Function found for mysterious heart disease gene

A new study from researchers at the University of Ottawa Heart Institute (UOHI), published today in Cell Reports, sheds light on a mysterious gene that likely influences cardiovascular health. After five years, UOHI researchers now know how one genetic variant works and suspect that it contributes to the development of heart disease through processes that promote chronic inflammation and cell division.Researchers at the Ruddy Canadian Cardiovascular Genetics Centre had initially identified a variant in a gene called SPG7 as a potential contributor to coronary artery disease several years ago, but its role in multiple health processes made it difficult to tease out how it affects heart disease.The gene holds instructions for producing a protein called SPG7. This protein resides in mitochondria — the small power plants of cells that produce the energy cells need to function. SPG7’s role is to help break down and recycle other damaged proteins within the mitochondria.Normally, SPG7 requires a partner protein to activate itself and start this breakdown process. But, in people who carry the genetic variant in question, SPG7 can activate itself in certain circumstances, leading to increased production of free radicals and more rapid cell division. These factors contribute to inflammation and atherosclerosis.”We think this variant would definitely heighten the state of inflammation, and we know that inflammation affects diabetes and heart disease,” said Dr. Stewart, Principal Investigator in the Ruddy Canadian Cardiovascular Genetics Centre and senior author of the study. “Interestingly, the variant also makes people more resistant to the toxic side effects of some chemotherapy drugs.”From an evolutionary perspective, this resistance could help such a genetic variant gain a stable place in the human genome. Between 13 and 15 per cent of people of European descent possess this variant.”The idea of mitochondria contributing to inflammation isn’t new,” concluded Dr. Stewart. …

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Exploding stars prove Newton’s law of gravity unchanged over cosmic time

Australian astronomers have combined all observations of supernovae ever made to determine that the strength of gravity has remained unchanged over the last nine billion years.Newton’s gravitational constant, known as G, describes the attractive force between two objects, together with the separation between them and their masses. It has been previously suggested that G could have been slowly changing over the 13.8 billion years since the Big Bang.If G has been decreasing over time, for example, this would mean that Earth’s distance to the Sun was slightly larger in the past, meaning that we would experience longer seasons now compared to much earlier points in Earth’s history.But researchers at Swinburne University of Technology in Melbourne have now analysed the light given off by 580 supernova explosions in the nearby and far Universe and have shown that the strength of gravity has not changed.”Looking back in cosmic time to find out how the laws of physics may have changed is not new” Swinburne Professor Jeremy Mould said. “But supernova cosmology now allows us to do this with gravity.”A Type 1a supernova marks the violent death of a star called a white dwarf, which is as massive as our Sun but packed into a ball the size of our Earth.Our telescopes can detect the light from this explosion and use its brightness as a ‘standard candle’ to measure distances in the Universe, a tool that helped Australian astronomer Professor Brian Schmidt in his 2011 Nobel Prize winning work, discovering the mysterious force Dark Energy.Professor Mould and his PhD student Syed Uddin at the Swinburne Centre for Astrophysics and Supercomputing and the ARC Centre of Excellence for All-sky Astrophysics (CAASTRO) assumed that these supernova explosions happen when a white dwarf reaches a critical mass or after colliding with other stars to ‘tip it over the edge’.”This critical mass depends on Newton’s gravitational constant G and allows us to monitor it over billions of years of cosmic time — instead of only decades, as was the case in previous studies,” Professor Mould said.Despite these vastly different time spans, their results agree with findings from the Lunar Laser Ranging Experiment that has been measuring the distance between Earth and the Moon since NASA’s Apollo missions in the 1960s and has been able to monitor possible variations in G at very high precision.”Our cosmological analysis complements experimental efforts to describe and constrain the laws of physics in a new way and over cosmic time.” Mr Uddin said.In their current publication, the Swinburne researchers were able to set an upper limit on the change in Newton’s gravitational constant of 1 part in 10 billion per year over the past nine billion years.The ARC Centre of Excellence for All-sky Astrophysics (CAASTRO) is a collaboration between The Australian National University, The University of Sydney, The University of Melbourne, Swinburne University of Technology, the University of Queensland, The University of Western Australia and Curtin University, the latter two participating together as the International Centre for Radio Astronomy Research. CAASTRO is funded under the Australian Research Council Centre of Excellence program, with additional funding from the seven participating universities and from the NSW State Government’s Science Leveraging Fund.The research is published this month in the Publications of the Astronomical Society of Australia.Story Source:The above story is based on materials provided by Swinburne University of Technology. Note: Materials may be edited for content and length.

