The study offers some insight into the evolution of modern human populations in small geographic areas as well as their initial spread throughout the world. For instance, the researchers were able to tease apart the genetic ancestries of eight different European groups and four groups in the Middle East. Their data set also supports an “out of Africa” model for the spread of the first modern humans, who colonized the rest of the world in stepping-stone fashion after leaving Africa. Genetic variation within populations accounts for most of human genetic diversity, the researchers confirm, but they also suggest that there is enough between-population variation to delineate and compare human populations on a fine scale.

Many animals possess protective markings to avoid predation, including patterns to reduce the risk of detection (camouflage), to indicate that the animal is toxic or inedible ('warning colours'), or to mimic another animal or object ('mimicry' and 'masquerade'). In addition, many creatures such as butterflies, moths, and fish possess two or more pairs of circular markings, often referred to as 'eyespots'. Many eyespots are effective in startling or intimidating predators, and can help to prevent or stop an attack. For the past 150 years it has been assumed that this is because they mimic the eyes of the predator's own enemies.

However, recent work by University of Cambridge zoologists, Martin Stevens, Chloe Hardman, and Claire Stubbins, indicates that this widely-held hypothesis has no experimental support.

Stevens, Hardman, and Stubbins tested the response of wild avian predators to artificial moths, created from waterproof paper. Specific patterns, such as intimidating eyespots of different shapes, sizes and number, and with different levels of eye mimicry, were printed on to the paper using a high quality printer. These 'moths' were then pinned to trees of various species at a height of one to three metres in the mixed deciduous Madingley Woods in Cambridgeshire, UK. Attached to each of the artificial moths was an edible mealworm as a temptation for woodland birds such as the blue tits, great tits, blackbirds, and house sparrows.

The zoologists discovered that artificial moths with circular markings survived no better than those with other conspicuous features and that the features of eyespots which most encouraged predators to avoid them are large size, a high number of spots, and conspicuousness in general.

As Dr Stevens explains, 'the birds were equally likely to avoid artificial moths with markings such as bars and squares as they were to avoid those with two eye-like markings. This leads us to conclude that eyespots work because they are highly conspicuous features, not because they mimic the eyes of the predators' own enemies. This suggests that circular markings on many real animals need not necessarily, as most accounts claim, mimic the eyes of other animals.'

Greenland's enormous ice sheet is home to enough ice to raise sea level by about 23 feet if the entire ice sheet were to melt into surrounding waters. Though the loss of the whole ice sheet is unlikely, loss from Greenland's ice mass has already contributed in part to 20th century sea level rise of about two millimeters per year, and future melt has the potential to impact people and economies across the globe. So NASA scientists used state-of-the-art NASA satellite technologies to explore the behavior of the ice sheet, revealing a relationship between changes at the surface and below. The new NASA study appears in the January issue of the quarterly Journal of Glaciology.

"The relationship between surface temperature and mass loss lends further credence to earlier work showing rapid response of the ice sheet to surface meltwater," said Dorothy Hall, a senior researcher in Cryospheric Sciences at NASA's Goddard Space Flight Center, in Greenbelt, Md., and lead author of the study.

A team led by Hall used temperature data captured each day from 2000 through 2006 from the Moderate Resolution Imaging Spectroradiometer (MODIS) instrument on NASA's Terra satellite. They measured changes in the surface temperature to within about one degree of accuracy from about 440 miles away in space. They also measured melt area within each of the six major drainage basins of the ice sheet to see whether melt has become more extensive and longer lasting, and to see how the various parts of the ice sheet are reacting to increasing air temperatures.

The team took their research at the ice sheet's surface a step further, becoming the first to pair the surface temperature data with satellite gravity data to investigate what internal ice changes occur as the surface melts. Geophysicist and co-author, Scott Luthcke, also of NASA Goddard, developed a mathematical solution, using gravity data from NASA's Gravity Recovery and Climate Experiment (GRACE) twin satellite system. "This solution has permitted greatly-improved detail in both time and space, allowing measurement of mass change at the low-elevation coastal regions of the ice sheet where most of the melting is occurring," said Luthcke.

The paired surface temperature and gravity data confirm a strong connection between melting on ice sheet surfaces in areas below 6,500 feet in elevation, and ice loss throughout the ice sheet's giant mass. The result led Hall's team to conclude that the start of surface melting triggers mass loss of ice over large areas of the ice sheet.

The beginning of mass loss is highly sensitive to even minor amounts of surface melt. Hall and her colleagues showed that when less than two percent of the lower reaches of the ice sheet begins to melt at the surface, mass loss of ice can result. For example, in 2004 and 2005, the GRACE satellites recorded the onset of rapid subsurface ice loss less than 15 days after surface melting was captured by the Terra satellite.

"We're seeing a close correspondence between the date that surface melting begins, and the date that mass loss of ice begins beneath the surface," Hall said. "This indicates that the meltwater from the surface must be traveling down to the base of the ice sheet -- through over a mile of ice -- very rapidly, where its presence allows the ice at the base to slide forward, speeding the flow of outlet glaciers that discharge icebergs and water into the surrounding ocean."

Hall underscores the importance of combining results from multiple NASA satellites to improve understanding of the ice sheet's behavior. "We find that when we look at results from different satellite sensors and those results agree, the confidence in the conclusions is very high," said Hall.

Hall and her colleagues believe that air temperature increases are responsible for increasing ice sheet surface temperatures and thus more-extensive surface melt. "If air temperatures continue rising over Greenland, surface melt will continue to play a large role in the overall loss of ice mass." She also noted that the team's detailed study using the high-resolution MODIS data show that various parts of the ice sheet are reacting differently to air temperature increases, perhaps reacting to different climate-driven forces. This is important because much of the southern coastal area of the ice sheet is already near the melting point (0 degrees Celsius) during the summer.

Changes in Greenland's ice sheet surface temperature have been measured by satellites dating back to 1981. "Earlier work has shown increasing surface temperatures from 1981 to the present," said Hall. "However, additional years with more accurate and finer resolution data now available using Terra's imager are providing more information on the surface temperature within individual basins on the ice sheet, and about trends in ice sheet surface temperature. Combining this data with data from GRACE, arms us with better tools to establish the relationship between surface melting and loss of ice mass."

The UK and Swiss team found that, contrary to common scientific predictions, dense plates tend to be held in the upper mantle, while younger and lighter plates sink more readily into the lower mantle.

The mantle is a zone underneath the Earth's crust encompassing its super hot molten core. It is divided into an upper and lower area, and is made up of a 2,900 km circumference of churning, viscous rock. It is constantly fed with new material from parts of tectonic plates which slide down from the surface into it.

The researchers' numerical models show how old, dense and relatively stiff plates tend to flatten upon reaching the upper-lower mantle boundary, 'draping' on top of it. Their models are helping to explain plate movements and earthquakes in the Western Pacific, where old plates currently sink below Tonga, the Mariana Islands and Japan.

By contrast, younger more malleable plates tend to bend and fold above the boundary of the lower mantle for tens of millions of years until they form a critical mass that can sink rapidly into the lower mantle.

When this mass moves into the lower mantle, the part of the plate still at the surface is pulled along at high speed. This explains why plate movements below Central and northern South America are much higher than expected for such young plates.

The scientists came to these conclusions by using a numerical model, originally used to show how buildings buckle and fold, which calculates the brittleness, stiffness and elasticity of tectonic plates alongside how the pressures and stresses inside the mantle would affect the plate on its downward descent.

They then compared the modelling with plate movement data. By comparing the two models, the team was able to build up a clear picture of how plates should move when stalled in the upper mantle and also show, for the first time, how tectonic plate rock is mixing within the mantle.

Commenting about the study, lead researcher Dr Saskia Goes, from Imperial College London's Department of Earth Science and Engineering, said:

"It is exciting to see direct evidence of plates transiting from the upper and lower mantle. This process has been predicted by models before, but no one has been able to link these predictions with observations, as we now do for plate motions."

When two tectonic plates collide, with one sliding below the other and sinking into mantle, it can lead to the formation of mountain belts, like the Andes, and island arcs, like Japan and, in some places, cause explosive volcanism and earthquakes. Dr Goes say more research is needed, but believes this study could potentially help scientists determine earthquake risks in parts of these zones where none have ever been recorded before.

"The speed with which the two plates converge, and the force with which they are pushed together, determine the size of the largest earthquakes and time between large tremors. Understanding what forces control the plate motions will ultimately help us determine the chances for large earthquakes in areas where plates converge, in places like the northern U.S., Java and northern Peru, but where no large earthquakes have been recorded in historic times," she adds.

