (NFL) professionals who believed they were suffering from neurological problems affecting their everyday lives as a consequence of their careers.The former players and 60 healthy volunteers were given a test that involved rearranging coloured balls in a series of tubes in as few steps as possible. Their brain activity was measured using functional magnetic resonance imaging (fMRI) while they did the test.The NFL group performed worse on the test than the healthy volunteers, but the difference was modest. More strikingly, the scans showed unusual patterns of brain activity in the frontal lobe. The difference between the two groups was so marked that a computer programme learned to distinguish NFL alumni and controls at close to 90 per cent accuracy based just on their frontal lobe activation patterns.”The NFL alumni showed some of the most pronounced abnormalities in brain activity that I have ever seen, and I have processed a lot of patient data sets in the past,” said Dr Adam Hampshire, lead author of the study, from the Department of Medicine at Imperial College London.The frontal lobe is responsible for executive functions: higher-order brain activity that regulates other cognitive processes. The researchers think the differences seen in this study reflect deficits in executive function that might affect the person’s ability to plan and organise their everyday lives.”The critical fact is that the level of brain abnormality correlates strongly with the measure of head impacts of great enough severity to warrant being taken out of play. This means that it is highly likely that damage caused by blows to the head accumulate towards an executive impairment in later life.”Dr Hampshire and his colleagues at the University of Western Ontario, Canada suggest that fMRI could be used to reveal potential neurological problems in American football players that aren’t picked up by standard clinical tests. Brain imaging results could be useful to retired players who are negotiating compensation for neurological problems that may be related to their careers. Players could also be scanned each season to detect problems early.The findings also highlight the inadequacy of standard cognitive tests for detecting certain types of behavioural deficit.”Researchers have put a lot of time into developing tests to pick up on executive dysfunction, but none of them work at all well. …

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Asbestos: More Prevalent Than You Think

Given the overwhelming evidence of asbestos’ harmfulness to human health and its connection to the deadly disease mesothelioma, many United States citizens are under the impression that by now, asbestos has been phased out of most domestically-produced materials. However, many people are not aware that the 1989 EPA ban on many asbestos products was successful appealed and radically altered in 1991 by the U.S. Fifth Court of Appeals.According to the EPA on this webpage, “Newspaper and magazine articles, Internet information, and currently available (but outdated) documents from the EPA and other federal agencies may contain incorrect statements about an EPA asbestos ban.” As a result, many products produced or imported for use in the U.S. construction industry may still contain asbestos.So what materials …

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Cruise Ship Injuries – Sources and Concerns

Taking a vacation on a cruise ship is a popular choice for many Americans and their families. Cruise ships offer exotic destinations, the promise of wonderful food, and a family-friendly environment that many find irresistible. How irresistible? Just look at some of the numbers. The worldwide cruising industry is incredibly large, with an estimated income of $40 billion in 2010 alone. Almost 15,000,000 Americans take a cruise every year, and each person spends an average of seven days aboard ship, spending an average of $1,800 per passenger. That means a family of four can expect to spend over $7,000 on an average cruise.Yet as popular as cruising is, there are potential downsides. Though major accidents and disasters are rare, they do happen. One of the most recent occurred in January of 2012 when the Costa Concordia sank off of Italy, resulting in the death of 32 people. But the big disasters are very rare. …

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World ocean systems undermined by climate change by 2100

Oct. 15, 2013 — An ambitious new study describes the full chain of events by which ocean biogeochemical changes triggered by humanmade greenhouse gas emissions may cascade through marine habitats and organisms, penetrating to the deep ocean and eventually influencing humans.Previous analyses have focused mainly on ocean warming and acidification, considerably underestimating the biological and social consequences of climate change. Factoring in predictable synergistic changes such as the depletion of dissolved oxygen in seawater and a decline in productivity of ocean ecosystems, the new study shows that no corner of the world ocean will be untouched by climate change by 2100.”When you look at the world ocean, there are few places that will be free of changes; most will suffer the simultaneous effects of warming, acidification, and reductions in oxygen and productivity,” said lead author Camilo Mora, assistant professor at the Department of Geography in the College of Social Sciences at the University of Hawai’i at Mānoa (UH Mānoa). “The consequences of these co-occurring changes are massive — everything from species survival, to abundance, to range size, to body size, to species richness, to ecosystem functioning are affected by changes in ocean biogeochemistry.”The human ramifications of these changes are likely to be massive and disruptive. Food chains, fishing, and tourism could all be impacted. The study shows that some 470 to 870 million of the world’s poorest people rely on the ocean for food, jobs, and revenues, and live in countries where ocean goods and services could be compromised by multiple ocean biogeochemical changes.Mora and Craig Smith with UH Mānoa’s School of Ocean and Earth Science and Technology (SOEST) worked with a 28-person international collaboration of climate modelers, biogeochemists, oceanographers, and social scientists to develop the study, which is due for publication October 15 in the scientific journal PLOS Biology.The researchers used the most recent and robust models of projected climate change developed for the Fifth Assessment Report of the Intergovernmental Panel on Climate Change (IPCC) to inform their analysis. They quantified the extent of co-occurrence of changes in temperature, pH, oxygen, and primary productivity based on two scenarios: a business-as-usual scenario wherein atmospheric CO2 concentrations could reach 900 ppm by 2100, and an alternative scenario under which concentrations only reach 550 ppm by 2100 (representing a concerted, rapid CO2 mitigation effort, beginning today).They discovered that most of the world’s ocean surface will be simultaneously impacted by varying intensities of ocean warming, acidification, oxygen depletion, or shortfalls in productivity. Only a very small fraction of the oceans, mostly in polar regions, will face the opposing effects of increases in oxygen or productivity, and nowhere will there be cooling or pH increase.”Even the seemingly positive changes at high latitudes are not necessary beneficial. Invasive species have been immigrating to these areas due to changing ocean conditions and will threaten the local species and the humans who depend on them,” said co-author Chih-Lin Wei, a postdoctoral fellow at Ocean Science Centre, Memorial University of Newfoundland, Canada.The researchers assembled global distribution maps of 32 marine habitats and biodiversity hotspots to assess their potential vulnerability to the changes. As a final step, they used available data on human dependency on ocean goods and services and social adaptability to estimate the vulnerability of coastal populations to the projected ocean biogeochemical changes.”Other studies have looked at small-scale impacts, but this is the first time that we’ve been able to look the entire world ocean and how co-occurring stressors will differentially impact the earth’s diverse habitats and people,” said co-author Andrew Thurber, a postdoctoral fellow at Oregon State University. …

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