Warming pushes Western US toward driest period in 1,000 years: Unprecedented Risk of Drought in 21st Century

Soil moisture 30 cm below ground projected through 2100 for high emissions scenario RCP 8.5. The soil moisture data are standardized to the Palmer Drought Severity Index and are deviations from the 20th century average. During the second half of the 21st century, the U.S. Southwest and Great Plains will face persistent drought worse than anything seen in times ancient or modern, with the drying conditions "driven primarily" by human-induced global warming, a new study predicts. The research says the drying would surpass in severity any of the decades-long "megadroughts" that occurred much earlier during the past 1,000 years -- one of which has been tied by some researchers to the decline of the Anasazi or Ancient Pueblo Peoples in the Colorado Plateau in the late 13th century. Many studies have already predicted that the Southwest could dry due to global warming, but this is the first to say that such drying could exceed the worst conditions of the distant past. The impacts today would be devastating, given the region's much larger population and use of resources. "We are the first to do this kind of quantitative comparison between the projections and the distant past, and the story is a bit bleak," said Jason E. Smerdon, a co-author and climate scientist at the Lamont-Doherty Earth Observatory, part of the Earth Institute at Columbia University. "Even when selecting for the worst megadrought-dominated period, the 21st century projections make the megadroughts seem like quaint walks through the Garden of Eden." "The surprising thing to us was really how consistent the response was over these regions, nearly regardless of what model we used or what soil moisture metric we looked at," said lead author Benjamin I. Cook of the NASA Goddard Institute for Space Studies and the Lamont-Doherty Earth Observatory. "It all showed this really, really significant drying." The new study, "Unprecedented 21st-Century Drought Risk in the American Southwest and Central Plains," will be featured in the inaugural edition of the new online journal Science Advances, produced by the American Association for the Advancement of Science, which also publishes the leading journal Science. Today, 11 of the past 14 years have been drought years in much of the American West, including California, Nevada, New Mexico and Arizona and across the Southern Plains to Texas and Oklahoma, according to the U.S. Drought Monitor, a collaboration of U.S. government agencies. The current drought directly affects more than64 million people in the Southwest and Southern Plains, according to NASA, and many more are indirectly affected because of the impacts on agricultural regions. Shrinking water supplies have forced western states to impose water use restrictions; aquifers are being drawn down to unsustainable levels, and major surface reservoirs such as Lake Mead and Lake Powell are at historically low levels. This winter's snowpack in the Sierras, a major water source for Los Angeles and other cities, is less than a quarter of what authorities call a "normal" level, according to a February report from the Los Angeles Department of Water and Power. California water officials last year cut off the flow of water from the northern part of the state to the south, forcing farmers in the Central Valley to leave hundreds of thousands of acres unplanted. "Changes in precipitation, temperature and drought, and the consequences it has for our society -- which is critically dependent on our freshwater resources for food, electricity and industry -- are likely to be the most immediate climate impacts we experience as a result of greenhouse gas emissions," said Kevin Anchukaitis, a climate researcher at the Woods Hole Oceanographic Institution. Anchukaitis said the findings "require us to think rather immediately about how we could and would adapt." Much of our knowledge about past droughts comes from extensive study of tree rings conducted by Lamont-Doherty scientist Edward Cook (Benjamin's father) and others, who in 2009 created the North American Drought Atlas. The atlas recreates the history of drought over the previous 2,005 years, based on hundreds of tree-ring chronologies, gleaned in turn from tens of thousands of tree samples across the United States, Mexico and parts of Canada. For the current study, researchers used data from the atlas to represent past climate, and applied three different measures for drought -- two soil moisture measurements at varying depths, and a version of the Palmer Drought Severity Index, which gauges precipitation and evaporation and transpiration -- the net input of water into the land. While some have questioned how accurately the Palmer drought index truly reflects soil moisture, the researchers found it matched well with other measures, and that it "provides a bridge between the [climate] models and drought in observations," Cook said. The researchers applied 17 different climate models to analyze the future impact of rising average temperatures on the regions. And, they compared two different global warming scenarios -- one with "business as usual," projecting a continued rise in emissions of the greenhouse gases that contribute to global warming; and a second scenario in which emissions are moderated. By most of those measures, they came to the same conclusions. "The results … are extremely unfavorable for the continuation of agricultural and water resource management as they are currently practiced in the Great Plains and southwestern United States," said David Stahle, professor in the Department of Geosciences at the University of Arkansas and director of the Tree-Ring Laboratory there. Stahle was not involved in the study, though he worked on the North American Drought Atlas. Smerdon said he and his colleagues are confident in their results. The effects of CO2 on higher average temperature and the subsequent connection to drying in the Southwest and Great Plains emerge as a "strong signal" across the majority of the models, regardless of the drought metrics that are used, he said. And, he added, they are consistent with many previous studies. Anchukaitis said the paper "provides an elegant and convincing connection" between reconstructions of past climate and the models pointing to the risk of future drought. Toby R. Ault of Cornell University is a co-author of the study. Funding was provided by the NASA Modeling, Analysis and Prediction Program, NASA Strategic Science, and the U.S. National Science Foundation.