A recent workshop on Biosupramolecular Chemistry organised by the European Science Foundation (ESF) strengthened Europe's platform for progress towards these goals by bringing together scientists in the relevant fields and identifying key research targets. The workshop also identified some applications close to fruition, including the engineering of bacteria to produce silks as strong for their thickness as spider webs. It has been a longstanding challenge to emulate the mechanical properties of spider silk, which combines stiffness and tensile strength with the ability to become elastic under high strains to protect against destruction. A recent project led by Thomas Scheibel at the Technical University of Munich is close to a solution that could have a host of practical applications ranging from biodegradable fishing line to body armour.

The artificial spider silk production exemplified the expertise and skills required for successful applications in biosupramolecular chemistry, in this case by combining genetic engineering with sophisticated micro-manipulation techniques to optimise production of the desired material. Firstly genes were inserted into the bacteria to produce proteins as similar as possible to spider silk. Then microfluidic approaches, dealing with fluids at very small scales, were used to fabricate the silk. Finally the mechanical properties were optimised further by substituting some of the amino acid components of the proteins.

Other applications of biosupramolecular chemistry are further off, but coming into range, according to the ESF workshop convenor, Professor Anthony Davis from Bristol University in the UK. But the most important aspect of the ESF workshop was the bringing together of scientists in two previously distinct fields, said Davis. "Our main aim was to get two groups of scientists talking to each other - the supramolecular chemists, and a group of biologists who might be termed 'biomolecular engineers'," said Davis. "Certainly this objective was fulfilled." Supramolecular chemists study and manipulate the interactions between molecules in general, while biomolecular engineers specialise in exploiting the large organic molecules found in Nature.

Biological macromolecules include proteins comprising amino acids, complex carbohydrates made from simpler sugar molecules, as well as both RNA and DNA made from nucleic acids. Unlike small molecules, these large constructions exhibit multiple chemical properties at different parts of their surface, which means that interactions between them depend on geometrical features. It is the geometrical arrangement of the component parts, as much as their chemical identity, that determines how a macromolecule will behave and interact with other molecules both large and small. Some molecules will only react or bind with certain others, often temporarily, on a "lock and key" basis determined by the relative shapes of the surface. Such transient associations between large molecules (supramolecules) are very important in biology, for example in the binding between antibodies and antigens in the immune response, and also between an enzyme and its substrate, i.e. the compound it is acting upon.

These looser interactions between large molecules are called non-covalent because they do not involve sharing of electrons, but instead exploit variations in electrical charge distribution in their vicinity. Since each individual bond is weak, non-covalent bonding relies on the collective strength of multiple bonds and is therefore only a viable mechanism for joining larger molecules together.

As well as being important for temporary binding, non-covalent bonding forces are also essential for maintaining the structure of large proteins, and for the DNA double helix, on a longer term basis, by holding the components together. This is a very complex subject given the huge number of combinations of components involved, and so a significant advance reported at the ESF Biosupramolecular conference by Andrei Lupas from the Max Planck Institute for Developmental Biology in Germany was of a dictionary representing proteins by motifs, that is smaller coherent arrangements of its constituent amino acids, derived from studying their evolutionary history. Lupas showed how such a dictionary could be used to derive evolutionary relationships between proteins. This could have great application in evolutionary biology and also for determining the role of proteins whose function is as yet largely unknown, as well as understanding diseases where protein interactions go wrong.

Having identified many promising avenues of research, the ESF workshop is likely to be followed up by further meetings, according to Davis."We hope to organise another meeting in 2009, and maybe keep going to create a regular series of symposia."

The attacks overcome a broad set of security measures called "disk encryption," which are meant to secure information stored in a computer's permanent memory. The researchers cracked several widely used technologies, including Microsoft's BitLocker, Apple's FileVault and Linux's dm-crypt, and described the attacks in a paper and video published on the Web Feb. 21.

The team reports that these attacks are likely to be effective at cracking many other disk encryption systems because these technologies have architectural features in common.

"We've broken disk encryption products in exactly the case when they seem to be most important these days: laptops that contain sensitive corporate data or personal information about business customers," said Alex Halderman, a Ph.D. candidate in Princeton's computer science department. "Unlike many security problems, this isn't a minor flaw; it is a fundamental limitation in the way these systems were designed."

The attack is particularly effective against computers that are turned on but are locked, such as laptops that are in a "sleep" or hibernation mode. One effective countermeasure is to turn a computer off entirely, though in some cases even this does not provide protection.

Halderman's Princeton collaborators included graduate students Nadia Heninger, William Clarkson, Joseph Calandrino, Ariel Feldman and Professor Edward Felten, the director of the Center for Information Technology Policy. The team also included Seth Schoen of the Electronic Frontier Foundation, William Paul of Wind River Systems and independent computer security researcher Jacob Appelbaum.

Felten said the findings demonstrate the risks associated with recent high-profile laptop thefts, including a Veterans Administration computer containing information on 26 million veterans and a University of California, Berkeley laptop that contained information on more than 98,000 graduate students and others. While it is widely believed that disk encryption would protect sensitive information in instances like these, the new research demonstrates that the information could easily be read even when data is encrypted.

"Disk encryption is often recommended as a magic bullet against the loss of private data on laptops," Felten said. "Our results show that disk encryption provides less protection than previously thought. Even encrypted data can be vulnerable if an intruder gets access to the laptop."

The new attacks exploit the fact that information stored in a computer's temporary working memory, or RAM, does not disappear immediately when a computer is shut off or when the memory chip is taken from the machine, as is commonly thought. Under normal circumstances, the data gradually decays over a period of several seconds to a minute. The process can be slowed considerably using simple techniques to cool the chips to low temperatures.

Disk encryption technologies rely on the use of secret keys -- essentially large random numbers -- to encode and protect information. Computers need these keys to access files stored on their own hard disks or other storage systems. Once an authorized user has typed in a password, computers typically store the keys in the temporary RAM so that protected information can be accessed regularly. The keys are meant to disappear as soon as the RAM chips lose power.

The team wrote programs that gained access to essential encryption information automatically after cutting power to machines and rebooting them. The method worked when the attackers had physical access to the computer and when they accessed it remotely over a computer network. The attack even worked when the encryption key had already started to decay, because the researchers were able to reconstruct it from multiple derivative keys that were also stored in memory.

In one extremely powerful version of the attack, they were able to obtain the correct encryption data even when the memory chip was physically removed from one computer and placed in another machine. After obtaining the encryption key, they could then easily access all information on the original machine.

"This method is extremely resistant to countermeasures that defensive programs on the original computer might try to take," Halderman said.

The attacks demonstrate the vulnerability of machines when they are in an active state, including "sleep mode" or the "screen lock" mode that laptops enter when their covers are shut. Even though the machines require a password to unlock the screen, the encryption keys are already located in the RAM, which provides an opportunity for attackers with malicious intent.

None of the attacks required specialized equipment. "I think we're going to see attackers doing things that people have previously though impractical or impossible," Appelbaum said.

The researchers were able to extend the life of the information in RAM by cooling it using readily available "canned air" keyboard dusting products. When turned upside down, these canisters spray very cold liquid. Discharging the cold liquid onto a memory chip, the researchers were able to lower the temperature of the memory to -50 degrees Celsius. This slowed the decay rates enough that an attacker who cut power for 10 minutes would still be able to recover 99.9 percent of the information in the RAM correctly.

"Hints of problems associated with computers retaining their temporary memory have appeared in the scientific literature, but this is the first systematic examination of the security implications," said Schoen.

The researchers posted the paper describing their findings on the website of Princeton's Center for Information Technology Policy. They submitted the paper for publication and it is currently undergoing review.

In the meantime, the researchers have contacted several manufacturers to make them aware of the vulnerability: Microsoft, which includes BitLocker in some versions of Windows Vista; Apple, which created FileVault; and the makers of dm-crypt and TrueCrypt, which are open-source products for Windows and Linux platforms.

"There's not much they can do at this point," Halderman said. "In the short term, they can warn their customers about the vulnerability and tell them to shut their computers down completely when traveling."

In the longer term, Halderman said new technologies may need to be designed that do not require the storing of encryption keys in the RAM, given its inherent vulnerability. The researchers plan to continue investigating this and other defenses against this new security threat.

Researchers at Rensselaer Polytechnic Institute have demonstrated that liquids embedded with nanoparticles show enhanced performance and stability when exposed to electric fields. The finding could lead to new types of miniature camera lenses, cell phone displays, and other microscale fluidic devices.

"This study may open up a new vista for using nanofluids in microscale and nanoscale actuator device applications," said Theodorian Borca-Tasciuc, a professor of mechanical engineering at Rensselaer, who led the research project.

The manipulation of small volumes of liquid is critical for fluidic digital display devices, optical devices, and microelectromechanical systems (MEMS) such as lab-on-chip analysis systems. Most research into such systems has been conducted with regular liquids, but not nanofluids, which are liquids embedded with different nanoparticles. Nanofluids have been shown to exhibit some attractive properties, including enhanced heat transfer and capillary properties, as compared with regular, or pure, liquids.

