Tuesday, June 8, 2010

PARENTS' PHYSICAL INACTIVITY INFLUENCES CHILDREN

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Children are more likely to watch high levels of television if their parents do, but parents do not need to be physically active to help their children to be active, a new study has found.

The paper, Parent and child physical activity and sedentary time: Do active parents foster active children? by Dr Russell Jago and colleagues in the Department of Exercise, Nutrition and Health Sciences at the University of Bristol is published online in BMC Public Health. The study has been funded by a grant from the British Heart Foundation.

Among children and adolescents, physical activity has been associated with a lower BMI and a reduced risk of heart disease. Regular physical activity is also known to help to prevent the development of type 2 diabetes, obesity and some cancers and is also associated with improved mental well-being.

The study found that higher parental TV viewing was associated with an increased risk of high levels of TV viewing for both boys and girls. For girls, the relative risk of watching more than four hours of TV per day was 3.67 times higher if the girl's parent watched two-four hours of TV per day, when compared to girls who watched less than two hours of TV per day.

For boys, the relative risk of watching more than four hours of TV per day was 10.47 times higher if the boy's parent watched more than four hours of TV per day when compared to boys who watched less than two hours of TV per day. There were no associations between the time that parents and children spend engaged in physical activity.

Dr Russ Jago, Senior Lecturer in the Department of Exercise, Nutrition and Health Sciences, said: "Physical activity has many positive effects on children's health while TV viewing has been associated with adverse health outcomes. Many children do not meet physical activity recommendations and exceed TV viewing guidelines.

"Our research suggests that parents do not need to be active for their children to be active. Parents should therefore look at ways in which they can help to facilitate physical activity for their children such as by encouraging walking to school or promoting outdoor free-play in safe areas close to home."

Dr Mike Knapton, Associate Medical Director at the BHF added: "Parents and children rooted to the sofa watching over four hours of television each night paints a worrying picture of kids' daily habits.

"Ideally parents and children should lead an active lifestyle together but if this isn't possible then parents need to take charge and ensure a healthier way of life for the next generation. It's time to switch off the box and get the nation's kids moving again."

Year six children and their parents were recruited from 40 primary schools in Bristol to participate in the study to examine parents and children's physical activity patterns. Parental and child physical activity and inactive time was assessed using accelerometers. These are small devices that provide accurate and reliable indices of physical activity among both children and adults.

The study is part of a larger project, the Bristol 3Ps Project, which examines the influences of peers and parents on physical activity participation in 10-11 year old children.

(Photo: Bristol U.)

University of Bristol

BURSTING 'BUBBLES' THE ORIGIN OF GALACTIC GAS CLOUDS

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Like bubbles bursting on the surface of a glass of champagne, ‘bubbles’ in our Galaxy burst and leave flecks of material in the form of clouds of hydrogen gas, researchers using CSIRO’s Parkes telescope have found.

Their study explains the origin of these clouds for the first time.

Swinburne University PhD student Alyson Ford (now at the University of Michigan) and her supervisors; Dr Naomi McClure-Griffiths (CSIRO Astronomy and Space Science) and Felix Lockman (US National Radio Astronomy Observatory), have made the first detailed observations of ‘halo’ gas clouds in our Galaxy.

Just as Earth has an atmosphere, the main starry disk of our Galaxy is surrounded by a thinner halo of stars, gas and ‘dark matter’.

The halo clouds skim the surface of our Galaxy, sitting 400 to 10 000 light-years outside the Galactic disk. They are big: an average-sized cloud contains hydrogen gas 700 times the mass of the Sun and is about 200 light-years across.

“We’re studying the clouds to understand what role they play in recycling material between the disk and halo,” Dr McClure-Griffiths said.

“The clouds can fall back down into the main body of the Galaxy, returning gas to it.”

The researchers studied about 650 clouds and found striking differences between them in different areas of the Galaxy. One part of the Galaxy had three times as many clouds as another next to it, and the clouds were twice as thick.

The region with lots of thick clouds is where lots of stars form, while the region with fewer clouds also forms fewer stars.

But the halo clouds aren’t found exactly where stars are forming right now. Instead, they seem to be linked to earlier star formation.

Massive stars grow old quickly. After a few million years they shed material into space as a ‘wind’ and then explode.

This violence creates bubbles in the gas in space, like the holes in a Swiss cheese.