Pyramid or plate? Explore these healthy diet options

Healthy diets come in all shapes and sizes. Pick one and discover how easy it is to eat healthy.  By Mayo Clinic Staff A healthy diet can be illustrated in many ways, but it's often found in the shape of a pyramid. Most people are familiar with MyPyramid developed by the Department of Agriculture, but that's history now. It's been replaced with MyPlate. However, many other healthy diets are still represented by food pyramids. These include the Asian, Latin American, Mediterranean and Vegetarian Food Guide pyramids, as well as the Mayo Clinic Healthy Weight Pyramid, just to name a few. These graphics reinforce the choices that are the foundation of a healthy diet. Pyramid or plate? Explore these healthy diet options These pyramids reflect the same general principles of healthy eating but allow for different food choices. Basic principles of a healthy diet Symbols, such as a pyramid, illustrate how the pieces of a healthy diet fit together. The base of the pyramid is typically made up of foods that should be the bulk of your healthy diet. In contrast, foods you should eat in smaller amounts or less frequently are shown in the smaller sections of the pyramid. The same principle applies to the dinner plate — half of the plate consists of fruits and vegetables, which should be the bulk of your diet. Of course, no single food provides all of the nutrients that your body needs, so the idea is to eat a variety of foods from each group in the proper proportions to get all the necessary nutrients and other substances that promote good health. In addition, most healthy-diet plans emphasize the following: Eat more plant foods, including fruits, vegetables and whole grains. Choose lean protein from a variety of sources. Limit sweets and salt. Control portion sizes. Be physically active.   Variations among healthy diet plans Most healthy diets are built on the same general principles, but there are key differences that reflect dietary preferences, food availability and cultural eating patterns. For example, the Latin American Diet Pyramid might mention tortillas and cornmeal, whereas the Asian Diet Pyramid might include noodles and rice. Other differences include: Food groups. The food groups among healthy-diet plans vary somewhat. For example, some versions have plant-based proteins — soybeans, beans and nuts — in a separate group from animal proteins found in meat, poultry, eggs and dairy products. This is because animal proteins are often higher in fat and cholesterol, and some diets limit or exclude animal proteins. Serving recommendations. Healthy-eating plans also vary in the recommended servings of each food group. The Mayo Clinic Healthy Weight Pyramid, for example, recommends a daily number of servings from each food group. Other plans offer more-general guidelines, such as eating particular foods at every meal, or on a weekly or monthly basis. For example, the Mediterranean Diet Pyramid recommends that you eat whole grains, vegetables and fruits at every meal. Putting the pyramid — or plate — to work for you To see how your eating habits match up to these healthy-diet plans, keep a food diary for several days. Then compare how much of your diet comes from the various groups. You may be surprised by the results. To eat healthier, start with gradual changes, such as eating more vegetables, fruits and whole grains, and limiting fats and sweets. Here are a few more tips to help you adopt healthier eating habits: Choose a variety of foods. This ensures that you get all of the calories, protein, vitamins, minerals and fiber you need. Choosing a wide range of foods also helps make your meals and snacks more interesting. Adapt the plan to your preferences. For example, a serving of grains doesn't only mean a slice of bread. It can be wild rice, whole-wheat pasta, grits, bulgur, cornmeal muffins or even popcorn. If you need to avoid milk because of lactose intolerance, try yogurt (lower in lactose) or fortified soy milk instead. Combine foods any way you like. For example, you might make a meal of tortillas (grain group) and beans (meat and beans group). Or you could top your fish with fruit salsa or serve steamed vegetables over pasta. The possibilities are virtually endless. Remember to be creative and go for good taste. A variety of healthy-eating plans are available, so why not try a few on for size? You can explore the world's cuisines and improve your diet at the same time. source : www.mayoclinic.org