Borca-Tasciuc's team placed droplets of water-based solutions containing bismuth telluride nanoparticles onto a Teflon-coated silicon wafer. When an electric field was applied to the droplet, the researchers observed a strong change in the angle at which the droplet contacted the wafer. This change was much higher than that observed in liquids without the nanoparticles when tested under the same conditions.

"You use the same electrical field, but you get more change in shape with the nanofluid. We know the nanoparticles are critical in this process because without them the effect is much less strong," Borca-Tasciuc said.

The ability to easily change the contact angle of droplets of nanofluids has potential applications for efficiently moving liquids in microsystems, creating new methods of focusing lenses in miniature cameras, or cooling computer chips. Borca-Tasciuc also envisions the research enabling new fully integrated micro- and nanoscale heat transfer systems that will not require a pump. "Our proof of concept really opens up many new exciting possibilities," he said.

Borca-Tasciuc said his investigations into nanofluids are driven by sheer curiosity, and fostered by a strong interdisciplinary collaboration with Rensselaer Materials Science and Engineering Professor Ganapathiraman Ramanath.

"At first, we were curious to see what would happen if we introduced charged nanostructures - such as the ones we synthesize for exploring new cooling strategies in nanodevices - to the process of liquid wetting. But what started as a single, one-off experiment has now mushroomed into an exciting new research topic and expanded the scope of our collaboration," Ramanath said.

A new nationally representative study shows a downward trend in the rate of "cognitive impairment" -- the umbrella term for everything from significant memory loss to dementia and Alzheimer's disease -- among people aged 70 and older.

The prevalence of cognitive impairment in this age group went down by 3.5 percentage points between 1993 and 2002 -- from 12.2 percent to 8.7 percent, representing a difference of hundreds of thousands of people.

And while the reasons for this decline aren't yet fully known, the authors say today's older people are much likelier to have had more formal education, higher economic status, and better care for risk factors such as high blood pressure, high cholesterol and smoking that can jeopardize their brains.

In fact, among the 11,000 people in the study, those with more formal education and personal wealth were less likely to have cognitive problems.

Interestingly, the more-educated seniors who had cognitive impairment were more likely to die within two years. But the researchers say this may actually result from a protective effect of better education on a person's "cognitive reserve" -- their ability to sustain more insults to their brain before significant thinking problems arise.

The study is published today online in the journal Alzheimer's and Dementia by a team led by two University of Michigan Medical School physicians and their colleagues. The study is based on data from the Health and Retirement Study (HRS), a national survey of older Americans funded by the National Institute on Aging and based at the U-M Institute for Social Research (ISR).

Lead author Kenneth Langa, M.D., Ph.D., calls the findings good news for today's seniors, noting that the new data support recent theories of how brains can be protected and preserved.

"From these results, we can say that brain health among older Americans seems to have improved in the decade studied, and that education and wealth may be a big piece of the puzzle," says Langa, an associate professor of internal medicine who also holds appointments in ISR and the VA Ann Arbor Healthcare System.

"We know mental stimulation has an impact on the way a person's brain is 'wired,' and that education early in life likely helps build up a person's cognitive reserve. We also know cardiovascular health has a close link with brain health," he continues. "So what we may be seeing here is the accumulated effects of better education and better cardiovascular prevention among the people who were over age 70 in 2002, compared with those who were over age 70 in 1993."

The research team's analysis, in fact, suggests that about 40 percent of the decrease in cognitive impairment over the decade was likely due to the increase in education levels and personal wealth between the two groups of seniors studied at the two time points.

Langa notes that school attendance requirements, high school graduation rates and college or technical school enrollment rates all increased during the years when the adults in the study were children and young adults. In 1990, 53 percent of people over age 65 had a high school diploma, but by 2003 that proportion had increased to 72 percent. The rates of college-educated older people also rose, from 11 percent to 17 percent. In recent years, research has suggested that the more education a person receives early in life, the more his or her brain will be able to stay sharp later.

At the same time, the use of cholesterol-lowering drugs, blood pressure medications and other preventive cardiovascular medications and strategies increased dramatically in the 1990s. These factors may have helped protect seniors' brain function by decreasing the incidence of vascular dementia - cognitive problems brought on by mini-strokes, strokes and decreased blood flow to and within the brain due to "hardened" or clogged arteries.

Improved cardiovascular health, combined with more education and wealth, may also help explain why death rates within two years were highest for those with CI who were highly educated. A good cognitive reserve can protect brains from minor insults, keeping them intact longer for thinking and memory by finding a way around a damaged area. But then when a major crisis, such as a stroke, occurs, that remaining reserve may be depleted quickly and death can come more quickly.

Richard Suzman, Ph.D., director of the Social and Behavioral Research Program at the NIA, which partially funded the study, notes that "the trend toward improved cognitive status is consistent with a dramatic decline in chronic disability among older Americans over the past two decades, especially in the areas of everyday function that depend on cognition. It will be important to pinpoint the influence of factors such as increased education, exercise, medications, cardiovascular health, and lifestyle to discover which ones contributed to this trend and to also replicate the findings in other studies."

The study divides individuals into four categories - no cognitive impairment, and mild, moderate and severe CI -- based on their performance on a standardized cognitive test.

But the authors caution that they could not tell which patients had true dementia, which requires additional clinical information, or Alzheimer's disease, which can be positively identified only on autopsy. However, the cutoff points for the different categories of CI were based on prior studies and on data from a new sub-study of the HRS designed to identify dementia specifically.

While the new study shows a decline in CI prevalence over time, the researchers note that the gains made in the 1990s and early 2000s might be offset by the damage that could result if the current epidemic of type 2 diabetes keeps growing among the elderly and if current middle-aged and younger people stick with unhealthy eating and exercise habits that lead to unhealthy weights and blood pressures.

Even if the proportion of older adults with CI keeps declining, the total number of older adults with CI and dementia will likely increase significantly due to the huge increase in the size of the over-65 population as the Baby Boom generation enters older age in the coming decades.

"This demographic reality will continue to make combating Alzheimer's disease and other types of dementia a top public health priority," said Allison Rosen, M.D., Sc.D., assistant professor of internal medicine at U-M and the Ann Arbor VA, and co-author of the study.

Meanwhile, they say, today's older Americans should not rest on their laurels - but instead should be pursuing activities that can keep their minds sharp and their cardiovascular risk low. From crossword puzzles and volunteer activities to blood pressure medications, today's seniors can work to boost their brain health now and prevent decline later.

"More and more studies suggest that walking and other types of physical activity are important for preventing cognitive and memory decline," says co-author Eric Larson, M.D., M.P.H., executive director of the Group Health Center for Health Studies in Seattle, where he has led many studies of the relationship between physical activity and brain health.

"The evidence seems to be showing that staying mentally engaged with the world in any fashion -- reading, talking with friends, going to church, going to movies - is also likely to help reduce your risk down the road," says Langa.

New research by University of Calgary, Faculty of Kinesiology researcher Dr. Tim Welsh says that regardless of their intentions, having an individual working on a different task - within your field of vision - could be enough to slow down your performance.

"Imagine a situation like a complex assembly line," said Welsh If you are doing a particular task and the person across from you is doing a different task, you'll be slowed down regardless of their performance."

The reason for this is a built-in response-interpretation mechanism that is hard-wired into our central nervous systems. If we see someone performing a task we automatically imagine ourselves performing that task. This behaviour is part of our mirror neuron system.

The findings from Welsh's latest work on the topic are founding a paper titled "Seeing vs. believing: Is believing sufficient to activate the processes of response co-representation?" published in the December, 2007 issue of the Journal of Human Movement Science.

His set-up involved an individual performing a simple computer task alone, then with a partner performing a different but related task, and alone again after being told that the partner was going to continue to perform the task in another room.

"When an individual could see their partner actually performing the task, the partner's performance interfered with their own performance, causing them to perform more slowly," Welsh explained. "When the partner left the room and the individual could only see the results of the partner's action - not the action itself - the interference effect was no longer observed and performance improved. We believe it's because the individual no longer represented - or modeled - their partners' actions, even though they could see the results of these actions."

Welsh says his research could have implications for some industrial work settings.

"In a situation where speed and accuracy in performing a certain task are important, I think an argument could be made for a work setting in which people work in isolation - or at least with people who doing very similar tasks," he said. "That will remove the involuntary modeling of another's behaviour, potentially improving speed and likely accuracy."

At least, that's what is suggested in a paper published today in the journal Human Brain Mapping authored by a group of professors in advertising and communication and neuroscience at the University of Florida.

The seven researchers used sophisticated brain-scanning technology to record how subjects' brains responded to television advertisements, while simultaneously collecting the subjects' reported impressions of the ads. By comparing the two resulting data sets, they say, they pinned down specific locations in the brain as the seat of many familiar emotions that ripple throughout it. The feat is another step toward gauging how people feel directly through functional magnetic resonance imaging, or fMRI, and other brain-scanning technology - without relying on what they claim to be feeling, the researchers say.