“Stellar winds and explosions sweep up gas from the Galactic disk into the lower halo.

“We’ve found this churned-up gas is ‘spritzing’ the surface of the Galactic disk in the form of halo clouds.”

A star-forming region is active for less than a million years, but a super-bubble in the Galaxy takes 20 or 30 million years to form.

“Just as yeast takes a while to make wine bubbly, stars take a while to make the Galaxy bubbly,” Dr McClure-Griffiths said.

The halo clouds are distinct from a larger population of ‘high-velocity clouds’ that also sail outside the galaxy. The halo clouds move in tandem with the rotating Galaxy, while the high-velocity clouds scud along much faster.

This study is the first to accurately locate the halo clouds in relation to the main body of the Galaxy. Its findings were presented overnight at a news conference at a meeting of the American Astronomical Society in Miami, Florida.

(Photo: A Ford (U. Michigan) and N. McClure-Griffiths (CSIRO Astronomy and Space Science))

Commonwealth Scientific and Industrial Research Organization

COMMUNITIES WITH WIDER SOCIAL NETWORKS HAVE MORE ECONOMIC OPPORTUNITY

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People who phone a diverse group of acquaintances tend to live in more affluent communities and have more socio-economic opportunities than those who talk primarily to people in their immediate vicinity, reports a new study published May 21 in the journal Science.

The researchers analyzed a giant data set from British Telecom -- mobile and landline telephone calling patterns from the United Kingdom -- which they cross-referenced with socio-economic census data to assess the role of social networks in the socio-economic status of communities.

"Communities that do well are communities whose members have diverse networks, while insular communities are more likely to be economically and socially disadvantaged. This is the first time that researchers have had the full telephone network data for an entire country, so you could scale up from individuals to see how community well-being varies with network structure," said Michael Macy, the Goldwin Smith Professor of Sociology at Cornell, who conducted the study with Nathan Eagle of the Massachusetts Institute of Technology and British Telecom research scientist Rob Claxton. "These new data sources, based on telephone call logs, allow us to measure network structure at the national level."

The researchers found, for example, that residents of prosperous Stratford-upon-Avon speak to people far beyond the town, while those in poorer Stoke-on-Trent speak mostly to each other.

"And it was not a matter of call volume," Macy said. "People in the advantaged communities allocate their calls in a more diverse pattern spatially and through diverse social networks." That's bad news for the folks of Stoke-on-Trent.

Previous studies using individuals as the units of analysis have found that economic opportunities come from outside a small circle of friends. Within organizations, people whose positions expose them to diverse contacts are rewarded with higher pay and promotions. Other studies, Macy said, have found that those with diverse social networks have more bargaining power, make more money and have greater success as entrepreneurs. The new study shows that the relationship between network structure and economic outcomes scales up from the individual to the community level.

The researchers did not use Twitter or Facebook data. "These social media may provide more data about diverse contacts compared to the telephone," Macy said. "If we follow up this study using social media data, we might find some interesting results to better understand the causal mechanisms from network structure to economic advantage or from economic advantage to network structure."

Macy and his co-authors are working on a paper that examines health, education, environmental quality and economic indicators like employment, income and wealth.

"We would also like to see if occupational and geographic mobility may be an important causal link in this correlation between network diversity and economic development," Macy said. "If people move physically and socially within networks, this may diversify their networks, and it may afford them greater access to resources and opportunities."

The researchers were struck by the magnitude of the correlation between network diversity and economic status, but they believe further study is necessary before their findings can translate into economic policy recommendations. "Knowing that a community has highly insular calling patterns may be potentially useful for targeting economic development efforts more strategically," Macy said. "But until we understand more, we can't be certain that this correlation is useful information for policy."

(Photo: Her Majesty's Stationery Office, London, 2004)

Cornell University

GRAPHANE YIELDS NEW POTENTIAL

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Graphane is the material of choice for physicists on the cutting edge of materials science, and Rice University researchers are right there with the pack – and perhaps a little ahead.

Researchers mentored by Boris Yakobson, a Rice professor of mechanical engineering and materials science and of chemistry, have discovered the strategic extraction of hydrogen atoms from a two-dimensional sheet of graphane naturally opens up spaces of pure graphene that look – and act – like quantum dots.

That opens up a new world of possibilities for an ever-shrinking class of nanoelectronics that depend on the highly controllable semiconducting properties of quantum dots, particularly in the realm of advanced optics.

