Video Games Used in New Treatment That May Fix 'Lazy Eye' in Older Children

A new study conducted in an eye clinic in India found that correction of amblyopia, also called "lazy eye," can be achieved in many older children, if they stick to a regimen that includes playing video games along with standard amblyopia treatment. At the 115^th Annual Meeting of the American Academy of Ophthalmology, Dr. Somen Ghosh will report on the approaches that allowed about a third of his study participants, who were between 10 and 18 years old, to make significant vision gains.

By the end of the one year study, nearly 30 percent of the 100 participants achieved significant vision gains. About 60 percent showed at least some improvement. Significant gains were more likely in children who participated in Groups 3 or 4 of the four treatment regimens. Treatment Group 3 completed daily video game practice and Group 4 took the supplement citicoline, which is associated with improved brain function. Improvement was more likely in children younger than age 14 than in those 14 and older.

The prevailing wisdom has been that if amblyopia is not diagnosed and corrected before a child reaches school age, it is difficult or impossible to correct. But recently the United States-based Pediatric Eye Disease Investigation Group (PEDIG) reported significant vision gains in 27 percent of older children in a study funded by the National Eye Institute. This report motivated Dr. Ghosh to test new approaches to learn what might be particularly effective in this age group.

His study was divided into four treatment groups. Students in all groups followed a basic treatment plan that required them to wear eyeglasses that blocked the stronger eye for at least two hours a day, during which time they practiced exercises using the weaker eye. This "patching" technique is a standard amblyopia treatment that works by making the weaker eye work harder. Group one followed only the basic plan and served as the control group, while groups two, three and four received additional treatments:

• Group 2 took a supplement that contained micronutrients considered important to good vision
• Group 3 played at least one hour of video games daily using only the weaker eye
• Group 4 took the supplement citicoline, which is associated with improved brain function

Saurav Sen, a 16 year old graduate of Dr. Ghosh's clinic, received a second chance to achieve good vision. At age 13 Sen began to experience serious vision problems, which negatively impacted his school work. Other doctors had told him it was too late to correct his amblyopia. He completed the regimen assigned to treatment Group 3.t

"Playing the shooting games while using just my weaker eye was hard at first, but after a few months I could win all game levels easily," said Sen. "I'm very happy that I stuck with the program. My vision has improved a lot, so that I now have no trouble studying or taking exams. My tennis game also improved, and of course I'm now a pro PC gamer."

"The cooperation of the patient is very important, maybe even crucial, to successful treatment of amblyopia," said Dr. Ghosh. "We should never give up on our patients, even the older children, but instead offer them hope and treatment designed to help them achieve better vision."

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For Midwesterners, More Boxcars Mean Cleaner Air

Shifting a fraction of truck-borne freight onto trains would have an outsized impact on air quality in the Midwest, according to researchers at the University of Wisconsin-Madison.

Much of that impact boils down to simple efficiency, according to Erica Bickford, a graduate student in UW-Madison's Nelson Institute for Environmental Studies. For each ton they carry, long-distance trucks go about 150 miles on a gallon of diesel fuel. Trains can move a ton more than 400 miles per gallon.

Shifting from road to rail 500 million tons of the freight passing through or to the Midwest would make a large dent in the carbon dioxide spilled into the air by the movement of goods.

"There's a 31 percent decrease in carbon dioxide produced by freight shipping in the region, and that's straight from emissions," says Bickford, who made a model of freight traffic in 10 Midwestern states from Kansas to Ohio that she presented December 8 in San Francisco at the fall meeting of the American Geophysical Union. "It's 21 million metric tons of CO₂, the equivalent of what's produced by about 4 million cars."

But carbon dioxide mixes fairly evenly in the atmosphere, spreading its effects around the globe. Bickford's study accounts for weather patterns and the way particular pollutants are distributed to determine how long other products of diesel engines -- like black carbon soot and the ozone ingredient and lung irritant nitrogen dioxide (NO₂) -- linger near their sources.

"The result is a much more thorough and local idea of the differences between truck and rail shipping," says Tracey Holloway, director of the Nelson Institute's Center for Sustainability and the Global Environment and Bickford's advisor. "If you're emitting CO₂ in Indiana or India it has the same impact. But something like soot, that has local impact."

More rail traffic would mean more pollutants near the tracks, but relief near roads frequented by trucks -- a tradeoff is unbalanced in favor of more densely populated areas.

"Black carbon and NO2 are harmful to everyone's health," Bickford says. "But because more people live near roads than railroad tracks, more people would benefit from the shifts in these pollutants."

As much as 16 percent less black carbon soot would linger near roads with heavy shipping traffic, according to Bickford's model, while the increase around rail corridors would be as high as 20 percent. Nitrogen dioxide would plummet by as much as 30 percent near roads, but rise by as much as 20 percent near railroad tracks.