"We are getting to the heart of the matter by really showing this process in the brain, and how it works," said Jon Morris, a professor of advertising and communications and lead author of the article. "We feel that this can be used to find out what people really feel about something, whether an advertisement or any other stimulus."

Using MRI or fMRI - the former creates internal images of the brain, while the latter tracks blood flow within the brain - to test consumers' responses to advertisements or other stimuli is not new. But according to the study, much of the previous research has found that, for example, responses to pleasant or unpleasant stimuli occurred throughout many regions of the brain, rather than in one specific location. As a result, the technique seemed of limited usefulness: Analysts could gauge only general response activity, not specific emotions.

"There was no real key happiness center, no key sad center, no key love center," Morris said. "What you got was brain activity, in general."

The UF team used an elaborate experimental system, currently under consideration for a patent, to try to narrow the search.

Because metallic or magnetic material can cause fMRI machines to malfunction, no television or sound equipment was allowed in the cylinder-like fMRI machines into which people are inserted. As a result, the researchers deployed a series of projections and mirrors to allow subjects to watch commercials. Sound reached them via tiny plastic pipes, similar to headphones once common on airplanes, rather than wires.

The 12 subjects also had hand-held devices that enabled them to report their feelings via a system called "Attitude Self Assessment Manikins" a version of the UF-developed Self-Assessment Manikin, or "SAM." The "AdSAM" system lets viewers describe how they are feeling and the strength of those feelings by clicking on projections of people-like icons, a process that Morris characterized as more direct than translating feelings into words. Morris uses the AdSAM system in his work as a consultant to advertisers.

Researchers showed the subjects three television commercials advertising Coke, Evian and Gatorade, respectively, as well as an anti-fur commercial and an ad promoting teaching. To guard against preconditioned response, all the ads were at least 10 years old.

The researchers compared the activity in the subjects' brains as recorded by the fMRI machines to their reported responses on the AdSAM system. With several of the ads, they found the fMRI data and response converged on two of three measures - pleasure-displeasure and excitement-calm. Under the AdSAM system, these "bipolar dimensions" - as well as a third, dominance-submissiveness - form the foundation for more specific emotions.

Where the researchers compared the AdSAM data on pleasure-displeasure and excitement-calm to the fMRI data, they found simultaneous spikes in four different and highly localized areas of the brain. According to the article, the findings suggest "that human emotions are multidimensional, and that self-report techniques ... correspond to a specific task but different functional regions of the brain."

Morris said the results are preliminary, but that follow-up studies could allow researchers to hone in on people's feelings with great specificity. That would be attractive to advertisers for obvious reasons, but psychologists might also find the techniques useful.

"Back in the 1950s, three psychologists found that all emotions could be measured in three dimensions," Morris said. "Now we have learned that this may be more than a method for reporting emotion. It may actually reflect the way creatures on this planet function - possibly exposing a direct link to predicting behavior."

Researchers are testing oral contraceptives - used in much the same way as in humans - and the results are promising, says Duane Kraemer, a professor in veterinary physiology and pharmacology and a world leader in embryo transfer who has been involved in cloning four different species in recent years.

Kraemer, one of the pill's creators, and other members of the research team are testing the contraceptive for use on wild animals, but the applications could most likely be used in pets, he believes.

"No one method will be useful in all situations," he stresses.

"This approach inhibits maturation of the egg and therefore prevents fertilization. The animals continue to cycle, so it will not yet be ideal for many pet owners. But there is an advantage for use in wild and feral animals."

Kraemer says the research team has recently started tests on domestic models for predators - animals such as feral pigs and cougars - but if successful, it could be used on a wide variety of animals, including dogs and cats, he explains. The team also has submitted grant applications for similar projects on coyotes and deer.

"A spinoff of this contraceptive could probably be used on many different species," he adds.

The $90,000 project is being funded by the U.S. Department of Agriculture and private donations.

The pill works by inhibiting the maturation of the egg, not the entire cycle, Kraemer says. The technical name for the drug is called a phosphodiesterase 3 inhibitor, and it is one member of a family of drugs being tested.

Similar compounds have been tested in laboratories elsewhere in mice and monkeys, and similar results have been obtained by in vitro (in laboratory) methods in cattle and humans.

The compound can be mixed with animal feed and must be eaten daily during the critical time. It may also be encapsulated to decrease the frequency it has to be consumed, Kraemer says.

"We believe we are the first to test this compound for this specific purpose," Kraemer notes. "We're trying new uses for this previously approved compound."

When perfected, the pill could eventually be used as an oral contraceptive for pets, but that may be a bit in the future, Kraemer says. In dogs, for example, the ovulation process is especially complex, but researchers are confident such a birth control pill can one day be successfully developed.

The need is apparent: According to the American Humane Society, about 7 million dogs and cats are euthanized each year at animal shelters. One female cat can lead to the production of 420,000 offspring in her lifetime.

In Texas, feral hogs have become a severe nuisance to farmers and ranchers, and the state has an estimated 3-4 million feral hogs, by far the most in the country. Deer are also becoming a problem to more communities each year because of overpopulation of deer herds.

Other species such as coyotes and even wild horses also need sufficient management control, experts note.

"The need for such an animal contraceptive is certainly there," Kraemer adds.

"We are confident we can develop this pill in the not too distant future, but we still have plenty of tests to complete. It's an exciting and much-needed project, but more funds will be needed, especially since deer and wild pigs are consumed by humans. One of the more interesting challenges will be to develop methods for feeding it to the target animals without affecting other species."

The technology uses data mining techniques to scour email and build up a picture of social network interactions. The technology could prevent serious security breaches, sabotage, and even terrorist activity.

Gilbert Peterson and colleagues at the Air Force Institute of Technology at Wright Patterson AFB, in Ohio are developing technology that could help any organization sniff out insider threats by analyzing email activity or find individuals among potentially tens of thousands of employees with latent interests in sensitive topics. The same technology might also be used to spot individuals who feel alienated within the organization as well as unraveling any worrying changes in their social network interactions.

Security efforts have tended to focus on outside electronic threats, explain Peterson and colleagues. However, they point out that it is insiders that pose the greatest threat to an organization. Insiders are members of the organization who may have access to sensitive information for legitimate purposes but who could betray that trust for illegitimate reasons.

An aggrieved employee, saboteur, or terrorist infiltrator with access to such information could potentially cause great harm. Spotting the potential for an insider attack quickly without recourse to huge numbers of investigators is essential to preventing such an occurrence.

Peterson and his colleagues have developed an approach to assist investigators looking for such insider threats based on an extended version of Probabilistic Latent Semantic Indexing (PLSI). This extended technology can discern employees’ interests from e-mail and create a social network graph showing their various interactions.

The researchers explain that individuals who have shown an interest in a sensitive topic but who have never communicated to others within the organization on this subject are often the most likely to be an insider threat. The software can reveal those people either with a secret interest in that topic or who may feel alienated from the organization and so communicate their interest in it only to those outside the organization.

Another important signal of alienation or a potential problem is a shift in the connections between an individual and others within the organization. If an individual suddenly stops communicating or socializing with others with whom they have previously had frequent contact, then the technology could alert investigators to such changes.

The research team has tested their approach on the archived body of messages from the liquidated Enron company e-mail system. Their PLSI results unearthed several individuals who represented potential insider threats. However, it should be noted that the individuals under indictment are the bosses of the organization. It was the core of the organization that is responsible for the illegal behavior, says Peterson. The team points out that while internet activity was not available for Enron, it is generally available from the same sources that supply e-mail history logs and so could be used to search more widely for insider threats. He adds that by turning the domain 'on its ear' in effect, the identify of the whistleblower could be revealed.

For a bird's-eye view of human impacts on the Earth, scientists can study satellite images showing the continents in mottled colors that correspond to vegetation, desertification or human habitation. But those photos cannot tell them much about the big blue mystery, oceans, and how human activities affect them.

Now, a team of researchers, including a Stanford University scientist, has constructed the first global map of human influences on marine ecosystems by gathering and interpreting massive amounts of data from the professional literature and from researchers around the world. This study suggests that about 41 percent of oceans bear a serious human "footprint " and that few blue spots on our planet are likely pristine.

"A series of papers have highlighted the role humans are having on the degradation of the oceans, through specific activities," said Fiorenza Micheli, an associate professor of biology at Stanford. "It's timely to put it all together-to show how all the different effects sum up."

Micheli, one of the principal investigators, is scheduled to discuss the project during a press briefing scheduled for 1 p.m. Thursday, Feb. 14, at the American Association for the Advancement of Science (AAAS) annual meeting in Boston. She also will discuss the work, which is described in a paper in the Feb. 15 issue of Science, during a seminar at 8:45 a.m. Friday, Feb. 15.