The theoretical work by Abhishek Singh and Evgeni Penev, both postdoctoral researchers in co-author Yakobson's group, was published online last week in the journal ACS Nano and will be on the cover of the print version in June. Rice was recently named the world's No. 1 institution for materials science research by a United Kingdom publication.

Graphene has become the Flat Stanley of materials. The one-atom-thick, honeycomb-like form of carbon may be two-dimensional, but it seems to be everywhere, touted as a solution to stepping beyond the limits of Moore's Law.

Graphane is simply graphene modified by hydrogen atoms added to both sides of the matrix, which makes it an insulator. While it's still technically only a single atom thick, graphane offers great possibilities for the manipulation of the material's semiconducting properties.

Quantum dots are crystalline molecules from a few to many atoms in size that interact with light and magnetic fields in unique ways. The size of a dot determines its band gap – the amount of energy needed to close the circuit – and makes it tunable to a precise degree. The frequencies of light and energy released by activated dots make them particularly useful for chemical sensors, solar cells, medical imaging and nanoscale circuitry.

Singh and Penev calculated that removing islands of hydrogen from both sides of a graphane matrix leaves a well with all the properties of quantum dots, which may also be useful in creating arrays of dots for many applications.

“We arrived at these ideas from an entirely different study of energy storage in a form of hydrogen adsorption on graphene,” Yakobson said. "Abhishek and Evgeni realized that this phase transformation (from graphene to graphane), accompanied by the change from metal to insulator, offers a novel palette for nanoengineering."

Their work revealed several interesting characteristics. They found that when chunks of the hydrogen sublattice are removed, the area left behind is always hexagonal, with a sharp interface between the graphene and graphane. This is important, they said, because it means each dot is highly contained; calculations show very little leakage of charge into the graphane host material. (How, precisely, to remove hydrogen atoms from the lattice remains a question for materials scientists, who are working on it, they said.)

"You have an atom-like spectra embedded within a media, and then you can play with the band gap by changing the size of the dot," Singh said. "You can essentially tune the optical properties."

Along with optical applications, the dots may be useful in single-molecule sensing and could lead to very tiny transistors or semiconductor lasers, he said.

Challenges remain in figuring out how to make arrays of quantum dots in a sheet of graphane, but neither Singh nor Penev sees the obstacles as insurmountable.

"We think the major conclusions in the paper are enough to excite experimentalists," said Singh, who will soon leave Rice to become an assistant professor at the Indian Institute of Science in Bangalore. "Some are already working in the directions we explored."

"Their work is actually supporting what we're suggesting, that you can do this patterning in a controlled way," Penev said.

When might their calculations bear commercial fruit? "That's a tough question," Singh said. "It won't be that far, probably -- but there are challenges. I don't know that we can give it a time frame, but it could happen soon."

(Photo: Evgeni Penev/Abhishek Singh)

Rice University

GRINDING MOUTH, WRINKLE EYE: PENN GRADUATE STUDENT DESCRIBES NEW SPECIES OF PLANT-EATING DINOSAUR

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A team of paleontologists, including a University of Pennsylvania doctoral candidate, has described a new species of dinosaur based upon an incomplete skeleton found in western New Mexico. The new species, Jeyawati rugoculus, comes from rocks that preserve a swampy forest ecosystem that thrived near the shore of a vast inland sea 91 million years ago.

The dinosaur, whose name translates to mean “grinding-mouth, wrinkle-eye,” was most likely an herbivore that ate the ferns and conifer trees found as fossils in the same rock layer. A basal hadrosauroid, the find included partial skull bones, several vertebrae and fragments of the ribs.

Jeyawati is a close relative of the duck-billed hadrosaurs, which were abundant across the Northern Hemisphere for much of the Late Cretaceous Epoch, between 80 and 65 million years ago. Jeyawati retains some primitive features of the teeth and jaws that preclude it from being a fully-fledged hadrosaur.

Jeyawati, pronounced “HEY-a-WHAT-ee,” is derived from two words in the language of the Zuni people, a Native American tribe located around the Zuni River in western New Mexico. The name is a reference to the sophisticated chewing mechanism evolved by the herbivorous lineage to which Jeyawati belongs.

The second part of the name, rugoculus, comes from the Latin words ruga and oculus and means “wrinkle eye,” describing a unique feature of the new species. One of the bones that forms the eye socket exhibits a peculiar rough or wrinkly texture on its outer side, suggesting that Jeyawati rugoculus might have sported one or more large scales above and behind its eye.