Holloway's research group is already working on further modeling to explore connected changes in the number of asthma and heart disease cases.

The effects of greater rail use would be particularly noticeable in the middle of the country, according to Bickford.

"We're sort of a freight crossroads in the Midwest," says Bickford, whose work was funded by the National Center for Freight and Infrastructure Research and Education at UW-Madison. "International shipping comes into the country on the coasts and then passes through our backyard on the way to its destination."

The study limited hypothetical changes in shipping to trips of more than 400 miles to ensure a cost savings for shippers, and to cargo -- such as automobiles and non-perishable food -- that could handle the slower trip in railcars. The 500 million tons Bickford selected for travel by rail represent about 5 percent of U.S. truck freight by weight.

"These aren't pie-in-the-sky figures," Holloway says. "They are reasonable and achievable."

And they come with non-pollution benefits, like reduced traffic congestion, wear on roads and demand for diesel fuel.

"Truck freight travels on publicly-funded roads, rail traffic on privately-built tracks," Bickford says. "But these benefits could be an impetus for public investment in rail infrastructure."

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British Butterfly Is Evolving to Respond to Climate Change

As global temperatures rise and climatic zones move polewards, species will need to find different environments to prevent extinction. New research, recently published in the journal Molecular Ecology, has revealed that climate change is causing certain species to move and adapt to a range of new habitats.

The study, led by academics at the Universities of Bristol and Sheffield, aimed to understand the role of evolution in helping a species to successfully track ongoing climate change.

With climate warming many species are moving further north in the UK, however, this may mean crossing a landscape with increasingly less of their preferred habitat. Evolutionary change in the ability to use geographically widespread habitats or increased ability to move longer distances can help species to track the warming climate and move northwards.

The Brown Argus butterfly is successfully expanding its distribution northwards in the UK and uses a range of distinct habitats. Using genetic techniques to detect evolutionary change, the researchers were able to show that the colonisation of new sites further north by the Brown Argus has involved significant adaptation during or following colonisation.

Furthermore, the results suggest that populations of the Brown Argus are adapted to different habitats and that pre-existing variation in habitat preference between populations has been important in allowing the colonisation of new habitats.

James Buckley, one of the researchers from the University's School of Biological Sciences, said: "To our knowledge, this is one of the first studies to identify genetic evidence for evolutionary change associated with range shifts driven by recent climate change."

The Natural Environment Research Council (NERC)-funded study found that evolutionary change is likely to affect the success of species' responses to climate change and that maximising genetic variation in ecological traits (such as habitat preference) across species' distributions should help species to move northwards and track the changing climate across a fragmented landscape.

James added: "These findings are important as understanding the likelihood and speed of such adaptive change is important in determining the rate of species extinction with ongoing climate change."

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Evolution Reveals Missing Link Between DNA and Protein Shape