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Omnivorous species are more resistant to fire effects

A study published on the journal PLOS ONE demonstrates that omnivorous species are the most resistant to fire.The main authors of the article are researchers Eduardo Mateos, from the Department of Animal Biology of the University of Barcelona (UB), and Xavier Santos, from the Research Centre in Biodiversity and Genetic Resources of the University of Porto. The article is also signed by experts Antoni Serra, from the Department of Animal Biology of UB; Teresa Saura and Ramon Vallejo, from the Department of Plant Biology of UB, and Santiago Sabat, from the Department of Ecology of UB and the Centre for Ecological Research and Forestry Applications (CREAF).The study analyses changes in composition and abundance in 274 species after the fire that happened in August 2003 in Sant Lloren del Munt i l’Obac Natural Park. It was developed within the monitoring of fauna recolonization developed in the burnt area after the fire.After the fireIt is the first time that a study compares different responses of a set of animal organisms to fire (snails, spiders, beetles, ants, grasshoppers, bugs, birds and reptiles). The study also enabled to analyse some causes that could explain species response, for instance dietary and mobility patterns.According to authors, omnivorous species are more resilient to fire probably due to their ability to adapt their dietary habits to available food resources, which vary between burnt and unburnt areas. Surprisingly, the study also demonstrates that high-mobility species — such as birds that move to unburnt areas — and low-mobility species — like snails that cannot hide and die by burning — are the ones that show more changes in composition.Professor Eduardo Mateos affirms that “postfire management practices must consider the strong relationship between animal and plant communities. If the main objective of is to maximize biodiversity, habitat management may provide mosaics to preserve heterogeneity; the study proves that this would be the best management practice.”Even if it seems to go against general opinion, results support the idea that fire may play a critical role for some threatened species, as the elimination of some species enables the appearance of certain species that can be more interesting regarding conservation. This would be the case of snail Xerocrassa montserratensis and Red-legged Partridge Alectoris rufa, two interesting species which appeared after the fire in the area.Other researchers and technicians also collaborated in the study. They belong to several institutions such as the Autonomous University of Barcelona, the University of Girona, the Centre for Ecological Research and Forestry Applications (CREAF), the Forest Sciences Centre of Catalonia (CTFC), the Natural History Museum of Barcelona, the Estacin Experimental de les Zonas ridas, the Mediterranean Centre for Environmental Studies (CEAM), the Oficina Tcnica de Parcs Naturals of the Barcelona Provincial Council and the Directorate General for the Environment and Biodiversity of the Goverment of Catalonia.Story Source:The above story is based on materials provided by Universidad de Barcelona. Note: Materials may be edited for content and length.

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How Earth might have looked: How a failed Saharan Atlantic Ocean rift zone sculped Africa’s margin

Break-up of the supercontinent Gondwana about 130 Million years ago could have lead to a completely different shape of the African and South American continent with an ocean south of today’s Sahara desert, as geoscientists from the University of Sydney and the GFZ German Research Centre for Geosciences have shown through the use of sophisticated plate tectonic and three-dimensional numerical modelling.The study highlights the importance of rift orientation relative to extension direction as key factor deciding whether an ocean basin opens or an aborted rift basin forms in the continental interior.For hundreds of millions of years, the southern continents of South America, Africa, Antarctica, Australia, and India were united in the supercontinent Gondwana. While the causes for Gondwana’s fragmentation are still debated, it is clear that the supercontinent first split along along the East African coast in a western and eastern part before separation of South America from Africa took place. Today’s continental margins along the South Atlantic ocean and the subsurface graben structure of the West African Rift system in the African continent, extending from Nigeria northwards to Libya, provide key insights on the processes that shaped present-day Africa and South America.Christian Heine (University of Sydney) and Sascha Brune (GFZ) investigated why the South Atlantic part of this giant rift system evolved into an ocean basin, whereas its northern part along the West African Rift became stuck.”Extension along the so-called South Atlantic and West African rift systems was about to split the African-South American part of Gondwana North-South into nearly equal halves, generating a South Atlantic and a Saharan Atlantic Ocean,” geoscientist Sascha Brune explains. “In a dramatic plate tectonic twist, however, a competing rift along the present-day Equatorial Atlantic margins, won over the West African rift, causing it to become extinct, avoiding the break-up of the African continent and the formation of a Saharan Atlantic ocean.”The complex numerical models provide a strikingly simple explanation: the larger the angle between rift trend and extensional direction, the more force is required to maintain a rift system. The West African rift featured a nearly orthogonal orientation with respect to westward extension which required distinctly more force than its ultimately successful Equatorial Atlantic opponent.Story Source:The above story is based on materials provided by Helmholtz Centre Potsdam – GFZ German Research Centre for Geosciences. Note: Materials may be edited for content and length.