Contraception Could Prevent 15 Million Unwanted Pregnancies Annually

Fifteen million unwanted pregnancies in 35 low- and middle-income countries could be avoided if women had access to and freedom to use contraception. Cynthia Graber reports.      February 12, 2015 By Cynthia Graber It sounds obvious—pregnancies could be avoided by using contraception. But 15 million unwanted pregnancies could be avoided annually in 35 low- and middle-income countries if women did in fact use modern contraception. That’s according to a study in the journal Human Reproduction. [Saverio Bellizzi et al, Underuse of modern methods of contraception: underlying causes and consequent undesired pregnancies in 35 low- and middle-income countries] Unwanted pregnancy has a wide range of serious consequences. Women may have to stop their education or employment. They might pursue unsafe abortions. And they can face disability, disease and death as a result of the pregnancy. To determine barriers to the use of contraception, researchers compared surveys and interviews of nearly 13,000 women who became pregnant unintentionally. They compared the data to that from more than a hundred thousand women who were sexually active and did not want to be pregnant. For women who were sexually active, did not want to be pregnant, but did not use contraception, 37 percent feared health side effects from contraception. Twenty-two percent said they or their partner objected. These issues outweighed cost or availability. Women also underestimated the risks of getting pregnant from unprotected sex. The World Health Organization’s Howard Sobel is one of the authors of the study. In a press release he says the research shows that health workers need to play a bigger role in educating and reassuring women, along with helping individuals determine the best contraceptive for them. He advises that effective, affordable contraception should be coupled with education about the myths of contraception—and information about the real risks of unintended pregnancies. —Cynthia Graber source – sciam

Glowing amino acid lights up growing brain cancer

Uptake of tagged glutamine allows scans to spot tumor changes during treatment Nathan Seppa 2:02pm, February 11, 2015 By injecting the amino acid glutamine that’s been tagged with a tracer compound into patients with brain cancer, scientists have devised a technique that might enable doctors to spot growth of such tumors with high accuracy. Glutamine and glucose provide nourishment for malignant cells in patients with glioma, a cancer of glial cells. These support cells for neurons become ravenous for both nutrients when cancerous, so spotting their high uptake with brain scans could provide a way to monitor the cancer. But glucose is also taken up widely by normal tissues in the brain. In contrast, glutamine is voraciously gobbled up by several cancers including glioma, researchers report in the Feb. 11 Science Translational Medicine. Venneti et al/Science Translational Medicine 2015 Tests in mice with glioma show that a glutamine analog toting a telltale radioactive tracer gets taken up readily by glioma cells but not by healthy cells. The tracer shows up in PET, or positron emission tomography, scans. This allows tumor delineation, scientists from Memorial Sloan Kettering Cancer Center in New York City and elsewhere report. In six glioma patients, brain scans revealed that while aggressive brain tumors took up the tagged glutamine readily, stable tumors did so only minimally, if at all. The imaging technique might enable doctors to more clearly track brain cancer growth, the authors say.

New alloy of steel is as strong and light as titanium

The GIFT development could lead to the new steel alloy replacing aluminum in lightweight, fuel-efficient automobiles and aircraft (Photo: Shutterstock) By altering metal alloy at a nanoscale level, researchers at the Graduate Institute of Ferrous Technology (GIFT) at Pohang University of Science and Technology in South Korea have created a new material that has the strength of steel and the lightness of titanium alloy. Made from an amalgam of steel, aluminum, carbon, manganese, and nickel, the new alloy promises to be low-cost and readily available due to its mix of common minerals. Previous research into lightweight steel has focused on mixing in aluminum in varying proportions to attempt to reduce the density, and therefore the weight. Unfortunately, upping the aluminum content in steel also badly affects its ductility (the way that a material behaves under tensile stress) which results in its increasing vulnerability to fracture. In an attempt to rectify this major impediment to producing a practical lightweight steel, the research team at GIFT uniformly distributed nanometer-sized B2 intermetallic compounds (an amalgam of two metals with equal numbers of atoms) in and around the steel grain structure. though incorporating B2 into steel has been tried in the past, it has ordinarily been harmful to the structure. However, by adding nickel to the admixture, the team was able to take advantage of the addition of B2, while also helping to increase the ductility of the steel alloy. As a result of this research, sturdier, lightweight and more ductile steel compounds may be developed, promising to alleviate the age old problem of brittle intermetallic compound alloys. In this vein, the researchers intend to collaborate with POSCO (formerly the Pohang Iron and Steel Company) to trial forge its new alloy later on this year. It is still early days in this research, and no plans have been announced as to whether this will go beyond a trial commercial process level. But the concept of producing a lightweight version of steel using an abundant mineral such as iron – the base component of steel – could open up a raft of possibilities. Not the least of which may be a new era of high-strength, lightweight steels that may one day usurp aluminum in the production of fuel efficient vehicles and other construction systems. Source: Pohang University