Fifty years after the pioneering discovery that a protein's three-dimensional structure is determined solely by the sequence of its amino acids, an international team of researchers has taken a major step toward fulfilling the tantalizing promise: predicting the structure of a protein from its DNA alone.
The team at Harvard Medical School (HMS), Politecnico di Torino / Human Genetics Foundation Torino (HuGeF) and Memorial Sloan-Kettering Cancer Center in New York (MSKCC) has reported substantial progress toward solving a classical problem of molecular biology: the computational protein folding problem.
The results will be published Dec. 7 in the journal PLoS ONE.
In molecular biology and biomedical engineering, knowing the shape of protein molecules is key to understanding how they perform the work of life, the mechanisms of disease and drug design. Normally the shape of protein molecules is determined by expensive and complicated experiments, and for most proteins these experiments have not yet been done. Computing the shape from genetic information alone is possible in principle. But despite limited success for some smaller proteins, this challenge has remained essentially unsolved. The difficulty lies in the enormous complexity of the search space, an astronomically large number of possible shapes. Without any shortcuts, it would take a supercomputer many years to explore all possible shapes of even a small protein.
"Experimental structure determination has a hard time keeping up with the explosion in genetic sequence information," said Debora Marks, a mathematical biologist in the Department of Systems Biology at HMS, who worked closely with Lucy Colwell, a mathematician, who recently moved from Harvard to Cambridge University. They collaborated with physicists Riccardo Zecchina and Andrea Pagnani in Torino in a team effort initiated by Marks and computational biologist Chris Sander of the Computational Biology Program at MSKCC, who had earlier attempted a similar solution to the problem, when substantially fewer sequences were available.
"Collaboration was key," Sander said. "As with many important discoveries in science, no one could provide the answer in isolation."
The international team tested a bold premise: That evolution can provide a roadmap to how the protein folds. Their approach combined three key elements: evolutionary information accumulated for many millions of years; data from high-throughput genetic sequencing; and a key method from statistical physics, co-developed in the Torino group with Martin Weigt, who recently moved to the University of Paris.
Using the accumulated evolutionary information in the form of the sequences of thousands of proteins, grouped in protein families that are likely to have similar shapes, the team found a way to solve the problem: an algorithm to infer which parts of a protein interact to determine its shape. They used a principle from statistical physics called "maximum entropy" in a method that extracts information about microscopic interactions from measurement of system properties.
"The protein folding problem has been a huge combinatorial challenge for decades," said Zecchina, "but our statistical methods turned out to be surprisingly effective in extracting essential information from the evolutionary record."
With these internal protein interactions in hand, widely used molecular simulation software developed by Axel Brunger at Stanford University generated the atomic details of the protein shape. The team was for the first time able to compute remarkably accurate shapes from sequence information alone for a test set of 15 diverse proteins, with no protein size limit in sight, with unprecedented accuracy.
"Alone, none of the individual pieces are completely novel, but apparently nobody had put all of them together to predict 3D protein structure," Colwell said.
To test their method, the researchers initially focused on the Ras family of signaling proteins, which has been extensively studied because of its known link to cancer. The structure of several Ras-type proteins has already been solved experimentally, but the proteins in the family are larger-with about 160 amino acid residues-than any proteins modeled computationally from sequence alone.
"When we saw the first computationally folded Ras protein, we nearly went through the roof," Marks said. To the researchers' amazement, their model folded within about 3.5 angstroms of the known structure with all the structural elements in the right place. And there is no reason, the authors say, that the method couldn't work with even larger proteins.
The researchers caution that there are other limits, however: Experimental structures, when available, generally are more accurate in atomic detail. And, the method works only when researchers have genetic data for large protein families. But advances in DNA sequencing have yielded a torrent of such data that is forecast to continue growing exponentially in the foreseeable future.
The next step, the researchers say, is to predict the structures of unsolved proteins currently being investigated by structural biologists, before exploring the large uncharted territory of currently unknown protein structures.
"Synergy between computational prediction and experimental determination of structures is likely to yield increasingly valuable insight into the large universe of protein shapes that crucially determine their function and evolutionary dynamics," Sander said.
This research was funded by the National Cancer Institute and the Engineering and Physical Sciences Research Council of the United Kingdom.
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Weight Loss Weapon Carb-cutting Enzyme Stopped By Bean Extract, Endocrinologists Say

UCLA researchers have found an extract in white kidney beans may help the body stop carbs from breaking down into sugars. A digestive enzyme in the body normally acts like scissors, literally cutting starches into little sugars. Phase 2 stops the enzyme from cutting, so the starches stay in the body as long fibers and are burned off quicker. Patients in the clinical studies who took Phase 2 lost body fat, not lean muscle.
Americans are getting fatter. In fact, more than 60 percent are overweight and 18 million have type 2 diabetes. It's an epidemic that's becoming more of a problem with each passing year. Now, a new discovery could help you shed those dangerous pounds and live a healthier life.
Pastas ... breads ... cereals ... We know them well. And doctors say it's carbs like these that are making us fat.
"The problem is that starches are broken down immediately into sugars. When starch breaks down into sugar, it stays in the bloodstream, but is eventually stored as fat," Steven Rosenblatt, a family practice doctor in Los Angeles, tells DBIS.
But if you can't bear to give up your favorite foods, there's a new option. UCLA researchers have found an extract in white kidney beans may help the body stop carbs from breaking down into sugars.
"By lowering the amount of starches in our diet and the amount of carbohydrates in our diet, we allow the body to slowly start to burn off that stored energy," says Rosenblatt. He with the bean extract, known as Phase 2, which is sold in pill form and is now even added to certain foods. Here's how Phase 2 works: A digestive enzyme in the body normally acts like scissors, literally cutting starches into little sugars. Phase 2 stops the enzyme from cutting, so the starches stay in the body as long fibers and are burned off quicker -- making losing weight and keeping a normal blood sugar much easier.
Doctors say patients in the clinical studies who took Phase 2 lost body fat, not lean muscle. The extract is not recommended for pregnant women or type one diabetics because their blood sugar could get too low. Mild nausea is the only known side effect. Nora Cosgrove's struggled with her weight all her life. She admits to probably having been on every diet, but nothing worked. But when her doctor said she was on the fast-track to developing type 2 diabetes, she tried Phase 2.
After three months, she lost 30 pounds and six dress sizes! "I'm not tired anymore," Cosgrove says. "That's the main thing."
The FDA recognizes Phase 2, but doctors say it isn't a miracle pill. Patients still need to watch what they eat and exercise. But at least they don't have to give up carbs for good. It is available over the counter at health food stores for about $25 a bottle.