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Stream of stars in Andromeda satellite galaxy shows cosmic collision

The Andromeda Galaxy is surrounded by a swarm of small satellite galaxies. Researchers from the Niels Bohr Institute, among others, have detected a stream of stars in one of the Andromeda Galaxy’s outer satellite galaxies, a dwarf galaxy called Andromeda II. The movement of the stars tells us that what we are observing is the remnant of a merger between two dwarf galaxies. Mergers between galaxies of such low mass has not been observed before. The results are published in the scientific journal, Nature.The galaxies in the early universe started off small and the theory of the astronomers is that the baby galaxies gradually grew larger and more massive by constantly colliding with neighbouring galaxies to form new, larger galaxies. Large, massive galaxies constantly attract smaller galaxies due to gravity and they eventually merge together and grow even larger.But not all of the small galaxies are being ‘eaten’ by the large galaxies. Some of them remain in an orbit around the large galaxy. The largest galaxy in our cosmic neighborhood is the Andromeda Galaxy, which is about 2.3 million light years away. Like our own galaxy, the Milky Way, Andromeda is a large spiral galaxy.Swarm of small galaxiesAndromeda is surrounded by a swarm of small galaxies — astronomers have counted more than 20. They have names like Andromeda I, II, III, IV…etc. …

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Team sport compensates for estrogen loss

When women enter menopause, their estrogen levels taper. This increases their risk of cardiovascular disease. New research from University of Copenhagen shows that interval-based team sport can make up for this estrogen loss as it improves their conditions, reduces blood pressure and thereby protects the cardiovascular system.While aging and an array of physical transformations go hand in hand for all, menopause has a significant influence on physical changes in women.Estrogen, the primary female sex hormone, is an important guardian of the female vascular system. Thus, as estrogen levels fall during menopause, the risks of increased blood pressure and development of cardiovascular disease increases.A new study by the University of Copenhagen’s Centre for Team Sport and Health documents and addresses the issue.Changes to the cardiovascular system occur soon after menopause”Results demonstrate that blood pressure among post-menopausal women is 10% higher immediately after menopause than in similarly-aged, pre-menopausal women. They also had higher levels of an early marker for arteriosclerosis,” explains postdoc Michael Nyberg.The new aspect of this study is that researchers have investigated the effects of estrogen in women of the same age, both before and after menopause. Previous studies didn’t look at similarly aged pre- and post-menopausal women. Instead, they investigated women with 15-20 year gaps in age. Therefore, they were unable to determine whether changes were due to age or estrogen loss.Results of the recent study have now been published in the journal, The American Journal of Physiology.Floorball prevents cardiovascular disease among womenIn a bid to prevent increased risk of cardiovascular disease, the study examined the effect of 12-week floorball training among post-menopausal women. The results were clear.”Following just 12 weeks of twice weekly practices, the women’s conditions had improved and their blood pressure was reduced by 4 mmHg, which correlates with a 40% lower risk of stroke,” explains Professor and Centre Director Jens Bangsbo.Continuing, Bangsbo asserts that, “Furthermore, there was a positive development in relation to levels of substances vital to blood vessel function, including a 20% decrease in markers associated with arteriosclerosis.””The results demonstrate that team sports that include interval exercise are a fantastic opportunity for hormone treatment, in relation to estrogen, because one can avoid an array of undesirable side-effects,” according to postdoc, Michael Nyberg.Team sport — fun as well as healthy”Another advantage of a team sport like floorball is that participants have fun. That’s important, because when a person is engaged in a team sport, they aren’t preoccupied with the otherwise intense exercise in which they are engaged. …

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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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Fish living near the equator will not thrive in the warmer oceans of the future

According to an international team of researchers, the rapid pace of climate change is threatening the future presence of fish near the equator.”Our studies found that one species of fish could not even survive in water just three degrees Celsius warmer than what it lives in now,” says the lead author of the study, Dr Jodie Rummer from the ARC Centre of Excellence for Coral Reef Studies (Coral CoE) at James Cook University.Dr Rummer and her colleagues studied six common species of fish living on coral reefs near the equator. She says many species in this region only experience a very narrow range of temperatures over their entire lives, and so are likely adapted to perform best at those temperatures.This means climate change places equatorial marine species most at risk, as oceans are projected to warm by two to three degrees Celsius by the end of this century.”Such an increase in warming leads to a loss of performance,” Dr Rummer explains. “Already, we found four species of fish are living at or above the temperatures at which they function best.”The team measured the rates at which fish use oxygen, the fuel for metabolism, across different temperatures — at rest and during maximal performance. According to the results, at warmer temperatures fish lose scope for performance. In the wild, this would limit activities crucial to survival, such as evading predators, finding food, and generating sufficient energy to breed.Because many of Earth’s equatorial populations are now living close to their thermal limits, there are dire consequences ahead if these fish cannot adapt to the pace at which oceans are warming.Dr Rummer suggests there will be declines in fish populations as species may move away from the equator to find refuge in areas with more forgiving temperatures.”This will have a substantial impact on the human societies that depend on these fish,” she says.A concentration of developing countries lies in the equatorial zone, where fish are crucial to the livelihoods and survival of millions of people, including those in Papua New Guinea and Indonesia.In an era of rapid climate change, understanding the link between an organism and its environment is crucial to developing management strategies for the conservation of marine biodiversity and the sustainable use of marine fisheries.”This is particularly urgent when considering food security for human communities.”Story Source:The above story is based on materials provided by ARC Centre of Excellence in Coral Reef Studies. Note: Materials may be edited for content and length.

