Deforestation of sandy soils a greater climate threat

Deforestation may have far greater consequences for climate change in some soils than in others, according to new research led by Yale University scientists — a finding that could provide critical insights into which ecosystems must be managed with extra care because they are vulnerable to biodiversity loss and which ecosystems are more resilient to widespread tree removal.In a comprehensive analysis of soil collected from 11 distinct U.S. regions, from Hawaii to northern Alaska, researchers found that the extent to which deforestation disturbs underground microbial communities that regulate the loss of carbon into the atmosphere depends almost exclusively on the texture of the soil. The results were published in the journal Global Change Biology.”We were astonished that biodiversity changes were so strongly affected by soil texture and that it was such an overriding factor,” said Thomas Crowther, a postdoctoral fellow at the Yale School of Forestry & Environmental Studies and lead author of the study. “Texture overrode the effects of all the other variables that we thought might be important, including temperature, moisture, nutrient concentrations, and soil pH.”The study is a collaboration among Yale researchers and colleagues at the University of Boulder, Colorado and the University of Kentucky.A serious consequence of deforestation is extensive loss of carbon from the soil, a process regulated by subterranean microbial diversity. Drastic changes to the microbial community are expected to allow more CO2 to escape into the atmosphere, with the potential to exaggerate global warming.Specifically, the researchers found that deforestation dramatically alters microbial communities in sandy soils, but has minimal effects in muddy, clay-like soils, even after extensive tree removal.According to the researchers, particles in fine, clay-like soil seem to have a larger surface area to bind nutrients and water. This capacity might buffer soil microbes against the disturbance of forest removal, they said. In contrast, sandy soils have larger particles with less surface area, retaining fewer nutrients and less organic matter.”If you disrupt the community in a sandy soil, all of the nutrients the microbes rely on for food are leached away: they’re lost into the atmosphere, lost into rivers, lost through rain,” Crowther said. “But in clay-like soil, you can cut down the forest and the nutrients remain trapped tightly in the muddy clay.”The researchers also examined how the effects of deforestation on microbial biodiversity change over time. Contrary to their expectations, they found no correlation, even over the course of 200 years.”The effects are consistent, no matter how long ago deforestation happened,” Crowther said. “In a clay soil, you cut down the forest and the nutrients are retained for long periods of time and the community doesn’t change. …

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Drug Abuse Among Unsuspecting Professionals

Addiction does not discriminate and our drug and alcohol programs here at Harmony reflect this fact well – with programs for young adults, men and women in all stages of life.The need for more addiction rehabs to focus on professionals in their programs has been highlighted in the news recently with professionals under fire for drug abuse. Last week, a high school IT teacher in England was sentenced to over 3 years in jail and permanently banned from teaching after being caught with more than 100 grams of cocaine in a narcotics lab in his home.His sentencing came after an investigation found that he was involved in high-level supply of cocaine leading to his arrest in 2012. At first the teacher denied being a distributor and said …

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‘Death stars’ in Orion blast planets before they even form

The Orion Nebula is home to hundreds of young stars and even younger protostars known as proplyds. Many of these nascent systems will go on to develop planets, while others will have their planet-forming dust and gas blasted away by the fierce ultraviolet radiation emitted by massive O-type stars that lurk nearby.A team of astronomers from Canada and the United States has used the Atacama Large Millimeter/submillimeter Array (ALMA) to study the often deadly relationship between highly luminous O-type stars and nearby protostars in the Orion Nebula. Their data reveal that protostars within 0.1 light-years (about 600 billion miles) of an O-type star are doomed to have their cocoons of dust and gas stripped away in just a few millions years, much faster than planets are able to form.”O-type stars, which are really monsters compared to our Sun, emit tremendous amounts of ultraviolet radiation and this can play havoc during the development of young planetary systems,” remarked Rita Mann, an astronomer with the National Research Council of Canada in Victoria, and lead author on a paper in the Astrophysical Journal. “Using ALMA, we looked at dozens of embryonic stars with planet-forming potential and, for the first time, found clear indications where protoplanetary disks simply vanished under the intense glow of a neighboring massive star.”Many, if not all, Sun-like stars are born in crowded stellar nurseries similar to the Orion Nebula. Over the course of just a few million years, grains of dust and reservoirs of gas combine into larger, denser bodies. Left relatively undisturbed, these systems will eventually evolve into fully fledged star systems, with planets — large and small — and ultimately drift away to become part of the galactic stellar population.Astronomers believe that massive yet short-lived stars in and around large interstellar clouds are essential for this ongoing process of star formation. At the end of their lives, massive stars explode as supernovas, seeding the surrounding area with dust and heavy elements that will get taken up in the next generation of stars. These explosions also provide the kick necessary to initiate a new round of star and planet formation. But while they still shine bright, these larger stars can be downright deadly to planets if an embryonic solar systems strays too close.”Massive stars are hot and hundreds of times more luminous than our Sun,” said James Di Francesco, also with the National Research Council of Canada. “Their energetic photons can quickly deplete a nearby protoplanetary disk by heating up its gas, breaking it up, and sweeping it away.”Earlier observations with the Hubble Space Telescope revealed striking images of proplyds in Orion. …