BACKGROUND: Scientists at the University of California, Los Angeles, examines the effect of white kidney bean extract (called Phase 2) on food and Glycemic Index (GI) levels. The research has resulted in the development of many new products for people on special GI diets, including a new pasta. It could especially benefit patients with diabetes, who need to closely monitor and control blood sugar levels, as well as serious athletes and overweight people.
ABOUT THE STUDY: Previous clinical trials found that 1 gram of the Phase 2 kidney bean extract affects blood glucose levels, while the new study shows that 2-3 grams affect GI levels. White kidney bean extract neutralizes the digestive enzyme necessary for starch to turn into glucose. It slows the digestion of starches and sugars, which can cause a rapid rise in blood sugar after eating. A previous UCLA study found that Phase 2 reduced starch absorption by 66%.
THE GLYCEMIC INDEX: Developed in the 1980s, the glycemic index (GI) ranks various foods according to how they affect blood sugar levels two to three hours after eating. Foods high in fat or protein don't raise levels very much, while certain carbohydrates are so easily broken down in intestine that blood sugar levels rise too quickly. The GI only tells you how rapidly a particular carbohydrate turns into glucose; it doesn't tell you how much of that carbohydrate is in a given serving of a particular food, or what percentage are 'available' carbohydrates, i.e., those that provide energy (starch and sugar, as opposed to fiber). You need to know both to fully understand how a given food affects blood sugar levels. The glycemic load (GL) measures the latter. A GI if 70 or more is high; 56 to 59 is medium; and 55 or less is low. A GL of 20 or more is high; 11 to 19 is medium; and 10 or less is low.
HOW DIGESTION WORKS: Food and drink must be changed into smaller molecules of nutrients to be absorbed into the blood and carried to cells throughout the body. It does this via the digestion process. Food is travels through the esophagus into the stomach, where it is dissolved and emptied into the small intestine. The digested nutrients are absorbed through the intestinal walls, while the rest is expelled as waste.
Editor's Note: This article is not intended to provide medical advice, diagnosis or treatment.
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Wood Biofuel Could Be a Competitive Industry by 2020

Fuel made from wood could become a competitive commercial alternative to fuel made from corn by 2020 if the wood biofuel industry is supported, according to a new University of British Columbia study.
Corn ethanol is currently blended with gasoline to satisfy government-mandated targets to include renewable content in transportation fuel. Compared to corn, wood-based biofuel is considered more sustainable but is not currently produced in large commercial quantities in Canada and the United States because the costs are too great.
The study, published in the most recent issue of the journal Biofuels Bioproducts & Biorefining, identifies several opportunities for reducing these costs. Researchers in UBC's Faculty of Forestry found that large-scale commercial production of wood-based ethanol, also known as cellulosic ethanol, will reduce capital and operation costs and assist in achieving the improvements necessary for wood-based ethanol to compete, without government support.
"As industrial production increases, cellulosic ethanol is likely to become more competitive with corn ethanol for a share of the renewable fuels market," says Jamie Stephen, a PhD candidate at UBC and lead author of the study.
Stephen's research indicates that the economic competitiveness of wood-based ethanol fuel production could be improved by reducing the capital costs of facilities and equipment, reducing enzyme costs and generating revenue from co-products like electricity. Today, the enzymes needed to breakdown wood products are one of the major costs associated with production. As industrial volumes of biofuel are produced and demand grows, technological learning and economies-of-scale will help reduce the cost.
The 2007 Energy Independence and Security Act in the United States requires that 117 billion litres (31 billion gallons) of ethanol be added to gasoline annually by 2022. In Canada, the federal government mandates that gasoline must include five per cent renewable fuel content.
Wood-based biofuel creates fewer greenhouse gas emissions and requires less water to produce. Cellulose, the main component of wood, is also the most abundant polymer on Earth and unlike the starch and sugars found in corn and sugarcane, people cannot digest it. Production of wood-based ethanol fuel doesn't use food supplies for fuel and competition for agricultural land can be reduced.
"If you do a purely economic production cost comparison between wood and corn today, corn will be the lower cost option," says Stephen. "If we consider other factors, like energy security, the environmental impact and availability of resources, cellulosic ethanol becomes a more competitive option for Canada and the United States."
In Canada, wood waste, corn stover and wheat straw are being considered for wood-based ethanol production.
Stephen notes that 35 years ago Brazil made the decision to invest heavily in sugarcane-ethanol production. Today, Brazil's flex-fuel vehicles run on fuels of up to 100 per cent ethanol and government subsidies for the industry have nearly disappeared.
"Commercial production of wood-based ethanol requires government support to be economically viable," says Stephen. "There has been a lot of investment in the research and development of cellulosic ethanol, especially in the United States and Canada. Huge advancements have been made to reduce the cost of production but there is still a long way to go before the volumes produced by the corn ethanol industry are attainable."
This study was supported by the Natural Sciences and Engineering Research Council of Canada (NSERC) and the British Columbia Innovation Council (BCIC).
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New Game to Raise Awareness of Energy

An energy quiz which tests people's knowledge of the amount of energy used by various devices and processes, such as leaving the lights switched on the Christmas tree, has been developed by researchers at the University of Southampton. 

