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The methods demostrated in this Live Monarch Foundation video will work for any butterfly species, but in this video, the patient is an adult male monarch butterfly, Danaus plexippus.
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Radiological Society of North America
97th Scientific Assembly and Annual Meeting
November 27 - December 2, 2011
McCormick Place, Chicago
People who eat baked or broiled fish on a weekly basis may be improving their brain health and reducing their risk of developing mild cognitive impairment (MCI) and Alzheimer's disease, according to a study presented today at the annual meeting of the Radiological Society of North America (RSNA).
"This is the first study to establish a direct relationship between fish consumption, brain structure and Alzheimer's risk," said Cyrus Raji, M.D., Ph.D., from the University of Pittsburgh Medical Center and the University of Pittsburgh School of Medicine. "The results showed that people who consumed baked or broiled fish at least one time per week had better preservation of gray matter volume on MRI in brain areas at risk for Alzheimer's disease."
Alzheimer's disease is an incurable, progressive brain disease that slowly destroys memory and cognitive skills. According to the National Institute on Aging, as many as 5.1 million Americans may have Alzheimer's disease. In MCI, memory loss is present but to a lesser extent than in Alzheimer's disease. People with MCI often go on to develop Alzheimer's disease.
For the study, 260 cognitively normal individuals were selected from the Cardiovascular Health Study. Information on fish consumption was gathered using the National Cancer Institute Food Frequency Questionnaire. There were 163 patients who consumed fish on a weekly basis, and the majority ate fish one to four times per week. Each patient underwent 3-D volumetric MRI of the brain. Voxel-based morphometry, a brain mapping technique that measures gray matter volume, was used to model the relationship between weekly fish consumption at baseline and brain structure 10 years later. The data were then analyzed to determine if gray matter volume preservation associated with fish consumption reduced risk for Alzheimer's disease. The study controlled for age, gender, education, race, obesity, physical activity, and the presence or absence of apolipoprotein E4 (ApoE4), a gene that increases the risk of developing Alzheimer's.
Gray matter volume is crucial to brain health. When it remains higher, brain health is being maintained. Decreases in gray matter volume indicate that brain cells are shrinking.
The findings showed that consumption of baked or broiled fish on a weekly basis was positively associated with gray matter volumes in several areas of the brain. Greater hippocampal, posterior cingulate and orbital frontal cortex volumes in relation to fish consumption reduced the risk for five-year decline to MCI or Alzheimer's by almost five-fold.
"Consuming baked or broiled fish promotes stronger neurons in the brain's gray matter by making them larger and healthier," Dr. Raji said. "This simple lifestyle choice increases the brain's resistance to Alzheimer's disease and lowers risk for the disorder."
The results also demonstrated increased levels of cognition in people who ate baked or broiled fish.
"Working memory, which allows people to focus on tasks and commit information to short-term memory, is one of the most important cognitive domains," Dr. Raji said. "Working memory is destroyed by Alzheimer's disease. We found higher levels of working memory in people who ate baked or broiled fish on a weekly basis, even when accounting for other factors, such as education, age, gender and physical activity."
Eating fried fish, on the other hand, was not shown to increase brain volume or protect against cognitive decline.
Coauthors are Kirk Erickson, Ph.D., Oscar Lopez, M.D., Lewis Kuller, M.D., H. Michael Gach, Ph.D., Paul Thompson, Ph.D., Mario Riverol, M.D., Ph.D., and James Becker, Ph.D.
Contact: Linda Brooks
[email protected]
630-590-7762
Radiological Society of North America
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Two distinct populations of rainbow trout -- one in Alaska, the other in Idaho -- share a genetic trait that could have huge implications for fisheries conservation and management, an eight-member research team reports.
The common trait is a similar rapid rate of development that has allowed these different salmomid subspecies to adapt to their native rivers in Alaska and Idaho. The researchers, in a paper put online ahead of publication in the journal Molecular Ecology, say the similarity, a gene variant, resides in a specific portion of their genomes from where this local adaptation is triggered.
Understanding and applying that knowledge could help guide current and future efforts to save species on the brink of extinction and help rejuvenate dwindling populations, especially as changing conditions alter fish environments, says lead author Michael R. Miller, a National Science Foundation-funded doctoral student in the University of Oregon lab of co-author Chris Doe, a UO biologist and Howard Hughes Medical Institute investigator.