Crystal Pattern Mapping Can Recover Obliterated Serial Numbers in Metals

From NIST Tech Beat: February 11, 2015 Contact: Laura Ost 303-497-4880 Researchers at the National Institute of Standards and Technology (NIST) have demonstrated a technique for mapping deformation in metals that can recover destroyed serial numbers on metal objects such as firearms, a common challenge in forensics. The technique might also meet other forensic needs such as reconstructing vehicle identification numbers or imprints on ammunition casings, the researchers suggest. Law enforcement agencies use serial numbers to track ownership of firearms and build criminal cases. But serial numbers can be removed by scratching, grinding or other methods. Analysts typically try to restore the numbers with acid or electrolytic etching or polishing, because deformed areas behave differently from undamaged material. But these methods don’t always work. As a possible alternative, NIST researchers used a technique called electron backscatter diffraction (EBSD) to read, in the crystal structure pattern, imprints on steel that had been removed by polishing. In EBSD, a scanning electron microscope scans a beam of electrons over the surface of a crystalline material such as a metal. The electrons strike atoms in the target and bounce back. Because the atoms are arranged in a regular pattern, the scattered electrons interact and form patterns that reveal the crystal’s structure on a scale down to tens of nanometers. The more perfect the crystal structure, the stronger and clearer the pattern. Software can then calculate the pattern quality to reveal crystal damage; areas with more damage produce lower quality patterns. In the NIST experiments, described in Forensic Science International,* researchers hammered the letter “X” into a polished stainless steel plate. The letter stamps were as deep as 140 micrometers, meeting federal regulations for firearm serial numbers. The researchers then polished the metal again to remove all visible traces of the letters, and collected the EBSD diffraction patterns and pattern quality data and analyzed them for evidence of the imprints. Ordinary SEM imaging methods revealed very faint outlines of the X stamps in the metal grains. However, pattern quality mapping more clearly revealed the outlines of the Xs, and according to the team, would probably be acceptable for submission as forensic evidence. The latter technique is significantly more sensitive to small amounts of crystal lattice damage. The technique is still experimental, but shows some promise. The NIST team found evidence of metal deformation down to about 760 micrometers below the surface, much deeper than the actual X stamps. Even so, the researchers say it’s not clear whether EBSD pattern quality mapping is more sensitive and/or more effective than conventional techniques for reconstructing serial numbers, or whether EBSD will work in cases of the most extreme destruction. Experimental comparison of the new technique to traditional techniques is under way. Currently, the NIST method is time-consuming: A technician would need three full days to reconstruct an 8-character number. With further development and optimization, such as making pixel sizes larger in the images, recovery time probably could be reduced to about an hour, according to the researchers. The researchers suggest that wide adoption of this technology might enable manufacturers to place “hidden” sub-surface serial numbers on firearms—numbers that would be invisible to criminals but clearly detectable by law enforcement with this new analysis method. The idea of using EBSD to recover firearm serial numbers was first proposed at a conference several years ago by Carl Necker of Los Alamos National Laboratory. *R.M. White and R.R. Keller. Restoration of firearm serial numbers using electron backscatter diffraction (EBSD). Forensic Science International. In press accepted manuscript. Published online Feb. 9, 2015. DOI: http://dx.doi.org/10.1016/j.forsciint.2015.02.003. source  : www.nist.gov

