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
Findings published today reveal that, while farmed salmon are genetically different to their wild counterparts, they are just as fertile. This is important information because millions of farmed salmon escape into the wild — posing threats to wild gene pools.Lead Researcher Prof Matt Gage from UEA’s school of Biological Sciences said: “Around 95 per cent of all salmon in existence are farmed, and domestication has made them very different to wild populations, each of which is locally adapted to its own river system.”Farmed salmon grow very fast, are aggressive, and not as clever as wild salmon when it comes to dealing with predators. These domestic traits are good for producing fish for the table, but not for the stability of wild populations.”The problem is that farmed salmon can escape each year in their millions, getting into wild spawning populations, where they can then reproduce and erode wild gene pools, introducing these negative traits.”We know that recently-escaped farmed salmon are inferior to wild fish in reproduction, but we do not have detailed information on sperm and egg performance, which could have been affected by domestication. Our work shows that farm fish are as potent at the gamete level as wild fish, and if farm escapes can revive their spawning behaviour by a period in the wild, clearly pose a significant threat of hybridisation with wild populations.”Researchers used a range of in vitro fertilization tests in conditions that mimicked spawning in the natural environment, including tests of sperm competitiveness and egg compatibility. All tests on sperm and egg form and function showed that farmed salmon are as fertile as wild salmon — identifying a clear threat of farmed salmon reproducing with wild fish.”Some Norwegian rivers have recorded big numbers of farmed fish present — as much as 50 per cent. Both anglers and conservationists are worried by farmed fish escapees which could disrupt locally adapted traits like timing of return, adult body size, and disease resistance.”Salmon farming is a huge business in the UK, Norway and beyond, and while it does reduce the pressure on wild fish stocks, it can also create its own environmental pressures through genetic disruption.”A viable solution is to induce ‘triploidy’ by pressure-treating salmon eggs just after fertilisation — where the fish grows as normal, but with both sex chromosomes; this is normal for farming rainbow trout. The resulting adult develops testes and ovaries but both are much reduced and most triploids are sterile. These triploid fish can’t reproduce if they escape, but the aquaculture industry has not embraced this technology yet because of fears that triploids don’t perform as well in farms as normal diploid fish, eroding profits.”Story Source:The above story is based on materials provided by University of East Anglia. Note: Materials may be edited for content and length.Read more
Pregnant women who eat a “prudent” diet rich in vegetables, fruits, whole grains and who drink water have a significantly reduced risk of preterm delivery, suggests a study published on bmj.com today. A “traditional” dietary pattern of boiled potatoes, fish and cooked vegetables was also linked to a significantly lower risk.Although these findings cannot establish causality, they support dietary advice to pregnant women to eat a balanced diet including vegetables, fruit, whole grains, and fish and to drink water.Preterm delivery (before 37 weeks of pregnancy) is associated with significant short and long term ill-health and accounts for almost 75% of all newborn deaths.Evidence shows that a mother’s dietary habits can directly affect her unborn child, so researchers based in Sweden, Norway and Iceland set out to examine whether a link exists between maternal diet and preterm delivery.Using data from the Norwegian Mother and Child Cohort Study, they analyzed preterm births among 66,000 women between 2002 and 2008.To be included, participants had to be free of diabetes, have delivered a live single baby, and completed a validated food frequency questionnaire on dietary habits during the first four to five months of pregnancy.Factors that may have affected the results (known as confounding), including a mother’s age, history of preterm delivery and education were taken into account. Preterm delivery was defined as delivery between 22 and <37 weeks of pregnancy.