Local reindeer grazing history is an important determinant in the response of an ecosystem’s carbon sink to climate warming, say researchers at the Arctic Centre of the University of Lapland. Their study was published in the journal Nature Climate Change on 16 March 2014. The research project has been funded by the Academy of Finland.The consequences of global climate warming on ecosystem carbon sink in tundra are of great interest, because carbon that is currently stored in tundra soils may be released to the atmosphere in a warmer climate. This could contribute to atmospheric carbon dioxide concentration, and thus create a positive feedback that intensifies global change.A major portion of the Arctic is grazed by reindeer. In northernmost Europe, the reindeer was domesticated a few centuries ago. In a field experiment in northern Norway, the effects of experimental warming were compared between lightly and heavily grazed tundra. The grazing history between these areas had varied for the past 50 years. Carbon balances showed that under the current climate, lightly grazed, dwarf-shrub-dominated tundra were a stronger carbon sink than heavily grazed, graminoid-dominated tundra. However, warming decreased the carbon sink in lightly grazed tundra, but had no effect in heavily grazed tundra. Thus, tundra with a long history of intensive grazing showed a weak response to climate warming.The main reason for this grazer-induced difference was that in heavily grazed tundra, graminoids with rapid growth rates were able to increase their photosynthesis and carbon fixation under increased temperatures. …Read more
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.Read more
Sep. 8, 2013 — A team of scientists at Karolinska Institutet and Harvard University has taken a major step towards treatment for heart attack, by instructing the injured heart in mice to heal by expressing a factor that triggers cardiovascular regeneration driven by native heart stem cells. The study, published in Nature Biotechnology, also shows that there was an effect on driving the formation of a small number of new cardiac muscle cells.”This is the beginning of using the heart as a factory to produce growth factors for specific families of cardiovascular stem cells, and suggests that it may be possible to generate new heart parts without delivering any new cells to the heart itself ,” says Kenneth Chien, a Professor at the medical university Karolinska Institutet in Sweden and Harvard University, USA, who led the research team behind the new findings.The study is based upon another recent discovery in the Chien lab, which was published in Cell Research. This study shows that VEGFA, a known growth factor for vascular endothelial cells in the adult heart, can also serve as a switch that converts heart stem cells away from becoming cardiac muscle and towards the formation of the coronary vessels in the fetal heart. To coax the heart to make the VEGFA, the investigators in the Nature Biotechnology study used new technology where synthetic messenger RNA (mRNA) that encodes VEGFA is injected into the muscle cell. Then, heart muscle produces a short pulse of VEGFA. The mRNA is synthetically modified so that it escapes the normal defense system of the body that is known to reject and degrade the non-modified mRNA as a viral invader.The study, performed in mice, shows that only a single administration of a short pulse of expression of VEGFA is required, if it can be delivered to the exact region where the heart progenitors reside. The therapeutic effect is long term, as shown by markedly improved survival following myocardial infarction with a single administration of the synthetic mRNA when given within 48 hours after the heart attack. The long-term effect appears to be based on changing the fate of the native heart stem cells from contributing to cardiac fibrotic scar tissue and towards cardiovascular tissue.”This moves us very close to clinical studies to regenerate cardiovascular tissue with a single chemical agent without the need for injecting any additional cells into the heart.” says Professor Chien.At the same time, he points out that these are still early days and there remains much to be done. In particular, it will become of interest to engineer new device technology to deliver the synthetic mRNA via conventional catheter technology. …Read more
Aug. 30, 2013 — An international team of researchers presents fresh evidence that confirms the existence of the superheavy chemical element 115. The experiment was conducted at the GSI Helmholtz Center for Heavy Ion Research, an accelerator laboratory located in Darmstadt. Under the lead of physicists from Lund University in Sweden, the group, which included researchers from Johannes Gutenberg University Mainz (JGU) and the Helmholtz Institute Mainz (HIM), was able to present a way to directly identify new superheavy elements.Share This:Elements beyond atomic number 104 are referred to as superheavy elements. They are produced at accelerator laboratories and generally decay after a short time. Initial reports about the discovery of an element with atomic number 115 were released from a research center in Russia in 2004. The then presented indirect evidence for the new element, however, was insufficient for an official discovery.For the new experiment, scientists at the Institute of Nuclear Chemistry at Mainz University took a sample of the exotic element americium. They deposited an americium layer on a thin foil, which was subsequently bombarded with calcium ions at the GSI facility. For the first time, the exploitation of a new detector system allowed registering photons along with the alpha-decay of the new element and its daughter products. Measured photon energies correspond to those expected for X-rays from these products and thus serve as the element’s fingerprint.”This can be regarded as one of the most important experiments in the field in recent years, because at last it is clear that even the heaviest elements’ fingerprints can be taken”, agreed Professor Dirk Rudolph from Lund University in Sweden and Professor Christoph Düllmann, professor at Mainz University and leading scientist at GSI Darmstadt and HIM. …Read more