Micheli said maps of human influence should "guide ocean zoning and management of coastal waters." Scientists increasingly advocate zoning oceans to protect the hidden ecosystems below the surface. "By seeing where different activities occur and whether they occur in sensitive ecosystems, we can design management strategies aimed at shifting activities away from the most sensitive areas," Micheli said.

The researchers compiled data on 17 different human impacts to oceans, including fishing, coastal development, fertilizer runoff and pollution from shipping traffic. Previous studies have worked on a smaller scale, or have focused on only one ecosystem or human activity, examining a single piece of the global puzzle. To make the picture complete, Micheli and her colleagues built a global map detailing how these numerous human impacts would add up and affect 20 types of ecosystems.

"For some human activities, we have global data, like commercial fisheries catches," Micheli said. "For others, we developed models to estimate global impacts." The team consulted marine scientists and dug into years of literature describing human effects on different ecosystems, such as coral reefs, rocky reefs and deep, open waters. They developed a system to quantify how powerful each human influence is, and how fragile each ecosystem is. To map the damage, Micheli and her colleagues divided the ocean into 1-square-kilometer "cells." They determined the impact to each cell by what human activities have touched it, how forceful that touch has been and which ecosystems are there.

Their results suggest that coral reefs are in trouble; nearly half have taken a hard human punch. Other spots of concern include seagrass beds, mangrove forests in estuaries, seamounts, rocky reefs and continental shelves. Soft-bottom shallow and deep ecosystems, as well as the open ocean, fared best, though even they were not pristine in a majority of locations.

The study also shows that human influence runs deepest in the North Sea, the South and East China Seas, the Caribbean Sea, the Mediterranean Sea, the Red Sea, the Persian Gulf, the Bering Sea, along the Eastern Coast of North America and in much of the western Pacific. The oceans around the Artic and Antarctic poles have been affected very little, but the dwindling polar ice sheets will leave them vulnerable in the future, research suggests. Very limited impacts are also seen around northern Australia, in areas across the western-central Pacific and in small areas scattered along the coasts of South America and Africa. These estimates of human impact are probably optimistic, Micheli said. The study did not account for historical impacts to the oceans whose traces might still linger, and it did not include all possible impacts to marine ecosystems, only the 17 for which data were available or could be modeled.

The worldwide impact map is a scaffold, which should be filled in with on-the-ground research, Micheli said. "Globally, it's important to see what the most impacted areas are and where are the last wildernesses," she said. "Our results and approach, augmented with additional local information, can also inform management at a local and regional scale. Looking at the data globally, some information is lost."

Micheli and her colleagues already are fleshing out one corner of their modeled world by gathering empirical data for marine ecosystems of the California Current region; the current flows south from Alaska along the coasts of Washington, Oregon, California and Baja California. When that project is complete, they will present their findings to environmental agencies, including the administrations of the marine sanctuaries off the western U.S. coast.

Micheli also will present a talk titled "Trophic Responses in Marine Reserves: Lessons from Temperate and Tropical Ecosystems" on Saturday, Feb. 16, in a symposium starting at 1:45 p.m. at the AAAS meeting. Focusing on how marine food webs recover in marine reserves, she will present examples of studies from tropical and temperate reef ecosystems. Of 920 species surveyed in 31 reserves, about 60 percent benefited from the reserves, Micheli said. She said these reserves have "an effect, not on just individual species but also on the structure of the whole food web, with greater abundances of top predators in reserves than unprotected areas." Marine reserves were first implemented in the 1960s, but Micheli said many have been established in the past decade, and studies are now answering long-standing questions about how well they work.

The 16-inch, 10-pound ancient frog, scientifically named Beelzebufo, or devil frog, links a group of frogs that lived 65 to 70 million years ago with frogs living today in South America.

Discovery of the voracious predatory fossil frog -- reported on-line this week in the journal Proceedings of the National Academy of Sciences (PNAS) -- is significant in that it may provide direct evidence of a one-time land connection between Madagascar, the largest island off Africa's southeast coast, and South America.

To identify Beelzebufo and determine its relationship to other frogs, Krause collaborated with fossil frog experts Susan Evans, lead author of the PNAS article, and Marc Jones of the University College London. The authors concluded that the new frog represents the first known occurrence of a fossil group in Madagascar with living representatives in South America.

"Beelzebufo appears to be a very close relative of a group of South American frogs known as 'ceratophyrines,' or 'pac-man' frogs, because of their immense mouths," said Krause, whose research was funded by the National Science Foundation (NSF). The ceratophryines are known to camouflage themselves in their surroundings, then ambush predators.

"The finding presents a real puzzle biogeographically, particularly because of the poor fossil record of frogs on southern continents," said Krause. "We're asking ourselves, 'What's a 'South American' frog doing half-way around the world, in Madagascar?'"

He said that because frogs "are not adept at dispersal across marine barriers, and since the few fossil frogs that are known from the Late Cretaceous in Africa are unrelated to Beelzebufo, one possibility is that there was a land connection between South America and Madagascar during that period."

Some geoscientists have suggested a lingering physical link between South America and Madagascar during the Late Cretaceous Period -- a link involving Antarctica. Antarctica in the Late Cretaceous was much warmer than it is today.

"The occurrence of this frog in Madagascar and its relatives' existence in South America provides strong evidence that the supercontinent Gondwana 'disassembled' during the latest part of the Cretaceous," said Richard Lane, program director in NSF's Division of Earth Sciences.

Krause and colleagues have hypothesized this connection based on previous discoveries of sauropod and theropod dinosaurs, crocodiles and mammals in Madagascar that were very closely related to forms in South America.

Beelzebufo is one of the largest frogs on record and was perhaps the largest frog ever to exist. The size and robustness of its bones and its relatedness to the rotund South American forms indicates it was also probably the heaviest frog to exist.

The size, girth, appearance, and predatory nature of the frog prompted its discoverers to call it the "armored frog from hell." They derived the genus name from the Greek word for devil (Beelzebub) and the Latin word for toad (bufo). The species name, ampinga, means "shield."

The largest living frog today is the goliath frog of West Africa, which attains lengths of 12.5 inches and weights of 7.2 pounds. The largest frog alive on Madagascar today, at just over four inches long, "would have been a nice hors d'oeuvre for Beelzebufo," Krause said.

Since the discovery of the first bones found in northwestern Madagascar in 1993, Krause and his team have gathered some 75 fossil fragments of Beelzebufo. Through the accumulation of these fossils, the team has been able to reconstruct the frog's skeleton, including nearly the entire skull.

Not only was the frog huge, it was powerful in design, had a protective shield, an extremely wide mouth and powerful jaws. These features made Beelzebufo capable of killing lizards and other small vertebrates, perhaps even hatchling dinosaurs.

It's hard to study a creature when you only catch fleeting glimpses of it. Up until recently, that was one of the big stumbling blocks for marine biologists and ecologists, but advances in electronic tracking technology have allowed them to peer farther across, and deeper under, the surface of the oceans than ever before.

Researchers from several institutions, including Stanford University, have joined their efforts in a Census of Marine Life project called Tagging of Pacific Predators (TOPP). Since the project began in 1999, they have attached more than 3,000 tags to sharks, seals, whales, tunas, squids, turtles, albatross and more. For the first time, these TOPP researchers are getting a glimpse of a pelagic ecosystem from the California Current to the North Pacific at daily, seasonal and yearly time scales.

Along with the white shark, the TOPP researchers also have been studying the routes and habits of two cousins of the white shark: the salmon shark, whose range extends from the glaciers of Alaska down to Baja California, where it crosses over the white sharks' territory along the continental coast, and the mako shark, which resides along the continental shelf off California. The team also has tagged thresher sharks and blue sharks.

Sharks are a vital part of oceanic ecosystems. As the top predators in the food chain, they regulate the populations of the species below them. If shark populations get in trouble, it can trigger a cascading effect all the way down the food chain. The TOPP team has used several distinct tag technologies to get a simultaneous view of how these sharks divide up the ocean turf.

Salvador Jorgensen, a postdoctoral researcher at Stanford University's Hopkins Marine Station and the Monterey Bay Aquarium, is part of the group that has been tagging and monitoring white sharks, more popularly known as great white sharks.

Jorgensen is scheduled to discuss the team's work during a symposium titled "Will Too Few Jaws Take Too Big a Bite" The Importance of Sharks to Ocean Ecosystems," beginning at 10:30 a.m. Sunday, Feb. 17, at the American Association for the Advancement of Science (AAAS) annual meeting in Boston. He also will discuss the work at a press briefing about the symposium scheduled for 3 p.m. that afternoon.

What they have found has opened up a whole new vista in the white shark's world. It turns out white sharks are quite the sightseers.