A team led by Dr Alex Rogers at the University's ECS -- Electronics and Computer Science, developed The Energy Quiz, a "game with a purpose" for BT to challenge its employees to test their knowledge about energy and ECS and will launch a new version on 12 December.

The online quiz, which can be found at: http://www.energy-quiz.org invites players to compete and to answer 12 questions about energy comparisons. For example, it asks: which uses more energy a Christmas tree with 100 lights continuously lit over the festive period or a dishwasher used once a week for month; or it compares heating water for a typical office for a year with a full Boeing 747 flying 400 miles with heating a typical office for a day versus driving a car 100 miles. BT has invited 200 employees to play the game and will roll it out to a further 3,500 in the next phase.

"For us this is a way of conserving energy and we are finding that there is a deficiency of knowledge about energy among our employees," said Simon Thompson, BT Chief Researcher. "We have also found that this kind of knowledge is often dull for people and they are not too interested in the statistics, so if we can encourage them to play a game around energy, it makes it more fun." According to Dr Rogers, The Energy Quiz can be tailored to specific work or home environments. With the release of an updated version worldwide this week, he plans to analyse the data to explore people's misconceptions about energy. "Our informal results so far show that people have a lot less intuition about energy than you would think," he said. "People think that home consumption is always higher than driving their car to work and they often assume that appliances in the foreground that make a lot of noise or generate heat use more energy over the course of a year than something hidden away in the background."

The Energy Quiz is one of a whole host of tools to monitor energy being developed at ECS. Dr Rogers and his team have also developed a range of tools to visualise the real-time carbon intensity of the UK electricity grid and they have developed tools for building energy monitoring.They are also developing computerised agents that can negotiate the charging of electric-powered cars in the most efficient way.

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Robotic Bug Gets Wings, Sheds Light On Evolution of Flight

When engineers at the University of California, Berkeley, outfitted a six-legged robotic bug with wings in an effort to improve its mobility, they unexpectedly shed some light on the evolution of flight.

Even though the wings significantly improved the running performance of the 10-centimeter-long robot -- called DASH, short for Dynamic Autonomous Sprawled Hexapod -- they found that the extra boost would not have generated enough speed to launch the critter from the ground. The wing flapping also enhanced the aerial performance of the robot, consistent with the hypothesis that flight originated in gliding tree-dwellers.

The research team, led by Ron Fearing, professor of electrical engineering and head of the Biomimetic Millisystems Lab at UC Berkeley, reports its conclusions online on Oct. 18, in the peer-reviewed journal Bioinspiration and Biomimetics.

Using robot models could play a useful role in studying the origins of flight, particularly since fossil evidence is so limited, the researchers noted.

First unveiled by Fearing and graduate student Paul Birkmeyer in 2009, DASH is a lightweight, speedy robot made of inexpensive, off-the-shelf materials, including compliant fiber board with legs driven by a battery-powered motor. Its small size makes it a candidate for deployment in areas too cramped or dangerous for humans to enter, such as collapsed buildings.

A robot gets its wings

But compared with its biological inspiration, the cockroach, DASH had certain limitations as to where it could scamper. Remaining stable while going over obstacles is fairly tricky for small robots, so the researchers affixed DASH with lateral and tail wings borrowed from a store-bought toy to see if that would help.

"Our overall goal is to give our robots the same all-terrain capabilities that other animals have," said Fearing. "In the real world, there will be situations where flying is a better option than crawling, and other places where flying won't work, such as in confined or crowded spaces. We needed a hybrid running-and-flying robot."

The researchers ran tests on four different configurations of the robotic roach, now called DASH+Wings. The test robots included one with a tail only and another that just had the wing's frames, to determine how the wings impacted locomotion.

With its motorized flapping wings, DASH+Wings' running speed nearly doubled, going from from 0.68 meters per second with legs alone to 1.29 meters per second. The robot could also take on steeper hills, going from an incline angle of 5.6 degrees to 16.9 degrees.

"With wings, we saw improvements in performance almost immediately," said study lead author Kevin Peterson, a Ph.D. student in Fearing's lab. "Not only did the wings make the robot faster and better at steeper inclines, it could now keep itself upright when descending. The wingless version of DASH could survive falls from eight stories tall, but it would sometimes land upside down, and where it landed was partly guided by luck."