The research employed two technologies developed at the UO: the cloning technology pioneered on zebra fish 35 years ago by molecular biologist George Streisinger and a speedy genome-analysis tool known as RAD (restriction-site associated DNA markers). Miller and UO biologist Eric Johnson, with input from William Cresko, also a UO biologist, published their initial RAD-tagging technique in 2005.
The clone lines of rainbow trout used in the study were provided by co-author Gary H. Thorgaard, a fish geneticist at Washington State University. He had worked briefly as a postdoctoral researcher with Streisinger in 1978 to learn about a then-developing zebra-fish cloning technique later detailed in a 1981 Nature paper.
Rainbow trout (Oncorhynchus mykiss) are members of the salmon family. They have a natal homing instinct in which they return to their native streams or rivers to spawn. Occasionally, some end up in other locations and have to adapt, or evolve, to survive in a new habitat. In studying the genetics of populations in the North Fork Clearwater River in north-central Idaho and in the Swanson River of south-central Alaska, researchers noted similar, speedy rates of development -- a conserved trait that generally is not the case in rainbow trout, Thorgaard noted.
"We found that these two very distinct populations are using the same conserved variant of the same gene sequence to achieve this adaptation," Miller said. "We have not identified the exact gene or gene mutations, but we have identified a region of the genome that is very similar."
RAD gene-sequencing technology allowed the researchers to sort through the fish genomes -- rainbow trout populations have between 58 and 64 chromosomes -- until they isolated the gene variants, also known as mutations or alleles. "RAD gives us much better details with a much higher resolution on genetic markers than what we could ever see before," Thorgaard said.
"RAD is being applied widely in the field of fisheries genetics," Miller said. "This technology is having a huge impact on salmon genetics, for conservation, management and restoration."
The findings suggest that the same genetic method of adaptation may be used by other salmonids, which includes salmon, steelhead trout, char, freshwater whitefish and graylings. The gene variant found in the study may have arrived just in time for struggling fish populations, researchers said.
"The study suggests that the same genetic types that are associated with adaptation in one population may also be used by another experiencing similar conditions in another area," Thorgaard said. "This increases our understanding of how adaptation occurs and could help in characterizing populations for conservation purposes."
Potentially, Miller said, matching fish with the same genetic variants could prove beneficial in increasing populations in distressed areas. "Many southern populations, in California, for instance, are already extinct or depressed, and these populations likely contain gene variants that may become important for the future adaptation of more northern populations as the environment changes," he said. "If these populations go extinct, we are potentially hindering the future adaptability of other populations."
Co-authors on the paper with Miller, Doe and Thorgaard were Joseph P. Brunelli and Paul A. Wheeler, both colleagues of Thorgaard at Washington State, and Sixin Liu, Caird E. Rexroad III and Yniv Palti, all of the National Center for Cool and Cold Water Aquaculture, Agricultural Research Service-USDA, in Kearneysville, W.Va. The National Science Foundation and U.S. Department of Agriculture supported the research.
The University of Oregon is among the 108 institutions chosen from 4,633 U.S. universities for top-tier designation of "Very High Research Activity" in the 2010 Carnegie Classification of Institutions of Higher Education. The UO also is one of two Pacific Northwest members of the Association of American Universities.
Contact: Jim Barlow
[email protected]
541-346-3481
University of Oregon
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Louie Schwartzberg is an award-winning cinematographer, director and producer who captures breathtaking images that celebrate life -- revealing connections, universal rhythms, patterns and beauty.
Louis Schwartzberg's notable career spans feature films, television shows, commercials and documentaries. He won two Clio Awards for TV advertising, including best environmental broadcast spot, an Emmy nomination for best cinematography and the Heartland Film Festival's Truly Moving Picture Award for the feature film “America’s Heart & Soul.” Schwartzberg founded Moving Art to use the power of media to inspire and entertain through television programming, DVD products, and full-length motion picture and IMAX films. His new film "Wings of Life" will be released by Disneynature.
