February 13, 2015University of Southern California - Health Sciences Medical researchers are breaking sound barriers for children born without a hearing nerve. Hearing loss manifests in various forms, most of which can be partially restored through hearing aids and cochlear implants. Those devices cannot help a small population of individuals who do not have a cochlear, or hearing, nerve -- these people are unable to perceive sound, no matter how loud, outside of feeling vibration. The ABI is considered revolutionary because it stimulates neurons directly at the human brainstem, bypassing the inner ear entirely.
Child's ear (stock image). Medical researchers have successfully implanted an auditory brainstem implant (ABI) device in four children who previously could not hear. A multi-institutional team of hearing and communication experts led by the Keck School of Medicine of the University of Southern California (USC) is breaking sound barriers for children born without a hearing nerve in a clinical trial backed by the National Institutes of Health (NIH). Launched in March 2014, the three-year study has enrolled five of 10 participants and successfully implanted an auditory brainstem implant (ABI) device in four children who previously could not hear. The research team will present preliminary findings at the American Association for the Advancement of Sciences (AAAS) 2015 Annual Meeting in San Jose, California, on Feb. 14. "Initial activation of the ABI is like a newborn entering the world and hearing for the first time, which means these children will need time to learn to interpret what they are sensing through the device as 'sound,'" said audiologist Laurie Eisenberg, Ph.D., a Keck School of Medicine of USC otolaryngology professor and study co-leader. "All of our study participants whose ABIs have been activated are progressing at expected or better rates. We are optimistic that, with intensive training and family support, these children will eventually be able to talk on the phone." Hearing loss manifests in various forms, most of which can be partially restored through hearing aids and cochlear implants. Those devices cannot help a small population of individuals who do not have a cochlear, or hearing, nerve -- these people are unable to perceive sound, no matter how loud, outside of feeling vibration. The ABI is considered revolutionary because it stimulates neurons directly at the human brainstem, bypassing the inner ear entirely. Surgeons outside the United States have been doing ABI surgeries in children for more than 10 years, but there was never a formal safety or feasibility study under regulatory oversight. In the United States, the ABI is approved for use only in patients 12 years or older with neurofibromatosis type II, an inherited disease that causes a non-malignant brain tumor on the hearing nerve, but it has shown limited effectiveness in adults. Scientists believe that the ABI would be more effective in younger children, when their brains are more adaptable. The clinical trial will attempt to prove that the surgery is safe in young children and allow researchers to study how the brain develops over time and how it learns to hear sound and develop speech. "Hearing loss can be devastating to a child's social development, and for some children, the ABI is their last viable chance to hear," said Keck School of Medicine of USC Professor Robert V. Shannon, Ph.D., an investigator for the trial and a leading scientist in the development of ABI technology since 1989. "Several of the young children who had ABIs implanted outside the United States have sought help at the USC-CHLA Center for Childhood Communication and we know that they now have the potential to understand speech. This really shows how powerful and flexible the brain is. By studying how the brain and the hearing system work together through this device, our team will set the gold standard for use of this technology." Story Source: The above story is based on materials provided by University of Southern California - Health Sciences. Note: Materials may be edited for content and length.
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sexta-feira, 13 de fevereiro de 2015
Auditory brainstem implant: Hearing experts break sound barrier for children born without hearing nerve
Marijuana use is associated with excessive daytime sleepiness in adolescents
A study published recently by researchers from Nationwide Children's Hospital, found 10 percent of adolescents sent to a Sleep Center for evaluation of excessive daytime sleepiness with testing results consistent with narcolepsy had urine drug screens positive for marijuana, confounding the results."Our findings highlight and support the important step of obtaining a urine drug screen, in any patients older than 13 years of age, before accepting test findings consistent with narcolepsy, prior to physicians confirming this diagnosis," said Mark L. Splaingard, MD, director of the Sleep Disorders Center at Nationwide Children's Hospital and senior-author on the study. "Urine drug screening is also important in any population studies looking at the prevalence of narcolepsy in adolescents, especially with the recent trend in marijuana decriminalization and legalization." Typically, a diagnosis of narcolepsy is made after a clinical evaluation for excessive daytime sleepiness, followed by a standardized multiple sleep latency test (MSLT) consisting of 4-5 