The flapping wings improved the lift-drag ratio, helping DASH+Wings land on its feet instead of just plummeting uncontrolled. Once it hit the ground, the robot was able to continue on its way. Wind tunnel experiments showed that it is aerodynamically capable of gliding at an angle up to 24.7 degrees.

Tree-dwellers vs. ground-runners

The engineering team's work caught the attention of animal flight expert Robert Dudley, a UC Berkeley professor of integrative biology, who noted that the most dominant theories on flight evolution have been primarily derived from scant fossil records and theoretical modeling.

He referenced previous computer models suggesting that ground-dwellers, given the right conditions, would need only to triple their running speed in order to build up enough thrust for takeoff. The fact that DASH+Wings could maximally muster a doubling of its running speed suggests that wings do not provide enough of a boost to launch an animal from the ground. This finding is consistent with the theory that flight arose from animals that glided downwards from some height.

"The fossil evidence we do have suggests that the precursors to early birds had long feathers on all four limbs, and a long tail similarly endowed with a lot of feathers, which would mechanically be more beneficial for tree-dwelling gliders than for runners on the ground," said Dudley.

Dudley said that the winged version of DASH is not a perfect model for proto-birds -- it has six legs instead of two, and its wings use a sheet of plastic rather than feathers -- and thus cannot provide a slam-dunk answer to the question of how flight evolved.

"What the experiments did do was to demonstrate the feasibility of using robot models to test hypotheses of flight origins," he said. "It's the proof of concept that we can actually learn something useful about biological performance through systematic testing of a physical model."

Among other robotic insects being tested in the Biomimetic Millisystems Lab is a winged, bipedal robot called BOLT (Bipedal Ornithopter for Locomotion Transitioning) that more closely resembles the size and aerodynamics of precursors to flying birds and insects.

"It's still notable that adding wings to DASH resulted in marked improvements in its ability to get around," said Fearing. "It shows that flapping wings may provide some advantages evolutionarily, even if it doesn't enable flight."

The National Science Foundation's Center of Integrated Nanomechanical Systems and the U.S. Army Research Laboratory helped support this research.

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Sunlight in Tropical Forest Driving Force Behind Ecological Niches of Tree Species

Not water, but sunlight is the main factor in determining the growth of the hundreds of tree species in tropical forests. The variation in physiological characteristics between tree species explains how the various species fit into their ecological niches, thereby contributing to diversity in tropical forests. This is the conclusion drawn by researchers from Wageningen University, part of Wageningen UR, and their colleagues from Utrecht University in a publication in the scientific journal PNAS.

Tropical forests are able to sustain hundreds of tree species on just a few hectares, but little is known about how this diversity has evolved. A study carried out by Frank Sterck, Lourens Poorter and Lars Markesteijn (Wageningen University) and Feike Schieving (Utrecht University) shows that the species examined all responded differently to variations in the availability of light and water because they had different physiological characteristics. Most of the species occupied a unique niche where they do better than the other species, which may contribute to the co-existence of these species and the diversity of the forest.

As part of the study, the researchers measured a range of physiological properties such as leaf surface area, wood density, photosynthesis capacity, leaf water potentials and resistance to water transport in tropical tree species from a Bolivian forest. They used a physiological plant model to calculate the speed at which the various species can grow when exposed to different combinations of water and light. The simulations show that variations in leaf production and photosynthesis capacity enable species to specialise for a variety of light niches. The sensitivity of stoma to drought in the various species (and therefore the water consumption) also varies, but this does not lead to trees becoming specialised for dry or moist locations in the same forest.

The researchers conclude that even in relatively dry tropical forests, light is the driving force behind niche specialisation in tree types. This makes sunlight more important than water in terms of whether different trees grow side-by-side or not. This is one of the first studies for which physiological plant models have been used to scale up plant characteristics to the growth and survival of various tree species in order to explain the wealth of species in a tropical forest. In future, these models will also be used to look into the distribution of plant species along climate gradients.

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Stress Reduction and Mindful Eating Curb Weight Gain Among Overweight Women

Many dread gaining weight during the holiday season, but there may be hope for those who find that stress causes them to reach for yet another helping of holiday goodies.
In a study by UCSF researchers published online in the Journal of Obesity, mastering simple mindful eating and stress-reduction techniques helped prevent weight gain even without dieting.

Women in the study who experienced the greatest reduction in stress tended to have the most loss of deep belly fat. To a greater degree than fat that lies just under the skin, this deep abdominal fat is associated with an elevated risk for developing heart disease or diabetes.