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Bright pulses of light could make space veggies more nutritious

Exposing leafy vegetables grown during spaceflight to a few bright pulses of light daily could increase the amount of eye-protecting nutrients produced by the plants, according to a new study by researchers at the University of Colorado Boulder.One of the concerns for astronauts during future extended spaceflights will be the onslaught of eye-damaging radiation they’ll be exposed to. But astronauts should be able to mitigate radiation-induced harm to their eyes by eating plants that contain carotenoids, especially zeaxanthin, which is known to promote eye health.Zeaxanthin could be ingested as a supplement, but there is evidence that human bodies are better at absorbing carotenoids from whole foods, such as green leafy vegetables.Already, NASA has been studying ways to grow fresh produce during deep space missions to maintain crew morale and improve overall nutrition. Current research into space gardening tends to focus on getting the plants to grow as large as possible as quickly as possible by providing optimal light, water and fertilizer. But the conditions that are ideal for producing biomass are not necessarily ideal for the production of many nutrients, including zeaxanthin.”There is a trade-off,” said Barbara Demmig-Adams, professor of distinction in the Department of Ecology and Evolutionary Biology and a co-author of the study published in the journal Acta Astronautica. “When we pamper plants in the field, they produce a lot of biomass but they aren’t very nutritious. If they have to fend for themselves — if they have to defend themselves against pathogens or if there’s a little bit of physical stress in the environment — plants make defense compounds that help them survive. And those are the antioxidants that we need.”Plants produce zeaxanthin when their leaves are absorbing more sunlight than they can use, which tends to happen when the plants are stressed. For example, a lack of water might limit the plant’s ability to use all the sunlight it’s getting for photosynthesis. To keep the excess sunlight from damaging the plant’s biochemical pathways, it produces zeaxanthin, a compound that helps safely remove excess light.Zeaxanthin, which the human body cannot produce on its own, plays a similar protective role in our eyes.”Our eyes are like a leaf — they are both about collecting light,” Demmig-Adams said. “We need the same protection to keep us safe from intense light.”The CU-Boulder research team — which also included undergraduate researcher Elizabeth Lombardi, postdoctoral researcher Christopher Cohu and ecology and evolutionary biology Professor William Adams — set out to determine if they could find a way to “have the cake and eat it too” by simultaneously maximizing plant growth and zeaxanthin production.Using the model plant species Arabidopsis, the team demonstrated that a few pulses of bright light on a daily basis spurred the plants to begin making zeaxanthin in preparation for an expected excess of sunlight. …

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Still no Field Sobriety Test for Marijuana

Photo Credit How do police identify a stoned driver?The standard field sobriety test involves having a driver walk heel to toe, turn on one foot and walk back heel to toe and stand on one leg for 30 seconds. This is said to catch almost 90% of drunk drivers – but does it do the same for stoned drivers?According to an article published in the New York Times it does not. In fact, only 30% of stoned drivers with THC in their systems fail these motor skills and the rates are even lower for veteran stoners who are used to being high.Crafting a standard field sobriety test that works for marijuana is becoming increasingly important as states legalize its recreational and medical use. Still little…

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Addiction Treatment After Naloxone

Photo Credit California is now following the footsteps of Colorado and other states that allows the use of naloxone or Narcan, an FDA approved, non-addictive drug that prevents heroin overdose.California Governor Jerry Brown signed Assembly Bill 635 into law, which took effect on January 1st of this year permitting the use of naloxone by non-medical professionals across the state. Just this week, Gil Kerlikowske the White House Director of National Drug Control Policy highlighted the effectiveness of naloxone as one of many attempts to limit the rise of heroin abuse and overdose in the US. Currently, more than 100 overdose deaths occur from heroin abuse in the US each day. The death of Philip Seymour Hoffman last week was one of an estimated 700 that occurred that…

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Kepler finds a very wobbly planet: Rapid and erratic changes in seasons

Imagine living on a planet with seasons so erratic you would hardly know whether to wear Bermuda shorts or a heavy overcoat. That is the situation on a weird, wobbly world found by NASA’s planet-hunting Kepler space telescope.The planet, designated Kepler-413b, precesses, or wobbles, wildly on its spin axis, much like a child’s top. The tilt of the planet’s spin axis can vary by as much as 30 degrees over 11 years, leading to rapid and erratic changes in seasons. In contrast, Earth’s rotational precession is 23.5 degrees over 26,000 years. Researchers are amazed that this far-off planet is precessing on a human timescale.Kepler 413-b is located 2,300 light-years away in the constellation Cygnus. It circles a close pair of orange and red dwarf stars every 66 days. The planet’s orbit around the binary stars appears to wobble, too, because the plane of its orbit is tilted 2.5 degrees with respect to the plane of the star pair’s orbit. As seen from Earth, the wobbling orbit moves up and down continuously.Kepler finds planets by noticing the dimming of a star or stars when a planet transits, or travels in front of them. Normally, planets transit like clockwork. Astronomers using Kepler discovered the wobbling when they found an unusual pattern of transiting for Kepler-413b.”Looking at the Kepler data over the course of 1,500 days, we saw three transits in the first 180 days — one transit every 66 days — then we had 800 days with no transits at all. …