Aug. 27, 2013 — Fifteen years ago, a hematologist came to Dianna Milewicz, M.D., Ph.D., with a puzzle: Multiple generations of an East Texas family suffered from a moderately severe bleeding disorder, but it wasn’t hemophilia.”No surgeon would do elective surgery because they bled too much after surgery,” said Milewicz, professor and director of the Division of Medical Genetics at The University of Texas Health Science Center at Houston (UTHealth). “So we collected DNA and plasma from the family and were able to determine that a genetic variant in the Factor V gene was causing production of an abnormal form of the Factor V protein, which we called FV-Short. Factor V is a protein known to be important for the blood to clot.”But her team at the UTHealth Medical School couldn’t pinpoint exactly how the variation was causing the clotting problem until they collaborated with Björn Dahlbӓck, M.D., Ph.D., from Lund University, Malmö, Sweden.”Dr. Dahlbӓck is a world expert on Factor V and he was very excited about the research,” said Milewicz, who holds the President George H.W. Bush Chair in Cardiovascular Research. She is also on the faculty of The University of Texas Graduate School of Biomedical Sciences and director of the John Ritter Research Program in Aortic and Vascular Diseases at UTHealth.”I was indeed very excited when hearing about the puzzling results because the knowledge at the time on the role of FV in coagulation could not explain the bleeding disorder. It has been a great privilege to work with Dr. Milewicz and her colleagues to decode the unexpected and intriguing mechanisms on how FV-Short caused the bleeding disorder,” said Dahlbäck who holds the chair as professor of Blood Coagulation Research at Lund University, Malmö, Sweden.The results were published in today’s online issue of the Journal of Clinical Investigation. Milewicz and Dahlbäck are senior co-authors.Genes make proteins that do everything from giving cells shape and structure to helping carry out biological processes. …Read more
Aug. 20, 2013 — Tiny, round, cold clouds in space have all the right characteristics to form planets with no parent star. New observations, made with Chalmers University of Technology telescopes, show that not all free-floating planets were thrown out of existing planetary systems. They can also be born free.Previous research has shown that there may be as many as 200 billion free-floating planets in our galaxy, the Milky Way. Until now scientists have believed that such “rogue planets,” which don’t orbit around a star, must have been ejected from existing planetary systems.New observations of tiny dark clouds in space point out another possibility: that some free-floating planets formed on their own.A team of astronomers from Sweden and Finland used several telescopes to observe the Rosette Nebula, a huge cloud of gas and dust 4600 light years from Earth in the constellation Monoceros (the Unicorn).They collected observations in radio waves with the 20-metre telescope at Onsala Space Observatory in Sweden, in submillimetre waves with APEX in Chile, and in infrared light with the New Technology Telescope (NTT) at ESO’s La Silla Observatory in Chile.”The Rosette Nebula is home to more than a hundred of these tiny clouds — we call them globulettes,” says Gösta Gahm, astronomer at Stockholm University, who led the project.”They are very small, each with diameter less than 50 times the distance between the Sun and Neptune. Previously we were able to estimate that most of them are of planetary mass, less than 13 times Jupiter’s mass. Now we have much more reliable measures of mass and density for a large number of these objects, and we have also precisely measured how fast they are moving relative to their environment,” he says.”We found that the globulettes are very dense and compact, and many of them have very dense cores. That tells us that many of them will collapse under their own weight and form free-floating planets. The most massive of them can form so-called brown dwarfs,” says team member Carina Persson, astronomer at Chalmers University of Technology.Brown dwarfs, sometimes called failed stars, are bodies whose mass lies between that of planets and stars.The study shows that the tiny clouds are moving outwards through the Rosette Nebula at high speed, about 80 000 kilometres per hour.”We think that these small, round clouds have broken off from tall, dusty pillars of gas which were sculpted by the intense radiation from young stars. They have been accelerated out from the centre of the nebula thanks to pressure from radiation from the hot stars in its centre,” explains Minja Mäkelä, astronomer at the University of Helsinki.According to Gösta Gahm and his team, the tiny dark clouds are being thrown out of the Rosette Nebula. …Read more
July 22, 2013 — People with epilepsy are ten times more likely to die early, before their mid-fifties, compared with the general population, according to a 41 year study in Sweden published today in the Lancet and part-funded by the Wellcome Trust.The findings reveal a striking correlation between premature death and mental illness in these patients and people with epilepsy were four times more likely to have received a psychiatric diagnosis in their lifetime compared with the general population.The figures are considerably higher than previously thought and have important implications for epilepsy management.Researchers at the University of Oxford and Karolinska Institutet studied 69,995 people with epilepsy born in Sweden between 1954 and 2009 and followed up over 41 years, between 1969 and 2009. They compared mortality and cause of death information from these patients with 660,869 age- and sex-matched people from the general population. The study also looked at the unaffected siblings of those with epilepsy, in order to rule out the influence of background factors such as genetic risk factors and upbringing.Throughout the course of the study, almost nine per cent (6,155) of people with epilepsy died compared with less than one per cent (4,892) of people from the general population.The most important cause of death in people with epilepsy that was not clearly related to the underlying disease process was death by external causes, such as accident or suicide, accounting for almost 16 per cent of deaths. Three quarters of these deaths were amongst patients who also had a psychiatric diagnosis.Although suicide and deaths from accidents were still relatively rare, the odds of a person with epilepsy committing suicide during the study were four times higher than the general population and there was a strong correlation with mental illness and substance abuse.Dr Seena Fazel, a Wellcome Trust Senior Clinical Research Fellow at the University of Oxford and main author of the study, said: “This is the largest report to date to look at psychiatric associations in epilepsy and their contribution to premature mortality. Our finding that three quarters of suicide and