Jorgensen and his colleagues have tagged more than 100 white sharks along the central California coast. Home to numerous seal and sea lion rookeries, the area along the continental shelf is practically one long lunch counter for the white sharks. But in spite of the fine dining available there, the sharks exhibit an urge to roam.

Through tracking the tagged sharks, the TOPP team has found two distant destinations that the sharks favor, both of which they visit on a regular, annual travel timetable. Each winter the white sharks head out from the California coast, with some going to the Hawaiian Islands. Most, however, head to another hotspot, out in the middle of the Pacific Ocean. This second location is roughly 1,300 miles from the mainland-about half the distance to Hawaii-and a few hundred miles to the south of the direct route to the islands. Dubbed "the white shark café" by the researchers, just what the attraction is out there remains something of a puzzle. But what is clear is that all the sharks that summer along the California coast show remarkable fidelity; when they return to the mainland, they head for the same local neighborhoods that they favor every summer.

"These animals appear again and again at very specific areas," Jorgensen said. Despite the sharks' ability to move through the ocean to wherever they please, they stick to consistent routes and destinations. It is a striking finding, because white sharks are found off South Africa and Australia, in addition to the West Coast of North America, but what the TOPP team and other researchers have found is that the populations do not appear to mix. New data presented by the TOPP team indicate that even between Pacific Ocean basin populations there are genetic differences. This means that white sharks, at least the females, have maintained long term isolation in the Eastern Pacific.

"This is really important in terms of management, so that management can focus on these population units," Jorgensen said. "And this really sets the stage for us to census the population, now that we know it is a confined population in the eastern Pacific."

There is another group of white sharks that tend to congregate near Guadalupe Island, offshore from Baja California, south of the California population that the TOPP team has been studying, but it is not yet clear whether they are distinct from the central California group.

Most of the tags used by the TOPP researchers have been electronic tags that are monitored by satellite. Those tags provide location data when the sharks are on the high seas. The other tags are acoustic tags; sensors installed along the California coast pick up the signal whenever one of the tagged sharks swims by.

The TOPP program maintains a live access server that gives regular updates on the locations of the sharks that have been tagged. "My favorite activity is to wake up and check where the sharks are," said Barbara Block, the Charles and Elizabeth Prothro Professor in Marine Sciences at Stanford University's Hopkins Marine Station.

A new study that examines the number of engineering graduates coming out of our nation's engineering schools reveals a mixed picture of how prepared each state is for meeting the need for high-tech workers in the coming years.

Greg Schuckman, Assistant Vice President of University Relations and Director of Federal Relations and Research Advancement at the University of Central Florida, authored the study after revisiting data that he had analyzed in 1998 while working for the American Association of Engineering Societies (AAES) in Washington, DC. "Over the past 20 years, the number of students earning bachelors degrees in engineering has declined by almost 3 percent nationally," says Schuckman. "While that statistic may not seem significant by itself, the decline comes at a time when the number of students receiving bachelors degrees overall in the United States has increased by more than 50 percent."

John Brooks Slaughter, Ph.D., P.E., President and CEO?of the National Action Council for Minorities in Engineering, Inc. (NACME) noted last year that, "Huge changes have occurred in our economy largely as a result of globalization and technological innovation. Manufacturing has declined while the information age requires more professional and high-tech skills from employees. It is estimated that more than a half million engineers will be needed over the next decade to replace those who retire and that at least that many new engineers will be needed to fill the demand that will exist at the end of that period. We find ourselves importing talent and exporting jobs, not just because it is less expensive to have the work performed by lower-wage skilled workers in developing countries but also because we do not produce enough native-born, well-qualified scientists and engineers in our nation's colleges and universities."

Overall, twenty states increased their production of engineering graduates while 30 states and the District of Columbia decreased between 1986 and 2006.

"The space race was won in no small part through the engineering prowess of young students who were emboldened by the launch of Sputnik." says Schuckman. "While there is no definitive 'Sputnik moment' today, the competitiveness challenge that nations such as China, India, and others pose to the U.S. is as real a threat to our way of life today as Sputnik was 50 years ago."

Sam Palmisano, President and CEO of the IBM Corporation and Honorary Co-Chair of the 2008 National Engineers Week, summed up the challenge: "We need to recruit engineers from a broad cross-section of society, and this means reaching out to populations that are underrepresented in the engineering professions. Only 11 percent in the United States today are women, 3 percent Blacks and 4 percent Hispanics. These statistics reveal a large reservoir of potential engineers that is not being fully tapped. I encourage you to use the E-Week 2008 campaign to inspire the next generation of engineers, reaching out to a diverse cross section of youngsters, independent of gender, ethnicity, or physical disability. And finally, let's engage the general public to see, touch and embrace engineering, the source of so much of the prosperity, growth and hope that are reaching more and more people around the globe."

A multidisciplinary research team from the Departments of Biology and Chemistry at York have been studying how bacteria capture the molecule used to make the "cloak", called sialic acid.

The researchers have now discovered an enzymatic activity that helps in the more efficient capture of sialic acids released from our cell surfaces. As well as using the sialic acid to make the "invisibility cloak" other bacteria use similar methods to capture sialic acid as a simple food source, so are literally eating us from the inside!

The research is published in the latest issue of the Journal of Biological Chemistry.

Dr Gavin Thomas, of the Department of Biology, who led the research said: "This novel enzyme, as well as other steps required for the formation of the 'invisibility cloak' that we have discovered in York, now offers the chance to develop novel antimicrobials against these bacteria."

The work, which was funded by the Biotechnology and Biological Sciences Research Council (BBSRC), was undertaken by Dr. Emmanuele Severi (Biology - Thomas lab) in collaboration with Dr. Jennifer Potts (Biology and Chemistry), Dr Andrew Leech (Biology) and Professor Keith Wilson and Dr Axel Müller (Chemistry and York Structural Biology Laboratory).

The team used the Centre for Magnetic Resonance based in the Department of Chemistry, and the Technology Facility in the Department of Biology.

Latino children, who make up one-fifth of the U.S. child population, also have the highest obesity and overweight rates of all ethnic groups.

A report on the study, funded by the Robert Wood Johnson Foundation, was released online ahead of print in the Journal of Pediatrics.

"While we cannot blame overweight and obesity solely on TV commercials, there is solid evidence that children exposed to such messages tend to have unhealthy diets and to be overweight," says study lead investigator Darcy Thompson, M.D., M.P.H., a pediatrician at Hopkins Children's.

Past research among English-speaking children has shown that TV ads influence food preferences, particularly among the more impressionable young viewers.

Researchers reviewed 60 hours of programming airing between 3 p.m. and 9 p.m., heavy viewing hours for school-age children, on Univision and Telemundo, the two largest Spanish-language channels in the United States, reaching 99 percent and 93 percent of U.S. Latino households, respectively. Univision content was recorded from its national network cable in Seattle, and Telemundo content was recorded on a local carrier in Tucson, Ariz.

Tallying two or three food commercials each hour, the investigators said one-third specifically targeted children. Nearly half of all food commercials featured fast food, and more than half of all drink commercials promoted soda and drinks with high sugar content.

To counter the effects of food commercials, the researchers suggest, young children should be restricted to two hours a day or less of TV viewing and parents should talk to them about healthy diet and food choices. Children younger than 2 should not be allowed to watch any TV, pediatricians advise.

Other recommendations:

* Pediatricians caring for Latino children should be aware of their patients' heavy exposure to food ads and the possible effects.

* Public health officials should urge policy makers to limit food advertising to children, something many European countries are already doing.

"We found that where the birds go in their first winter, a process called natal dispersal, may determine the area, within several hundred miles, where they will breed over their lifetime," said Colin Studds, the University of Maryland PhD student who led [C1]the study. "An important factor appears to be the availability of water in their winter habitat."

The study appears in the February 18 issue of the Proceedings of the National Academy of Sciences. Co-authors of the paper are Peter Marra, of the Smithsonian Migratory Bird Center, and Kurt Kyser, of Queen's University, Ontario.

The American redstart is a warbler that migrates between breeding grounds in North America and winter spots in the Caribbean and South America. The team studied redstarts that winter over in Jamaica in two very different habitats that are right next to each other.

"One is a very lush mangrove with water and lots of insects for the birds to eat," Studds said. "Right beside it is a fairly harsh dry habitat, with very little water and not as good a food supply."

By studying the tail feathers of young redstarts between their first and subsequent summer nestings, the researchers found that the difference between wintering over in the lush mangrove or in the drier real estate next door may help set off a lifelong cycle of habitat location.

The mangrove birds leave earlier to breed, don't migrate as far north, and return to the water and food-rich mangrove. The birds from the lower rent district leave later for breeding grounds, must migrate farther north, and when they return to Jamaica, the mangrove is occupied and they are, once again, scrabbling in the scrub.