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Signs point to sharp rise in drugged driving fatalities

The prevalence of non-alcohol drugs detected in fatally injured drivers in the U.S. has been steadily rising and tripled from 1999 to 2010 for drivers who tested positive for marijuana — the most commonly detected non-alcohol drug — suggesting that drugged driving may be playing an increasing role in fatal motor vehicle crashes.To assess these trends researchers at Columbia University’s Mailman School of Public Health examined toxicological testing data from the National Highway Traffic Safety Administration’s Fatality Analysis Reporting System and found that of 23,591 drivers who were killed within one hour of a crash, 39.7% tested positive for alcohol and 24.8% for other drugs. While positive results for alcohol remained stable, the prevalence of non-alcohol drugs rose significantly from 16.6% in 1999 to 28.3% in 2010; for marijuana, rates rose from 4.2% to 12.2%. Findings are online in the American Journal of Epidemiology.This study is based on data from six U.S. states that routinely performed toxicological testing on drivers involved in fatal car crashes — California, Hawaii, Illinois, New Hampshire, Rhode Island, and West Virginia.The results showed that alcohol involvement was more prevalent in men (43.6%) than in women (26.1%), but trends were stable for both sexes. In contrast, the substantial increase in the prevalence of marijuana was reported for all age groups and both sexes.”Although earlier research showed that drug use is associated with impaired driving performance and increased crash risk, trends in narcotic involvement in driver fatalities have been understudied,” said Guohua Li, MD, DrPH, professor of Epidemiology and Anesthesiology and director of the Center for Injury Epidemiology and Prevention. “Given the increasing availability of marijuana and the ongoing opioid overdose epidemic, understanding the role of controlled substances in motor vehicle crashes is of significant public health importance.”Joanne Brady, a PhD candidate in epidemiology and the lead author of the study, notes that research from 2007 to 2013 shows an increase in drivers testing positive for marijuana in roadside surveys, as well as drivers involved in fatal crashes in in California and increased use by patients treated in Colorado healthcare settings. “The marked increase in its prevalence as reported in the present study is likely germane to the growing decriminalization of marijuana,” noted Ms. Brady. Over the last 17 years, 20 states and Washington, D.C. …

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Overweight, obese children face high risk of hypertension

Oct. 10, 2013 — High body weight in children and adolescents is strongly associated with the likelihood of hypertension, according to a Kaiser Permanente Southern California study published today in The Journal of Clinical Hypertension.Researchers found that young people who are overweight are twice as likely as their normal-weight peers to have hypertension; moderately obese youths have four times higher risk; and extremely obese children and adolescents are 10 times more likely to have hypertension. The study also found 10 percent of youths who are extremely obese have hypertension and nearly half have occasional blood pressure measurements in the hypertensive range. Earlier studies showed that between 1 to 5 percent of youth have hypertension.”This study’s findings suggest that pediatricians need to be particularly vigilant about screening overweight and obese children for hypertension because high blood pressure can be asymptomatic for many years,” said Corinna Koebnick, PhD, lead author and researcher at Kaiser Permanente Southern California’s Department of Research & Evaluation.Researchers examined the electronic health records of nearly 250,000 children aged 6 to 17 years who were enrolled in Kaiser Permanente in Southern California between January 1, 2007 and December 31, 2009. The study used the first four consecutive blood pressures measured routinely as a part of clinical care during the 36-month time period.”High blood pressure in children is a serious health condition that can lead to heart and kidney disease,” said researcher David Cuan, MD, Department of Pediatrics, Kaiser Permanente Riverside Medical Center. “While it is generally recommended that pediatricians measure blood pressure in children three years and older at every health care visit, this study shows the importance of screening overweight and obese young people in particular as they have an increased likelihood of hypertension.”The present results also suggest that the currently used classifications for overweight and obesity in children may be an effective tool for identifying children at high risk for hypertension. For this study, researchers used sex-specific BMI-for-age growth charts developed by the Centers for Disease Control and Prevention combined with the World Health Organization definitions for overweight and obesity in adults. Being above the threshold for overweight was an indicator for prehypertension, while being above the threshold for obesity was an indicator for hypertension.”This study highlights a great use of existing high-quality data for addressing important scientific questions, in this case, the challenge of screening asymptomatic children for hypertension,” said Matthew F. Daley, MD, a pediatrician and a researcher at the Institute for Health Research, Kaiser Permanente Colorado. “The findings of this study suggest that we should focus our limited resources on the children who need the most timely follow up.”Kaiser Permanente can conduct transformational health research like this in part because it has the largest private patient-centered electronic health record system in the world. …

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Peering into genetic defects, scientists discover a new metabolic disease