“Jeyawati apparently endured a hard life,” said Andrew T. McDonald, lead author of the study and a doctoral candidate in Penn’s Department of Earth and Environmental Sciences. “Several of the rib fragments have a swollen, rough surface, indicating that the animal suffered broken ribs at some point in its life and that those injuries healed before the animal's death.”

Although the fossil remains were discovered in 1996, it has only now been confirmed that the species is unique. Jeyawati is a member of an assemblage of dinosaurs and other animals unknown as recently as 15 years ago.

McDonald began his classification of the find while a student at the University of Nebraska, before completing the work with Peter Dodson, professor of anatomy and paleontontology in the schools of Veterinary Medicine and Arts and Sciences at Penn.

“From looking at the more complete remains of species related to Jeyawati, we can make several assumptions,” McDonald said, “including that the creature probably walked on all fours but was also capable of rearing up on two legs.”

The bones now reside at the Arizona Museum of Natural History, where specimens of other dinosaurs uncovered in this region are also located.

Dinosaurs that coexisted with Jeyawati include Zuniceratops, the earliest known North American horned dinosaur, and Nothronychus, a strange herbivorous beast belonging to a lineage that, until the discovery of Nothronychus, was known only from Asia.

The partial skull and other fragments of Jeyawati were discovered by paleontologist Douglas Wolfe, principal investigator of the Zuni Basin Paleontological Project. Subsequent excavation and collection was carried out for 13 years with the aid of James Kirkland, state paleontologist with the Utah Geological Survey, and volunteers from the Southwest Paleontological Society, among others.

In 2006, McDonald, then an undergraduate geology student, began a project to describe the fossil. The analysis revealed that the bones were sufficiently distinct from those of other dinosaurs to warrant the naming of a new species.

(Photo: Lukas Panzarin)

University of Pennsylvania

ELECTRIC ASH FOUND IN EYJAFJALLAJOKULL'S PLUME

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In the first peer-reviewed scientific paper to be published about the Icelandic volcano since its eruption in April 2010, UK researchers write that the ash plume which hovered over Scotland carried a significant and self-renewing electric charge.

The volcano-chasing researchers argue this adds a further dimension to understanding the detailed nature of volcanic plumes and their effects on air travel.

The paper, published Thursday 27 May, in IOP Publishing's Environmental Research Letters, is published as the UK continues to face the possibility of further flight disruption from future volcanic activity.

Shortly after the volcano's active eruption phase began in mid-April, the Met Office contacted Joseph Ulanowski from the Science and Technology Research Institute at the University of Hertfordshire, who last year, together with Giles Harrison from the Department of Meteorology at the University of Reading, had developed a specialist weather balloon which could assess the location and composition of the volcanic ash clouds.

Their balloons, originally designed and used to study the properties of desert dust clouds, are able to assess not only the size of atmospheric particles but also the electric charge present.

Measurements made last year with the balloons in Kuwait and off the west coast of Africa showed clearly that desert dust could become strongly electrified aloft. Charging modifies particle behaviour, such as how effectively particles grow and are removed by rain.

A hastily scrambled team travelled to a site near Stranraer in Scotland where a balloon was launched, detecting a layer of volcanic ash 4km aloft, about 600m thick, with very abrupt upper and lower edges.

From their measurements, the researchers conclude that neither energy from the volcanic source - more than 1200 kilometres away - nor weather conditions could have been responsible for the position of the charge found by the balloon.

The presence of charge deep inside the plume, rather than on its upper and lower edges, contradicts expectations from models assuming solely weather-induced charging of layer clouds.

Giles Harrison said, "Detailed volcanic plume properties, such as the particle size, concentration and charge found by our weather balloon are important in predicting the impact on aircraft."

(Photo: Terje Sorgjerd, Getty Images)

Institute of Physics

STUDENTS HARNESS VIBRATIONS FROM WIND FOR ELECTRICITY

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A gusty day makes stop signs quiver and leaves flutter. It's these vibrations a Cornell research group is harnessing and transforming into electricity for a new kind of energy storage system.

The Vibro-Wind Research Group, led by Frank Moon, the Joseph Ford Professor of Mechanical and Aerospace Engineering, is working on an efficient, low-cost method of converting vibrations from wind energy to electricity. Much the way solar panels now grace many rooftops, the researchers envision buildings outfitted with vibro-wind panels, which would store the energy they convert from even the gentlest of breezes.