"You're training the mind to notice, but to not automatically react based on habitual patterns -- to not reach for a candy bar in response to feeling anger, for example," said UCSF researcher Jennifer Daubenmier, PhD, from the Osher Center for Integrative Medicine. "If you can first recognize what you are feeling before you act, you have a greater chance of making a wiser decision."

Daubenmier led the current study with UCSF psychologist Elissa Epel, PhD. The study, published online in October, is part of ongoing UCSF research into how stress and the stress hormone cortisol are linked to eating behavior, fat and health.

Recognizing Sensations of Hunger, Fullness and Taste Satisfaction

The women who participated were not on calorie-counting diets. Instead, 24 of the 47 chronically stressed, overweight and obese women were randomly assigned to mindfulness training and practice, and the other 23 served as a control group. Although no diets were prescribed, all participants attended one session about the basics of healthy eating and exercise.

The training included nine weekly sessions, each lasting 2 1/2 hours, during which the women learned stress reduction techniques and how to be more aware of their eating by recognizing bodily sensations -- including hunger, fullness and taste satisfaction. At week six they attended an intensive seven-hour, silent meditation retreat.

They were asked to set aside 30 minutes daily for meditation exercises and to practice mindful eating during meals. Researchers used a scientifically tested survey to gauge psychological stress before and after the four-month study, and recorded the women's fat and cortisol levels.

The UCSF researchers looked for changes in the amount of deep abdominal fat and overall weight. They also measured secretion of cortisol shortly after awakening, a time when cortisol peaks in those under chronic stress.

Cortisol secretion runs in a daily cycle and normally ramps up when we awaken. But secretion also is triggered by both real and perceived threats. If we wake up, anticipate the day's events, and experience these thoughts as stressful, cortisol secretion may spike even higher, Daubenmier said.

On Average, Mindful, Obese Women Did not Gain Weight in Study

Among women in the treatment group, changes in body awareness, chronic stress, cortisol secretion and abdominal fat were clearly linked. Those who had greater improvements in listening to their bodies' cues, or greater reductions in stress or cortisol, experienced the greatest reductions in abdominal fat.

Among the subset of obese women in the study, those who received the mindfulness training had significant reductions in cortisol after awakening and also maintained their total body weight, compared to women in the waitlist group, who had stable cortisol levels and continued to gain weight.

The stress-reduction and mindful-eating techniques used in the study were adapted from methods developed three decades ago by Jon Kabat-Zinn, PhD, the first director of the Stress Reduction Clinic at the University of Massachusetts Medical School and a founding member of the Cambridge Zen Center. The mindful-eating techniques used in the UCSF study are part of a larger program of mindful eating developed by Jean Kristeller, PhD, of Indiana State University.

Ongoing Study of Pregnant Women

"In this study we were trying to cultivate people's ability to pay attention to their sensations of hunger, fullness and taste satisfaction as a guide for limiting how much they eat," Daubenmiersaid. "We tried to reduce eating in response to emotions or external cues that typically drive overeating behavior."

Daubenmier said the small study is preliminary and must be confirmed in ongoing, follow-up research. Furthermore, when the entire study group was included in the analysis -- overweight as well as obese women -- the researchers found no significant differences in weight change between women who practiced stress reduction and mindful eating and those on the waiting list.

In a separate, ongoing study with lower-income, pregnant women who are overweight, Epel,Daubenmier and colleagues are teaching similar mindful-eating techniques. Pregnancy is a time when heavy women tend to gain an excessive amount of weight and later find it very hard to lose it. Furthermore, excessive weight gain during pregnancy can harm the baby's health.

"We are intervening at a critical point, when the health of the next generation is being shaped,"Epel said. "We hope to improve the health of both the mothers and their babies."

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Intermittent, Low-Carbohydrate Diets More Successful Than Standard Dieting, Study Finds

An intermittent, low-carbohydrate diet was superior to a standard, daily calorie-restricted diet for reducing weight and lowering blood levels of insulin, a cancer-promoting hormone, according to recent findings.
Researchers at Genesis Prevention Center at University Hospital in South Manchester, England, found that restricting carbohydrates two days per week may be a better dietary approach than a standard, daily calorie-restricted diet for preventing breast cancer and other diseases, but they said further study is needed.

"Weight loss and reduced insulin levels are required for breast cancer prevention, but [these levels] are difficult to achieve and maintain with conventional dietary approaches," said Michelle Harvie, Ph.D., SRD, a research dietician at the Genesis Prevention Center, who presented the findings at the 2011 CTRC-AACR San Antonio Breast Cancer Symposium, held Dec. 6-10, 2011.