"The secret lives of bats, butterflies, hummingbirds, and bumblebees come to life before our eyes as Schwartzberg and his talented team highlight how the determination and interdependence of these diminutive creatures somehow keep our chaotic world in balance."
Jason Buchanan, Rovi
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Credit: New Scientist Magazine
Direct effects of climate warming on biodiversity pose a serious conservation challenge for marine life, according to new research published in Science. Marine life may need to relocate faster than land species as well as speed up alterations in the timing of major life cycle events. This challenges previous thinking that marine life in the ocean would respond more gradually than species on land because of slower warming in the oceans.
"Analyses of global temperature found that the rate at which marine life needs to relocate is as fast, or in some places faster, than for land species. This is despite ocean warming being three times slower than land" says paper co-author, Dr Elvira Poloczanska from CSIRO's Climate Adaptation Flagship.
Dr Poloczanska said that globally, an increasing number of species are responding to climate change by changing their distributions and the timing of life cycle events such as breeding, spawning and migrations.
She said that a one degree change in ocean temperature may mean that marine plants and animals will have to travel hundreds of kilometres to stay in their comfort zones. This can present major problems for marine organisms, particularly those that are unable to move long distances such as corals.
This collaborative work was led by Dr Mike Burrows from the Scottish Association of Marine Science, UK, and Dr David Schoeman of the University of Ulster, UK, and is a product from the Marine Impacts Working Group at the National Centre for Ecological Analysis and Synthesis, California. Dr Poloczanska and Associate Professor Anthony J. Richardson from the CSIRO Climate Adaptation Flagship and the University of Queensland lead the working group.
Writing in Science, the team considered two indicators to measure the pace of change in temperatures over the past 50 years: the shift in temperature across the landscape and seascape, and; the shift in temperature seasonality with warming. Another of the paper's co-authors, University of Queensland Associate Professor Anthony Richardson, explains that the rate at which marine life relocates depends not only on how much the temperature changes but also on how far a species needs to travel to reach its preferred temperature conditions.
Marine species need to travel long distances to find a preferred temperature zone because temperature varies relatively little across much of the oceans compared to on land.
"On the land in flat areas such as deserts, for example, animals and plants must relocate over long distances to find a change in temperature but in mountainous areas this change can be found in shorter distances. Marine animals and plants will have to travel long distances in many parts of the ocean, where temperature changes relatively little, to remain in their preferred temperature" Associate Professor Richardson said.
"In warm areas such as the Equator, which is a marine biodiversity hotspot, marine life will have to travel very far to find a suitable temperature zone and we are concerned that threats to biodiversity may be high" The same applies for changes in timing for reproduction activities such as flowering, and breeding migrations.
"The seasonal temperature cycle is relatively reduced in the ocean compared with land, so again this means that if a plant or animal wants to maintain its thermal environment and keep pace with warming, it will need to move its reproduction earlier in the year as much, or more, in the ocean than on land" Associate Professor Richardson said.
The study also identifies patterns of climate change are not uniform, with regions warming and some even cooling at different rates. For example, large areas of the Southern Ocean are cooling and shifts in the distribution of marine life away from polar regions are expected.
"While organisms may respond to aspects of climate change other than temperature, we studied the global thermal environment because it is probably the most important variable controlling global distribution and timing of marine life" said Dr Poloczanska
"Although we only looked at the ocean surface, and many marine species may live deeper, the majority of these ultimately rely on production at the sunlit ocean surface or have larval stages that disperse in shallower depths," she said.
Contact: Anne Leitch
[email protected]
61-738-335-652
CSIRO Australia
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Ocean acidification can no longer remain on the periphery of the international debates on climate change and the environment and should be addressed by the UN Framework Convention on Climate Change and other global environmental conventions, urges IUCN and the International Ocean Acidification Reference User Group (RUG) at the climate change summit in Durban.
In the run up to the United Nations Conference on Sustainable Development, which will take place in Rio de Janeiro in June next year (Rio+20), world experts from RUG call for decision makers to urgently address the critical issue of ocean acidification.
“The increasing amounts of carbon dioxide that we emit into the atmosphere every day are changing our oceans, steadily increasing their acidity, and dramatically affecting marine life,” says Professor Dan Laffoley Marine Vice Chair of IUCN’s World Commission on Protected Areas and Chair of RUG. “This may also have severe impacts on human life in the future. Only by reducing our CO2 emissions and enhancing the protection of oceans to strengthen their ability to recover, can we effectively address this issue. Policy makers in Durban, and in Rio in June next year, need to recognize this and take appropriate actions.”