The cycle begins for the young redstart when it leaves its northern birthplace and migrates south for its first winter. Studds' team measured a hydrogen isotope called deuterium, found in the fledglings' tail feathers, an indicator of where the bird was hatched and, in subsequent summers, where it breeds. "Once the isotope in the feathers, it doesn't change," Studds says.

The isotope measurement showed that the birds that had the good fortune to spend their first winter in the mangrove stayed in the good life, while the birds that had wintered in the dry area usually had a harder life year round.

"The birds in the lush mangrove have access to more insects, which helps them maintain their weight," says Studds. "This helps them to leave sooner on spring migration and arrive sooner in the more southern breeding areas, where spring is just beginning,"

The birds in the dry area, however, need about another seven days to bulk up, "a long time," says Studds. The later start means that by the time they head north, the southern breeding habitat is already taken and the birds have to keep flying, some as far north as Canada, to find the right spring conditions for breeding.

Where a redstart spends its first winter also seems to be determined, in part, by its ability hold its territory. "About seventy percent of the birds in the mangrove are males," Studds says. "In the harsh habitat, they were mostly females and young males."

While these redstarts appear to be thriving today, the research team says their findings point to the need to consider conservation measures in the winter habitat.

"The models predict increasing drought in the Caribbean," says Studds. "Rain is very important to these birds. If their winter habitat gets drier and their departure dates get later, populations in southern areas could see big declines."

The team next hopes next to research the redstart's breeding grounds. "By analyzing isotopes in feathers of redstarts arriving to breed in Maryland, we plan to ask whether birds dispersing here from northern areas spent the winter in different habitats compared to birds dispersing from southern areas," Studds says.

While the new technique has yet to be tested in clinical trials, it may someday allow doctors to screen people for certain diseases simply by sampling their breath, according to the research team from JILA, a joint institute of NIST and CU-Boulder. "This technique can give a broad picture of many different molecules in the breath all at once," said Jun Ye, a fellow of JILA and NIST who led the research.

CU-Boulder graduate research assistant Michael Thorpe, Ye, CU-Boulder doctoral student Matthew Kirchner and former CU graduate student David Balslev-Clausen describe the research in a paper that appeared in the Feb. 18 online edition of Optics Express, the free, open-access journal published by the Optical Society of America. Known as optical frequency comb spectroscopy, the technique is powerful enough to sort through all the molecules in human breath and sensitive enough to distinguish rare molecules that may be biomarkers for specific diseases, said Ye.

When breathing, people inhale a complex mixture of gases, including nitrogen, oxygen, carbon dioxide, water vapor and traces of other gases like carbon monoxide, nitrous oxide and methane, said Ye, an adjoint professor of physics at CU-Boulder. Exhaled breath contains less oxygen, more carbon dioxide and a rich collection of more than a thousand types of other molecules, most of which are present only in trace amounts.

Just as bad breath can indicate dental problems, excess methylamine may signal liver and kidney disease, ammonia may be a sign of renal failure, elevated acetone levels can indicate diabetes and nitric oxide levels can be used to diagnose asthma, Ye said.

When many breath molecules are detected simultaneously, highly reliable, disease-specific information can be collected, said Ye. Asthma, for example, can be detected much more reliably when carbonyl sulfide, carbon monoxide and hydrogen peroxide are all detected simultaneously with nitric oxide.

While current breath analysis using biomarkers is a noninvasive and low-cost procedure, approaches are limited because the equipment is either not selective enough to detect a diverse set of rare biomarkers or not sensitive enough to detect particular trace amounts of molecules exhaled in human breath, Ye said.

"The new technique has the potential to be low-cost, rapid and reliable, and is sensitive enough to detect a much wider array of biomarkers all at once for a diverse set of diseases," he said.

The optical frequency comb is a very precise laser for measuring different colors, or frequencies, of light, said Ye. Each comb line, or "tooth," is tuned to a distinct frequency of a particular molecule's vibration or rotation, and the entire comb covers a broad spectral range -- much like a rainbow of colors -- that can identify thousands of different molecules.

Laser light can detect and distinguish specific molecules because different molecules vibrate and rotate at certain distinct resonant frequencies that depend on their composition and structure, he said. He likened the concept to different radio stations broadcasting on separate radio frequencies.

The optical frequency comb was developed in the 1990s by Ye's JILA, NIST and CU-Boulder colleague John L. "Jan" Hall and Theodor W. Hänsch of Germany's Max-Planck Institute, who shared the 2005 Nobel Prize in physics with Roy J. Glauber for their work.

Ye's group has pioneered the application of frequency combs to spectroscopy, or the analysis of light emitted or absorbed by matter. The technique allows for many different gases to be detected all at once with high sensitivity through their interaction with light from such "combs," demonstrated by Thorpe, Ye and colleagues in the journal Science, in 2006.

To test the technology, Ye's team had several CU-Boulder volunteer students breathe into an optical cavity -- a space between two curved mirrors -- and then directed sets of ultrafast laser pulses into the cavity. As the light pulses ricocheted around the cavity tens of thousands of times, the researchers determined which frequencies of light were absorbed, indicating which molecules -- and their quantities -- were present by the amount of light they absorbed.

Ye and his colleagues detected trace signatures of gases like ammonia, carbon monoxide and methane from the samples of volunteers. In one measurement, they detected carbon monoxide in a student smoker that was five times higher compared to a nonsmoking student, Ye said.

Michael Goodisman could be called the Maury Povich of the yellow jacket world. In his laboratory, Goodisman determines the paternity of yellow jackets to study family dynamics within a colony. Even though only one family lives within a colony, each yellow jacket queen mates with several males, creating a complex family tree.

"Social insects such as yellow jackets have been described as one of the greatest achievements of evolution because of the incredible cooperative nature of their societies," said Goodisman, an assistant professor in the Georgia Institute of Technology's School of Biology. "I wanted to know why the females would risk this cooperative nature by having multiple partners."

Mating with multiple partners can also lead to disease and wasted time and energy, according to Goodisman. Plus, each new yellow jacket has siblings and half-siblings during the same breeding season, allowing for potential conflict and infighting between the subfamilies.

"Weird things can start happening within families, so we looked to see if there was any evidence of this kind of selfish behavior within the colony," explained Goodisman, whose projects are funded by the National Science Foundation (NSF).

Goodisman wondered if yellow jacket workers would kill new queens that had a different father or if they were more likely to turn their sister larvae into reproducing queens instead of sterile workers. Turning a worker into a queen is easier than it seems - it simply requires a comb nest with larger holes. The larger holes signal to the workers to feed the developing larvae different food, resulting in queens.

"You can actually take developing workers and if they're young enough, put them into queen cells and they will develop into queens," explained Goodisman.

Goodisman, graduate student Jennifer Kovacs and Eric Hoffman, formerly a postdoctoral researcher at Georgia Tech who is now an assistant professor at the University of Central Florida, tested the paternity of each insect to investigate whether any of the males in a colony fathered more queens than workers.

Similar to human paternity tests, comparing DNA sequences of two yellow jackets can show if one is related to another. Goodisman determined the genetic makeup of each of the queen's male mates. He then determined what proportion of workers and new queens each male mate sired.

The results from the DNA fingerprinting showed that males fathered an equal number of queens and workers in a colony, allowing Goodisman to believe there is no conflict within a colony because of multiple mating.

"Instead of intense competition, yellow jackets seem to exhibit extreme cooperative and helping behaviors," noted Goodisman. Results of this study were published in the journal Molecular Ecology.

Since Goodisman found no disadvantage to having mixed families in the colony, he believed there must be a benefit to the colony for each queen having multiple partners.

Goodisman, Hoffman and Kovacs compared the number of times a yellow jacket queen mated to how successful her colony was. Success was judged based on the number of worker and queen cells in the nest. The findings of this study were published in the journal Evolution.

No correlation was found between the number of mates and the number of worker cells. However, queens that effectively mated four or more times produced significantly more queen cells in the comb than queens that effectively mated fewer than four times. Colonies typically survive only one year, so the number of queens produced at the end of the season represents the entire reproductive output of the colony and, by extension, the original queen. Only inseminated queens survive the winter and emerge in the spring. Thus, Goodisman found that the benefit to multiple mating is that the queen's colony is more successful.

Another avenue of Goodisman's research is to investigate how yellow jacket development leads to a caste system with queens, males and workers - each with a different role in the colony. The queens mate with males to produce new queens and workers, but don't require a male to produce new males. The female workers maintain and expand the colony, while the new queens and males just hang out and eat until it's time to mate.

"The division of labor has made these animals so incredibly successful in cooperative behaviors, but workers and queens are genetically the same," explained Goodisman.

Goodisman aimed to determine how these insects start with the same DNA but end up as such different insects. With help from Hoffman and graduate student Brendan Hunt, Goodisman learned that yellow jackets of the same developmental age express many genes in common regardless of their caste or gender. They also found that certain genes are turned on or off to create the different castes.