accident deaths in epilepsy also had a diagnosis of mental illness strongly identifies this as a high risk population to focus preventative strategies and more intensive treatment.”Improving the identification, monitoring and treatment of psychiatric problems in epilepsy patients could make an important contribution to reducing the risk of premature death that we’re currently seeing in these patients.”The study also reveals that the odds of dying in a non-vehicle accident, such as drug poisoning or drowning, were more than five times higher for people with epilepsy than control populations.”Our findings also highlight general accidents as a major, preventable cause of death in epilepsy patients and suggest that specific warnings, in addition to those already given around driving, should be provided to patients at the time of diagnosis to ensure they are aware of the risks,” added Dr Fazel.Professor Charles Newton from the Wellcome Trust programme at the Kenyan Medical Research Institute (KEMRI) and the Department of Psychiatry at Oxford University, said: “Although it is well -recognised that psychiatric and addiction disorders occur in epilepsy, in high income (Western) countries, epilepsy is often managed by neurologists only. The findings from this study would suggest that clinical epilepsy services should review their liaison with psychiatric and addiction services as a priority.”This is the first study to look at the odds of premature death in people with epilepsy compared with their unaffected siblings, revealing that they do not differ significantly from odds of death in epilepsy compared with general population controls. This provides further weight to the evidence that epilepsy as a disease is an independent risk factor for death by any cause.Read more
July 17, 2013 — A novel material with world record-breaking surface area and water adsorption abilities has been synthesized by researchers from Uppsala University, Sweden.The results are published today in PLOS ONE.The magnesium carbonate material that has been given the name Upsalite is foreseen to reduce the amount of energy needed to control environmental moisture in the electronics and drug formulation industry as well as in hockey rinks and ware houses. It can also be used for collection of toxic waste, chemicals or oil spill and in drug delivery systems, for odor control and sanitation after fire.”In contrast to what has been claimed for more than 100 years in the scientific literature, we have found that amorphous magnesium carbonate can be made in a very simple, low-temperature process,” says Johan Goméz de la Torre, researcher at the Nanotechnology and Functional Materials Division.While ordered forms of magnesium carbonate, both with and without water in the structure, are abundant in nature, water-free disordered forms have been proven extremely difficult to make. In 1908, German researchers claimed that the material could indeed not be made in the same way as other disordered carbonates, by bubbling CO2 through an alcoholic suspension. Subsequent studies in 1926 and 1961 came to the same conclusion.”A Thursday afternoon in 2011, we slightly changed the synthesis parameters of the earlier employed unsuccessful attempts, and by mistake left the material in the reaction chamber over the weekend. Back at work on Monday morning we discovered that a rigid gel had formed and after drying this gel we started to get excited,” says Johan Goméz de la Torre.A year of detailed materials analysis and fine tuning of the experiment followed. One of the researchers got to take advantage of his Russian skill since some of the chemistry details necessary for understanding the reaction mechanism was only available in an old Russian PhD thesis.”After having gone through a number of state of the art materials characterization techniques it became clear that we had indeed synthesized the material that previously had been claimed impossible to make,” says Maria Strømme, professor of nanotechnology and head of the nanotechnology and functional materials division.The most striking discovery was, however, not that they had produced a new material but it was instead the striking properties they found that this novel material possessed. It turned out that Upsalite had the highest surface area measured for an alkali earth metal carbonate; 800 square meters per gram.”This places the new material in the exclusive class of porous, high surface area materials including mesoporous silica, zeolites, metal organic frameworks, and carbon nanotubes,” says Strømme.In addition we found that the material was filled with empty pores all having a diameter smaller than 10 nano meters. This pore structure gives the material a totally unique way of interacting with the environment leading to a number of properties important for application of the material. Upsalite is for example found to absorb more water at low relative humidities than the best materials presently available; the hydroscopic zeolites, a property that can be regenerated with less energy consumption than is used in similar processes today.”This, together with other unique properties of the discovered impossible material is expected to pave the way for new sustainable products in a number of industrial applications,” says Maria Strømme.The discovery will be commercialized though the University spin-out company Disruptive Materials (www.Disruptivematerials.com) that has been formed by the researchers together with the holding company of Uppsala UniversityRead more
July 11, 2013 — Bioenergy with carbon capture and storage (BECCS) can reverse the global warming trend and push temperatures back below the global target of 2°C above pre-industrial levels, even if current policies fail and we initially overshoot this target.This is according to a new study, published today, 11 July, in IOP Publishing’s journal Environmental Research Letters, which shows that ambitious temperature targets can be exceeded then reclaimed by implementing BECCS around mid-century.The researchers, from Chalmers University of Technology in Sweden, show that if BECCS is implemented on a large-scale along with other renewable energy sources, temperature increases can be as low as 1.5°C by 2150.Co-author of the study, Professor Christian Azar, said: “What we demonstrate in our paper is that even if we fail to keep temperature increases below 2°C, then we can reverse the warming trend and push temperatures back below the 2°C target by 2150.”To do so requires both large-scale use of BECCS and reducing other emissions to near-zero levels using other renewables — mainly solar energy — or nuclear power.”BECCS is a greenhouse gas mitigation technology based on bioenergy that produces fuel for power plants or transportation while simultaneously removing carbon dioxide from the atmosphere. Trees and crops give off carbon dioxide when they are burnt as fuel, but also act as a carbon sink as they grow beforehand, absorbing carbon dioxide from the atmosphere. These two processes cancel each other out, resulting in net zero emissions of carbon dioxide.When combined with carbon capture and storage — techniques that aim to pull carbon dioxide out of the flue gases from power plants and redirect it into geological storage locations — the overall carbon dioxide emissions are negative. If applied on a global scale, this could help to reverse global warming.In their study, the researchers developed an integrated global energy system and climate model that enabled them to assess the most cost-effective way forward for a given energy demand scenario and temperature target.They find that stringent temperature targets can be met at significantly lower costs if BECCS is implemented 30 to 50 years from now, although this may cause a temporary overshoot of the 2°C target.”The most policy relevant implication of our study is that even if current political gridlock causes global warming in excess of 2°C, we can reverse the temperature trend and reach targets later. This means that 2°C targets or even more ambitious targets can remain on the table in international climate negotiations,” Azar continues.However, the authors caution against interpreting their study as an argument for delaying emission reductions in the near-term.Azar says: “BECCS can only reverse global warming if we have net negative emissions from the entire global energy system. This means that all other CO2 emissions need to be reduced to nearly zero.”Also, temperatures can only be reduced by about 0.6°C per century, which is too slow to act as an ’emergency brake’ if climate damages turn out to be too high. The more we reduce emissions now, the more ambitious targets we can achieve in the long term — even with BECCS.”Read more
July 3, 2013 — Scientists have identified the genetic cause of a rare skin condition that causes the hands and feet to turn white and spongy when exposed to water.The study, led by researchers from Queen Mary, University of London, has provided scientists with an insight into how the skin barrier functions and could help with research into a variety of conditions.Diffuse non-epidermolytic palmoplantar keratoderma (NEPPK) is a rare condition in which individuals have thickened, yellowish skin over their palms and soles, thickened nails and suffer from excessive sweating. When their hands and feet are exposed to water, the skin quickly turns white and spongy and individuals are prone to fungal infections.While prevalence in the general population is estimated at one in 40,000 it is much higher in northern Sweden (up to one in 200 people), where a single ancestral genetic mutation is believed to have originated and then subsequently passed down from generation to generation.A team led by David Kelsell, Professor of Human Molecular Genetics at Queen Mary studied DNA from a number of families of British and Swedish origin in which the skin condition is present. Using high throughput DNA sequencing methods they were able to pin down the underlying cause of the condition to mutations in the AQP5 gene, which encodes a water channel protein known as aquaporin 5. All individuals who have inherited an AQP5 mutation will present with this rare skin condition.Professor Kelsell, from the Blizard Institute at Barts and The London School of Medicine and Dentistry, Queen Mary, said: “Aquaporins are a family of proteins known as “the plumbing system for cells” as they form pores which allow water to flow through cells rapidly.”We knew aquaporin 5 was present in high amounts in the sweat glands, salivary glands and tear ducts — routes by which the body loses water. Here we’ve demonstrated it is also found in the skin, with higher amounts in the hands and feet.”Co-author Dr Diana Blaydon, also from the Blizard Institute, explained: “The AQP5 gene mutation appears to result in a protein that has a wider channel than usual, forming a bigger pore in the cell membrane allowing more water to permeate it.”Further work is needed to understand exactly how the mutations identified and the associated changes in the skin barrier lead to NEPPK.Professor Kelsell added: “While we’ve studied aquaporins in the skin, these results also give us an idea of what might be happening in internal aquaporins, which are found in structures throughout the body, including the kidneys, cornea and lungs.”Read more
July 2, 2013 — More people die from heart-disease during the winter months, and according to a new study published in the journal Cell Metabolism, the increase in mortality is possibly due to the accelerated growth of atherosclerotic plaque in the blood vessels caused by the activation of brown fat by the cold.It has long been known that the number of deaths from cardiovascular diseases increases during the winter. It has been speculated that this might be the result of over-exertion while shovelling snow and a general decrease in physical activity, although the underlying mechanisms have been unclear. The present study, which has been conducted by researchers at Karolinska Institutet, and Linköping University in Sweden, and three universities in China, demonstrates a new principle by which the cold increases the risk of atherosclerosis.The researchers conducted their study on a strain of mice genetically modified with a propensity for atherosclerosis. Mice, like humans, have both white and brown body fat. Normal rolls of fat consist mainly of white fat, which is a repository of surplus calories; brown adipose tissue, on the other hand, can convert fat into heat. This heat-generation process is activated by cold temperatures and has been considered beneficial to the health since it can reduce the amount of unnecessary white adipose tissue in the body.”At first, we thought that the cold activation of brown fat would only make the mice thinner and healthier,” says Yihao Cao at the Department of Microbiology, Tumour and Cell Biology at Karolinska Institutet, and the Department of Medicine and Health at Linköping University. “Instead, we found that they ended up having more fat stored in the blood vessels. This came as a surprise and was the opposite of what we thought would happen.”It turned out that exposure to low temperatures accelerated the formation of atherosclerotic plaque in the mice, which can cause myocardial infarction and brain haemorrhaging. Moreover, the cold made the plaque less stable, and if such plaque ruptures, stored fat can leak into the blood, blocking vessels in the heart and brain. The cold-activated breakdown of fatty acids in the mice’s brown fat led to the accumulation of low-density lipoproteins (LDL) in the blood and an increase in fat storage in the plaque.”If this is also true for humans, it might be wise to recommend that people who suffer from cardiovascular disease should avoid exposure to the cold and to put on warm clothes when they are outside during the winter,” says Professor Yihai Cao.The researchers hope to be able to extend their work on mice to studies on humans.”It would be an extremely important discovery if we found this to be the case in humans too,” says Professor Yihai Cao. …Read more