</p>The researchers identified three distinct dietary patterns, interpreted as “prudent” (vegetables, fruits, oils, water as a beverage, whole grain cereals, poultry, fibre rich bread), “Western” (salty and sweet snacks, white bread, desserts, processed meat products), and “traditional” (potatoes, fish, gravy, cooked vegetables, low fat milk).Among the 66,000 pregnant women, preterm delivery occurred in 3,505 (5.3%) cases.After adjusting for several confounding factors, the team found that an overall “prudent” dietary pattern was associated with a significantly reduced risk of preterm delivery, especially among women having their first baby, as well as spontaneous and late preterm delivery.They also found a significantly reduced risk of preterm delivery for the “traditional” dietary pattern. However, the “Western” dietary pattern was not independently associated with preterm delivery.This indicates that increasing the intake of foods associated with a prudent dietary pattern is more important than totally excluding processed food, fast food, junk food, and snacks, say the authors.They stress that a direct (causal) link cannot be drawn from the results, but say the findings suggest that “diet matters for the risk of preterm delivery, which may reassure medical practitioners that the current dietary recommendations are sound but also inspire them to pay more attention to dietary counselling.”These findings are important, as prevention of preterm delivery is of major importance in modern obstetrics. They also indicate that preterm delivery might actually be modified by maternal diet, they conclude.In an accompanying editorial, Professor Lucilla Poston at King’s College London, says healthy eating in pregnancy is always a good idea.She points to several studies that have proposed the benefit of a diet rich in fruit and/or vegetables in prevention of premature birth, and says health professionals “would therefore be well advised to reinforce the message that pregnant women eat a healthy diet.”Read more
Members of the German research network BIOACID (Biological Impacts of Ocean Acidification) are developing a model that links ecosystem changes triggered by ocean acidification and climate change with their economic and societal consequences. Workshops and interviews with stakeholders from the Norwegian fishing industry and tourism sector, the government and environmental organisations help them to identify key aspects for their assessment.During the past ten years, scientists have learned a lot about the effects of ocean acidification on marine ecosystems. It has become obvious that with rising carbon dioxide emissions from human activities, oceans absorb larger amounts of this greenhouse gas and become more acidic. The increase of acidity, rising water temperatures and other stressors may alter marine ecosystems dramatically — with consequences for economy and society.Do stakeholders of the economic sectors which depend on the sea already observe signs of ocean change? Which are their most urgent questions towards science? Within the framework of the German research network BIOACID (Biological Impacts of Ocean Acidification), scientists from the University of Bremen investigated stakeholders’ state of knowledge and identified focal points for further research. Between March and November 2013, they held workshops and interviewed more than 30 Norwegian fishers, representatives from fishing associations, aquaculture, tourism, environmental organisations and governmental agencies. They aim to develop a model that yields insights into the overall impacts of ocean change for ecosystems and the services they provide to human societies.”Taking a systems view can help to analyse socio-economic impacts of ocean acidification and find ways to mitigate them and adapt to them,” Dr. Stefan Gling-Reisemann, researcher at the Sustainability Research Center (artec) at the University of Bremen explains. “This is why we connect stakeholders and scientists and adapt further research to the demands of society.” Norway was chosen because the fishing industry, a branch that is likely to be hit first by effects of climate change, plays a very important economic role there. …Read more
Sep. 11, 2013 — Some of the hottest days and coldest nights in parts of Europe have warmed more than four times the global average change since 1950, according to a new paper by researchers from the Grantham Research Institute on Climate Change and the Environment at the London School of Economics and Political Science and the University of Warwick, which is published today (11 September 2013) in the journal Environmental Research Letters.The researchers translated observations of weather into observations of climate change using a gridded dataset of observations stretching back to 1950. The hottest 5 per cent of days in summer have warmed fastest in a band from southern England and northern France to Denmark. By contrast, the average and slightly hotter than average days have warmed most in regions further south in France and Germany. In eastern Spain and central Italy there has been broad warming across all types of days, but in most places those days which are cooler than average have not warmed so much.The paper points out that some locations and temperature thresholds have seen little change since 1950. The authors suggest that the results highlight the scale of the difference between global change and the local climate changes felt by individuals.Dr. David Stainforth, the lead author on the paper, said: “Climate is fundamentally the distributions of weather. As climate changes, the distributions change. But they don’t just shift, they change shape. How they change shape depends on where you are. …Read more