scheduled day time nap opportunities in which speed of sleep onset and presence of rapid eye movement sleep (REM) are both calculated. However, adult studies have shown that a variety of different medications and illicit drugs may affect MSLT results. This 10-year retrospective study of 383 children is the first to examine the prevalence of positive drug screens in pediatric patients undergoing MSLT. The study, published in Journal of Clinical Sleep Medicine, found that 43 percent of children with urine drug screens positive for marijuana actually had test results consistent with narcolepsy or abnormal REM sleep patterns. No child younger than 13 years of age had a postivie urine drug screen. The data showed that males were more likely to have a positive urine drug screen and MSLT findings consistent with narcolepsy. "We believe that many of the children who had positive urine drug testing for marijuana and testing consistent with narcolepsy had improvement of the symptom of excessive day time sleepiness after enrollment in a community drug program, because most didn't come back for repeat diagnostic studies once they were drug-free," said Dr. Splaingard, also a faculty member at The Ohio State University College of Medicine. "A key finding of this study is that marijuana use may be associated with excessive daytime sleepiness in some teenagers," said Dr. Splaingard. "A negative urine drug screen finding is an important part of the clinical evaluation before accepting a diagnosis of narcolepsy and starting treatment in a teenager." Story Source: The above story is based on materials provided by Nationwide Children's Hospital. Note: Materials may be edited for content and length. Journal Reference:
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Canon’s New 11-24mm f/4L USM Lens is a Distortion-Busting Beast
Ultra-wide zoom lenses aren’t known for their straight lines… and I’m not talking about design. When you hit focal lengths as low as 11mm, you’re bound to get some distortion at the edges, making an 11-24mm lens less usable at the bottom end of the focal length spectrum.This, however, doesn’t seem to be the case with Canon’s latest long-rumored lens: the new 11-24mm f/4L USM wide angle zoom. Canon is showing an incredible amount of transparency with this video, and they’re being praised for it online. By showing you moving video shots at varying focal lengths, they demonstrate distortion at the edges (or lack thereof) much more directly than a still would. Canon could have shared stills, even unedited stills, and much more easily hidden any issues the lens had. Instead, they shot video, and it’s undeniably impressive how little distortion this lens demonstrates even at 11 and 14mm.
Of course, it wouldn’t be a gear release without a tagline, and the tagline here is “the widest angle of view ever achieved for a rectilinear full-frame Digital SLR lens.” How wide? 126º05’ diagonal. That is REALLY wide… So who is actually going to need these crazy specs in the real world? According to Canon:
Spec-wise, this new monster of an ultra-wide boasts an all new optical design comprised of 16 elements in 11 groups, with a three group zoom system and rear focus. Canon credits the lack of distortion to four aspherical lens elements that help keep lines straight, “from the center of the image to the periphery, across the entire zoom range.” There’s also a Super UD element and one UD lens element to help eliminate chromatic aberration, and “liberal” amounts of Canon’s coatings to minimize ghosting and flare. Pardon me a moment while I wipe the drool off my keyboard. In the meantime, check out these sample shots taken with the new lens and posted by Canon Japan:
As with any piece of gear, we’ll reserve full judgement until we get it in a 500px photographer’s hands to try out in earnest, but this lens looks incredibly promising. Landscape and architectural photographers in particular will delight at the lack of distortion… well, right up until they see the price tag. The last bit of info about this lens is the hardest to swallow: the lens will cost you $3,000. So if you’re interested, we suggest you suck it up, dig into that secret camera gear overseas bank account (you have one of those right?), and pre-order it now at B&H… expensive as it is, it’ll probably fly off the shelves. source : http://bit.ly/17361nb |
Johnson & Johnson projects aim to spot who'll get a disease
Thu, 02/12/2015 - 10:58amLinda A. Johnson, AP Business Writer
Imagine being able to identify people likely to develop a particular disease - and then stop it before it starts. This isn't a science fiction tale. It's the ambitious goal of three research projects just launched by Johnson & Johnson's pharmaceutical research arm, Janssen Research & Development, that the company says are aimed at redefining health care. The projects announced Thursday ultimately aim to prevent illnesses, particularly ones related to aging and lifestyle. That way, as people live longer, fewer of their "golden years" are plagued by poor health, disability and staggering medical bills. "A hundred years from now, someone's going to look back on us and say, `Can you believe they waited until you got a disease and then did something?'" Dr. William Hait, head of Janssen R&D, predicted in an exclusive interview with The Associated Press. Instead, the world's biggest maker of health care products will try to find ways to prevent common, frightening and