Monitoring epilepsy in the brain with a wireless system

Wed, 02/11/2015 - 12:56pm Laure-Anne Pessina, EPFL   Source: Thinkstock/EPFLThe large majority of the 50 million people around the world who suffer from epilepsy can be treated by anticonvulsant drugs. Yet a handful of patients do not respond to the standard treatment. More and more of them are turning to surgery to give them back a normal life. The principle is to locate, with the help of electrodes, the region in the brain that is the source of the epilepsy and, in the most serious cases, remove it. The current presurgical phase is complex and highly invasive. Patients undergo a cranial operation to have electrodes implanted on the surface of their cortex. Once the wound is closed, the patients must remain in bed in intensive care for several weeks with wires passing through their cranium. The electrodes are connected the entire time to a recording machine, which is used to identify the source of the epilepsy during seizures. Researchers at EPFL are now developing a network of wireless microelectrodes that will monitor the patients' brain activity with great precision, without requiring them to remain confined to their hospital bed. Gürkan Yilmaz presented this research as part of his doctoral thesis, conducted in collaboration with doctors and researchers from Inselspital (University Hospital of Bern). A number of in vivo tests have been carried out successfully. Greater precision and less damage to the brain The new wireless method still needs a cranial operation, but it offers a number of advantages. In addition to suppressing cumbersome wires and sparing patients the ordeal of staying in intensive care during the presurgical phase, it extends the monitoring time, thanks to the reduced risk of infection. The source of the epilepsy can also be identified more precisely. "We are developing electrodes that are less than 100 micrometers in diameter, versus 10 millimeters for electrodes used in traditional intracranial electroencephalograms," says Yilmaz. "As a result, measurements are much more precise, and the fewest possible neurons are removed during the operation. This allows us to minimise the damage that can result from this type of operation." With the new system, which consists of a network of electrodes, a microchip and an antenna, the electric signals are captured and processed under the skin in a miniaturised station. The internal device is powered from the outside by wireless power transfer, more specifically by electromagnetic induction. Thanks to this energy, the internal system can process a large amount of data, and then transfer the results to an external unit. "We could use a mobile phone to receive the data, but for reasons of data security, it is not the preferred method," says Gürkan Yilmaz. At this stage, in vivo tests have been successfully run on laboratory mice. Innovative, less invasive therapies Medical doctors are showing a significant interest in this technology. Claudio Pollo, a neurosurgeon in charge of epilepsy surgery at Bern University Hospital, explains the potential represented by such a system. "We would be able to observe epileptogenesis at the level of a few cells rather than tens of thousands of cells," he notes. "This would enable us to remove smaller epileptogenic zones, and to develop innovative therapies. For example, when a given region cannot be removed, we could deliver electrical stimulation to the lesions to prevent seizures." And this type of surgery produces excellent results. "The recovery rate is nearly 80%, when talking about temporal lobe epilepsy. More and more children are operated on, and this drastically changes their future." In the laboratory, the researchers continue their work. Their goals include adjusting the size of the electrodes so that they can measure the activity of a single neuron. Source: EPFL

Group Social Activity Keeps People Mentally Sharp

Clubs and parties beat one-on-one encounters for preventing cognitive decline Dec 18, 2014 By Erica Westly A BELLO Getty Images Social activity is well known to influence mental health, particularly as people age—but the details behind this phenomenon are unclear. Different types of social interactions may be more or less important, depending on the circumstances. One-on-one relationships, such as those between spouses, may yield specific emotional benefits. When it comes to slowing cognitive decline, however, group interactions have more power, according to a recent study published in Social Science & Medicine. The study analyzed data from more than 3,400 adults aged 50 and older. Subjects who reported high engagement with social groups such as book clubs and community organizations performed better on tests measuring cognitive skills such as working memory. Individual relationships such as friendships, meanwhile, appeared to have no effect on cognitive ability. The mental boost from group activity was also more pronounced with age: group-connected subjects closer to age 50 had the cognitive capacities of someone about five years younger, whereas those near 80 years old were rejuvenated by about 10 years, putting them mentally closer to a 70-year-old. Group relationships require effort to maintain, and they reinforce self-identity, both of which may sharpen thinking skills, says Catherine Haslam, a clinical psychology professor at the University of Queensland in Australia and lead author of the study. Conversely, the ease of interactions with spouses or family members may make them less stimulating. “The difference in terms of keeping mentally active is those group relationships,” Haslam says. source : www.scientificamerican.com