Sep. 10, 2013 — Use of stimulant medications to treat Attention-Deficit/Hyperactivity Disorder (ADHD) in children and adolescents has increased significantly over the past several years. This trend toward increased use of prescription stimulants extends beyond ADHD to other types of neuropsychiatric disorders in children and teens as well, including Autism Spectrum Disorder (ASD), according to a study published in Journal of Child and Adolescent Psychopharmacology.Share This:Søren Dalsgaard, MD, PhD, Helena Skyt Nielsen, PhD, and Marianne Simonsen, PhD, Aarhus University (Denmark), Lundbeck Foundation Initiative for Integrative Psychiatric Research (Denmark), and Hospital of Telemark (Norway), conducted a study of more than 850,000 children born in Denmark between 1990 and 2001. They found that 61% of children with ADHD, 16% of children with ASD, and 3% of those with other psychiatric disorders were treated with one or more medications typically prescribed for ADHD—methylphenidate, dexamphetamine, and atomoxetine. The data indicated significant increases in the prescription rates of these medications during the years 2003 to 2010.”This study utilizes a population-based national cohort of children and adolescents, and assesses stimulant treatment in children and adolescents with ASD,” says Harold S. Koplewicz, MD, Editor-in-Chief of JCAP, and President, Child Mind Institute, New York, NY. “This is the largest and first prospective study to quantify the change in the use of treatment with ADHD medications over time.”Share this story on Facebook, Twitter, and Google:Other social bookmarking and sharing tools:|Story Source: The above story is based on materials provided by Mary Ann Liebert, Inc., Publishers. Note: Materials may be edited for content and length. For further information, please contact the source cited above. Journal Reference:Søren Dalsgaard, Helena Skyt Nielsen, Marianne Simonsen. …Read more
Sep. 3, 2013 — New drugs which may have the potential to stop faulty brain cells dying and slow down the progression of Parkinson’s, have been identified by scientists in a pioneering study which is the first of its kind.Experts from the world leading Sheffield Institute for Translational Neuroscience (SITraN) conducted a large scale drugs trial in the lab using skin cells from people with this progressive neurological condition which affects one in every 500 people in the UK.The researchers tested over 2,000 compounds to find out which ones could make faulty mitochondria work normally again.Mitochondria act as the power generators in all cells of our body, including the brain. Malfunctioning mitochondria are one of the main reasons why brain cells die in Parkinson’s.One of the promising medications identified though the research is a synthetic drug called ursodeoxycholic acid (UDCA).This licenced drug has been in clinical use for several decades to treat certain forms of liver disease which means that researchers will be able to immediately start a clinical trial to test its safety and tolerability in people with Parkinson’s.This will discover the optimum dose to ensure that enough of the drug reaches the part of the brain where Parkinson’s develops.Based on this information, larger randomized controlled trials can be carried out to assess the potential of UDCA to treat Parkinson’s.The extensive drug screen, which took over five years to complete, was funded by leading research charity Parkinson’s UK, and was carried out in collaboration with the University of Trondheim, Norway.Dr Oliver Bandmann, Reader in Neurology at SITraN, said: “Parkinson’s is so much more than just a movement disorder.It can also lead to depression and anxiety, and a host of distressing day to day problems like bladder and bowel dysfunction.”The best treatments currently available only improve some of the symptoms, rather than tackle the reason why Parkinson’s develops in the first place, so there is a desperate need for new drug treatments which could actually slow down the disease progression.””We are hopeful that this group of drugs can one day make a real difference to the lives of people with Parkinson’s.”The results of the ground breaking study are published in the leading Neuroscience journal BRAIN.Dr Kieran Breen, Director of Research and Innovation at Parkinson’s UK commented: “This is a really exciting time for Parkinson’s research. For the first time, we are starting to identify drugs that will treat the Parkinson’s — possibly slow down or halt its progression — rather than just the symptoms.”This will bring us closer to our ultimate goal of a cure for Parkinson’s. We look forward to working closely with Dr Bandmann to develop this treatment.”Read more