Sep. 5, 2013 — An international team of scientists, including University of Colorado School of Medicine and Children’s Hospital Colorado researchers, has discovered a new disease related to an inability to process Vitamin B12.The disorder is rare but can be devastating.”Some people with rare inherited conditions cannot process vitamin B 12 properly,” says CU researcher Tamim Shaikh, PhD, a geneticist and senior author of a paper about the new disease. “These individuals can end up having serious health problems, including developmental delay, epilepsy, anemia, stroke, psychosis and dementia.”The discovery is important because it could help doctors diagnose the disease and, eventually, could lead to prevention or treatment. But there is more to the story than that.A 9-year-old Colorado boy named Max Watson, who because of his metabolic disease uses a computer to communicate, was the first patient in whom this discovery was made.His older sister Abbey, 15, volunteered in the CU lab that helped achieve this medical breakthrough.His parents cooperated with the study knowing that the results likely would not help their son but might help future patients.The discovery, published today in The American Journal of Human Genetics, illustrates the complex and relatively new realm of medical discovery where researchers peer into the genetic make-up of patients to discern what went wrong to cause a disease.Vitamin B 12 also is called cobalamin. The new disease is called cobalimin X, or cblX.Obtained from foods such as milk, eggs, fish and meat, B 12 is essential to human health because it helps the body convert food into fuel. It’s vital to the nervous system and for making red blood cells.Max was born with symptoms that looked like he had a B 12 problem called cobalamin C deficiency or cblC for short, which, like its newly discovered counterpart, can show up in utero.The gene for cblC had been discovered by researchers who studied several hundred patients with similar symptoms. A few of those patients, however, did not have the genetic mutation that that was common to the cblC patients. And some, like Max, had symptoms that didn’t quite match up.”We knew from early on that something was unusual about this patient,” says Johan Van Hove, MD, a CU professor in the Department of Pediatrics, who saw Max when the boy was just a few months old.Max was labeled as having cblC — but Van Hove and others on a team of metabolism experts at Children’s Hospital Colorado had their doubts. Some of Max’s symptoms seemed too severe for that diagnosis.So Shaikh, an associate professor in the medical school’s pediatrics department, and CU colleagues, used what is called next generation genetic sequencing to delve into Max’s DNA. They also looked at genes of patients who didn’t fit the cobalamin C model, obtained from partners at the National Institutes of Health, and in Canada and Switzerland.All of those patients carried mutations that hadn’t been identified before. …

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New low-temperature chemical reaction explained

Sep. 4, 2013 — In all the centuries that humans have studied chemical reactions, just 36 basic types of reactions have been found. Now, thanks to the work of researchers at MIT and the University of Minnesota, a 37th type of reaction can be added to the list.The newly explained reaction — whose basic outlines had been known for three decades, but whose workings had never been understood in detail — is an important part of atmospheric reactions that lead to the formation of climate-affecting aerosols; biochemical reactions that may be important for human physiology; and combustion reactions in engines.The new analysis is explained in a paper by MIT graduate student Amrit Jalan, chemical engineering professor William Green, and six other researchers, published in the Journal of the American Chemical Society.Stephen Klippenstein, a senior scientist at the Argonne National Laboratory in Illinois who was not involved in this research, says, “I think this may be the best paper I have read this year. It uses a multitude of theoretical methods … to explore multiple aspects of a novel discovery that has important ramifications in atmospheric chemistry, combustion kinetics and biology.”The reaction’s details sound esoteric: a low-temperature oxidation that results in the decomposition of complex organic molecules known as gamma-ketohydroperoxides. When he first described the reaction in the scientific literature 30 years ago, Stefan Korcek of the Ford Motor Company proposed a hypothesis for how the reaction might take place. The new work shows that Korcek had the right concept, although some details differ from his predictions.The original discovery was the result of analyzing how engine oils break down through oxidation — part of an attempt to produce oils that would last longer. That’s important, Green points out, since waste oil is among the largest hazardous waste streams in the United States.In analyzing the problem, Korcek realized that “there were fundamental things about the way even simple hydrocarbons react with oxygen that we didn’t understand,” Green says. By examining the products of the reaction, which included carboxylic acids and ketones, Korcek outlined an unusually complex multipart reaction. But for the next three decades, nobody found a way to verify whether the reaction or the steps he outlined could work.Jalan says that the MIT researchers’ analysis came about almost by accident. “I was looking at that paper for a different study,” he says, “and I came across [Korcek’s] work, which hadn’t been verified either theoretically or experimentally. …

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Ability to delay gratification may be linked to social trust