June 30, 2013 — Scientists at Karolinska Institutet in Sweden have identified the neuronal circuits in the spinal cord of mice that control the ability to produce the alternating movements of the legs during walking. The study, published in the journal Nature, demonstrates that two genetically-defined groups of nerve cells are in control of limb alternation at different speeds of locomotion, and thus that the animals’ gait is disturbed when these cell populations are missing.Share This:Most land animals can walk or run by alternating their left and right legs in different coordinated patterns. Some animals, such as rabbits, move both leg pairs simultaneously to obtain a hopping motion. In the present study, the researchers Adolfo Talpalar and Julien Bouvier together with professor Ole Kiehn and colleagues, have studied the spinal networks that control these movement patterns in mice. By using advanced genetic methods that allow the elimination of discrete groups of neurons from the spinal cord, they were able to remove a type of neurons characterized by the expression of the gene Dbx1.”It was classically thought that only one group of nerve cells controls left right alternation,” says Ole Kiehn who leads the laboratory behind the study at the Department of Neuroscience. “It was then very interesting to find that there are actually two specific neuronal populations involved, and on top of that that they each control different aspect of the limb coordination.”Indeed, the researchers found that the gene Dbx1 is expressed in two different groups of nerve cells, one of which is inhibitory and one that is excitatory. The new study shows that the two cellular populations control different forms of the behaviour. Just like when we change gear to accelerate in a car, one part of the neuronal circuit controls the mouse’s alternating gait at low speeds, while the other population is engaged when the animal moves faster. Accordingly, the study also show that when the two populations are removed altogether in the same animal, the mice were unable to alternate at all, and hopped like rabbits instead.There are some animals, such as desert mice and kangaroos, which only hop. The researchers behind the study speculate that the locomotive pattern of these animals could be attributable to the lack of the Dbx1 controlled alternating system.Share this story on Facebook, Twitter, and Google:Other social bookmarking and sharing tools:|Story Source: The above story is reprinted from materials provided by Karolinska Institutet, via AlphaGalileo. …Read more
June 27, 2013 — People have differing abilities to release and react to insulin depending on ethnicity, according to a new study from researchers at Lund University in Sweden, Stanford University and Kitasato University.The results show that healthy subjects of all ethnicities were able to maintain a normal glucose level, but did so in different ways.”Africans tend to have lower insulin sensitivity. However, they appear to compensate for this by releasing larger quantities of insulin. Among those of East Asian origin, the reverse appears to be the case. They have very good insulin sensitivity, but appear to have a poorer ability to release more insulin if it is needed. Caucasians fall somewhere between the two extremes. Both insulin release and insulin sensitivity are affected,” says Damon Tojjar, a doctoral student at the Lund University Diabetes Centre (LUDC).When the researchers looked more closely at the research subjects who were at risk of developing diabetes and the subjects who had already been diagnosed, the same pattern was observed. Their results were generally worse, however, as their insulin production or insulin sensitivity had begun to fail as part of the disease.”The findings are consistent with what we see in clinical settings — East Asians are more sensitive to developing diabetes and they do so at a lower BMI. Because a lack of insulin is a condition for developing diabetes, it is not surprising that East Asians show lower insulin release and generally need to start insulin treatment at an earlier stage. The situation in Africa is still so complicated and heterogeneous that new studies are needed,” says Professor Leif Groop from LUDC.The researchers are not sure of the reasons for the physiological background to the changes, but suggest some possible explanations.”Our findings and the fantastic developments in genetic research make us optimistic that we can continue to map the important differences that cause a failure in the production of insulin and reduced insulin sensitivity, so that we can emphasise personalised treatment in the future,” concludes Damon Tojjar.About the studyIn type 2 diabetes, there are two main physiological functions that fail — the body’s ability to produce insulin and the body’s insulin sensitivity, i.e. the vast majority of cells’ ability to absorb glucose from the blood. …Read more