Aug. 19, 2013 — The use of LSD, magic mushrooms, or peyote does not increase a person’s risk of developing mental health problems, according to an analysis of information from more than 130,000 randomly chosen people, including 22,000 people who had used psychedelics at least once.Researcher Teri Krebs and clinical psychologist Pål-Ørjan Johansen, from the Norwegian University of Science and Technology’s (NTNU) Department of Neuroscience, used data from a US national health survey to see what association there was, if any, between psychedelic drug use and mental health problems.The authors found no link between the use of psychedelic drugs and a range of mental health problems. Instead they found some significant associations between the use of psychedelic drugs and fewer mental health problems.The results are published in the journal PLOS ONE and are freely available online after 19 August.Symptoms and mental health treatment consideredThe researchers relied on data from the 2001-2004 National Survey on Drug Use and Health, in which participants were asked about mental health treatment and symptoms of a variety of mental health conditions over the past year. The specific symptoms examined were general psychological distress, anxiety disorders, mood disorders, and psychosis.Armed with this information, Krebs and Johansen were able to examine if there were any associations between psychedelic use and general or specific mental health problems. They found none.”After adjusting for other risk factors, lifetime use of LSD, psilocybin, mescaline or peyote, or past year use of LSD was not associated with a higher rate of mental health problems or receiving mental health treatment,” says Johansen.Could psychedelics be healthy for you?The researchers found that lifetime use of psilocybin or mescaline and past year use of LSD were associated with lower rates of serious psychological distress. Lifetime use of LSD was also significantly associated with a lower rate of outpatient mental health treatment and psychiatric medicine prescription.The design of the study makes it impossible to determine exactly why the researchers found what they found.”We cannot exclude the possibility that use of psychedelics might have a negative effect on mental health for some individuals or groups, perhaps counterbalanced at a population level by a positive effect on mental health in others,” they wrote.Nevertheless, “recent clinical trials have also failed to find any evidence of any lasting harmful effects of psychedelics,” the researchers said, which supports the robustness of the PLOS ONE findings.In fact, says Krebs, “many people report deeply meaningful experiences and lasting beneficial effects from using psychedelics.””Other studies have found no evidence of health or social problems among people who had used psychedelics hundreds of times in legally-protected religious ceremonies,” adds Johansen.What’s the bottom line on psychedelic use?Psychedelics are different than most other recreational drugs. Experts agree that psychedelics do not cause addiction or compulsive use, and they are not known to harm the brain.When evaluating psychedelics, as with any activity, it is important to take an objective view of all the evidence and avoid being biased by anecdotal stories either of harm or benefit, the researchers say.”Everything has some potential for negative effects, but psychedelic use is overall considered to pose a very low risk to the individual and to society,” Johansen says, “Psychedelics can elicit temporary feelings of anxiety and confusion, but accidents leading to serious injury are extremely rare.””Early speculation that psychedelics might lead to mental health problems was based on a small number of case reports and did not take into account either the widespread use of psychedelics or the not infrequent rate of mental health problems in the general population,” Krebs explains.”Over the past 50 years tens of millions of people have used psychedelics and there just is not much evidence of long-term problems,” she concludes.Both researchers were supported by the Research Council of Norway.Read more
July 30, 2013 — Raising fish in tanks that contain hiding places and other obstacles can make the fish both smarter and improve their chances of survival when they are released into the wild, according to an international team of researchers.”It’s a key problem in that we are very good at rearing fish, but we’re really not very good at releasing those animals in the wild such that they survive,” said Victoria Braithwaite, professor of fisheries and biology, Penn State. “There’s a mismatch between the way we raise them and the real world.”Juvenile Atlantic salmon raised in tanks that including pebble and rock hiding places and floating artificial plants were better able to navigate mazes and showed signs of improved brain function compared to the salmon reared in standard hatchery tanks, Braithwaite said. This may help