often deadly disorders, including Alzheimer's disease, cancer, heart disease, immune conditions and Type 1 diabetes, the first planned target. Janssen is partnering with the Juvenile Diabetes Research Foundation to find ways to prevent Type 1 diabetes, which is steadily becoming more prevalent. Billions of research dollars will be needed to accomplish the goals, and it could easily take a generation, cautions analyst Steve Brozak, president of WBB Securities. But Brozak said Johnson & Johnson is one of just a few organizations that have the resources - money and scientific talent - to succeed at what he called a shift to "true modern medicine" that's as revolutionary as Henry Ford creating the manufacturing assembly line. "This is visionary stuff here," Brozak said. "Nobody's ever tried this." Still, advances in the understanding of human genetics and diagnostic testing, and existing treatments that already help prevent widespread illnesses, have made Hait optimistic. For example, blood testing and then use of cholesterol-lowering statin pills to prevent heart attacks and strokes in at-risk patients is widespread in developed countries. Ditto for colonoscopies and removal of any discovered polyps to prevent colon cancer, and Pap smears to spot cervical cell abnormalities that could turn into cancer. Whatever medical approaches to prevention turn out to work, Johnson & Johnson, based in New Brunswick, New Jersey, is positioned to offer far more than a Band-Aid: It's a leading maker of diagnostic tests, vaccines, surgical equipment, prescription pills, injected biologic medicines and consumer health products. In addition, Janssen has nearly 10,000 scientists and other employees, Johnson & Johnson has "innovation centers" around the world that collaborate with university researchers, and the company made a $16 billion profit last year. While the three new research programs Janssen's created share the goal of blocking illness, the approaches vary: -The Janssen Prevention Center, which began operating at three locations on Jan. 1, will focus on preventing some conditions that most burden the elderly - and health care systems straining to pay for their care. Those include Alzheimer's, cancer and heart disease. The center, based in Leiden, Holland, will build on J&J's expertise in vaccines, potentially a good strategy for conditions that strike so many people. -The Janssen Human Microbiome Institute will study the microbiome, bacteria living in and on the body that have recently been found to have a key role in our health. Learning more about that role could help in creating treatments for autoimmune disorders such as rheumatoid arthritis, multiple sclerosis and inflammatory bowel disorders, many of which lack good treatments. -The Disease Interception Accelerator, just beginning in Raritan, New Jersey, will explore genetic defects and other causes of diseases so they can be detected long before they are currently diagnosed. The goal would be to quickly intervene to prevent disease. "We're sifting through opportunities where we think the need is great and the ability to diagnose (early) exists, and then we're seeding proposals," Hait said. The first program targets Type 1 diabetes, a complex hormonal disorder that is very expensive to treat and often causes premature death, plus complications from blindness and amputations. It involves the immune system attacking and gradually destroying beta cells in the pancreas that produce insulin, which is needed to move sugar from the bloodstream into cells to provide energy. The Juvenile Diabetes Research Foundation has worked for decades on ways to identify children at high risk, and blood tests for certain antibodies can now do so, even in newborns, years before they'll develop symptoms, said Chief Scientific Officer Dr. Richard Insel. National screening programs in the U.S. and Germany are working to find those youngsters, and multiple patient studies are under way here to try to "rebalance" overly aggressive immune systems to stop them from attacking beta cells, Insel said. One gives participants tiny doses of insulin by mouth, another is trying a rheumatoid arthritis drug to tamp down the immune system and a third is trying to reduce levels of certain harmful immune cells. JDRF and Janssen now are planning specific research projects that can build on that work and other findings to prevent diabetes early on, which is important because Type 1 inexplicably is striking children in Europe at younger ages, Insel said. "Decades ago, we never would have been thinking about prevention of this disease," he said. "We're in a very different position today, a fantastic position." Source: Associated Press |
GM to build 200-mile electric car at Michigan plant
Thu, 02/12/2015 - 11:35amAssociated Press
