Misleading mineral may have resulted in overestimate of water in moon

The amount of water present in the moon may have been overestimated by scientists studying the mineral apatite, says a team of researchers led by Jeremy Boyce of the UCLA Department of Earth, Planetary and Space Sciences.Boyce and his colleagues created a computer model to accurately predict how apatite would have crystallized from cooling bodies of lunar magma early in the moon’s history. Their simulations revealed that the unusually hydrogen-rich apatite crystals observed in many lunar rock samples may not have formed within a water-rich environment, as was originally expected.This discovery has overturned the long-held assumption that the hydrogen in apatite is a good indicator of overall lunar water content.”The mineral apatite is the most widely used method for estimating the amount of water in lunar rocks, but it cannot be trusted,” said Boyce, who is an adjunct assistant professor in the UCLA College of Letters and Science. “Our new results show that there is not as much water in lunar magma as apatite would have us believe.”The research was published online March 20 in the journal Science on and will be published in a future print edition.For decades, scientists believed the moon was almost entirely devoid of water. However, the discovery of hydrogen-rich apatite within lunar rocks in 2010 seemed to hint at a more watery past. Scientists originally assumed that information obtained from a small sample of apatite could predict the original water content of a large body of magma, or even the entire moon, but Boyce’s study indicates that apatite may, in fact, be deceptive.Boyce believes the high water content within lunar apatite results from a quirk in the crystallization process rather than a water-rich lunar environment. When water is present as molten rock cools, apatite can form by incorporating hydrogen atoms into its crystal structure. However, hydrogen will be included in the newly crystallizing mineral only if apatite’s preferred building blocks, fluorine and chlorine, have been mostly exhausted.”Early-forming apatite is so fluorine-rich that it vacuums all the fluorine out of the magma, followed by chlorine,” Boyce said. “Apatite that forms later doesn’t see any fluorine or chlorine and becomes hydrogen-rich because it has no choice.”Therefore, when fluorine and chlorine become depleted, a cooling body of magma will shift from forming hydrogen-poor apatite to forming hydrogen-rich apatite, with the latter not accurately reflecting the original water content in the magma.Understanding the story of lunar apatite has implications beyond determining how much water is locked inside lunar rocks and soil. According to the predominant theory of how the moon originally formed, hydrogen and other volatile elements should not be present at all in lunar rocks.Many scientists theorize that the moon formed when a giant impact tore free a large chunk of Earth more than 4 billion years ago. If this “giant impact” model is correct, the moon would have been completely molten, and lighter elements such as hydrogen should have bubbled to the surface and escaped into space. …

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Seal teeth offer glimpse into the environmental past of Russia’s Lake Baikal

March 21 marks World Water Day — and a fitting time to consider one of the most unique mammals in Earth’s waters.The nerpa, also known as the Baikal seal, is the only seal that lives exclusively in fresh water. This earless seal can be found in just one place, Russia’s Lake Baikal, where it is at the top of the food web. And now, Wellesley scientists have found that the teeth of this particular seal may hold the strongest evidence of the effects of decades of environmental pollution, nuclear testing, and climate change on Lake Baikal — the deepest, oldest, and most bio-diverse lake in the world.”The Baikal seal teeth are a chemical record of the lake,” said Marianne Moore, Wellesley Professor of Biological Sciences. By analyzing the chemical composition of hundreds of seal teeth, Professor Moore and her co-researchers, post-doctoral fellow Ted Ozersky and Wellesley student Xiu Ying (Annie) Deng ’15, are working to reconstruct the Baikal seal’s diet and contaminant burdens over the last 80 years. The teeth were collected from ice harvested in the area by fellow scientists in Russia.Baikal seals can live up to 40 and 50 years, and much like the rings of a tree trunk, the layers of dentine within their teeth can be studied and linked to environmental patterns and changes over a period of time. Moore, Ozersky, and Deng are looking for evidence of toxic metals such as uranium, mercury, cadmium, and zinc inside the teeth samples, which date back to the period before industrialization in the region.Why not just measure these toxic elements in the water? Professor Moore explained that these metals show up at extremely low levels in the water. The teeth of the nerpa are actually better indicators due to biomagnification, the process by which the concentration of a substance increases with each level of the food chain. Because the Baikal seal is at the top of its food web, their teeth hold the best clues into the lake’s environmental past.”Ultimately, the goal of our project is to study contamination levels in Lake Baikal as reflected by the seals, and to tie these patterns to changes in the watershed, such as the introduction of mining in the area, an increase in coal burning, and other environmental events,” said Dr. Ozersky.Still early in the project, the Wellesley researchers have already made a surprising discovery: levels of some toxic metals such as uranium were higher in the mid 1970’s than in seals today. …