conservation fish hatcheries raise and release fish that are better adapted to survive in the wild.Conservation fish hatcheries raise cod, salmon, trout and other types of fish and release them in places where their species may be threatened, or where their populations are declining.”The philosophy of most fish hatcheries is to rear a large number of fish and hope some survive,” said Braithwaite. “What this study is suggesting is that you could raise fewer, but smarter fish, and you will still have higher survivability once you release them.”The researchers, who released their findings today (July 31) in the Proceedings of the Royal Society B, placed pebbles and rocks at the bottom of the tank and added plastic plants weighted down so they would float vertically in the water. Braithwaite said the objects created a more natural, three-dimensional ecosystem.”In the hatchery the world is homogenous, life is boring and monotonous,” Braithwaite said. “The water flow is the same, you don’t have to find your food and you don’t have to avoid predators.”The researchers also moved the objects around about once a week during the eight-week study, which took place in Norway.When the researchers placed the salmon in a maze, the fish raised in the enriched tanks made fewer mistakes when trying to escape the maze, Braithwaite said. The performance of the salmon from the enriched tank continued to improve with each trial, and they learned to solve the maze much faster than fish reared the standard way.The brains of the fish from the enriched tank were also different from the fish raised in the standard hatchery tanks, according to the researchers.They noted increased expressions of a gene in a region of the fish’s brain that is associated with learning and memory, an indication of increased brain function and growth. The fish raised in standard tanks did not show this sign of increased brain development.Interacting with the environment can influence gene expression in the brain, Braithwaite said.”The brain is a very plastic organ, it’s a dynamic structure,” said Braithwaite, who worked with Ann Gro Vea Salvanes, professor of biology; OlavMoberg, doctoral student; Tome Ole Nilsen, researcher in marine development biology; Knut Helge Jensen, senior engineer in evolutionary ecology, all at the University of Bergen, Norway; and Lars O.E. Ebbesson, group leader of integrative fish biology, Uni Research, Bergen. Braithwaite said the enriched tanks created significant improvement in the intelligence and adaptability of the fish, but were relatively inexpensive and easy to implement. …Read more
July 14, 2013 — At the end of the last Ice Age, as the world began to warm, a swath of the North Pacific Ocean came to life. During a brief pulse of biological productivity 14,000 years ago, this stretch of the sea teemed with phytoplankton, amoeba-like foraminifera and other tiny creatures, who thrived in large numbers until the productivity ended — as mysteriously as it began — just a few hundred years later.Researchers have hypothesized that iron sparked this surge of ocean life, but a new study led by Woods Hole Oceanographic Institution (WHOI) scientists and colleagues at the University of Bristol (UK), the University of Bergen (Norway), Williams College and the Lamont Doherty Earth Observatory of Columbia University suggests iron may not have played an important role after all, at least in some settings. The study, published in the journal Nature Geoscience, determines that a different mechanism — a transient “perfect storm” of nutrients and light — spurred life in the post-Ice Age Pacific. Its findings resolve conflicting ideas about the relationship between iron and biological productivity during this time period in the North Pacific — with potential implications for geo-engineering efforts to curb climate change by seeding the ocean with iron.”A lot of people have put a lot of faith into iron — and, in fact, as a modern ocean chemist, I’ve built my career on the importance of iron — but it may not always have been as important as we think,” says WHOI Associate Scientist Phoebe Lam, a co-author of the study.Because iron is known to cause blooms of biological activity in today’s North Pacific Ocean, researchers have assumed it played a key role in the past as well. They have hypothesized that as Ice Age glaciers began to melt and sea levels rose, they submerged the surrounding continental shelf, washing iron into the rising sea and setting off a burst of life.Past studies using sediment cores — long cylinders drilled into the ocean floor that offer scientists a look back through time at what has accumulated there — have repeatedly found evidence of this burst, in the form of a layer of increased opal and calcium carbonate, the materials that made up phytoplankton and foraminifera shells. But no one had searched the fossil record specifically for signs that iron from the continental shelf played a part in the bloom.Lam and an