This file photo taken Tuesday, May 13, 2014 shows a row of Google self-driving cars outside the Computer History Museum in Mountain View, Calif. California's Department of Motor Vehicles will miss a year-end deadline to adopt new rules for cars of the future because regulators first have to figure out how they'll know whether "driverless" vehicles are safe. (AP Photo/Eric Risberg)The small hatchback will be based on the Chevrolet Bolt concept car shown at the Detroit auto show last month. GM has said it would be built starting in 2017. The price does not include a $7,500 federal tax credit. The car, which hasn't officially been named, will be made at a factory in Orion Township, Michigan, and sold in all 50 states. It's designed to compete with Silicon Valley automaker Tesla Motors, which plans to start selling a 200-mile-per-charge car about the same time. The price of Tesla's Model 3 including the tax credit is likely to be well below $30,000. The Bolt looks like a cross between a Volkswagen Golf and BMW's funky electric i3. Designers said it will have SUV-like cargo room and a high seating position, two attributes that have made small SUVs popular in the U.S. "We are moving quickly because of its potential to completely shake up the status quo for electric vehicles," GM North America President Alan Batey said Thursday in a statement. GM said it hasn't determined how many jobs the new car will bring to the factory, which now has about 1,700 hourly workers who make the Chevrolet Sonic subcompact and the Buick Verano compact. Source: Associated Press
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Tackling the "achilles' heel" of OLED displays
Thu, 02/12/2015 - 11:15amRob Matheson, MIT News Office
Many of those displays were made using organic light-emitting diodes, or OLEDs — semiconducting films about 100 nanometers thick, made of organic compounds and sandwiched between two electrodes, that emit light in response to electricity. This allows each individual pixel of an OLED screen to emit red, green, and blue, without a backlight, to produce more saturated color and use less energy. The film can also be coated onto flexible, plastic substrates. But there’s a reason why these darlings of the showroom are not readily available on shelves: They’re not very cost-effective to make en masse. Now, MIT spinout Kateeva has developed an “inkjet printing” system for OLED displays — based on years of Institute research — that could cut manufacturing costs enough to pave the way for mass-producing flexible and large-screen models. In doing so, Kateeva aims to “fix the last ‘Achilles’ heel’ of the OLED-display industry — which is manufacturing,” says Kateeva co-founder and scientific advisor Vladimir Bulovic, the Fariborz Maseeh Professor of Emerging Technology, who co-invented the technology. Called YIELDjet, Kateeva’s technology platform is a massive version of an inkjet printer. Large glass or plastic substrate sheets are placed on a long, wide platform. A component with custom nozzles moves rapidly, back and forth, across the substrate, coating it with OLED and other materials — much as a printer drops ink onto paper. An OLED production line consists of many processes, but Kateeva has developed tools for two specific areas — each using the YIELDjet platform. The first tool, called YIELDjet FLEX, was engineered to enable thin-film encapsulation (TFE). TFE is the process that gives thinness and flexibility to OLED devices; Kateeva hopes flexible displays produced by YIELDjet FLEX will hit the shelves by the end of the year. The second tool, which will debut later this year, aims to cut costs and defects associated with patterning OLED materials onto substrates, in order to make producing 55-inch screens easier. By boosting yields, as well as speeding up production, reducing materials, and reducing maintenance time, the system aims to cut manufacturing costs by about 50 percent, says Kateeva co-founder and CEO Conor Madigan SM ’02 PhD ’06. “That combination of improving the speed, improving the yield, and improving the maintenance is what mass-production manufacturers want. Plus, the system is scalable, which is really important as the display industry shifts to larger substrate sizes,” he says. The other Kateeva co-founders and technology co-inventors are MIT Provost Martin Schmidt, now a scientific advisor; Jianglong Chen SM ’03, PhD ’07, now program director; and Valerie Leblanc PhD ’07, now staff scientist. Getting flexible TFE was invented to coat flexible OLED screens with a barrier as solid as glass, but bendable. But it is prone to contamination and other issues. Traditional TFE processing methods enclose the substrate in a vacuum chamber, where a vapor of the encapsulating film is sprayed onto the substrate through a metal stencil. This process is slow and expensive — primarily because of wasted material — and requires stopping the machine frequently for cleaning. There are also issues with defects, as the coating that hits the chamber walls and stencil can potentially flake off and fall onto the substrate in between adding layers. But moisture, and even some air particles, can sneak into the chamber, which is deadly to OLEDs: When electricity hits OLEDs contaminated with water and air particles, the resulting chemical reactions reduce the OLEDs’ quality and lifespan. Any displays contaminated during manufacturing are discarded and, to make up for lost yield, companies boost retail prices. Only two companies now sell OLED television displays, with 55-inch models selling for $3,000 to $4,000 — about $1,000 to $3,000 more than their 55-inch LCD and LED counterparts. YIELDjet FLEX aims to solve many TFE issues. A key innovation is encasing the printer in a nitrogen chamber, cutting exposure to oxygen and moisture, as well as cutting contamination with particles — notorious for diminishing OLED yields — by 10 times over current methods that use vacuum chambers. “Low-particle nitrogen is the best low-cost, inert environment you can use for OLED manufacturing,” Madigan says. In its TFE process, the YIELDjet precisely coats organic