Sep. 4, 2013 — A person’s ability to delay gratification — forgoing a smaller reward now for a larger reward in the future — may depend on how trustworthy the person perceives the reward-giver to be, according to a new study by researchers at the University of Colorado Boulder.A body of research that stretches back more than a half-century has shown that the ability to delay gratification is linked to a number of better life outcomes. On average, people who were able to delay gratification as children go on to have higher SAT scores, for example. They also tend to be more socially conscious as adolescents, less obese as adults, and less likely to abuse drugs or alcohol.But despite the long history of studying delayed gratification, little research has focused on the role of social trust in a person’s ability to wait for a larger payoff in the future.”Most of the time, when people talk about delaying gratification, they talk about basic processes of evaluation and self-control,” said Laura Michaelson, a CU-Boulder doctoral student in the Department of Psychology and Neuroscience and co-lead author of the new study appearing in the online journal Frontiers in Psychology.In general, people who choose not to delay gratification have often been characterized as irrational and as having poor impulse control. But if the role of social trust is considered, it introduces the possibility that the person who is choosing not to delay gratification may be acting rationally after all, the researchers said.”If you don’t trust someone, it’s rational not to wait for them to give you $20 in a month instead of $15 now,” said study co-lead author Alejandro de la Vega, also a doctoral student in CU-Boulder’s Department of Psychology and Neuroscience.To determine the role of social trust, the research team — which also included Christopher Chatham, a former CU-Boulder doctoral student now at Brown University, and psychology and neuroscience Professor Yuko Munakata — recruited participants using Amazon’s Mechanical Turk, an online tool that can be used by scientists to quickly connect with a large number of people from a broad range of backgrounds.The researchers paid participants up to $1 to participate in an experiment in which they were asked to read the profiles of three fictional characters and then rate them on their trustworthiness. Participants were then asked whether they would opt to take a smaller amount of money offered immediately from each character or a larger amount of money that they would have to wait to collect.The results showed that the participants were less likely to delay gratification when they distrusted the person who was offering the reward. A second experiment — which relied on a larger group but asked each participant to read the profile of only one character — had similar results. The second study also paired one of three sketches of a face with each character.”This offers an alternative explanation for why certain populations might be notoriously bad at delaying gratification or notoriously impulsive, like criminals and addicts,” Michaelson said. “It had been chalked up to a lack of self-control. But it may be the case that they are poor at delaying gratification because they have low social trust.”The findings could have implications for determining the best intervention strategies to use with children who find it difficult to delay gratification. …

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Study relies on twins and their parents to understand height-IQ connection

Aug. 27, 2013 — The fact that taller people also tend to be slightly smarter is due in roughly equal parts to two phenomena — the same genes affect both traits and taller people are more likely than average to mate with smarter people and vice versa — according to a study led by the University of Colorado Boulder.The study did not find that environmental factors contributed to the connection between being taller and being smarter, both traits that people tend to find attractive.The modest correlation between height and IQ has been documented in multiple studies stretching back to the 1970s. But the reasons for the relationship between the two traits has not been well understood.The technique developed by the researchers at CU-Boulder to tease out those reasons may open the door for scientists to better understand why other sexually selected traits — characteristics that individuals find desirable in mates — tend to be linked. People who are attractive because of one trait tend to have other attractive traits as well.”Not just in humans but also in animals, you see that traits that are sexually attractive tend to be correlated,” said Matthew Keller, assistant professor of psychology and neuroscience at CU-Boulder and lead author of the study appearing in the journal PLOS Genetics. “So if you have animals that are high on one sexually selected trait they are often high on other ones, too. And the question has always been, ‘What’s the cause of that?’ And it has always been very difficult to tease apart the two potential genetic reasons that those could be related.”The key to the technique developed by Keller, also a fellow at CU-Boulder’s Institute for Behavioral Genetics, and his colleagues is using data collected about fraternal twins, identical twins and, importantly, their parents.It has been common in the past to use information about identical twins and fraternal twins to determine whether a particular trait is inherited, caused by environmental factors or affected by some combination of both. This kind of twin study assumes that each twin grows up with the same environmental factors as his or her sibling.If a trait that’s present in one twin is just as often present in the other — regardless of whether the twins are fraternal or identical — then the trait is likely caused by environmental conditions. On the other hand, if a trait is generally found in both identical twins but only in one of a set of fraternal twins, it’s likely that the trait is inherited, since identical twins have the same genetic material but fraternal twins do not.Similar studies also can be done for linked traits, such as height and IQ. But while scientists could determine that a pair of traits is passed down genetically, they could not further resolve whether inherited traits were linked due to the same genes influencing both traits, called “pleiotropy,” or because people who have those traits are more likely to mate with each other, known as “assortative mating.”The new CU-Boulder study solves this problem by including the parents of twins in its analysis. While this has occasionally been done in the past for single traits, information on parents has not previously been used to shed light on why two traits are genetically correlated. …

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Ytterbium atomic clocks set record for stability