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Ambitious new pollution targets needed to protect Lake Erie from massive ‘dead zone’

Reducing the size of the Lake Erie “dead zone” to acceptable levels will require cutting nutrient pollution nearly in half in coming decades, at a time when climate change is expected to make such reductions more difficult.That’s one of the main conclusions of a comprehensive new study that documents recent trends in Lake Erie’s health. It offers science-based guidance to policymakers seeking to reduce the size of toxic algae blooms and oxygen-starved regions called hypoxic zones, or dead zones — two related water-quality problems that have seen a resurgence in the lake since the mid-1990s.The report from the multi-institution EcoFore-Lake Erie project states that a 46 percent reduction in the amount, or load, of phosphorus pollution would be needed to shrink Lake Erie’s Central Basin hypoxic zone to a size last seen in the mid-1990s — a time that coincided with the recovery of several recreational and commercial fisheries in the lake’s west and central basins.Phosphorus is a nutrient used in crop fertilizers. Excess phosphorus washes off croplands during rainstorms and flows downstream in rivers that feed the Great Lakes. Once in the lakes, phosphorus can trigger algae blooms. When the algae die and sink to the lake bottom, oxygen-consuming bacteria feed on them and create hypoxic zones in the process. Many fish shun these oxygen-starved waters, which significantly reduce the amount of suitable habitat available to the fish.The study, accepted for publication in a forthcoming edition of the Journal of Great Lakes Research, calls for Central Basin phosphorus reductions considerably higher than other recent recommendations, including a proposal issued last year by the Ohio Lake Erie Phosphorus Task Force aimed at avoiding Western Basin toxic algae blooms. The new report is a synthesis of the major findings from the EcoFore-Lake Erie project, created in 2005 and supported by the U.S. National Oceanic and Atmospheric Administration’s Center for Sponsored Coastal Ocean Research.”The new target is very ambitious but is achievable if the region agrees to adopt agricultural practices that help reduce the amount of phosphorus-bearing fertilizer washing off fields,” said aquatic ecologist Donald Scavia, director of the University of Michigan’s Graham Sustainability Institute and EcoFore-Lake Erie principal investigator. “We believe this EcoFore synthesis report provides important input to the U.S. and Canadian teams charged with setting new phosphorus load targets for Lake Erie.”The EcoFore recommendations are aimed at policymakers who will update the binational Great Lakes Water Quality Agreement. …

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

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

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Can the solution to climate change help eliminate poverty?

It is clear that climate change and poverty are two separate problems that affect all corners of the world, but can the solution to one help eliminate the other? Richard Munang and Jessica Andrews, authors of “Harnessing Ecosystem-Based Adaptation: To Address the Social Dimensions of Climate Change,” published in Environment: Science and Policy for Sustainable Development, think that we can.Ecosystem-Based Adaptation (EbA) is becoming more widely recognized as a possible solution to addressing climate change. “EbA is the use of biodiversity and ecosystem services as part of an overall adaptation to help people and communities adapt to the negative effects of climate change at local, regional, and global levels.” It works by providing sustainable social benefits for a local community within climate change adaptation practices. This idea understands the relationship and interconnectivity between many different facets of life; ecological, social/cultural, economic, and institutional.EbA is built to successfully implement sustained social and environmental achievements. Developing a community’s resilience in the face of climate change impacts improves the wellness of the entire ecosystem. “EbA can accelerate income gains, improve health, and secure food production, all while ensuring the sustainable development of local resources.” Munang and Andrews provide examples where this program has been successful. In Togo, Africa, EbA aided in the revitalization of water reservoirs, as well as cereal and vegetable production in the savannah region, directly benefiting women and youth groups. The extraordinary and integral component of this program is the collaboration between nongovernmental and civil society organizations (NGOs and CSOs, respectively) and the local community. This resulted in improved access to water, an array of social benefits, and a trained community competent to take an active role in future resilience efforts.However, there are some problems. The success of EbA depends largely on the involvement of the local community in the planning and implementation process, while also taking into consideration the overall political context and land use conflicts. …