films over the display area as part of the TFE structure. The organic layer flattens and smoothes the surface to provide ideal conditions for depositing the subsequent layers in the TFE structure. Depositing onto a smooth, clean surface dramatically improves the quality of the TFE structure, enabling high yields and reliability, even after repeated flexing and bending, Madigan says. Taking off the mask Kateeva’s other system offers an improvement over the traditional vacuum thermal evaporation (VTE) technique — usually somewhere in the middle of the production line — that uses shadow masks (thin metal squares with stenciled patterns) to drop red, green, and blue OLED materials onto a substrate. Much like conventional TFE processing, VTE involves placing a substrate inside a vacuum chamber, and spraying through the shadow mask a vapor of OLED material in precise patterns of red, green, and blue. But materials are wasted when the vapor is sprayed on the mask and chamber. Coating the chamber and mask can also lead to particle contamination as the material flakes off, so excessive cleaning maintenance is required, Madigan says. This isn’t necessarily bad for making small, smartphone screens: “If a substrate sheet with, say, 100 small displays on its surface has five defects, you may toss five, and all the rest are perfect,” Madigan explains. And smaller shadow masks are more reliable. But manufacturers start to lose money when they’re tossing one or two large-screen displays due to particle contamination or defects across the substrate. Kateeva’s system, which, like its TFE system, is enclosed in a nitrogen chamber, precisely positions substrates — large enough for six 55-inch displays — beneath print heads, which contain hundreds of nozzles. These nozzles are tuned to deposit tiny droplets of OLED material in exact locations to create the display’s pixels. “Doing this over three layers removes the need for shadow masks at larger scales,” Madigan says. As with its YIELDjet FLEX system, Madigan says this YIELDjet product for OLED TV displays can help manufacturers save more than 50 percent over traditional methods. In January, Kateeva partnered with Sumitomo, a leading OLED-materials supplier, to further optimize the system for volume production. Revolutionizing at MIT The idea for Kateeva started in the early 2000s at MIT. Over several years, Madigan, Bulovic, Schmidt, Chen, and Leblanc had become involved in a partnership with Hewlett-Packard (HP) on a project to make printable electronics. They had developed a variety of methods for manufacturing OLEDs — which Madigan had been studying since his undergraduate years at Princeton University. Other labs at that time were trying to make OLEDs more energy efficient, or colorful, or durable. “But we wanted to do something completely different that would revolutionize the industry, because that’s what we should be doing in a place like MIT,” Madigan says. Soon, however, HP pulled out of the project. “That left all this novel intellectual property sitting on a shelf that may never be used again,” Bulovic says. Instead of letting those patents go to waste, however, the researchers launched Kateeva in 2008 to commercially tackle OLED manufacturing. A few years before, Bulovic had cut his teeth in the startup scene with QD Vision — which is currently developing quantum-dot technology for LED television displays — and was able to connect the group with local venture capitalists. Madigan, on the other hand, was sharpening his entrepreneurial skills at the MIT Sloan School of Management. Among other things, the Entrepreneurship Lab class introduced him to the nuts and bolts of startups, including customer acquisition and talking to investors. And Innovation Teams helped him study markets and design products for customer needs. “There was no handbook, but I benefitted a lot from those two classes,” he says. In 2009, just when OLEDs were starting to gain mainstream popularity, Kateeva launched T-Jet, a precursor to YIELDjet. In that system, nozzles would drop OLED materials onto a plate, etched with a certain pattern. The plate was heated to 100 degrees Celsius to dry the ink, brought close to the substrate without touching it, and heated to 300 C to transfer the dry, patterned vapor onto the substrate. “It was a cool concept, but inkjet was still cheaper,” Madigan says. So in 2012, Kateeva pivoted, switching gears to its YIELDjet system. Today, the system is a platform, Bulovic says, that, in the future, can be tweaked to print solid stage lighting panels, solar cells, nanostructure circuits, and luminescent concentrators, among other things. “All those would be enabled by the semiconductor printer Kateeva has been able to develop,” he says. “OLED displays are just the first application.” Source: MIT |
Flexible smartphones and color-saturated television displays were some highlights at this year’s Consumer Electronics Showcase, held in January in Las Vegas.
First glimpse of a chemical bond being born
February 12, 2015SLAC National Accelerator Laboratory Scientists have gotten the first glimpse of the transition state where two atoms begin to form a weak bond on the way to becoming a molecule. This fundamental advance, long thought impossible, will have a profound impact on the understanding of how chemical reactions take place and on efforts to design reactions that generate energy, create new products and fertilize crops more efficiently.