June 11, 2013 — Using wood for energy is considered cleaner than fossil fuels, but a Dartmouth College-led study finds that logging may release large amounts of carbon stored in deep forest soils.Global atmospheric studies often don’t consider carbon in deep (or mineral) soil because it is thought to be stable and unaffected by timber harvesting. But the Dartmouth findings show deep soil can play an important role in carbon emissions in clear-cutting and other intensive forest management practices. The findings suggest that calls for an increased reliance on forest biomass be re-evaluated and that forest carbon analyses are incomplete unless they include deep soil, which stores more than 50 percent of the carbon in forest soils.”Our paper suggests the carbon in the mineral soil may change more rapidly, and result in increases in atmospheric carbon dioxide, as a result of disturbances such as logging,” said Dartmouth Professor Andrew Friedland, a co-author. “Our paper suggests that increased reliance on wood may have the unintended effect of increasing the transfer of carbon from the mineral soil to the atmosphere. So the intended goal of reducing carbon in the atmosphere may not be met.”The federal government is looking to wood, wind, solar, hydropower and other renewable energy sources to address concerns about climate change and energy security. Woody biomass, which includes trees grown on plantations, managed natural forests and logging waste, makes up about 75 percent of global biofuel production. Mineral soil carbon responses can vary highly depending on harvesting intensity, surface disturbance and soil type.”Analysis of forest carbon cycles is central to understanding and mitigating climate change, and understanding forest carbon cycles requires an in-depth analysis of the storage in and fluxes among different forest carbon pools, which include aboveground live and dead biomass, as well as the belowground organic soil horizon, mineral soil horizon and roots,” Friedland said.Co-authors included Dartmouth’s Thomas Buchholz, a former post-doctoral student, and Claire Hornig, a recent undergraduate student, and researchers from the University of Vermont, Lund University in Sweden and the Vermont Department of Forest, Parks and Recreation. The research was supported by awards to Friedland from the Northeastern States Research Cooperative and the Porter Fund.Friedland’s research focuses on understanding the effects of atmospheric deposition of pollutants and biomass harvesting on elemental cycling processes in high-elevation forests in the Northeastern United States. He considers many elements including carbon, trace elements such as lead and major elements such as nitrogen and calcium. He also is examining issues related to personal choices, energy use and environmental impact.The results appear in the journal Global Change Biology-Bioenergy.Read more
June 3, 2013 — Researchers at Karolinska Institutet in Sweden have found a promising strategy for defeating neuroblastoma — a malignant form of cancer in children — that focuses on the so-called MYCN protein. A specific chemical molecule helps to break down MYCN, which either kills the cancer cell or makes it mature into a harmless neuron. The discovery, which is published in the scientific journal PNAS, raises hopes for new and more effective treatments in the future.Neuroblastoma is the third most common form of cancer in children. It usually develops before the age of two and affects around two dozen children per year in Sweden and around 800 in the US. The tumours are normally located in the peripheral nervous system, but in very young infants they can sometimes spread over the entire body. Current therapies are tough and have serious side effects, and for many of the patients the prognosis is poor. In its most aggressive form only a minority survive, which makes finding alternative treatments particularly urgent.In the case of neuroblastoma, extra copies of the gene that encodes the MYCN protein are normally found in the cancer cell. This in turn is a clear indication of a poor prognosis, as it has long been known that the incorrect activation of the MYCN and similar MYC genes causes cancer. The strategy of the research group for defeating the disease was therefore to identify substances that prevent MYC-triggered cell division or that kill cancer cells in an MYC-specific manner.”We have found that a small chemical molecule, that is known from previous studies to inhibit the activity of the c-MYC-protein, also inhibits the activity of MYCN,” says Principal Investigator Marie Arsenian Henriksson, Professor of molecular tumour biology at Karolinska Institutet. “The substance disrupts the binding between MYCN and another protein called Max, which results in the degradation of MYCN and subsequently either to cell death in neuroblastoma cells with extra copies of the MYCN gene, or to their development into neurons, at which point their malignity disappears. …Read more
June 3, 2013 — More time in front of the TV set and higher exposure to TV adverts may lead to increased consumption of sweetened beverages among children. This is the conclusion of a new study from the University of Gothenburg, Sweden.The parents of more than 1,700 two- to four-year-olds in Sweden responded to questions about their children’s TV and screen habits and consumption of sweetened drinks.About one parent in seven indicated that they tried to reduce their children’s exposure to TV adverts; the same parents stated that their children were less prone to drink soft drinks and other sweetened beverages. Children of parents who were less strict about TV adverts were twice as likely to consume sweetened beverages every week.The study was conducted in 2007-2010 as part of the EU research project IDEFICS — Identification and Prevention of Dietary and Lifestyle -Induced Health Effects in Children and Infants. It reveals a very clear link between children’s TV habits and their consumption of sweetened drinks.’The children who watched more TV were more likely to drink these beverages. In fact, each additional hour in front of the TV increased the likelihood of regular consumption by 50 per cent. A similar link was found for total screen time,’ says Stina Olafsdottir, PhD student at the Department of Food and Nutrition, and Sport Science and one of the researchers behind the study.The study also found that children with higher exposure to food adverts on TV were more likely to consume sweetened beverages on a regular basis in a follow-up study conducted two years after the initial study. However, exposure to TV adverts could not explain the link between TV habit and beverage consumption entirely. It is therefore likely that the TV programmes watched also matter or that children simply enjoy drinking these types of beverages while watching TV.The IDEFICS study is funded under the EU’s Sixth Framework Programme. Eight countries are participating: Belgium, Cyprus, Estonia, Germany, Hungary, Italy, Spain and Sweden. The study presented here is based entirely on Swedish data. …Read more
Apr. 9, 2013 — Environmental change can drive hard-wired evolutionary changes in animal species in a matter of generations. A University of Leeds-led study, published in the journal Ecology Letters, overturns the common assumption that evolution only occurs gradually over hundreds or thousands of years.