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Remote sensing moisture model could aid farmers

Global farmers could get better decision-making help as refinements are made to North Alabama soil moisture modeling research being done by an atmospheric science doctoral student at The University of Alabama in Huntsville (UAH).The models indicate how much added moisture would be needed in a given area versus historical data to achieve various crop yields, and they could aid in making expensive infrastructure investments by helping to determine their economic viability.”The important thing that I want to stress is that this is not a predictive model, it is a decision-support model. It helps farmers and officials make decisions based on historical weather patterns,” says doctoral student Vikalp Mishra. In areas where water is in short supply, irrigation infrastructure can be expensive and the model could help to determine its economic cost effectiveness.Mishra was the primary author of a paper with his advisor and UAH associate professor of atmospheric science Dr. John Mecikalski, UAH Earth System Science Center principle researcher James Cruise, and researchers from the University of Maryland-College Park and the U.S. Dept. of Agriculture’s Hydrology and Remote Sensing Laboratory in Beltsville, Md.The model uses satellite data to determine the amount of soil moisture present and then estimates yields based on available moisture. Water is at the center of nearly all farming decisions. It affects the crop cultivar, the variety of seed planted, the amount and type of fertilizer required and the amount of irrigation needed to produce a given weight of grain.Researchers begin by using satellite derived evapotranspiration estimates at thermal infrared bands to deduce the amount of moisture being transpired by plants. Moisture data are derived from the Geostationary Operational Environmental Satellites (GOES). GOES data are inputted into the Atmosphere-Land Exchange Inverse (ALEXI) model, previously developed by Dr. …

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Nasty parasitic worm, common in wildlife, now infecting U.S. cats

When Cornell University veterinarians found half-foot-long worms living in their feline patients, they had discovered something new: The worms, Dracunculus insignis, had never before been seen in cats.”First Report of Dracunculus Insignis in Two Naturally Infected Cats from the Northeastern USA,” published in the February issue of the Journal of Feline Medicine and Surgery, document the first proof that this raccoon parasite can infect cats.The worms can grow to almost a foot long and must emerge from its host to lay eggs that hatch into larvae. It forms a blister-like protrusion in an extremity, such as a leg, from which it slowly emerges over the course of days to deposit its young into the water.Worms in the Dracunculus genus are well known in human medicine. D. insignis’ sister worm, the waterborne Guinea worm, infected millions of humans around the world until eradication efforts beginning in the 1980s removed it from all but four countries — with only 148 cases reported in 2013. Other Dracunculus worms infect a host of other mammals — but Dranunculus insignis mainly infects raccoons and other wild mammals and, in rare cases, dogs. It does not infect humans.The cats that contracted the Dranunculus insignis worms likely ingested the parasites by drinking unfiltered water or by hunting frogs,” said Araceli Lucio-Forster, a Cornell veterinary researcher and the paper’s lead author.It takes a year from the time a mammal ingests the worm until the females are ready to migrate to an extremity and start the cycle anew.While the worms do little direct harm beyond creating shallow ulcers in the skin, secondary infections and painful inflammatory responses may result from the worm’s emergence from the host. There are no drugs to treat a D. insignis infection — the worms must be removed surgically.”Although rare in cats, this worm may be common in wildlife and the only way to protect animals from it is to keep them from drinking unfiltered water and from hunting — in other words, keep them indoors,” said Lucio-Forster.Story Source:The above story is based on materials provided by Cornell University. The original article was written by Joe Schwartz. Note: Materials may be edited for content and length.