This illustration shows atoms forming a tentative bond, a moment captured for the first time in experiments with an X-ray laser at SLAC National Accelerator Laboratory. The reactants are a carbon monoxide molecule, left, made of a carbon atom (black) and an oxygen atom (red), and a single atom of oxygen, just to the right of it. They are attached to the surface of a ruthenium catalyst, which holds them close to each other so they can react more easily. When hit with an optical laser pulse, the reactants vibrate and bump into each other, and the carbon atom forms a transitional bond with the lone oxygen, center. The resulting carbon dioxide molecule detaches and floats away, upper right. The Linac Coherent Light Source (LCLS) X-ray laser probed the reaction as it proceeded and allowed the movie to be created. Scientists have used an X-ray laser at the Department of Energy's SLAC National Accelerator Laboratory to get the first glimpse of the transition state where two atoms begin to form a weak bond on the way to becoming a molecule. This fundamental advance, reported Feb. 12 in Science Express and long thought impossible, will have a profound impact on the understanding of how chemical reactions take place and on efforts to design reactions that generate energy, create new products and fertilize crops more efficiently. "This is the very core of all chemistry. It's what we consider a Holy Grail, because it controls chemical reactivity," said Anders Nilsson, a professor at the SLAC/Stanford SUNCAT Center for Interface Science and Catalysis and at Stockholm University who led the research. "But because so few molecules inhabit this transition state at any given moment, no one thought we'd ever be able to see it." Bright, Fast Laser Pulses Achieve the Impossible The experiments took place at SLAC's Linac Coherent Light Source (LCLS), a DOE Office of Science User Facility. Its brilliant, strobe-like X-ray laser pulses are short enough to illuminate atoms and molecules and fast enough to watch chemical reactions unfold in a way never possible before. Researchers used LCLS to study the same reaction that neutralizes carbon monoxide (CO) from car exhaust in a catalytic converter. The reaction takes place on the surface of a catalyst, which grabs CO and oxygen atoms and holds them next to each other so they pair up more easily to form carbon dioxide. In the SLAC experiments, researchers attached CO and oxygen atoms to the surface of a ruthenium catalyst and got reactions going with a pulse from an optical laser. The pulse heated the catalyst to 2,000 kelvins -- more than 3,000 degrees Fahrenheit -- and set the attached chemicals vibrating, greatly increasing the chance that they would knock into each other and connect. The team was able to observe this process with X-ray laser pulses from LCLS, which detected changes in the arrangement of the atoms' electrons -- subtle signs of bond formation -- that occurred in mere femtoseconds, or quadrillionths of a second. "First the oxygen atoms get activated, and a little later the carbon monoxide gets activated," Nilsson said. "They start to vibrate, move around a little bit. Then, after about a trillionth of a second, they start to collide and form these transition states." 'Rolling Marbles Uphill' The researchers were surprised to see so many of the reactants enter the transition state -- and equally surprised to discover that only a small fraction of them go on to form stable carbon dioxide. The rest break apart again. "It's as if you are rolling marbles up a hill, and most of the marbles that make it to the top roll back down again," Nilsson said. "What we are seeing is that many attempts are made, but very few reactions continue to the final product. We have a lot to do to understand in detail what we have seen here." Theory played a key role in the experiments, allowing the team to predict what would happen and get a good idea of what to look for. "This is a super-interesting avenue for theoretical chemists. It's going to open up a completely new field," said report co-author Frank Abild-Pedersen of SLAC and SUNCAT. A team led by Associate Professor Henrik Öström at Stockholm University did initial studies of how to trigger the reactions with the optical laser. Theoretical spectra were computed under the leadership of Stockholm Professor Lars G.M. Pettersson, a longtime collaborator with Nilsson. Preliminary experiments at SLAC's Stanford Synchrotron Radiation Lightsource (SSRL), another DOE Office of Science User Facility, also proved crucial. Led by SSRL's Hirohito Ogasawara and SUNCAT's Jerry LaRue, they measured the characteristics of the chemical reactants with an intense X-ray beam so researchers would be sure to identify everything correctly at the LCLS, where beam time is much more scarce. "Without SSRL this would not have worked," Nilsson said. The team is already starting to measure transition states in other catalytic reactions that generate chemicals important to industry. "This is extremely important, as it provides insight into the scientific basis for rules that allow us to design new catalysts," said SUNCAT Director and co-author Jens Nørskov. Story Source: The above story is based on materials provided by SLAC National Accelerator Laboratory. Note: Materials may be edited for content and length. Journal Reference:
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Dogs know that smile on your face
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Common biomarkers of sleep debt found in humans, rats