Traditional wind energy harvesting requires the use of large, expensive turbines, or windmills. The vibro-wind setup would require a fraction of the space and cost much less.

"The thing with turbines and windmills is that you need wide open space, and you need it to be away from the city, because people don't like the way they look," explained Rona Banai '10, a chemical engineering major and chief student engineer of the Vibro-Wind group.

Looking into the feasibility of vibro-wind panels isn't just about engineering. The group includes co-principal investigator Kevin Pratt, assistant professor of architecture, and architecture major Jamie Pelletier '10, who are working on design issues to address integration of panels into buildings.

This past semester, the students -- exclusively undergraduates -- tested a prototype consisting of a panel mounted with oscillators they made out of pieces of foam. They set up their experiment on top of Rhodes Hall, hoped for windy days and monitored how much energy they captured with each quiver of the oscillators.

The trickiest part -- the actual conversion from mechanical to electrical energy -- was done using a piezoelectric transducer, which is a device made of a ceramic or polymer that emits electrons when stressed.

Banai in particular has also researched an alternative to the piezoelectric transducer, checking feasibility of using an electromagnetic coil instead. The pros and cons are some of the things she's now working to put into a report, she said.

Vibration energy harvesting is nothing new, but according to Moon, interest in the subject has grown in the past few years in such areas as defense and civil infrastructure. The soldier of the future, for example, could shed the need for heavy batteries or other equipment, instead creating and storing electrical energy just by walking. Or civil engineers could rig buildings or bridges with sensors to detect fires and other instabilities, and the sensors would be powered by vibrational energy.

"We are taking research that's been in progress, and we are trying to extend it into a new type of energy harvesting," Moon said.

(Photo: Cornell U.)

Cornell University

ADVANCES MADE IN WALKING, RUNNING ROBOTS

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Researchers at Oregon State University have made an important fundamental advance in robotics, in work that should lead toward robots that not only can walk and run effectively, but use little energy in the process.

By achieving an optimal approach with robotic mechanisms, studies are moving closer to robots that could take on dangerous missions in the military, create prosthetic limbs for humans that work much better, or even help some people who use wheelchairs to gain “walking” abilities.

The newest findings from the Dynamic Robotics Laboratory at OSU are being presented at two conferences, including the IEEE Conference on Robotics and Automation.

The OSU research program has received a new $750,000 grant for its work from the Human Frontiers Science Program, administered through the National Science Foundation. Work to actually build a robot with some of the newest features should be completed by this summer.

“Researchers have been working toward robot locomotion for a long time based mostly on experience and intuition,” said Jonathan Hurst, an assistant professor of robotics and mechanical design at OSU. “What we’ve done is taken a step back to analyze the fundamental dynamics of the mechanical system, what behavior is really possible for a given robotic system. A rock can’t fly, no matter what software you write for it.

“This is an important advance and gives us a new foundation to tell what actually will and won’t work before we even try to build it,” he said.

Right now, most applications of robotics are done with machines working in a precise or controlled situation – picking something up off an assembly line, spot welding an automobile in an exact way thousands of times a day.

But in terms of locomotion, Hurst said, humans and other animals are a tough act to follow. Using limited energy, they can move easily over uneven terrain, and respond with a fascinating balance of muscles and tendons. They have different ways to deal with forces, such as holding something in place rigidly, or also responding to outside influences – like the delicate act of holding a cup of coffee level during a bumpy car ride.

In their recent studies, the OSU researchers essentially proved that these two abilities are mutually exclusive. Humans deal with this problem by flexing opposing pairs of muscles, to change the dynamic properties of their arm. For a robot, the more it is able to do one of these tasks, the less able it is to do the other.

Existing robots that can walk and run, Hurst said, tend to be as rigid as possible while still achieving a basic gait. But this approach uses a huge amount of energy, significantly reducing their value and possible applications in the real world. The OSU researchers are working toward something that has similar or better performance, but uses far less energy – the best of both worlds, and closer to the abilities of animals.

“If robotic locomotion is ever to achieve some of what we want, it will have to use less energy,” Hurst said. “There are machines that can walk with no active controls at all, using barely any energy, but they fall if they run into the smallest bump. We need to use as much of that passive ability as possible and only use motors or active controls if it’s really necessary, so we can save energy in the process.”