Reducing greenhouse gas emissions into the atmosphere, particularly CO2, which is the main driver of climate change and the main cause of ocean acidification, is one of the goals of the UN Framework Convention on Climate Change. But the latest RUG publication calls for a broader strategy to reduce ocean acidification, alongside those tackling other threats to the marine environment such as overfishing and pollution.
According to the experts, although both climate change and ocean acidification are caused by excessive amounts of CO2 emissions, and so should be tackled together, not all approaches used to address the former will be effective in the fight against the latter.
"For example, ‘geoengineering' solutions, such as reflecting solar radiation, which are often suggested to deal with climate change, will not address the progressive acidification of the ocean," says Dr John Baxter of the Scottish Natural Heritage and Deputy Chair of the RUG. "Both climate change and acidification need to be taken into account when designing solutions to these challenges."
Each year, the ocean absorbs approximately 25% of all the CO2 we emit. Its acidity has increased by 30% since the beginning of the Industrial Revolution and acidification will continue at an unprecedented rate in the coming decades. This can have a negative impact on marine organisms, especially the 'calcifying’ ones such as shellfish, molluscs, coral reefs and various types of zooplankton and phytoplankton. Increasing ocean acidity requires them to use more energy to build their shells, which has potentially severe ecological consequences. If the current acidification rate continues, it could lead to extinctions of some species and impact others that feed on them.
“Through its ability to absorb large amounts of CO2, the ocean plays a crucial role in moderating the rate and severity of climate change”, says Dr Carol Turley from the Plymouth Marine Laboratory and the Knowledge Exchange Coordinator for the UK Ocean Acidification Research Programme, one of the partners of the Reference User Group. “But in many ways our ocean is also a victim of its own success, as this capacity jeopardizes its future health, its biodiversity and its ability to continue to provide us with food and sustainable economic development. Ocean acidification requires urgent and effective action now, before it’s too late. The obvious action is to reduce CO2 emissions to the atmosphere."
Download Paper-Ocean Acidification Acting on Evidence-Messages for Rio+20
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ETAP Communication |
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Observations at submarine springs found along the coast of Mexico's Yucatan Peninsula are giving scientists a preview of the possible fate of coral reef ecosystems in response to ocean acidification.
The naturally low pH (a measure of acidity) in the water around the springs creates conditions similar to those that will result from the widespread acidification of surface waters that scientists expect to occur as the oceans absorb increasing amounts of carbon dioxide from the atmosphere. Ecological surveys around the springs found small, patchily distributed colonies of only a few species of corals, without the structurally complex corals that compose the framework of the nearby Mesoamerican Barrier Reef, one of the Caribbean's largest coral reef ecosystems.
A team led by scientists at the University of California, Santa Cruz, has been studying the submarine springs at Puerto Morelos near the Mesoamerican reef for the past three years. The researchers reported their findings in a paper published in the journal Coral Reefs (published online Nov. 20).
"This study has some good news and some bad news for corals," said coauthor Adina Paytan, a research professor in the Institute of Marine Sciences at UC Santa Cruz. "The good news is that some species of corals are able to calcify and grow at very low pH. The bad news is that these are not the ones that build the framework of the coral reefs. So if this is an indication of what will happen with future ocean acidification, the reefs will not be as we know them today."
The submarine springs, known as "ojos," occur along the eastern coast of the Yucatan Peninsula. Limestone "karst" landforms near the coast feature underground drainage systems that discharge brackish water at the ojos. The discharged water has lower pH than the surrounding seawater, and these conditions have existed for thousands of years. Lowering the pH affects the chemical equilibrium of seawater with respect to calcium carbonate, reducing the concentration of carbonate ions and making it harder for organisms such as corals to build and maintain structures of calcium carbonate.