Stating that sleep is an essential biological process seems as obvious as saying that the sun rises every morning. Yet, researchers' understanding of the molecular mechanisms underlying the effects of sleep loss is still in its earliest stages. The risk for a host of metabolic disorders, including weight gain, diabetes, obesity, and cardiovascular disease, associated with reduced sleep is driving basic investigations on the topic.In a study published this week in the Proceedings of the National Academy of Sciences, Amita Sehgal, PhD, a professor of Neuroscience at the Perelman School of Medicine at the University of Pennsylvania and a Howard Hughes Medical Institute investigator, along with co-first authors Aalim M. Weljie, PhD, a research assistant professor of Systems Pharmacology and Translational Therapeutics, and Peter Meerlo, PhD, from the University of Groningen, The Netherlands, found common molecules signifying perturbed metabolism in response to sleep restriction in a comprehensive metabolic profiling of blood from both rats and humans. Their findings point to an overall shift in how lipids are metabolized and evidence of systemic oxidative stress due to decreased sleep in both species. Oxidative stress and lipid metabolism are important factors in metabolic diseases, although further work needs to be done to establish a mechanistic link between the markers found and specific diseases, stress the researchers. "One possibility is that sleep drives metabolite clearance and so acts as a reparative process at the metabolic level," says Sehgal. "The impact of sleep restriction on circadian biology is particularly relevant given what we now know about how metabolites also oscillate in humans on a daily basis." Metabolites are chemical intermediates or end products of metabolism, so while they are generated through the breakdown of fats, carbohydrates, and proteins, their function is not restricted to these processes. They also have roles in signaling, regulating enzymatic activity, growth, and development. Of Rats and Humans The team subjected rats and humans to chronic sleep restriction over five days. Sleep restriction, versus sleep deprivation, curtails sleep time, but does not eliminate sleep. "Sleep restriction more closely represents real-world situations in humans and is a condition experienced by millions of people every day," notes Sehgal. In both studies, metabolite levels were compared in blood that was collected following adequate sleep opportunity in rats and humans to establish a baseline and then following restricted sleep. The team then produced a comprehensive metabolite profile from the blood of sleep-restricted rats and humans. Of the 38 metabolites they found to be unique in the sleep-restricted rats, half were known lipids. A majority of the metabolites from the sleep-restricted human participants were also lipid or fatty acid-related compounds. Seven types of a phospholipid called plasmalogens, related to oxidative stress, were elevated in the sleep-restricted rats. Overall, they found a significant shift in lipid metabolism, with sleep restriction, with higher levels of phospholipids in both rats and humans. The team found that some neurotransmitters and gut metabolites (possibly from intestinal microbes) are also altered due to sleep restriction. "While we don't yet know why the lipids are changed in both species, these shifts are very intriguing, given the epidemiological links between restricted sleep and metabolic disorders, such as diabetes, obesity, and metabolomics syndrome," says Weljie. "I'm sure there's a connection." When they compared the list of significantly altered metabolites in rats and humans compared to the baseline before sleep restriction, they found that two metabolites -- oxalic acid and diacylglycerol 36:3 -- were depleted under sleep-restricted conditions and restored after recovery sleep in both species. Oxalic acid is a waste product derived from processing foods in the diet such as plants, primarily from the breakdown of vitamin C and some amino acids. Diacylglycerol is a precursor molecule in the production of triglycerides, a molecule in which most fat is stored in the body, and also has a function in signaling in cells. The researchers suggest that these two molecules could serve as potential biomarkers since they are present in both species. "These cross-species markers are exciting for a couple reasons," adds Weljie. "First, there is a need for quantitative markers of sleep debt and sleep quality, and this approach suggests that metabolites may be useful in this regard. Second, because we found the same metabolites in the humans and rats, it opens the door for us investigate mechanistic questions regarding the metabolic effects of sleep in rats that may have clinical and therapeutic application." Overall, this work provides a potential link between the known pathologies of reduced sleep duration and metabolic dysfunction. "This is consistent with other studies that suggest that one of the functions of sleep is restorative, involving clearance of metabolites in the brain and reinstating an antioxidant balance in peripheral tissues. Sleep loss, on the other hand, induces an oxidative metabolic state," says Sehgal. Namni Goel, Arjun Senguptaa, Matthew S. Kayser, Ted Abel, Morris J. Birnbaum (now with Pfizer, Inc.), and David F. Dinges, all from Penn, are co-authors. The authors thank the subjects who participated in the experiments and the staff of the Division of Sleep and Chronobiology, who helped acquire the material for metabolomic analysis. This research was supported by HHMI, the Department of the Navy Office of Naval Research Award (N00014-11-1-0361), the National Aeronautics and Space Administration (NNX14AN49G, NCC 9-58), the National Institutes of Nursing Research (NR004281), the Defense Advanced Research Projects Agency and the US Army Research Office (W911NF1010093). Story Source: The above story is based on materials provided by Perelman School of Medicine at the University of Pennsylvania. Note: Materials may be edited for content and length. Journal Reference:
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Magnitude of plastic waste going into the ocean calculated: 8 million metric tons of plastic enter the oceans per year