Aug. 22, 2013 — A pair of experimental atomic clocks based on ytterbium atoms at the National Institute of Standards and Technology (NIST) has set a new record for stability. The clocks act like 21st-century pendulums or metronomes that could swing back and forth with perfect timing for a period comparable to the age of the universe.NIST’s ultra-stable ytterbium lattice atomic clock. Ytterbium atoms are generated in an oven (large metal cylinder on the left) and sent to a vacuum chamber in the center of the photo to be manipulated and probed by lasers. Laser light is transported to the clock by five fibers (such as the yellow fiber in the lower center of the photo). Credit: Burrus/NIST View hi-resolution imageNIST physicists report in the Aug. 22 issue of Science Express that the ytterbium clocks’ tick is more stable than any other atomic clock. Stability can be thought of as how precisely the duration of each tick matches every other tick. The ytterbium clock ticks are stable to within less than two parts in 1 quintillion (1 followed by 18 zeros), roughly 10 times better than the previous best published results for other atomic clocks.This dramatic breakthrough has the potential for significant impacts not only on timekeeping, but also on a broad range of sensors measuring quantities that have tiny effects on the ticking rate of atomic clocks, including gravity, magnetic fields, and temperature. And it is a major step in the evolution of next-generation atomic clocks under development worldwide, including at NIST and at JILA, the joint research institute operated by NIST and the University of Colorado Boulder.”The stability of the ytterbium lattice clocks opens the door to a number of exciting practical applications of high-performance timekeeping,” NIST physicist and co-author Andrew Ludlow says.Each of NIST’s ytterbium clocks relies on about 10,000 rare-earth atoms cooled to 10 microkelvin (10 millionths of a degree above absolute zero) and trapped in an optical lattice — a series of pancake-shaped wells made of laser light. …

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New water splitting technique efficiently produces hydrogen fuel

Aug. 1, 2013 — A University of Colorado Boulder team has developed a radically new technique that uses the power of sunlight to efficiently split water into its components of hydrogen and oxygen, paving the way for the broad use of hydrogen as a clean, green fuel.The CU-Boulder team has devised a solar-thermal system in which sunlight could be concentrated by a vast array of mirrors onto a single point atop a central tower up to several hundred feet tall. The tower would gather heat generated by the mirror system to roughly 2,500 degrees Fahrenheit (1,350 Celsius), then deliver it into a reactor containing chemical compounds known as metal oxides, said CU-Boulder Professor Alan Weimer, research group leader.As a metal oxide compound heats up, it releases oxygen atoms, changing its material composition and causing the newly formed compound to seek out new oxygen atoms, said Weimer. The team showed that the addition of steam to the system — which could be produced by boiling water in the reactor with the concentrated sunlight beamed to the tower — would cause oxygen from the water molecules to adhere to the surface of the metal oxide, freeing up hydrogen molecules for collection as hydrogen gas.”We have designed something here that is very different from other methods and frankly something that nobody thought was possible before,” said Weimer of the chemical and biological engineering department. “Splitting water with sunlight is the Holy Grail of a sustainable hydrogen economy.”A paper on the subject was published in the Aug. 2 issue of Science. The team included co-lead authors Weimer and Associate Professor Charles Musgrave, first author and doctoral student Christopher Muhich, postdoctoral researcher Janna Martinek, undergraduate Kayla Weston, former CU graduate student Paul Lichty, former CU postdoctoral researcher Xinhua Liang and former CU researcher Brian Evanko.One of the key differences between the CU method and other methods developed to split water is the ability to conduct two chemical reactions at the same temperature, said Musgrave, also of the chemical and biological engineering department. While there are no working models, conventional theory holds that producing hydrogen through the metal oxide process requires heating the reactor to a high temperature to remove oxygen, then cooling it to a low temperature before injecting steam to re-oxidize the compound in order to release hydrogen gas for collection.”The more conventional approaches require the control of both the switching of the temperature in the reactor from a hot to a cool state and the introduction of steam into the system,” said Musgrave. “One of the big innovations in our system is that there is no swing in the temperature. The whole process is driven by either turning a steam valve on or off.””Just like you would use a magnifying glass to start a fire, we can concentrate sunlight until it is really hot and use it to drive these chemical reactions,” said Muhich. …

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A week’s worth of camping synchs internal clock to sunrise and sunset

Aug. 1, 2013 — Spending just one week exposed only to natural light while camping in the Rocky Mountains was enough to synch the circadian clocks of eight people participating in a University of Colorado Boulder study with the timing of sunrise and sunset.The study, published online today in the journal Current Biology, found that the synchronization happened in that short period of time for all participants, regardless of whether they were early birds or night owls during their normal lives.”What’s remarkable is how, when we’re exposed to natural sunlight, our clocks perfectly become in synch in less than a week to the solar day,” said CU-Boulder integrative physiology Professor Kenneth Wright, who led the study.Electrical lighting, which became widely available in the 1930s, has affected our internal circadian clocks, which tell our bodies when to prepare for sleep and when to prepare for wakefulness. The ability to flip a switch and flood a room with light allows humans to be exposed to light much later into the night than would be possible naturally.Even when people are exposed to electrical lights during daylight hours, the intensity of indoor lighting is much less than sunlight and the color of electrical light also differs from natural light, which changes shade throughout the day.To quantify the effects of electrical lighting, a research team led by Wright, who also is the director of CU-Boulder’s Sleep and Chronobiology Laboratory, monitored eight participants for one week as they went about their normal daily lives. The participants wore wrist monitors that recorded the intensity of light they were exposed to, the timing of that light, and their activity, which allowed the researchers to infer when they were sleeping.At the end of the week, the researchers also recorded the timing of participants’ circadian clocks in the laboratory by measuring the presence of the hormone melatonin. The release of melatonin is one of the ways our bodies signal the onset of our biological nighttime. Melatonin levels decrease again at the start of our biological daytime.The same metrics were recorded during and after a second week when the eight participants — six men and two women with a mean age of 30 — went camping in Colorado’s Eagles Nest Wilderness. During the week, the campers were exposed only to sunlight and the glow of a campfire. Flashlights and personal electronic devices were not allowed.On average, participants’ biological nighttimes started about two hours later when they were exposed to electrical lights than after a week of camping. During the week when participants went about their normal lives, they also woke up before their biological night had ended.After the camping trip — when study subjects were exposed to four times the intensity of light compared with their normal lives — participants’ biological nighttimes began near sunset and ended at sunrise. They also woke up just after their biological night had ended. …