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Oil composition boost makes hemp a cooking contender

Scientists at the University of York today report the development of hemp plants with a dramatically increased content of oleic acid. The new oil profile results in an attractive cooking oil that is similar to olive oil in terms of fatty acid content having a much longer shelf life as well as greater heat tolerance and potentially more industrial applications.Researchers in the Centre for Novel Agricultural Products (CNAP) in the Department of Biology at York say that high oleic acid varieties are a major step towards developing hemp as a commercially attractive break crop for cereal farmers. The research is published in Plant Biotechnology Journal.Using fast-track molecular plant breeding, the scientists selected hemp plants lacking the active form of an enzyme involved in making polyunsaturated fatty acids. These plants made less poly-unsaturated fatty acids and instead accumulated higher levels of the mono-unsaturated oleic acid. The research team used conventional plant breeding techniques to develop the plants into a “High Oleic Hemp” line and higher oleic acid content was demonstrated in a Yorkshire field trial.Oil from the new line was almost 80 per cent oleic acid, compared with typical values of less than 10 per cent in the standard hemp line. This high mono-unsaturated/low poly-unsaturated fatty acid profile increases the oil’s thermal stability and oil from the new line was shown to have around five times the stability of standard hemp oil. This not only makes the oil more valuable as a cooking oil but also increases its usefulness for high temperature industrial processes.As oilseed rape faces declining yields and increasing attacks from pest and disease, UK farming needs another break crop to ensure the sustainability of its agriculture and maintain cereal yields. An improved hemp crop, yielding high quality oil would provide an excellent alternative. Hemp is a low-input crop and is also dual-purpose, with the straw being used as a fibre (for bedding, composites and textiles), for biomass and as a source of high value waxes and secondary metabolites.Professor Ian Graham, from CNAP, said: “The new line represents a major improvement in hemp as an oil crop. Similar developments in soybean and oilseed rape have opened up new markets for these crops, due to the perceived healthiness and increased stability of their oil.”In 2014 field trials of the new High Oleic Hemp are being rolled out across Europe in order to establish agronomic performance and yield under a range of environmental conditions in advance of launching a commercial crop.Story Source:The above story is based on materials provided by University of York. …

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Unique new dataset CLIMBER: Climatic niche characteristics of the butterflies in Europe

Scientists from the Helmholtz Centre for Environmental Research — UFZ present CLIMBER: Climatic niche characteristics of the butterflies in Europe -a unique dataset on the climatic niche characteristics of 397 European butterflies representing impressive 91% of the European species. The information provided in this dataset is of great relevance for basic and applied ecology and provides a combination of high quality standards and open access, data ready to use for a broad range of applications. The data paper describing the characteristics of the compilation was published in the open access journal ZooKeys.Global change seriously threatens biodiversity at all organisational levels ranging from properties of single species, through communities and species assemblages to whole ecosystems including the provision of ecosystem services for human well-being. Detailed information on species’ ecological niche characteristics is indispensable for a better understanding of the relationship between the occurrence and performance of wild species and their environment and, moreover, for an improved assessment of the impacts of global change.Knowledge on species characteristics such as habitat requirements is already available in the ecological literature for butterflies, but information about their climatic requirements is still lacking. The new CLIMBER dataset attempts to fill this gap by providing unique information on the climatic niche characteristics of 397 European butterflies. These characteristics are obtained by combining detailed information on butterfly distributions in Europe, which also led to the ‘Distribution Atlas of European Butterflies’ (Kudrna 2002), the ‘Climatic Risk Atlas of European Butterflies (Settele et al. 2008) and the ‘Distribution Atlas of Butterflies in Europe’ (Kudrna et al. 2011).The application potential of this database ranges from theoretical aspects such as assessments of past niche evolution or analyses of trait interdependencies to the very applied aspects of measuring, monitoring and projecting historical, ongoing and potential future responses to climate change using butterflies as an indicator. Good knowledge of the ecological characteristics relevant for the reaction of species and communities to particular drivers of global change is needed, which can then be utilised as powerful indicators for conservation planning and action.”By combining a comprehensive database on the distribution of European butterflies with publicly available climatic data in combination with a constantly high level of quality control at crucial steps of the data generation, CLIMBER represents a unique and ready-to-use dataset for a broad variety of potential applications, “comments Dr. Oliver Schweiger, Helmholtz Centre for Environmental Research — UFZ.”By providing public access to this dataset, we hope to contribute to improvements of the scientific understanding of how climate change affects species and communities and to improve monitoring and conservation actions for climate change mitigation,” he adds on the choice of open access for the dataset.Story Source:The above story is based on materials provided by Pensoft Publishers. …