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The 192 countries with a coast bordering the Atlanta, Pacific and Indian oceans, Mediterranean and Black seas produced a total of 2.5 billion metric tons of solid waste. Of that, 275 million metric tons was plastic, and an estimated 8 million metric tons of mismanaged plastic waste entered the ocean in 2010. A plastic grocery bag cartwheels down the beach until a gust of wind spins it into the ocean. In 192 coastal countries, this scenario plays out over and over again as discarded beverage bottles, food wrappers, toys and other bits of plastic make their way from estuaries, seashores and uncontrolled landfills to settle in the world's seas. How much mismanaged plastic waste is making its way from land to ocean has been a decades-long guessing game. Now, the University of Georgia's Jenna Jambeck and her colleagues in the National Center for Ecological Analysis and Synthesis working group have put a number on the global problem. Their study, reported in the Feb. 13 edition of the journal Science, found between 4.8 and 12.7 million metric tons of plastic entered the ocean in 2010 from people living within 50 kilometers of the coastline. That year, a total of 275 million metric tons of plastic waste was generated in those 192 coastal countries. Jambeck, an assistant professor of environmental engineering in the UGA College of Engineering and the study's lead author, explains the amount of plastic moving from land to ocean each year using 8 million metric tons as the midpoint: "Eight million metric tons is the equivalent to finding five grocery bags full of plastic on every foot of coastline in the 192 countries we examined." To determine the amount of plastic going into the ocean, Jambeck "started it off beautifully with a very grand model of all sources of marine debris," said study co-author Roland Geyer, an associate professor with the University of California, Santa Barbara's Bren School of Environmental Science & Management, who teamed with Jambeck and others to develop the estimates. They began by looking at all debris entering the ocean from land, sea and other pathways. Their goal was to develop models for each of these sources. After gathering rough estimates, "it fairly quickly emerged that the mismanaged waste and solid waste dispersed was the biggest contributor of all of them," he said. From there, they focused on plastic. "For the first time, we're estimating the amount of plastic that enters the oceans in a given year," said study co-author Kara Lavender Law, a research professor at the Massachusetts-based Sea Education Association. "Nobody has had a good sense of the size of that problem until now." The framework the researchers developed isn't limited to calculating plastic inputs into the ocean. "Jenna created a framework to analyze solid waste streams in countries around the world that can easily be adapted by anyone who is interested," she said. "Plus, it can be used to generate possible solution strategies." Plastic pollution in the ocean was first reported in the scientific literature in the early 1970s. In the 40 years since, there were no rigorous estimates of the amount and origin of plastic debris making its way into the marine environment until Jambeck's current study. Part of the issue is that plastic is a relatively new problem coupled with a relatively new waste solution. Plastic first appeared on the consumer market in the 1930s and '40s. Waste management didn't start developing its current infrastructure in the U.S., Europe and parts of Asia until the mid-1970s. Prior to that time, trash was dumped in unstructured landfills--Jambeck has vivid memories of growing up in rural Minnesota, dropping her family's garbage off at a small dump and watching bears wander through furniture, tires and debris as they looked for food. "It is incredible how far we have come in environmental engineering, advancing recycling and waste management systems to protect human health and the environment, in a relatively short amount of time," she said. "However, these protections are unfortunately not available equally throughout the world." Some of the 192 countries included in the model have no formal waste management systems, Jambeck said. Solid waste management is typically one of the last urban environmental engineering infrastructure components to be addressed during a country's development. Clean water and sewage treatment often come first. "The human impact from not having clean drinking water is acute, with sewage treatment often coming next," she said. "Those first two needs are addressed before solid waste, because waste doesn't seem to have any immediate threat to humans. And then solid waste piles up in streets and yards and it's the thing that gets forgotten for a while." As the gross national income increases in these countries, so does the use of plastic. In 2013, the most current numbers available, global plastic resin production reached 299 million tons, a 647 percent increase over numbers recorded in 1975. Plastic resin is used to make many one-use items like wrappers, beverage bottles and plastic bags. With the mass increase in plastic production, the idea that waste can be contained in a few-acre landfill or dealt with later is no longer viable. That was the mindset before the onslaught of plastic, when most people piled their waste--glass, food scraps, broken pottery--on a corner of their land or burned or buried it. Now, the average American generates about 5 pounds of trash per day with 13% of that being plastic. But knowing how much plastic is going into the ocean is just one part of the puzzle, Jambeck said. With between 4.8 and 12.7 million metric tons going in, researchers like Law are only finding between 6,350 and 245,000 metric tons floating on the ocean's surface. "This paper gives us a sense of just how much we're missing," Law said, "how much we need to find in the ocean to get to the total. Right now, we're mainly collecting numbers on plastic that floats. There is a lot of plastic sitting on the bottom of the ocean and on beaches worldwide." Jambeck forecasts that the cumulative impact to the oceans will equal 155 million metric tons by 2025. The planet is not predicted to reach global "peak waste" before 2100, according to World Bank calculations. "We're being overwhelmed by our waste," she said. "But our framework allows us to also examine mitigation strategies like improving global solid waste management and reducing plastic in the waste stream. Potential solutions will need to coordinate local and global efforts." |