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Ice-free Arctic winters could explain amplified warming during Pliocene

July 29, 2013 — Year-round ice-free conditions across the surface of the Arctic Ocean could explain why Earth was substantially warmer during the Pliocene Epoch than it is today, despite similar concentrations of carbon dioxide in the atmosphere, according to new research carried out at the University of Colorado Boulder.In early May, instruments at the Mauna Loa Observatory in Hawaii marked a new record: The concentration of carbon dioxide climbed to 400 parts per million for the first time in modern history.The last time researchers believe the carbon dioxide concentration in the atmosphere reached 400 ppm — between 3 and 5 million years ago during the Pliocene — Earth was about 3.5 to 9 degrees Fahrenheit warmer (2 to 5 degrees Celsius) than it is today. During that time period, trees overtook the tundra, sprouting right to the edges of the Arctic Ocean, and the seas swelled, pushing ocean levels 65 to 80 feet higher.Scientists’ understanding of the climate during the Pliocene has largely been pieced together from fossil records preserved in sediments deposited beneath lakes and on the ocean floor.”When we put 400 ppm carbon dioxide into a model, we don’t get as warm a planet as we see when we look at paleorecords from the Pliocene,” said Jim White, director of CU-Boulder’s Institute of Arctic and Alpine Research and co-author of the new study published online in the journal Palaeogeography, Paleoclimatology, Palaeoecology. “That tells us that there may be something missing in the climate models.”Scientists have proposed several hypotheses in the past to explain the warmer Pliocene climate. One idea, for example, was that the formation of the Isthmus of Panama, the narrow strip of land linking North and South America, could have altered ocean circulations during the Pliocene, forcing warmer waters toward the Arctic. But many of those hypotheses, including the Panama possibility, have not proved viable.For the new study, led by Ashley Ballantyne, a former CU-Boulder doctoral student who is now an assistant professor of bioclimatology at the University of Montana, the research team decided to see what would happen if they forced the model to assume that the Arctic was free of ice in the winter as well as the summer during the Pliocene. Without these additional parameters, climate models set to emulate atmospheric conditions during the Pliocene show ice-free summers followed by a layer of ice reforming during the sunless winters.”We tried a simple experiment in which we said, ‘We don’t know why sea ice might be gone all year round, but let’s just make it go away,’ ” said White, who also is a professor of geological sciences. “And what we found was that we got the right kind of temperature change and we got a dampened seasonal cycle, both of which are things we think we see in the Pliocene.”In the model simulation, year-round ice-free conditions caused warmer conditions in the Arctic because the open water surface allowed for evaporation. Evaporation requires energy, and the water vapor then stored that energy as heat in the atmosphere. The water vapor also created clouds, which trapped heat near the planet’s surface.”Basically, when you take away the sea ice, the Arctic Ocean responds by creating a blanket of water vapor and clouds that keeps the Arctic warmer,” White said.White and his colleagues are now trying to understand what types of conditions could bridge the standard model simulations with the simulations in which ice-free conditions in the Arctic are imposed. If they’re successful, computer models would be able to model the transition between a time when ice reformed in the winter to a time when the ocean remained devoid of ice throughout the year.Such a model also would offer insight into what could happen in our future. …

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Pathways activated in most K9 bone tumors not driving the worst bone tumors