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Seed-filled buoys may help restore diverse sea meadows in San Francisco Bay

A pearl net filled with seedpods, tethered by a rope anchored in the coastal mud but swaying with the tide, could be an especially effective way to restore disappearing marine meadows of eelgrass, according to a new study.The resulting crop of eelgrass grown by SF State researchers is as genetically diverse as the natural eelgrass beds from which the seeds were harvested, said Sarah Cohen, an associate professor of biology at the Romberg Tiburon Center. As eelgrass meadows are threatened by a number of human activities, restoration plans that maintain diversity are more likely to succeed, she noted.The emphasis on genetic diversity is a relatively new concern in ecosystem restoration projects, where there has been an understandable urgency to move plants and animals back into an area as quickly as possible. “It’s taken a little longer for people to say, ‘we need to know who we’re moving,'” Cohen said, “and to explore how successful different genotypes are in different settings, so we can more strategically design the movement of individuals for restoration.”Eelgrass restoration projects are challenging because it’s not easy to plant seedlings under the water, and seeds scattered over a large area could be washed away from the restoration site. Instead, RTC researchers tested the Buoy Deployed Seeding (BuDS) restoration technique. They first harvested eelgrass seedpods from several eelgrass beds in San Francisco Bay, then suspended the pods within floating nets over experimental tanks (called mesocosms) supplied with Bay water and with or without sediment from the original eelgrass areas. As the seeds inside each pod ripened, a few at a time, they dropped out of the nets and began to grow within the tanks.The researchers then examined “genetic fingerprints” called microsatellites from the plants to measure the genetic diversity in each new crop. Genetic diversity can be measured in a number of ways, by looking at the number of different variants in a gene in a population, for instance, or by examining how these variants are mixed in an individual.Based on these measurements and others, the new crops were nearly as genetically diverse as their parent grass beds, Cohen and colleagues found. “These offspring impressively maintained the genetic diversity and distinctiveness of their source beds in their new mesocosm environments at the RTC-SFSU lab,” said Cohen.”I think it’s impressive how well it worked for a relatively small scale design,” she added, “and that’s one of the things we wanted to point out in the paper, since a lot of eelgrass restoration projects are so small, up to a few acres.”Sea grass meadows are a key marine environment under siege. In their healthy state, they stabilize coastal sediment and provide a huge nursery for a variety of algae, fish, shellfish and birds. But a variety of human influences, from bridge building to runoff pollution to smothering loads of sediment, have threatened these grass beds globally.They’re often overlooked and misunderstood, Cohen said. …

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Crocodilians can climb trees and bask in the tree crowns

When most people envision crocodiles and alligators, they think of them waddling on the ground or wading in water — not climbing trees. However, a University of Tennessee, Knoxville, study has found that the reptiles can climb trees as far as the crowns.Vladimir Dinets, a research assistant professor in the Department of Psychology, is the first to thoroughly study the tree-climbing and -basking behavior. The research is published in the journal Herpetology.Dinets and his colleagues observed crocodilian species on three continents — Australia, Africa and North America — and examined previous studies and anecdotal observations. They found that four species climbed trees — usually above water — but how far they ventured upward and outward varied by their sizes. The smaller crocodilians were able to climb higher and further than the larger ones. Some species were observed climbing as far as four meters high in a tree and five meters down a branch.”Climbing a steep hill or steep branch is mechanically similar, assuming the branch is wide enough to walk on,” the authors wrote. “Still, the ability to climb vertically is a measure of crocodiles’ spectacular agility on land.”The crocodilians seen climbing trees, whether at night or during the day, were skittish of being approached, jumping or falling into the water when an approaching observer was as far as 10 meters away. This response led the researchers to believe that the tree climbing and basking are driven by two conditions: thermoregulation and surveillance of habitat.”The most frequent observations of tree-basking were in areas where there were few places to bask on the ground, implying that the individuals needed alternatives for regulating their body temperature,” the authors wrote. “Likewise, their wary nature suggests that climbing leads to improved site surveillance of potential threats and prey.”The data suggests that at least some crocodilian species are able to climb trees despite lacking any obvious morphological adaptations to do so.”These results should be taken into account by paleontologists who look at changes in fossils to shed light on behavior,” said Dinets. “This is especially true for those studying extinct crocodiles or other Archosaurian taxa.”Dinets collaborated with Adam Britton from Charles Darwin University in Australia and Matthew Shirley from the University of Florida.Research by Dinets published in 2013 found another surprising crocodilian characteristic — the use of lures such as sticks to hunt prey. …