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Ballistic transport in graphene suggests new type of electronic device

Using electrons more like photons could provide the foundation for a new type of electronic device that would capitalize on the ability of graphene to carry electrons with almost no resistance even at room temperature — a property known as ballistic transport.Research reported this week shows that electrical resistance in nanoribbons of epitaxial graphene changes in discrete steps following quantum mechanical principles. The research shows that the graphene nanoribbons act more like optical waveguides or quantum dots, allowing electrons to flow smoothly along the edges of the material. In ordinary conductors such as copper, resistance increases in proportion to the length as electrons encounter more and more impurities while moving through the conductor.The ballistic transport properties, similar to those observed in cylindrical carbon nanotubes, exceed theoretical conductance predictions for graphene by a factor of 10. The properties were measured in graphene nanoribbons approximately 40 nanometers wide that had been grown on the edges of three-dimensional structures etched into silicon carbide wafers.”This work shows that we can control graphene electrons in very different ways because the properties are really exceptional,” said Walt de Heer, a Regent’s professor in the School of Physics at the Georgia Institute of Technology. “This could result in a new class of coherent electronic devices based on room temperature ballistic transport in graphene. Such devices would be very different from what we make today in silicon.”The research, which was supported by the National Science Foundation, the Air Force Office of Scientific Research and the W.M. Keck Foundation, was reported February 5 in the journal Nature. The research was done through a collaboration of scientists from Georgia Tech in the United States, Leibniz Universitt Hannover in Germany, the Centre National de la Recherche Scientifique (CNRS) in France and Oak Ridge National Laboratory — supported by the Department of Energy — in the United States.For nearly a decade, researchers have been trying to use the unique properties of graphene to create electronic devices that operate much like existing silicon semiconductor chips. But those efforts have met with limited success because graphene — a lattice of carbon atoms that can be made as little as one layer thick — cannot be easily given the electronic bandgap that such devices need to operate.De Heer argues that researchers should stop trying to use graphene like silicon, and instead use its unique electron transport properties to design new types of electronic devices that could allow ultra-fast computing — based on a new approach to switching. Electrons in the graphene nanoribbons can move tens or hundreds of microns without scattering.”This constant resistance is related to one of the fundamental constants of physics, the conductance quantum,” de Heer said. …

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Gastric bypass improves insulin secretion in pigs

The majority of gastric bypass patients mysteriously recover from their type 2 diabetes within days, before any weight loss has taken place. A study at Lund University Diabetes Centre in Sweden has now shown that the insulin-producing beta cells increase in number and performance after the surgery.”We have suspected this for a while, but there have not previously been any models to prove it,” says Dr Nils Wierup, who led the research.The small study involved gastric bypass surgery on just four pigs, but is the only study of its kind and therefore unique.The results confirm that neither weight loss nor reduced food intake are required in order for the procedure to raise the number of beta cells, as the pigs had identical body weight and ate exactly the same amount of food.Type 2 diabetes develops when the body’s insulin-producing beta cells stop working, or when the body is not able to use the insulin that the cells produce.The majority of people who suffer from obesity and undergo a gastric bypass operation recover from their diabetes within days of the procedure. The operation involves altering the connection between the stomach and the intestines so that food bypasses the stomach and parts of the small intestine and instead goes straight into the small intestine. Until now, it has been a mystery why patients’ blood sugar levels normalise.The group at Lund University Diabetes Centre found that the pigs’ beta cells improve their insulin secretion. The researchers also studied tissue from the pigs’ pancreas, the organ where the beta cells are located, something that is almost impossible to do in humans. They found that the number of beta cells increased after the operation.The group have previously studied the effects of gastric bypass on humans.”The reason why we have now studied pigs is that they are omnivores like us and their gastrointestinal physiology is similar to that of humans. This basic research in GI tract functions is mutually beneficial, since it also helps the further refinements of surgical methods,” says Jan Hedenbro, surgeon at Aleris Obesitas, who has collaborated with Lund University Diabetes Centre on the project.The researchers hope that the findings could lead to new methods of treatment for type 2 diabetes in the future.”However, we are first going to repeat the study on pigs with obesity and diabetes,” concludes Nils Wierup.Story Source:The above story is based on materials provided by Lund University. Note: Materials may be edited for content and length.