Instead, researchers found significant genetically transmitted changes in laboratory populations of soil mites in just 15 generations, leading to a doubling of the age at which the mites reached adulthood and large changes in population size. The results have important implications in areas such as disease and pest control, conservation and fisheries management because they demonstrate that evolution can be a game-changer even in the short-term.
Professor Tim Benton, of the University of Leeds’ Faculty of Biological Sciences, said: “This demonstrates that short-term ecological change and evolution are completely intertwined and cannot reasonably be considered separate. We found that populations evolve rapidly in response to environmental change and population management. This can have major consequences such as reducing harvesting yields or saving a population heading for extinction.”
Although previous research has implied a link between short-term changes in animal species’ physical characteristics and evolution, the Leeds-led study is the first to prove a causal relationship between rapid genetic evolution and animal population dynamics in a controlled experimental setting.
The researchers worked with soil mites that were collected from the wild and then raised in 18 glass tubes. Forty percent of adult mites were removed every week from six of the glass tubes. A similar proportion of juveniles were removed each week in a further six tubes, while no “harvesting” was conducted in the remaining third of the tubes.
Lead author Dr Tom Cameron, a postdoctoral Fellow in the Faculty of Biological Sciences at Leeds at the time of the research and now based in Umeå University, Sweden, said: “We saw significant evolutionary changes relatively quickly. The age of maturity of the mites in the tubes doubled over about 15 generations, because they were competing in a different way than they would in the wild. Removing the adults caused them to remain as juveniles even longer because the genetics were responding to the high chance that they were going to die as soon as they matured. When they did eventually mature, they were so enormous they could lay all of their eggs very quickly.”
The initial change in the mites’ environment — from the wild into the laboratory — had a disastrous effect on the population, putting the mites on an extinction trajectory. However, in every population, including those subjected to the removal of adults or juveniles, the trajectory switched after only five generations of evolution and the population sizes began to increase.
The researchers found that the laboratory environment was selecting for those mites that grew more slowly. Under the competitive conditions in the tubes, the slow growing mites were more fertile when they matured, meaning they could have more babies.
Dr Cameron said: “The genetic evolution that resulted in an investment in egg production at the expense of individual growth rates led to population growth, rescuing the populations from extinction. This is evolutionary rescue in action and suggests that rapid evolution can help populations respond to rapid environmental change.”
Short-term ecological responses to the environment — for instance, a reduction in the size of adults because of a lack of food — and hard-wired evolutionary changes were separated by placing mites from different treatments into a similar environment for several generations and seeing whether differences persisted.
Professor Benton said: “The traditional idea would be that if you put animals in a new environment they stay basically the same but the way they grow changes because of variables like the amount of food. However, our study proves that the evolutionary effect — the change in the underlying biology in response to the environment — can happen at the same time as the ecological response. Ecology and evolution are intertwined,” he said.
Unpicking evolutionary change from ecological responses is particularly important in areas such as the management of fisheries, where human decisions can result in major changes to an entire population’s environment and life histories. The size at which cod in the North Sea mature is about half that of 50 years ago and this change has been linked to a collapse in the cod population because adult fish today are less fertile than their ancestors.
“The big debate has been over whether this is an evolutionary response to the way they are fished or whether this is, for instance, just the amount of food in the sea having a short-term ecological effect. Our study underlined that evolution can happen on a short timescale and even small 1 to 2 per cent evolutionary changes in the underlying biology caused by your harvesting strategy can have major consequences on population growth and yields. You can’t just try to bring the environment back to what it was before and expect everything to return to normal,” Professor Benton said.
The research was funded by the Natural Environment Research Council (NERC) and involved researchers from the University of Leeds and Professor Stuart Piertney of the University of Aberdeen’s School of Biological Sciences.Read more
Dec. 18, 2012 — Hypnotherapy helps fight IBS symptoms. These are the findings of a thesis from Sahlgrenska Academy, University of Gothenburg, Sweden which proposes implementing this treatment method into the care of severe sufferers of this common disease.