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Water supply availability ‘to dominate U.S. natural resource management’

Water supply is the most pressing environmental issue facing the United States according to a survey of policy makers and scientists revealed in a new publication in BioScience by researchers at the University of York and the University of California, Davis.A question on the water supply necessary to sustain human populations and ecosystem resilience was ranked as having the greatest potential, if it was answered, to increase the effectiveness of policies related to natural resource management in the United States. The publication comes as California suffers its worst drought in nearly half a century.The question emerged from a previous collaboration among decision makers and scientists that yielded 40 research questions that most reflected the needs of those with jurisdiction over natural resources. That research also was published in BioScience.The survey, by Dr Murray Rudd of the Environment Department at York and Dr Erica Fleishman, of the John Muir Institute of the Environment at UC Davis, asked managers, policymakers and their advisers, and scientists to rank the questions on the basis of their applicability to policy.The 602 respondents included 194 policymakers, 70 government scientists, and 228 academic scientists.Other questions that were ranked as of high importance to policy included those on methods for measuring the benefits humans receive from ecosystems; the effects of sea-level rise, storm surge, erosion and variable precipitation on coastal ecosystems and human communities; and the effect on carbon storage and ecosystem resilience of different management strategies for forests, grasslands, and agricultural systems .Dr Rudd said, “We found a significant difference in research priorities between respondents. Importantly, there was no evidence of a simple science-policy divide. Priorities did not differ between academics and government employees or between scientists (academic and government) and policymakers.”Our results suggest that participatory exercises such as this are a robust way of establishing priorities to guide funders of research and researchers who aim to inform policy.”Dr Fleishman added, “The consensus in priorities is even more striking as California’s current drought leads to unprecedented reductions in water supply and delivery.”Story Source:The above story is based on materials provided by University of York. Note: Materials may be edited for content and length.

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Nature can, selectively, buffer human-caused global warming, say scientists

Can naturally occurring processes selectively buffer the full brunt of global warming caused by greenhouse gas emissions resulting from human activities?Yes, find researchers from the Hebrew University of Jerusalem, Johns Hopkins University in the US and NASA’s Goddard Space Flight Center.As the globe warms, ocean temperatures rise, leading to increased water vapor escaping into the atmosphere. Water vapor is the most important greenhouse gas, and its impact on climate is amplified in the stratosphere.In a detailed study, the researchers from the three institutions examined the causes of changes in the temperatures and water vapor in the tropical tropopause layer (TTL). The TTL is a critical region of our atmosphere with characteristics of both the troposphere below and the stratosphere above.The TTL can have significant influences on both atmospheric chemistry and climate, as its temperature determines how much water vapor can enter the stratosphere. Therefore, understanding any changes in the temperature of the TTL and what might be causing them is an important scientific question of significant societal relevance, say the researchers.The Israeli and US scientists used measurements from satellite observations and output from chemistry-climate models to understand recent temperature trends in the TTL. Temperature measurements show where significant changes have taken place since 1979.The satellite observations have shown that warming of the tropical Indian Ocean and tropical Western Pacific Ocean — with resulting increased precipitation and water vapor there — causes the opposite effect of cooling in the TTL region above the warming sea surface. Once the TTL cools, less water vapor is present in the TTL and also above in the stratosphere,Since water vapor is a very strong greenhouse gas, this effect leads to a negative feedback on climate change. That is, the increase in water vapor due to enhanced evaporation from the warming oceans is confined to the near- surface area, while the stratosphere becomes drier. Hence, this effect may actually slightly weaken the more dire forecasted aspects of an increasing warming of our climate, the scientists say.The researchers are Dr. Chaim Garfinkel of the Fredy and Nadine Herrmann Institute of Earth Sciences at the Hebrew University and formerly of Johns Hopkins University, Dr. D. …