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New light on star death: Super-luminous supernovae may be powered by magnetars

Oct. 16, 2013 — Astronomers at Queen’s University Belfast have shed new light on the rarest and brightest exploding stars ever discovered in the universe.The research is published Oct. 17 in Nature. It proposes that the brightest exploding stars, called super-luminous supernovae, are powered by magnetars — small and incredibly dense neutron stars, with gigantic magnetic fields, that spin hundreds of times a second.Scientists at Queen’s Astrophysics Research Centre observed two super-luminous supernovae — two of the Universe’s brightest exploding stars — for more than a year. Contrary to existing theories, which suggested that the brightest supernovae are caused by super-massive stars exploding, their findings suggest that their origins may be better explained by a type of explosion within the star’s core which creates a smaller but extremely dense and rapidly spinning magnetic star.Matt Nicholl, a research student at the Astrophysics Research Centre at Queen’s School of Mathematics and Physics, is lead author of the study. He said: “Supernovae are several billions of times brighter than the Sun, and in fact are so bright that amateur astronomers regularly search for new ones in nearby galaxies. It has been known for decades that the heat and light from these supernovae come from powerful blast-waves and radioactive material.”But recently some very unusual supernovae have been found, which are too bright to be explained in this way. They are hundreds of times brighter than those found over the last fifty years and the origin of their extreme properties is quite mysterious.”Some theoretical physicists predicted these types of explosions came from the biggest stars in the universe destroying themselves in a manner quite like a giant thermonuclear bomb. But our data doesn’t match up with this theory.”In a supernova explosion, the star’s outer layers are violently ejected, while its core collapses to form an extremely dense neutron star — weighing as much as the Sun but only tens of kilometers across. We think that, in a small number of cases, the neutron star has a very strong magnetic field, and spins incredibly quickly — about 300 times a second. …

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Circadian rhythms in skin stem cells protect us against UV rays

Oct. 10, 2013 — Human skin must cope with UV radiation from the sun and other harmful environmental factors that fluctuate in a circadian manner. A study published by Cell Press on October 10th in the journal Cell Stem Cell has revealed that human skin stem cells deal with these cyclical threats by carrying out different functions depending on the time of day. By activating genes involved in UV protection during the day, these cells protect themselves against radiation-induced DNA damage. The findings could pave the way for new strategies to prevent premature aging and cancer in humans.Share This:”Our study shows that human skin stem cells posses an internal clock that allows them to very accurately know the time of day and helps them know when it is best to perform the correct function,” says study author Salvador Aznar Benitah an ICREA Research Professor who developed this project at the Centre for Genomic Regulation (CRG, Barcelona), and who has recently moved his lab to the Institute for Research in Biomedicine (IRB Barcelona). “This is important because it seems that tissues need an accurate internal clock to remain healthy.”A variety of cells in our body have internal clocks that help them perform certain functions depending on the time of day, and skin cells as well as some stem cells exhibit circadian behaviors. Benitah and his collaborators previously found that animals lacking normal circadian rhythms in skin stem cells age prematurely, suggesting that these cyclical patterns can protect against cellular damage. But until now, it has not been clear how circadian rhythms affect the functions of human skin stem cells.To address this question, Benitah teamed up with his collaborators Luis Serrano and Ben Lehner of the Centre for Genomic Regulation. They found that distinct sets of genes in human skin stem cells show peak activity at different times of day. Genes involved in UV protection become most active during the daytime to guard these cells while they proliferate — that is, when they duplicate their DNA and are more susceptible to radiation-induced damage.”We know that the clock is gradually disrupted in aged mice and humans, and we know that preventing stem cells from accurately knowing the time of the day reduces their regenerative capacity,” Benitah says. …

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Exercise provides some benefits for depression

Sep. 11, 2013 — Exercise may benefit people suffering from depression, according to an updated systematic review published in The Cochrane Library. The authors of the review found evidence to suggest that exercise reduces symptoms of depression, although they say more high quality trials are needed.Worldwide, more than 120 million people suffer from depression. Antidepressants and psychological therapies are recommended as effective treatments for depression. However, antidepressants have side-effects and some people prefer not to receive, or may not have access to, psychological therapies. Physical exercise is also used as a treatment for depression. There are a number of reasons why it might work such as changing hormone levels that affect mood or providing a distraction from negative thoughts.The previous version of the Cochrane review found only limited evidence of benefit for exercise in depression. However, more trials have now been completed, leading researchers to carry out a further update. Altogether, they reviewed the results of 39 trials involving 2,326 people diagnosed with depression. The severity of patients’ symptoms was assessed using standard scales of depression.In 35 trials comparing exercise with control treatments or no treatment, the researchers saw moderate benefits of exercise for treating depression. …

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Nasal inhalation of oxytocin improves face blindness