This study was published in the journal BMC Biology and Goodisman plans to continue this gene expression research in collaboration with Soojin Yi, also an assistant professor in Georgia Tech's School of Biology.

"We're going to use more sophisticated techniques to look at thousands of genes at once to really make big statements about how different queens are from workers and males," said Goodisman.

Decision-making within a colony also intrigues Goodisman. Different events occur in the colony based on the time of year. For example, the queen constructs a nest and rears the first cohort of workers in the spring. Once the workers mature, they take over the task of colony maintenance and expand the nest by constructing a worker nest throughout the spring and summer. At the end of the summer, the colony begins to produce males and new reproductive queens.

"We want to know who's telling the workers to stop making more workers and start making queens, so we're studying the life cycle of yellow jacket colonies," explained Goodisman. "Is it an environmental cue or possibly a cue from the queen""

Even though some people think that yellow jackets are just a backyard nuisance, there are benefits to having yellow jackets around, contends Goodisman. They kill insects, suppress fly populations and eat roadkill, he says.

And he's quick to point out, "Yellow jackets are not here for our pleasure. They're reproducing, surviving and doing a great job at it."

Europe is aiming to capitalise on core strengths in the field and build critical mass by combining the diverse range of skills required within a coherent research network, following a major workshop organised by the European Science Foundation (ESF).

The materials called MOFs (Metal Organic Frameworks) represent one of the biggest breakthroughs in solid state science whose potential is only just being realised, according to the ESF workshop convenor Gérard Férey. “The domain is currently exploding, and there are so many potential applications that it is difficult to decide how to prioritise them. The only limit is our imagination,” said Férey.

There is no doubt though that the first big application of MOFs - storage of gases - will be highly important, given the urgency of developing alternatives to fossil fuels for automobiles. “For hydrogen storage, MOFs are already used, and many carmakers have these products in prototypes,” said Férey.

MOFs are porous materials with microscopic sized holes, resembling honeycombs at molecular dimensions. This property of having astronomical numbers of tiny holes within a relatively small volume can be exploited in various ways, one of which is as a repository for gases. Gas molecules diffuse into the MOF solid and are contained within its pores. In the case of gas storage, MOFs offer the crucial advantage of soaking up some of the gas pressure exerted by the molecules. This makes hydrogen derived from non-fossil energy sources such as fuel cells, or even genetically engineered plants, potentially viable as a fuel for cars while the alternative of pressurised canisters is not. The key difference is that the amount of gas stored in a conventional cylinder at say 200 atmospheres pressure could be accommodated in an MOF vessel of the same size at just 30 atmospheres, which is much safer.

The porous nature of MOFs enables them to be exploited in quite another way as catalysts to accelerate chemical reactions for a wide variety of materials production and pharmaceutical applications, although this field, as Férey noted, is still in its infancy. Yet already the field is gaining interest beyond academia from serious companies, with a significant development at the ESF workshop being the presence and support of German chemicals giant BASF. This in turn has provided high endorsement of the field’s potential and has stimulated interest from other companies, according to Férey.

But several challenges remain before this potential can be realised, the first one being to assemble research and development teams with the right body of skills. As Férey noted, many of the skills already exist but the researchers need to expand their horizons and focus more broadly on the big picture beyond their specialised domains. There is also the technical challenge of learning first how these materials are formed, and then applying the knowledge to design MOFs matched to specific requirements. MOFs are crystalline solids that form in highly regular patterns from solutions, just as salts and sugars do. Researchers need to learn how to manipulate the starting conditions to obtain just the crystalline composition and arrangement they want.

These snarled molecules grip other molecules to move them around, to speed up important chemical reactions or to grab onto our genes, turning them "on" and "off" to affect which proteins our cells make.

Recently, scientists have discovered that RNA-the stringy molecule that translates our genetic code into protein-can act a lot like a protein itself. RNA can form loopy bundles that shut genes down or start them up without the help of proteins. Since the discovery of these RNA clumps, called "riboswitches," in 2002, scientists have been striving to understand how they work and how they form. Now, researchers at Stanford University are looking closer than ever at how the three-dimensional twists and turns in a riboswitch come together by grabbing it and tugging it straight. By physically pulling on this loopy RNA, they have determined for the first time how a three-dimensional molecular structure folds, step by step.

The researchers used a machine called an "optical trap" to grab and hold the ends of an RNA molecule with laser beams. Based on technology developed by Bell Labs researchers in 1986, the machine was designed by a team led by Steven Block, the Stanford W. Ascherman, M.D., Professor and a professor of applied physics and of biology. The optical trap allows them to hold the ends of the RNA tightly, so they can pull it pin-straight, then let it curl up again. In the Feb. 1 issue of Science, their paper, of which Block is senior author, describes the development of every loop and fold in one particular RNA riboswitch, and the energy it takes to form or straighten each one-an unprecedented achievement that opens the door for equally thorough studies of other molecules and their behaviors.

The researchers are the first to study the energy and folding behavior of a riboswitch in this detailed, physical way. More important, they are the first to use directly applied force to determine how a molecule makes a three-dimensional bundle, a tertiary structure. No other research has tracked the formation of such a complex structure, fold by fold.

Previous studies typically have used biochemical techniques rather than lasers, which can directly grab and tug the RNA. Biochemical techniques give less clear estimates of how molecules fold in real time. They often give a description of the molecule's average folding behavior, which must be interpreted by mathematical models. Crystallography-a technique involving freezing the molecule in place-provides a good picture of its shape, but not how it forms or the energy involved.

"What we're interested in is understanding, in a very fundamental way, how biomolecules take the shapes they do, and how they perform the functions they do," Block said. "No one has been able to explore in great detail tertiary structure yet." RNA riboswitches must have this tertiary structure to work.

"Most RNAs just make secondary [two-dimensional] structure. But the ones that really do stuff," he added, "those all have tertiary structure."

RNA has the job of copying the genetic code from DNA (transcription), and using that code to build the proteins organisms need to live (translation). To make RNA, a protein called RNA polymerase moves along the length of a strand of DNA. It reads a pattern in the building blocks of DNA, nucleic acids whose names are abbreviated A, C, G and T, and it makes RNA with a complementary pattern. This long strand of RNA is then the recipe for a specific protein. Another structure called a "ribosome," which is also made of RNA, then reads this recipe and makes a protein to order.

The RNA copied from DNA generally does not twist up very much, often only forming two-dimensional loops or tight bends called "hairpins." Occasionally, its loops and hairpins form a three-dimensional structure that does nothing. Sometimes, though, this snarl of loops and hairpins works as a riboswitch. The RNA begins to bundle up while it is being made, so the jumbled portion is attached to a tail still under construction. The riboswitch must have a tertiary structure, because it likes to make a pocket and grab small molecules. When a riboswitch clutches the right molecule, it folds up even more tightly, tugging on its own incipient long tail and changing its shape in a way that will affect its eventual protein product. That RNA tail usually has a hairpin fold that straightens out when pulled. By tugging out this kink in the RNA, a riboswitch changes how the RNA is translated into protein, effectively turning the gene on or off.

The riboswitch Block's team studied grabbed onto a molecule called adenine, the nucleic acid dubbed "A." Whenever the riboswitch gripped a free-floating adenine, a gene that makes a protein crucial to adenine production stopped working correctly. The RNA responsible for translating it to the protein had changed shape. The riboswitch regulated how much adenine was available in the cell; when there was plenty, it shut down the adenine factory. Before scientists discovered riboswitches, they thought only proteins controlled genes this way. "Your average RNA at random is not going to do that," Block said. "These are highly evolved things."

The researchers who study molecular folding in Block's lab cannot actually see an RNA molecule under the microscope, but they can see two polystyrene beads; they attach one on either end, and that creates a dumbbell shape the laser beams can manipulate. Their largest beads are 1,000 nanometers across, so 1,000 of them lined up would be a millimeter long. The beads are enormous relative to the RNA, and so are the lasers holding them. To keep the lasers from coming too close together and merging their light into a single beam, the researchers need to attach some extra length to the RNA. To do this, they tack a long strand of DNA on one side.

Under the microscope, the two plastic beads look like tiny pearls against a gray backdrop. The researchers pull the beads apart, taking into account two factors: force and extension. By understanding how much force it takes to cause a certain amount of extension of the RNA, they can describe with unsurpassed accuracy how the folds form and the energy needed to make each fold happen.

"When you pull it apart, different structures will pop open-pop, pop, pop-and you can see the order in which different structural elements get pulled apart," Block said. "You can map out the order in which the pieces come together, for both folding and unfolding."

To build a clear picture of how their riboswitch folded in real time, the researchers mapped out the energy of the molecule's folding based on the forces required to uncurl it and the time the RNA took to re-curl. Block calls the energy graph the "crown jewel of the work,"