In part because it’s consistent with these goals, the OSU researchers also hope to win what’s called the “W” Prize, a $200,000 award that’s been promised for the first robot that can move 10 kilometers within 10,000 seconds, through and over obstacles, using less energy than it would take a human to do the same task.

Part of the OSU research are studies under way with colleagues in England to examine ostriches, and make direct comparisons to the robot behavior. Animals, including ostriches, have a great ability to respond to unexpected disturbances while running, and can provide insights into the needed robotic equivalent – combining spring-mass models with “force control actuators.”

“Long term, there’s no reason we shouldn’t be able to build robots or robotic devices with excellent locomotion ability,” Hurst said. “Clearly this might be useful for some military or police applications in highly dangerous situations. But I could also see great improvements possible with prosthetic limbs that work much better than existing technology, or even the creation of exoskeletons that might allow someone with limited motor ability to walk effectively.”

(Photo: Oregon State University)

Oregon State University

NASA'S SWIFT SURVEY FINDS 'SMOKING GUN' OF BLACK HOLE ACTIVATION

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Data from an ongoing survey by NASA's Swift satellite have helped astronomers solve a decades-long mystery about why a small percentage of black holes emit vast amounts of energy.

Only about one percent of supermassive black holes exhibit this behavior. The new findings confirm that black holes "light up" when galaxies collide, and the data may offer insight into the future behavior of the black hole in our own Milky Way galaxy. The study will appear in the June 20 issue of The Astrophysical Journal Letters.

The intense emission from galaxy centers, or nuclei, arises near a supermassive black hole containing between a million and a billion times the sun's mass. Giving off as much as 10 billion times the sun's energy, some of these active galactic nuclei (AGN) are the most luminous objects in the universe. They include quasars and blazars.

"Theorists have shown that the violence in galaxy mergers can feed a galaxy's central black hole," said Michael Koss, the study's lead author and a graduate student at the University of Maryland in College Park. "The study elegantly explains how the black holes switched on."

Until Swift's hard X-ray survey, astronomers never could be sure they had counted the majority of the AGN. Thick clouds of dust and gas surround the black hole in an active galaxy, which can block ultraviolet, optical and low-energy, or soft X-ray, light. Infrared radiation from warm dust near the black hole can pass through the material, but it can be confused with emissions from the galaxy's star-forming regions. Hard X-rays can help scientists directly detect the energetic black hole.

Since 2004, the Burst Alert Telescope (BAT) aboard Swift has been mapping the sky using hard X-rays.

"Building up its exposure year after year, the Swift BAT Hard X-ray Survey is the largest, most sensitive and complete census of the sky at these energies," said Neil Gehrels, Swift's principal investigator at NASA's Goddard Space Flight Center in Greenbelt, Md.

The survey, which is sensitive to AGN as far as 650 million light-years away, uncovered dozens of previously unrecognized systems.

"The Swift BAT survey is giving us a very different picture of AGN," Koss said. The team finds that about a quarter of the BAT galaxies are in mergers or close pairs. "Perhaps 60 percent of these galaxies will completely merge in the next billion years. We think we have the 'smoking gun' for merger-triggered AGN that theorists have predicted."

Other members of the study team include Richard Mushotzky and Sylvain Veilleux at the University of Maryland and Lisa Winter at the Center for Astrophysics and Space Astronomy at the University of Colorado in Boulder.

"We've never seen the onset of AGN activity so clearly," said Joel Bregman, an astronomer at the University Michigan, Ann Arbor, who was not involved in the study. "The Swift team must be identifying an early stage of the process with the Hard X-ray Survey."

Swift, launched in November 2004, is managed by Goddard. It was built and is being operated in collaboration with Penn State, the Los Alamos National Laboratory in New Mexico, and General Dynamics in Falls Church, Va.; the University of Leicester and Mullard Space Sciences Laboratory in the United Kingdom; Brera Observatory and the Italian Space Agency in Italy; plus additional partners in Germany and Japan.

(Univ. of Maryland))

NASA

MILK: 2 GLASSES A DAY TONES MUSCLES, KEEPS THE FAT AWAY IN WOMEN, STUDY SHOWS

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Women who drink two large glasses of milk a day after their weight-lifting routine gained more muscle and lost more fat compared to women who drank sugar-based energy drinks, a McMaster study has found.