Sep. 5, 2013 — Prosopagnosia (face blindness) may be temporarily improved following inhalation of the hormone oxytocin.This is the finding of research led by Dr Sarah Bate and Dr Rachel Bennetts of the Centre for Face Processing Disorders at Bournemouth University that will be presented today, Friday 6 September, at the British Psychological Society’s Joint Cognitive and Developmental annual conference at the University of Reading.Dr Bate explained: “Prosopagnosia is characterised by a severe impairment in face recognition, whereby a person cannot identify the faces of their family or friends, or even their own face”The researchers tested twenty adults (10 with prosopagnosia and 10 control participants). Each participant visited the laboratory on two occasions, approximately two weeks apart. On one visit they inhaled the oxytocin nasal spray, and on the other visit they inhaled the placebo spray. The two sprays were prepared by an external pharmaceutical company in identical bottles, and neither the participants nor the researchers knew the identity of the sprays until the data had been analysed.Regardless of which spray the person inhaled, the testing sessions had an identical format. Participants inhaled the spray, then sat quietly for 45 minutes to allow the spray to take effect. They then participated in two face processing tests: one testing their ability to remember faces and the other testing their ability to match faces of the same identity.The researchers found that the participants with prosopagnosia achieved higher scores on both face processing tests in the oxytocin condition. Interestingly, no improvement was observed in the control participants, suggesting the hormone may be more effective in those with impaired face recognition systems.The initial ten participants with prosopagnosia had a developmental form of the condition. Individuals with developmental prosopagnosia have never experienced brain damage, and this form of face blindness is thought to be very common, affecting one in 50 people. Much more rarely, people can acquire prosopagnosia following a brain injury. …

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Out-of-hospital cardiac arrest survival just 7 percent

Sep. 1, 2013 — Survival for out-of-hospital cardiac arrest is just 7%, according to research presented at ESC Congress 2013 by Professor Xavier Jouven and Dr Wulfran Bougouin from France.Professor Jouven said: “Sudden cardiac death (SCD) is an important public health problem, accounting for more than 400,000 deaths every year. The main cause is ventricular tachyarrhythmias which are often triggered by acute ischaemic events that can occur in persons with or without known heart disease. The survival rate from cardiac arrest has remained low over the last 40 years despite major investment and the epidemiology of SCD in Western Europe is unclear.” The Paris Sudden Death Expertise Centre (SDEC) Registry is a population based registry using multiple sources to collect every case of cardiac arrest in Greater Paris (population 6.6 million) according to the Utstein Style.1 Cases are continuously recorded (within hours of occurrence) and standardised follow-up is initiated on admission to the intensive care unit. Incidence, prognostic factors and outcomes are recorded.The results reported today reveal the 2 year experience of the SDEC Registry. From May 2011 to December 2012, 3,670 sudden cardiac arrests, with resuscitation attempted, occurred. Most cases occurred at home (72%) with bystanders in 81% of cases, performing cardiopulmonary resuscitation (CPR) in only 42% of cases. Among those cases only 34% of patients were admitted alive at hospital and 7% were discharged alive.Professor Jouven said: “The majority of sudden cardiac deaths occur outside hospital so specific programmes are needed in the community. Friends and relatives of people at risk of SCD should learn CPR and attend regular training to keep their skills up-to-date.” Therapeutic hypothermia and early coronary reperfusion were both significantly associated with survival (p<0.001) but these procedures were used in just 58% of patients admitted to hospital. Professor Jouven said: “These interventions markedly improve survival yet are given to just over half of patients. …

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New test to predict women at risk of pregnancy complications?

Sep. 2, 2013 — Researchers from The University of Manchester and Central Manchester University Hospitals NHS Trust have identified proteins in the blood that could be used to predict whether a woman in her first pregnancy is at increased risk of developing pre-eclampsia.Pre-eclampsia is a complication of pregnancy where the mother develops high blood pressure and protein is present in the urine. In some cases, this can develop into a serious condition for both mother and baby and the only cure is delivery of the baby, often prematurely.Women who have had pre-eclampsia previously are at higher risk of recurrence and are closely monitored during pregnancy, but there is no way of determining who is at high risk in first-time mothers.The researchers, led by Dr Richard Unwin and Dr Jenny Myers from the Manchester Biomedical Research Centre, a partnership between the Trust and the University analysed samples which had been collected as part of the international SCOPE study at 15 weeks of pregnancy — before any clinical signs of disease are present. Proteins were identified which differed between those women who developed pre-eclampsia and those who did not.Three of these proteins were studied further in a larger number of pregnant mothers using a new method that allows the levels of several proteins to be measured at once. Two proteins, which have not previously been linked to pre-eclampsia risk, were shown to be at least as good a predictor of disease risk as the current best marker, placental growth factor,. These two new potential markers are called pregnancy specific glycoprotein 5 and 9 (PSG5 and PSG9).The findings will have a significant impact for identifying the condition in first time pregnancies, researchers believe.Dr Jenny Myers, from the Institute of Human Development at The University of Manchester and the Maternal and Fetal Heath Research Centre at Saint Mary’s Hospital, said: “We hope that these two new markers will be of benefit in the future for women at risk from pre-eclampsia to allow early intervention and/or closer monitoring.”We also hope to understand the biology of the disease better by determining why these proteins are higher in women with pre-eclampsia and whether they have a role in the development of the placenta.”Dr Unwin, from the Centre for Advanced Discovery and Experimental Therapeutics (CADET) at the Manchester Biomedical Research Centre, said: “What we have also done here is to develop a suite of laboratory methods which can identify and begin to validate real disease markers from patient blood samples, even before symptoms have developed, and we are hoping to continue applying these methods to other major diseases, such as diabetes, Alzheimer’s disease or stroke.”The research, published in the journal Molecular and Cellular Proteomics, also involved members from Manchester Academic Health Science Centre (MAHSC) a partnership between the University and six leading NHS Trusts which aim to help health care organisations reap the benefits of research and innovation to drive improvements in care.