Harvie and her colleagues compared three diets during four months for effects on weight loss and blood markers of breast cancer risk among 115 women with a family history of breast cancer. They randomly assigned patients to one of the following diets: a calorie-restricted, low-carbohydrate diet for two days per week; an "ad lib" low-carbohydrate diet in which patients were permitted to eat unlimited protein and healthy fats, such as lean meats, olives and nuts, also for two days per week; and a standard, calorie-restricted daily Mediterranean diet for seven days per week.

Data revealed that both intermittent, low-carbohydrate diets were superior to the standard, daily Mediterranean diet in reducing weight, body fat and insulin resistance. Mean reduction in weight and body fat was roughly 4 kilograms (about 9 pounds) with the intermittent approaches compared with 2.4 kilograms (about 5 pounds) with the standard dietary approach. Insulin resistance reduced by 22 percent with the restricted low-carbohydrate diet and by 14 percent with the "ad lib" low-carbohydrate diet compared with 4 percent with the standard Mediterranean diet.

"It is interesting that the diet that only restricts carbohydrates but allows protein and fats is as effective as the calorie-restricted, low-carbohydrate diet," Harvie said.

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Innovative Approaches Help Sleep Apnea Sufferers Benefit from CPAP

People with obstructive sleep apnea are more likely to stick to prescribed treatment when a partner or parent is involved with their treatment, according to a team of sleep researchers.
Obstructive sleep apnea occurs when the upper airway collapses during sleep. It is the most common type of sleep-disordered breathing, and chances of it occurring become more elevated in obese people.

The first line of treatment for sleep apnea is a non-invasive in-home treatment called CPAP, continuous positive airway pressure therapy. However, if patients do not use the equipment properly, or at all, it cannot help.

Amy M. Sawyer, assistant professor of nursing, Penn State, and her team are looking for the best ways to encourage patients to adhere to the CPAP treatment.

"There is inconsistency in how people use and adhere to CPAP," said Sawyer. "Patients are expected to use CPAP for the eight hours or so that they are asleep. Unfortunately, most patients do not use CPAP for the duration of their sleep time."

A CPAP machine is connected to a nasal, oral or full-face mask. The CPAP machine delivers positive pressure by air, which keeps the upper airway open and unable to collapse -- a definitive problem of obstructive sleep apnea sufferers. Keeping the airway open prevents drops in oxygen levels during sleep and reduces sleep disturbance. As a result, people treated with CPAP have less daytime sleepiness, better cognitive function and generally feel more refreshed. Treating obstructive sleep apnea also lessens other health risks, including cardiovascular disease and diabetes.

The researchers were looking at different types of interventions to promote CPAP use, the team reports in the current issue of Sleep Medicine Reviews. Sawyer and her team looked at 80 studies to determine what works and what factors are important to consider when helping obstructive sleep apnea people start CPAP therapy.

"Collectively, these studies suggest that patients who experience difficulties and proactively seek solutions to resolve problems (active coping) are more likely to be adherent than those who use passive coping styles," the researchers noted.

Many different factors can affect whether or not patients follow through on their prescribed treatment -- disease and patient characteristics, treatment requirements, technological device factors and side effects, and psychological and social factors. One of the studies that the researchers reviewed showed that about half of newly diagnosed sleep apnea patients would not use CPAP if it made them feel claustrophobic.

Several intervention studies use telecommunications to help patients adhere to their treatment. This method can involve weekly phone calls or wireless telemonitoring of patients.

The researchers determined that CPAP adherence intervention should be done on a case-by-case basis. If social support is involved -- such as a parent or partner -- patients are likely to continue their treatment. With social support sources providing insight, CPAP users are more readily able to identify their own improvements with treatment. If patients do not have social support available to them, then telecommunications may be a good option for them.

"This study highlights the need for individualized considerations for initiating and managing CPAP treatment with diverse patient groups," said Sawyer.

Sawyer is currently directing a clinical trial at the Penn State College of Medicine, Hershey, Pa., to test an individualized approach to helping patients begin CPAP treatment. The trial is funded by grants from the National Institutes of Health, National Institute of Nursing Research; and American Nurses Foundation, Sigma Theta Tau International.

Also working on this research were Nalaka Gooneratne, assistant professor of medicine, and Dafna Ofer, physician, University of Pennsylvania School of Medicine; Kathy C. Richards, professor of nursing, University of Pennsylvania School of Nursing; Carole L. Marcus, professor of pediatrics, Children's Hospital of Philadelphia; and Terri E. Weaver, professor and dean, University of Illinois at Chicago School of Nursing.

A grant from the National Institutes of Health, National Institute of Nursing Research supported the team's research.

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News And Articles

• Innovative Approaches Help Sleep Apnea Sufferers Benefit from CPAP
• Intermittent, Low-Carbohydrate Diets More Successful Than Standard Dieting, Study Finds
• Stress Reduction and Mindful Eating Curb Weight Gain Among Overweight Women

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