The study appears in the June issue of Medicine and Science in Sport and Exercise.

"Resistance training is not a typical choice of exercise for women," says Stu Phillips, professor in the Department of Kinesiology at McMaster University. "But the health benefits of resistance training are enormous: It boosts strength, bone, muscular and metabolic health in a way that other types of exercise cannot."

A previous study conducted by Phillips' lab showed that milk increased muscle mass and fat loss in men. This new study, says Phillips was more challenging because women not only steer clear of resistance training they also tend to steer away from dairy products based on the incorrect belief that dairy foods are fattening.

"We expected the gains in muscle mass to be greater, but the size of the fat loss surprised us," says Phillips. "We're still not sure what causes this but we're investigating that now. It could be the combination of calcium, high-quality protein, and vitamin D may be the key, and. conveniently, all of these nutrients are in milk.

Over a 12-week period, the study monitored young women who did not use resistance-training exercise. Every day, two hours before exercising, the women were required not to eat or drink anything except water. Immediately after their exercise routine, one group consumed 500ml of fat free white milk; the other group consumed a similar-looking but sugar-based energy drink. The same drinks were consumed by each group one hour after exercising.

The training consisted of three types of exercise: pushing (e.g. bench press, chest fly), pulling (e.g. seated lateral pull down, abdominal exercises without weights), and leg exercises (e.g. leg press, seated two-leg hamstring curl). Training was monitored daily one on one by personal trainers to ensure proper technique.

"The women who drank milk gained barely any weight because what they gained in lean muscle they balanced out with a loss in fat" said Phillips. "Our data show that simple things like regular weightlifting exercise and milk consumption work to substantially improve women's body composition and health." Phillips' lab is now following this study up with a large clinical weight loss trial in women.

McMaster University

PENN RESEARCHERS ADD GENETIC DATA TO ARCHAEOLOGY AND LINGUISTICS TO GET PICTURE OF AFRICAN POPULATION HISTORY

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Genetic researchers from the University of Pennsylvania have combined data from existing archaeological and linguistic studies of Africa with human genetic data to shed light on the demographic history of the continent from which all human activity emerged.

The study reveals not just a clearer picture of the continent’s history but also the importance of having independent lines of evidence in the interpretation of genetic and genomic data in the reconstruction of population histories.

The study is published in the current issue of the Proceedings of the National Academy of Sciences.

The results, according to Penn geneticist Sarah Tishkoff, a Penn Integrates Knowledge professor with joint appointments in the schools of Medicine and Arts and Science, is that genetic variation in Africa is structured geographically, and to a lesser extent, linguistically. The findings are consistent with the notion that populations in close geographic proximity that speak linguistically similar languages are more likely to exchange genes.

Furthermore, genetic variation in Africa appears consistent with the natural, geographic barriers that limit gene flow. In particular, there are geographic, and therefore genetic, distinctions between northern African and sub-Saharan African populations due to the vast desert that limited migration.

“Focusing on particular exceptions to these broad patterns will enable us to discern and fully appreciate the complex population histories that have contributed to extant patterns of genetic variation,” said Tishkoff, the David and Lyn Silfen University Associate Professor. “Disentangling past population histories is a formidably complicated task that benefits from the synthesis of archaeological, linguistic and genetic data.”

With this three-pronged approach, a clearer picture emerges.

Archaeology provides insights into ancient technology and culture, affording a timeline for the emergence of innovations. Historical linguistic data complement the archaeological record by contributing an independent phylogenetic analysis of language relationships and providing clues about ancient population migration and admixture events. Genetic data provide an independent data source to understand the biological relationships among modern peoples and likely points of origin and expansion of their ancestors.

“The details of modern human demography are complex and not well understood, so we have taken a cross-disciplinary approach to highlight broad patterns of population history in Africa,” said Laura Scheinfeldt of the Department of Genetics at Penn’s School of Medicine.

Patterns will continue to emerge as geneticists from Penn and elsewhere further analyze a mountain of genetic data acquired from these understudied populations.

The development of sequencing and genotyping technologies has advanced at an unprecedented rate and is allowing for the genotyping of millions of single-nucleotide polymorphisms and the sequencing of millions of nucleotides across populations.

This data, coupled with computational methods for inferring demographic parameters and testing demographic models – for example, maximum likelihood and approximate Bayesian computation -- can refine our understanding of African past population histories.