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Tiny fish make ‘eyes’ at their killer

Aug. 19, 2013 — Small prey fish can grow a bigger ‘eye’ on their rear fins as a way of distracting predators and dramatically boosting their chances of survival, new scientific research has found.Researchers from Australia’s ARC Centre of Excellence for Coral Reef Studies (CoECRS) have made a world-first discovery that, when constantly threatened with being eaten, small damsel fish not only grow a larger false ‘eye spot’ near their tail — but also reduce the size of their real eyes.The result is a fish that looks like it is heading in the opposite direction — potentially confusing predatory fish with plans to gobble them up, says Oona Lönnstedt, a graduate student at CoECRS and James Cook University.For decades scientists have debated whether false eyespots, or dark circular marks on less vulnerable regions of the bodies of prey animals, played an important role in protecting them from predators — or were simply a fortuitous evolutionary accident.The CoECRS team has found the first clear evidence that fish can change the size of both the misleading spot and their real eye to maximise their chances of survival when under threat.”It’s an amazing feat of cunning for a tiny fish,” Ms Lonnstedt says. “Young damsel fish are pale yellow in colour and have this distinctive black circular ‘eye’ marking towards their tail, which fades as they mature. We figured it must serve an important purpose when they are young.””We found that when young damsel fish were placed in a specially built tank where they could see and smell predatory fish without being attacked, they automatically began to grow a bigger eye spot, and their real eye became relatively smaller, compared with damsels exposed only to herbivorous fish, or isolated ones.”We believe this is the first study to document predator-induced changes in the size of eyes and eye-spots in prey animals.”When the researchers investigated what happens in nature on a coral reef with lots of predators, they found that juvenile damsel fish with enlarged eye spots had an amazing five times the survival rate of fish with a normal-sized spot.”This was dramatic proof that eyespots work — and give young fish a hugely increased chance of not being eaten.”We think the eyespots not only cause the predator to attack the wrong end of the fish, enabling it to escape by accelerating in the opposite direction, but also reduce the risk of fatal injury to the head,” she explains.The team also noted that when placed in proximity to a predator the young damsel fish also adopted other protective behaviours and features, including reducing activity levels, taking refuge more often and developing a chunkier body shape less easy for a predator to swallow.”It all goes to show that even a very young, tiny fish a few millimetres long have evolved quite a range of clever strategies for survival which they can deploy when a threatening situation demands,” Ms Lonnstedt says.

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Breaking up the superbugs’ party

Aug. 13, 2013 — The fight against antibiotic-resistant superbugs has taken a step forward thanks to a new discovery by scientists at The University of Nottingham.A multi-disciplinary research team at the University’s Centre for Biomolecular Sciences has uncovered a new way of inhibiting the toxicity and virulence of the notorious superbug, Pseudomonas aeruginosa.This bacteria produces an armoury of virulence factors and is resistant to many conventional antibiotics. It is almost impossible to eradicate P. aeruginosa from the lungs of people with cystic fibrosis and is therefore a leading cause of death among sufferers. The bug also causes a wide range of infections particularly among hospital patients.The new discovery concerns the bacterial cells’ ability to ‘talk’ to each other by producing and sensing small chemical signal molecules. This is called ‘quorum sensing’ (QS) and enables a population of individual bacteria to act socially rather than as individuals. QS allows a population of bacteria to assess their numerical strength and make a decision only when the population is ‘quorate’.The mechanism through which QS signals work is by activating gene expression upon interaction of a QS signal molecule with a receptor protein. In many disease-causing bacteria, QS controls genes which are essential for infection. These genes code for virulence factors such as toxins which cause damage to host tissues and the immune system. Interfering with the QS signalling process blocks bacterial virulence and renders bacteria unable to cause infection. …

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