July 23, 2013 — Many cancers show inappropriate activation of a cell signaling pathway called NOTCH. In the developing body, NOTCH tells brain cells to grow and proliferate. It should be quiet in the adult body, but cancers restart NOTCH to drive their own growth, far and beyond the rate of healthy tissues. A Colorado State University and University of Colorado Cancer Center study expected to find NOTCH signaling elevated in K9 osteosarcoma samples, gathered from patients at the CSU Flint Animal Cancer Center. What they found surprised the researchers: overall, NOTCH signaling was elevated in K9 osteosarcoma, but aspects of Notch signaling were noticeably deactivated in the worst cancers.”We split the samples into two groups: poor responders who had gone less than 100 days after treatment before the progression of their disease, and strong responders who had made it more than 300 days after their treatment without disease progression. Then we could explore the genetic differences between these two groups,” says Dawn Duval, PhD, CU Cancer Center investigator and associate professor of molecular oncology at Colorado State University.Specifically, Duval and colleagues including first author Deanna Dailey, DVM, looked at the expression of a protein called HES1, which is used as a proxy to test for NOTCH activation. High HES1 means that upstream, NOTCH is firing. Low HES1 means it’s not firing or that some other pathway is interfering. They expected to find a linear increase in HES1 as cancers and outcomes got worse — more HES1 would have meant more NOTCH signaling and results in other cancers imply that the more NOTCH, the worse the outcomes.”What we found is that the poor responders had lower HES1. That fit nothing we expected,” Duval says.The osteosarcoma samples from dogs with disease progression in the shortest amount of time, also had the lowest levels of HES1.”We had to go back and try to figure out what was happening, so we measured HES1 levels in normal bone samples and matched bone tumors. …

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Scientists prove ticks harbor Heartland virus, a recently discovered disease in the United States

July 22, 2013 — Scientists have for the first time traced a novel virus that infected two men from northwestern Missouri in 2009 to populations of ticks in the region, providing confirmation that lone star ticks are carrying the recently discovered virus and humans in the area are likely at risk of infection. The findings were published online today in the American Journal of Tropical Medicine and Hygiene.Dubbed Heartland virus or HRTV, the infection causes fever, headaches, and low white blood cell and platelet counts. The two men infected in 2009, who live about 70 miles apart, were sufficiently ill to require hospitalization. They eventually recovered, and no other cases have been reported. Disease experts anticipate, however, that more people could become infected. The Missouri Department of Health and Senior Services is working with the US Centers for Disease Control and Prevention (CDC) to identify additional cases and determine the role of this novel virus as a human pathogen.”Ten samples of ticks tested positive for the Heartland virus, nine of which were collected from the property of one of the patients and one that came from conservation lands nearby,” said Harry M. Savage, PhD, a research entomologist at CDC in Fort Collins, Colorado and the lead author of the paper. “It’s pretty strong evidence that the virus is persisting from season to season in tick populations and that these ticks play an important role in disease transmission.”There is no treatment available for HRTV. Unlike other tick-borne diseases like Lyme, ehrlichiosis and Rocky Mountain spotted fever, HRTV is a virus and thus does not respond to antibiotics.Disease HuntingHRTV was discovered when a doctor at the hospital treating the two infected men, who had reported being bitten by ticks, sent blood samples to a CDC laboratory in Atlanta for testing. All involved assumed the tests would reveal ehrlichiosis, the tick-borne disease that is most common in the area. …

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Bees ‘betray’ their flowers when pollinator species decline

July 22, 2013 — Remove even one bumblebee species from an ecosystem and the impact is swift and clear: Their floral “sweethearts” produce significantly fewer seeds, a new study finds.The study, to be published by the Proceedings of the National Academy of Sciences, focused on the interactions between bumblebees and larkspur wildflowers in Colorado’s Rocky Mountains. The results show how reduced competition among pollinators disrupts floral fidelity, or specialization, among the remaining bees in the system, leading to less successful plant reproduction.”We found that these wildflowers produce one-third fewer seeds in the absence of just one bumblebee species,” says Emory University ecologist Berry Brosi, who led the study. “That’s alarming, and suggests that global declines in pollinators could have a bigger impact on flowering plants and food crops than was previously realized.”The National Science Foundation (NSF) funded the study, co-authored by ecologist Heather Briggs of the University of California-Santa Cruz.About 90 percent of plants need animals, mostly insects, to transfer pollen between them so that they can fertilize and reproduce. Bees are by far the most important pollinators worldwide and have co-evolved with the floral resources they need for nutrition.During the past decade, however, scientists have reported dramatic declines in populations of some bee species, sparking research into the potential impact of such declines.Some studies have indicated that plants can tolerate losing most pollinator species in an ecosystem as long as other pollinators remain to take up the slack. Those studies, however, were based on theoretical computer modeling.Brosi and Briggs were curious whether this theoretical resilience would hold up in real-life scenarios. Their team conducted field experiments to learn how the removal of a single pollinator species would affect the plant-pollinator relationship.”Most pollinators visit several plant species over their lifetime, but often they will display what we call floral fidelity over shorter time periods,” Brosi explains. “They’ll tend to focus on one plant while it’s in bloom, then a few weeks later move on to the next species in bloom. You might think of them as serial monogamists.”Floral fidelity clearly benefits plants, because a pollinator visit will only lead to plant reproduction when the pollinator is carrying pollen from the same plant species. “When bees are promiscuous, visiting plants of more than one species during a single foraging session, they are much less effective as pollinators,” Briggs says.The researchers conducted their experiments at the Rocky Mountain Biological Laboratory near Crested Butte, Colorado. Located at 9,500 feet, the facility’s subalpine meadows are too high for honeybees, but they are buzzing during the summer months with bumblebees. …

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