“The incorporation of archaeological and linguistic data will be important for establishing testable hypotheses and elucidating the evolutionary processes or forces that have shaped the genomic landscape in Africa,” Tishkoff said.

Analyzing patterns of population structure and ancestry in Africans illuminates the history of human populations and is critical for undertaking medical genomic studies on a global scale. Understanding ancestry not only provides insight into historical migration patterns and human origins and provides a greater understanding of evolutionary forces, it also allows researchers to examine disease susceptibility and pharmacogenic response and to develop personalized drugs and treatments, a frontier in public health.

Tishkoff’s prior work with this data set revealed genomic diversity among African and African-American populations far more complex than originally thought, reflecting deep historical, cultural and linguistic impacts on gene flow among populations.

(Photo: Sarah Tishkoff)

University of Pennsylvania

STUDY FINDS 'LAW-LIKE' PATTERNS IN HUMAN PREFERENCE BEHAVIOR

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In a study appearing in the journal PLoS ONE, Massachusetts General Hospital (MGH) scientists describe finding mathematical patterns underlying the way individuals unconsciously distribute their preferences regarding approaching or avoiding objects in their environment. These patterns appear to meet the strict criteria used to determine whether something is a scientific law and, if confirmed in future studies, could potentially be used to guide diagnosis and treatment of psychiatric disorders.

"Law-like processes are important in science for their predictive value, and finding patterns in behavior that meet criteria for lawfulness is extremely rare," explains Hans Breiter, MD, principal investigator of the MGH Phenotype Genotype Project in Addiction and Mood Disorder (http://pgp.mgh.harvard.edu), who led the study. "The patterns we observed appear to describe the unconscious range of preference an individual has with a specificity suggestive of that of a fingerprint. We look forward to learning what other scientists find about these patterns." These patterns – which the authors group together under the name relative preference theory – incorporate features of several older theories of reward and aversion into a single theory.

The PLoS ONE study reports on the outcome of three sets of experiments. In each, healthy participants were presented with a series of images and could vary the amount of time they viewed each image by pressing the keys of a keypad. The first group of participants viewed a series of four human faces – average-looking male, average-looking female, attractive male and attractive female. The second group was presented with a series of photographs of images ranging from children, food, sports and musical instruments to war, disaster, and drug paraphernalia. The third group viewed four different images of food – two of normal appearing meals, one in which the food was abnormally colored, and one of raw, unprepared food – on two different days. For one viewing, participants were hungry, for the other, they had just eaten. Responses were measured by whether participants increased, decreased, or did nothing to change how long they viewed particular images.

All three experiments showed the same patterns in both groups and individuals, patterns that contained a set of features that varied between people. These patterns describe how groups and individuals make tradeoffs between approaching and avoiding items; how value is attributed to objects, which is linked assessments of other objects of the same type; and how individuals set limits to how strongly they will seek or avoid objects.

The authors note that these patterns incorporate aspects of three existing theories in reward/aversion: prospect theory, which includes the fact that people are more strongly motivated to avoid negative outcomes than to attain positive outcomes; the matching law, which describes how the rates of response to multiple stimuli are proportional to the amount of reward attributed to each stimulus; and alliesthesia, which notes that the value placed on something depends on whether it is perceived to be scarce – for example, hungry people place greater value on food than do those who have just eaten.

One of the key differences between relative preference theory (RPT) and earlier theories is that RPT evaluates preferences relating to the intrinsic value of items to an individual, rather than relating preferences to values set by external forces – such as how the overall economy sets the value of the dollar. The patterns observed in this study are similar at the individual and group levels – a relationship known as "scaling."

"In order for behavioral patterns to be considered law-like, they need to be described mathematically, recur in response to many types of stimuli, remain stable in the face of statistical noise, and potentially show scaling across different levels of measurement," explains Anne Blood, PhD, deputy principal investigator of the Phenotype Genotype Project, director of the MGH Mood and Motor Control Laboratory, and a co-author of the PLoS ONE report.

"Relative preference theory meets those requirements, but these observations need to be confirmed by other scientists," she adds. Other work by our team is examining how these RPT patterns are affected by depression and addiction, with the goal of developing RPT as an Internet tool for psychiatric diagnosis." Earlier studies by the MGH investigators also connected aspects of RPT to reward circuits in the brain, using magnetic resonance imaging, and to measures of genetic variability.

Massachusetts General Hospital

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