Paytan's team monitored the pH and other conditions at ten ojos and conducted ecological surveys around each site. The researchers found that the number of coral species and the size of coral colonies declined with increasing proximity to the center of an ojo. Only a few species of hard corals were found in waters with the lowest carbonate saturation levels, closest to the ojos. These species are rarely major contributors to the framework of Caribbean reefs, but their ability to form carbonate skeletons in low-pH conditions warrants further study, Paytan said.
"We need to understand the mechanisms that allow these corals to calcify at these low-pH conditions. We should also make sure that the places where these species occur are protected," she said.
The low pH and low carbonate saturation near the ojos are comparable to the conditions scientists expect to see worldwide due to ocean acidification by the year 2100. Other conditions at the ojos are different, however, including somewhat lower salinity and high nutrient concentrations in the discharge water. Evidence from previous studies suggests that the low salinity is not responsible for the patterns seen around the ojos, since coral species that tolerate similarly low salinity occur in the region but were not found near the ojos. The high nutrient concentrations may benefit the corals, helping them compensate for the increased energy needed for calcification under low-pH conditions.
Elizabeth Crook, a graduate student in Earth and planetary sciences at UC Santa Cruz, is first author of the Coral Reefs paper. In addition to Crook and Paytan, the coauthors include Donald Potts, professor of ecology and evolutionary biology at UCSC, and Mario Rebolledo-Vieyra and Laura Hernández at the Centro de Investigación Científica de Yucatán. This research was funded by the National Science Foundation.
Contact: Tim Stephens
[email protected]
831-459-2495
University of California - Santa Cruz
Posted at 02:21 AM | Permalink | Comments (0)
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Fossil snails known as turritellid gastropods; they're about 13 million years old. Credit: Shanan Peters |
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Much of our knowledge about past life has come from the fossil record, but how accurately does that record reflect the true history and drivers of biodiversity on Earth?
"It's a question that goes back a long way to the time of Darwin, who looked at the fossil record and tried to understand what it tells us about the history of life," says Shanan Peters, a geoscientist at the University of Wisconsin-Madison.
In fact, the fossil record can tell us a great deal, Peters says in results of a new study.
In a paper published this week in the journal Science, he and colleague Bjarte Hannisdal of the University of Bergen in Norway show that the evolution of marine life over the past 500 million years has been driven by both ocean chemistry and sea-level changes.
"These results tell us that the number of species in the oceans through time has been influenced by the amount and availability of carbon, oxygen and sulfur, and by sea level," says Lisa Boush, program director in the National Science Foundation (NSF)'s Division of Earth Sciences, which funded the research.
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Sedimentary rocks in the Grand Canyon, Arizona; they reflect patterns of long-ago seas. Credit: Shanan Peters |
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"The study allows us to better understand how modern changes in the environment might affect biodiversity today--and in the future."
The time period studied covers most of the Phanerozoic eon, which extends to the present and includes the evolution of most plant and animal life.
Hannisdal and Peters analyzed fossil data from the Paleobiology Database, along with paleoenvironmental proxy records and data on the rock record.
These data reflect ancient global climates, tectonic movements, continental flooding and changes in biogeochemistry, especially in Earth's oxygen, carbon and sulfur cycles.
The scientists used a method called information transfer, which allowed them to identify causal relationships, not just general associations, between biodiversity and environmental proxy records.
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Horn corals about 450 million years old; they're often found in the fossil record. Credit: Shanan Peters |
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"We find an interesting web of connections between these different systems, which combine to drive what we see in the fossil record," Peters says.
For example, marine biodiversity is closely related to the sulfur cycle, says Peters. The "signal" from sea-level--how much the continents are covered by shallow seas--is also important in the history of marine animal diversity, the researchers found.
The dramatic changes in marine biodiversity seen in the fossil record, Peters says, "likely arose through biological responses to changes in the global carbon and sulfur cycles, and to sea level, through geologic time."
Despite its incompleteness, the fossil record is a good representation of marine biodiversity over the past half-billion years, the scientists believe.
The findings also emphasize the interconnectedness of Earth's physical, chemical and biological processes.
"Earth systems are all connected," says Peters. "It's important to realize that when we perturb one thing, we're not just affecting that one thing.
"The challenge is understanding how that perturbation of one thing, for example, the carbon cycle, will affect the future biodiversity of the planet."
Contact: Cheryl Dybas
[email protected]
703-292-7734
National Science Foundation
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