Irritable bowel syndrome, or IBS, is an very common stomach disease that manifests as abdominal pain and discomfort, disturbed bowel movements, abdominal swelling and bloating. Recent studies indicate that 10-15 percent of all Swedes suffer from IBS to varying degrees.
Yet researchers still do not know what causes the condition and no effective treatment is available for those suffering from most severe symptoms.
Studies at Sahlgrenska Academy, University of Gothenburg, show that psychological treatment using hypnosis may offer effective, lasting relief. The studies are part of a thesis which concludes that hypnotherapy should be used in clinical care of patients with severe IBS.
“We have four different studies showing that hypnotherapy helps treat IBS, even when the treatment is not provided by highly specialized hypnotherapy centers. The treatment improves gastrointestinal symptoms and quality of life, and patient satisfaction is very high. The method also makes efficient use of health care resources,” says Perjohan Lindfors, doctoral student at Sahlgrenska Academy, University of Gothenburg.
Share this story on Facebook, Twitter, and Google:
Other social bookmarking and sharing tools:
Note: Materials may be edited for content and length. For further information, please contact the source cited above.
Need to cite this story in your essay, paper, or report? Use one of the following formats:
Note: If no author is given, the source is cited instead.Read more
May 21, 2013 — In two critical reports released at the Arctic Council Ministerial Meeting in Kiruna, Sweden on May 15th, the scientific expertise of the Wildlife Conservation Society helped inform an international body of senior government officials about changing conditions in the Arctic, and potential responses to those changes.
The scientific reports reviewed by the ministers are products of contributions from various experts, representing a range of knowledge and traditions — including indigenous perspectives.
The first report, entitled “Arctic Biodiversity Assessment — Status and Trends,” provides the best available science and traditional ecological knowledge on the status and trends of biodiversity in the Arctic. It looks at all aspects of Arctic biodiversity, including all taxonomic groups and ecosystems, and includes a section on recommendations for conservation actions and policy.
WCS Canada’s Associate Conservation Zoologist Dr. Don Reid is the lead author of the “Mammals” chapter of this report, which documents recent and ongoing changes to distribution and abundance of marine and terrestrial mammals, along with an assessment of the likely causes of those changes. In addition, he contributed to the “Synthesis” chapter, which brings together the key findings of all the chapters and lays out recommendations for dealing with trends that have been or may soon be problematic for conservation of species and ecosystems.
Reid summarizes the changes as both negative and positive depending on the species, “The Arctic is changing fast, and for mammals, the changes are most obvious in the shifts in habitat that a warming climate is driving,” said Reid. On the oceans, ice creates habitat, but summer ice is disappearing, creating problems for polar bears, walrus and seals, but opportunities for some whales. On land, substantial tundra is changing to shrub land, which means a loss of feeding habitats for some species such as reindeer, but a novel area of expansion for moose.”
Reid goes on to point out that, “These climate-driven changes then overlay the various other human-induced forces that Arctic wildlife face. This includes new mines, roads, pipelines, oil and gas developments, and increased industrial pollutants, creating a growing complexity of management issues that will require harmonized regulatory regimes internationally, and greater involvement of northern communities in the conservation of the wildlife which are so crucial to their food security and culture.”
A second report, the Arctic Resilience Report (ARR), features the insights of WCS Beringia Director Dr. Martin Robards and makes a science-based assessment of the integrated impacts of change in the Arctic. The report looks at the potential for large shifts in ecosystem services that affect human well-being, and how drivers of change interact to affect the ability of ecosystems and human populations to adapt or transform. In addition, this report offers an evaluation of adaptive strategies.
Dr. Robards is a lead author on the Background/Introduction chapters and the author of Chapter Seven that presents one of four case studies. His chapter discusses the rapid increase in Arctic shipping in the narrow confines of the Bering Strait — the gateway for all vessel traffic passing between the Arctic and Pacific Ocean.
“We found great political challenges for responding to the rapid increase in international vessel traffic in a manner that minimizes risks to the incredible aggregations of marine mammals and the food security of indigenous communities,” said Dr. Robards. “However, there are also great opportunities for learning from successful efforts elsewhere such as on the eastern seaboard of the United States where Atlantic right whales have received greater protection through attention to vessel speeds and routing. Through our continuing work in the Arctic, WCS is well-suited to offer a unique perspective on the issue and to be a critical voice in offering science-based solutions to these challenges that benefit from the active engagement of the region’s indigenous communities.”
Approximately 300 people including ministers, delegates from the eight Arctic states (Canada, Denmark, Finland, Iceland, Norway, Russia, Sweden, and the United States), representatives of indigenous peoples, scientists, and observers gathered in Kiruna to mark the end of the two-year Swedish chairmanship and the beginning of the Canadian chairmanship of the Arctic Council.
The Council is a high level intergovernmental forum promoting cooperation, coordination and interaction among the Arctic States. This includes active involvement by Permanent Participants, including Arctic Indigenous representatives, on common Arctic issues, such as sustainable development and environmental protection.Read more