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Mysterious ocean circles off the Baltic coast explained

Are they bomb craters from World War II? Are they landing marks for aliens? Since the first images of the mysterious ocean circles off the Baltic coast of Denmark were taken in 2008, people have tried to find an explanation. Now researchers from the University of Southern Denmark and University of Copenhagen finally present a scientific explanation.The first pictures appeared in 2008, taken by a tourist and showing some strange circular formations in the shallow waters off the famous white cliffs of chalk on the island Mn in Denmark. In 2011, the circles came back, and this time there were so many that they made it to the media.Investigating biologists then concluded that the circles consisted of eelgrass plants growing on the bottom of the shallow water. But only now scientists can explain why the eelgrass grows in circles here — eelgrass usually grows as continuous meadows on the seabed.”It has nothing to do with either bomb craters or landing marks for aliens. Nor with fairies, who in the old days got the blame for similar phenomena on land, the fairy rings in lawns being a well known example,” say biologists Marianne Holmer from University of Southern Denmark and Jens Borum from University of Copenhagen.The circles of eelgrass can be up to 15 meters in diameter and their rim consists of lush green eelgrass plants. Inside the circle there can be seen only very weak or no eelgrass plants.”We have studied the mud that accumulates among the eelgrass plants and we can see that the mud contains a substance that is toxic to eelgrass,” explain Holmer and Borum.The poison is sulfide, a substance that accumulates in the seabed off the island of Mn, because it is very calcareous and iron-deficient.”Most mud gets washed away from the barren, chalky seabed, but like trees trap soil on an exposed hillside, eelgrass plants trap the mud. And therefore there will be a high concentrations of sulfide-rich mud among the eelgrass plants,” explain the researchers.Sulfide is toxic enough to weaken the old and new eelgrass plants but not toxic enough to harm adult and strong plants. And since eelgrass spreads radially from the inside out the oldest and weakest plants are located in the center of the growth circle.Jens Borum and Marianne Holmer say: “Eelgrass populations grow vegetatively by stolons which spread radially in all directions and therefore each plant creates a circular growth pattern. …

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Frog-killing fungus paralyzes amphibian immune response

Oct. 17, 2013 — A fungus that is killing frogs and other amphibians around the world releases a toxic factor that disables the amphibian immune response, Vanderbilt University investigators report Oct. 18 in the journal Science.The findings represent “a step forward in understanding a long-standing puzzle — why the amphibian immune system seems to be so inept at clearing the fungus,” said Louise Rollins-Smith, Ph.D., associate professor of Pathology, Microbiology and Immunology. Although the identity of the toxic fungal factor (or factors) remains a mystery, its ability to inhibit a wide range of cell types — including cancerous cells — suggests that it may offer new directions for the development of immunosuppressive or anti-cancer agents.The populations of amphibian species have been declining worldwide for more than 40 years. In the late 1990s, researchers discovered that an ancient fungus, Batrachochytrium dendrobatidis, was causing skin infections, and the fungus is now recognized as a leading contributor to global amphibian decline.Rollins-Smith, an immunologist, and her colleagues have been studying the immune response to the fungus for more than 10 years.”Amphibians have excellent and complex immune systems — nearly as complex as humans — and they should be able to recognize and clear the fungus,” she said.In early studies, the investigators demonstrated that some frogs produce anti-microbial peptides in the skin that offer a first layer of defense against the fungus. But when the fungus gets into the layers of the skin, Rollins-Smith said, the conventional lymphocyte (immune cell)-mediated immune response should be activated to clear it.They found in the current studies that recognition of the fungus by macrophage and neutrophil cells was not impaired.”We think it’s not a block at the initial recognition stage,” Rollins-Smith said. “The macrophages and neutrophils can see it as a pathogen, they can eat it up, they can do their thing.”But during the next stage of the immune response, when lymphocytes should be activated, the fungus exerts its toxic effects. The investigators demonstrated that B. dendrobatidis cells and supernatants (the incubation liquid separated from the cells) impaired lymphocyte proliferation and induced cell death of lymphocytes from frogs, mice and humans. The toxic fungal factor also inhibited the growth of cancerous mammalian cell lines.The toxic factor was resistant to heat and proteases (enzymes that cut proteins into pieces), suggesting that it is not a protein. …