international team of colleagues revisited the sediment core data to directly test this hypothesis. They sampled GGC-37, a core taken from a site near Russia’s Kamchatka Peninsula, about every 5 centimeters, moving back through time to before the biological bloom began. Then they analyzed the chemical composition of their samples, measuring the relative abundance of the isotopes of the elements neodymium and strontium in the sample, which indicates which variant of iron was present. The isotope abundance ratios were a particularly important clue, because they could reveal where the iron came from — one variant pointed to iron from the ancient Loess Plateau of northern China, a frequent source of iron-rich dust in the northwest Pacific, while another suggested the younger, more volcanic continental shelf was the iron source.What the researchers found surprised them.”We saw the flux of iron was really high during glacial times, and that it dropped during deglaciation,” Lam says. “We didn’t see any evidence of a pulse of iron right before this productivity peak.”The iron the researchers did find during glacial times appeared to be supplemented by a third source, possibly in the Bering Sea area, but it didn’t have a significant effect on the productivity peak. …Read more
May 29, 2013 — During the last ice age, when thick ice covered the Arctic, many scientists assumed that the deep currents below that feed the North Atlantic Ocean and help drive global ocean currents slowed or even stopped. But in a new study in Nature, researchers show that the deep Arctic Ocean has been churning briskly for the last 35,000 years, through the chill of the last ice age and warmth of modern times, suggesting that at least one arm of the system of global ocean currents that move heat around the planet has behaved similarly under vastly different climates.
“The Arctic Ocean must have been flushed at approximately the same rate it is today regardless of how different things were at the surface,” said study co-author Jerry McManus, a geochemist at Columbia University’s Lamont-Doherty Earth Observatory.
Researchers reconstructed Arctic circulation through deep time by measuring radioactive trace elements buried in sediments on the Arctic seafloor. Uranium eroded from the continents and delivered to the ocean by rivers, decays into sister elements thorium and protactinium. Thorium and protactinium eventually attach to particles falling through the water and wind up in mud at the bottom. By comparing expected ratios of thorium and protactinium in those ocean sediments to observed amounts, the authors showed that protactinium was being swept out of the Arctic before it could settle to the ocean bottom. From the amount of missing protactinium, scientists can infer how quickly the overlying water must have been flushed at the time the sediments were accumulating.
“The water couldn’t have been stagnant, because we see the export of protactinium,” said the study’s lead author, Sharon Hoffmann, a geochemist at Lamont-Doherty.
The upper part of the modern Arctic Ocean is flushed by North Atlantic currents while the Arctic’s deep basins are flushed by salty currents formed during sea ice formation at the surface. “The study shows that both mechanisms must have been active from the height of glaciation until now,” said Robert Newton, an oceanographer at Lamont-Doherty who was not involved in the research. “There must have been significant melt-back of sea ice each summer even at the height of the last ice age to have sea ice formation on the shelves each year. This will be a surprise to many Arctic researchers who believe deep water formation shuts down during glaciations.”
The researchers analyzed sediment cores collected during the U.S.-Canada Arctic Ocean Section cruise in 1994, a major Arctic research expedition that involved several Lamont-Doherty scientists. In each location, the cores showed that protactinium has been lower than expected for at least the past 35,000 years. By sampling cores from a range of depths, including the bottom of the Arctic deep basins, the researchers show that even the deepest waters were being flushed out at about the same rate as in the modern Arctic.
The only deep exit from the Arctic is through Fram Strait, which divides Greenland and Norway’s Svalbard islands. The deep waters of the modern Arctic flow into the North Atlantic via the Nordic seas, contributing up to 40 percent of the water that becomes North Atlantic Deep Water — known as the “ocean’s lungs” for delivering oxygen and salt to the rest of world’s oceans.
One direction for future research is to find out where the missing Arctic protactinium of the past ended up. “It’s somewhere,” said McManus. “All the protactinium in the ocean is buried in ocean sediments. If it’s not buried in one place, it’s buried in another. Our evidence suggests it’s leaving the Arctic but we think it’s unlikely to get very far before being removed.”Read more