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CONTENT REMOVED

Spinach dip is probably one of my favorite appetizers.However, despite the spinach -giving it a healthy sounding name- it is loaded with saturated fat and calories.Most recipes contain either a lot of cheese or sour cream and mayo, which when coupled with bread, crackers, or flatbread make this appetizer a day’s worth of calories all by itself.Factoid: Chili’s Spinach and Artichoke Dip w/tortilla chips clocks in at 1440 calories and 92 grams of fat in just about a 1 cup serving! I present to you my much healthier goto spinach dip recipe for when I need a healthy appetizer to take to a party or when I’m entertaining guests.Heck, sometimes I make a batch and eat it as a meal. It’s so good that you’ll …

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How tiny organisms make a big impact on clean water

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

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A bacterium reveals the crucible of its metallurgical activity

Oct. 14, 2013 — Magnetotactic bacteria have the ability to synthesize nanocrystals of magnetite (Fe3O4) enabling them to align themselves with the terrestrial magnetic field in order to find the position in the water column that is most favorable to their survival. The alignment of the nanomagnets is similar to that of a compass needle. The magnetite crystal synthesis process is a complex one, and it is little understood at the present time. Magnetite is a compound of oxygen and iron in a mixture of two different oxidation states [Fe(II)Fe(III)2O4]. In this study, the researchers have described the mechanism by which the bacterium produces these two states, one of which, Fe(III), is essentially insoluble.Share This:The determination of the structure of the protein MamP has shown for the first time that a section of this protein possesses an original folding structure known as a magnetochrome. This structure is only found in magnetotactic bacteria. The structure has a crucible-like shape capable of containing iron. Additional experiments have shown that MamP has the ability to oxidize iron from the Fe(II) state to the Fe(III) state, and to stabilize the latter in its crucible. Mutagenesis studies and the phenotyping of magnetotactic bacteria variants have confirmed the physiological importance of this crucible.Finally, a number of in vitro experiments have shown that MamP is capable of producing a magnetite precursor when incubated in the presence of Fe(II) alone, proving that the Fe (III) results from the activity of this protein.This fundamental study reveals part of the process whereby iron is biomineralized and nanomagnets are synthesized in magnetotactic bacteria. …

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Soft shells and strange star clusters

Oct. 10, 2013 — PGC 6240 is an elliptical galaxy that resembles a pale rose in the sky, with hazy shells of stars encircling a very bright centre. Some of these shells are packed close to the centre of the galaxy, while others are flung further out into space. Several wisps of material have been thrown so far that they appear to be almost detached from the galaxy altogether.Astronomers have studied PGC 6240 in detail due to this structure, and also because of its surrounding globular clusters — dense, tightly packed groups of gravitationally bound stars that orbit galaxies. Over 150 of these clusters orbit our own galaxy, the Milky Way, all composed of old stars.All the globular clusters around a certain galaxy form at approximately the same time, giving them all the same age. This is echoed within the clusters — all the stars within a single cluster form at around the same time, too. Because of this, most galaxies have cluster populations of pretty similar ages, both in terms of overall cluster, and individual stars. However, PGC 6240 is unusual in that its clusters are varied — while some do contain old stars, as expected, others contain younger stars which formed more recently.The most likely explanation for both the galaxy’s stacked shell structure and the unexpectedly young star clusters is that PGC 6240 merged with another galaxy at some point in the recent past. Such a merger would send ripples through the galaxy and disrupt its structure, forming the concentric shells of material seen here. It would also ignite a strong burst of star formation in the galaxy, which would then trigger similar activity in nearby space — leading to the creation of new, younger globular clusters around PGC 6240.PGC 6240 is an elliptical galaxy in the southern constellation of Hydrus (The Water Snake). …

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Antibiotic resistance in agricultural environments: A call to action

Sep. 26, 2013 — Antibiotic resistant pathogens are an emerging, critical human health issue. The World Health Organization (WHO) has declared antibiotic resistance as a top health issue worldwide. Two million Americans are infected each year with diseases resistant to known antibiotics; between ten and fifteen thousand die.Jean McLain, PhD, will present “Antibiotic Resistance in Agricultural Environments: A Call to Action,” on Tuesday, Nov. 5, 2013 at 4:30 PM. The presentation is part of the American Society of Agronomy, Crop Science Society of America, and the Soil Science Society of America Annual Meetings, Nov. 3-7 in Tampa, Florida. The theme of this year’s conference is “Water, Food, Energy, & Innovation for a Sustainable World.”Most people equate antibiotic resistance to the medical field. However, antibiotic resistance is also in our soils. And, the field of agriculture has been blamed for making this worse by using concentrated feed operations that leak antibiotics into surrounding waterways. …

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Underlying ocean melts ice shelf, speeds up glacier movement

Sep. 12, 2013 — Warm ocean water, not warm air, is melting the Pine Island Glacier’s floating ice shelf in Antarctica and may be the culprit for increased melting of other ice shelves, according to an international team of researchers.”We’ve been dumping heat into the atmosphere for years and the oceans have been doing their job, taking it out of the air and into the ocean,” said Sridhar Anandakrishnan, professor of geosciences, Penn State. “Eventually, with all that atmospheric heat, the oceans will heat up.”The researchers looked at the remote Pine Island Glacier, a major outlet of the West Antarctic Ice Sheet because it has rapidly thinned and accelerated in the recent past.”It has taken years and years to do the logistics because it is so remote from established permanent bases,” said Anandakrishnan.Pine Island Glacier or PIG lies far from McMurdo base, the usual location of American research in Antarctica. Work done in the southern hemisphere’s summer, December through January 2012-13, included drilling holes in the ice to place a variety of instruments and using radar to map the underside of the ice shelf and the bottom of the ocean. Penn State researchers did the geophysics for the project and the research team’s results are reported today (Sept. 13) in Science.The ice shelf is melting more rapidly from below for a number of reasons. The oceans are warmer than they have been in the past and water can transfer more heat than air. More importantly, the terrain beneath the ice shelf is a series of channels. The floating ice in the channel has ample room beneath it for ocean water to flow in. The water melts some of the ice beneath and cools. …

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Breaking deep-sea waves, as high as a skyscraper, reveal mechanism for global ocean mixing

Sep. 9, 2013 — Waves breaking over sandy beaches are captured in countless tourist photos. But enormous waves breaking deep in the ocean are seldom seen, although they play a crucial role in long-term climate cycles.A University of Washington study for the first time recorded such a wave breaking in a key bottleneck for circulation in the world’s largest ocean. The study was published online this month in the journal Geophysical Research Letters.The deep ocean is thought of as dark, cold and still. While this is mostly true, huge waves form between layers of water of different density. These skyscraper-tall waves transport heat, energy, carbon and nutrients around the globe. Where and how they break is important for the planet’s climate.”Climate models are really sensitive not only to how much turbulence there is in the deep ocean, but to where it is,” said lead author Matthew Alford, an oceanographer in the UW Applied Physics Laboratory. He led the expedition to the Samoan Passage, a narrow channel in the South Pacific Ocean that funnels water flowing from Antarctica.”The primary importance of understanding deep-ocean turbulence is to get the climate models right on long timescales,” Alford said.Dense water in Antarctica sinks to the deep Pacific, where it eventually surges through a 25-mile gap in the submarine landscape northeast of Samoa.”Basically the entire South Pacific flow is blocked by this huge submarine ridge,” Alford said. “The amount of water that’s trying to get northward through this gap is just tremendous — 6 million cubic meters of water per second, or about 35 Amazon Rivers.”In the 1990s a major expedition measured these currents through the Samoan Passage. The scientists inferred that a lot of mixing must also happen there, but couldn’t measure it.In the summer of 2012 the UW team embarked on a seven-week cruise to track the 800-foot-high waves that form atop the flow, 3 miles below the ocean’s surface. …

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