Friday, April 9, 2010

FEW DRIVE WELL WHILE YAKKING ON PHONE

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A new study from University of Utah psychologists found a small group of people with an extraordinary ability to multitask: Unlike 97.5 percent of those studied, they can safely drive while chatting on a cell phone.

These individuals - described by the researchers as "supertaskers" - constitute only 2.5 percent of the population. They are so named for their ability to successfully do two things at once: in this case, talk on a cell phone while operating a driving simulator without noticeable impairment.

The study, conducted by psychologists Jason Watson and David Strayer, is now in press for publication later this year in the journal Psychonomic Bulletin and Review.

This finding is important not because it shows people can drive well while on the phone - the study confirms that the vast majority cannot - but because it challenges current theories of multitasking. Further research may lead eventually to new understanding of regions of the brain that are responsible for supertaskers' extraordinary performance.

"According to cognitive theory, these individuals ought not to exist," says Watson. "Yet, clearly they do, so we use the supertasker term as a convenient way to describe their exceptional multitasking ability. Given the number of individuals who routinely talk on the phone while driving, one would have hoped that there would be a greater percentage of supertaskers. And while we'd probably all like to think we are the exception to the rule, the odds are overwhelmingly against it. In fact, the odds of being a supertasker are about as good as your chances of flipping a coin and getting five heads in a row."

The researchers assessed the performance of 200 participants over a single task (simulated freeway driving), and again with a second demanding activity added (a cell phone conversation that involved memorizing words and solving math problems). Performance was then measured in four areas-braking reaction time, following distance, memory, and math execution.

As expected, results showed that for the group, performance suffered across the board while driving and talking on a hands-free cell phone.

For those who were not supertaskers and who talked on a cell phone while driving the simulators, it took 20 percent longer to hit the brakes when needed and following distances increased 30 percent as the drivers failed to keep pace with simulated traffic while driving. Memory performance declined 11 percent, and the ability to do math problems fell 3 percent.

However, when supertaskers talked while driving, they displayed no change in their normal braking times, following distances or math ability, and their memory abilities actually improved 3 percent.

The results are in line with Strayer's prior studies showing that driving performance routinely declines under "dual-task conditions" - namely talking on a cell phone while driving - and is comparable to the impairment seen in drunken drivers.

Yet contrary to current understanding in this area, the small number of supertaskers showed no impairment on the measurements of either driving or cell conversation when in combination. Further, researchers found that these individuals' performance even on the single tasks was markedly better than the control group.

"There is clearly something special about the supertaskers," says Strayer. "Why can they do something that most of us cannot? Psychologists may need to rethink what they know about multitasking in light of this new evidence. We may learn from these very rare individuals that the multitasking regions of the brain are different and that there may be a genetic basis for this difference. That is very exciting. Stay tuned."

Watson and Strayer are now studying expert fighter pilots under the assumption that those who can pilot a jet aircraft are also likely to have extraordinary multitasking ability.

The current value society puts on multitasking is relatively new, note the authors. As technology expands throughout our environment and daily lives, it may be that everyone - perhaps even supertaskers - eventually will reach the limits of their ability to divide attention across several tasks.

"As technology spreads, it will be very useful to better understand the brain's processing capabilities, and perhaps to isolate potential markers that predict extraordinary ability, especially for high-performance professions," Watson concludes.

(Photo: Valoree Dowell, The University of Utah)

The University of Utah

WHAT IF ALL SOFTWARE WAS OPEN SOURCE? A CODE TO UNLOCK THE DESKTOP

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What if all software was open source? Anybody would then be able to add custom features to Microsoft Word, Adobe Photoshop, Apple iTunes or any other program. A University of Washington project may make this possible.

"Microsoft and Apple aren't going to open up all their stuff. But they all create programs that put pixels on the screen. And if we can modify those pixels, then we can change the program's apparent behavior," said James Fogarty, a UW assistant professor of computer science and engineering.

His approach hijacks the display to customize the user's interaction with the program. He will demonstrate his system April 14 in Atlanta at the Association for Computing Machinery's Conference on Human Factors in Computing Systems.

"We really see this as a first step toward a scenario where anybody can modify any application," Fogarty said. "In a sense, this has happened online. You've got this mash-up culture on the Web because everybody can see the HTML. But that hasn't been possible on the desktop."

These days a Web page might include a map from Google, an embedded video from YouTube and a list of recent headlines. This is not yet possible on the personal computer.

"Let's say I'm writing a paper in Microsoft Word but I want to listen to music at the same time," explained co-author Morgan Dixon, a UW doctoral student in computer science and engineering.

Right now he would have to click back and for the between Word and iTunes, but the system he helped create can simply add a few iTunes buttons to the Word toolbar.

"I'm using some program that I love," Dixon said, "and I'm going to stick in some features from some other program that I love, so I have a more unified interface."

More importantly, having more control over widely used programs would allow people to benefit from accessibility tools that have been gathering dust in academic research labs.

One example is target-aware pointing, which can make many interfaces easier for people with muscular dystrophy, Parkinson's disease, cerebral palsy or other motor-control disabilities. On such tool, the bubble cursor, highlights the button closest to it, making it easier for people with disabilities to click a button without having to hit it dead on. Fogarty and Dixon show the first implementation of a bubble cursor in various commercial applications.

"The human-computer interaction community has done 30 years of research on how to make computers more accessible to people with disabilities. But no one change is perfect for everybody," Fogarty said. "That's why you don't see these tools out there."

His research allows people to personalize programs based on their needs.

The UW tool, named Prefab, takes advantage of the fact that almost all displays are made from prefabricated blocks of code such as buttons, sliders, check boxes and drop-down menus. Prefab looks for those blocks as many as 20 times per second and alters their behavior.

The researchers are continuing to develop Prefab and are exploring options for commercialization.

Prefab unlocks previously inaccessible interfaces, allowing people to add the same usability tool to all the applications they run on their desktop. The system could translate a program's interface into a different language, or reorder menus to bump up favorite commands.

The authors hope Prefab will spur development of new innovations.

"If you come up with a new technology, too often it's evaluated in a test environment," Fogarty said. "This lets researchers put it into practice in something real, like Photoshop or iTunes."

Prefab can also produce more advanced effects. One demonstration that will be presented at the conference creates multiple previews of a single image in Photoshop. Behind the scenes, Prefab moves the sliders to different points, captures the output and then displays all of them on a single screen. This could save time by showing a range of effects the user frequently adjusts.

The system could also allow programs to move from computer screens to mobile devices, which do not have a standard operating system.

"It dramatically lowers the threshold to getting new innovation into existing, complex programs," Fogarty said.

University of Washington

STUDY SHOWS CHOCOLATE REDUCES BLOOD PRESSURE AND RISK OF HEART DISEASE

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Easter eggs and other chocolate may be good for you – at least in small quantities and preferably if it's dark chocolate – according to research that shows just one small square of chocolate a day can lower your blood pressure and reduce your risk of heart disease. The study is published online in the European Heart Journal.

Researchers in Germany followed 19,357 people, aged between 35 and 65, for at least ten years and found that those who ate the most amount of chocolate – an average of 7.5 grams a day – had lower blood pressure and a 39% lower risk of having a heart attack or stroke compared to those who ate the least amount of chocolate – an average of 1.7 grams a day. The difference between the two groups amounts to six grams of chocolate: the equivalent of less than one small square of a 100g bar.

Dr Brian Buijsse, a nutritional epidemiologist at the German Institute of Human Nutrition, Nuthetal, Germany, who led the research said: "People who ate the most amount of chocolate were at a 39% lower risk than those with the lowest chocolate intakes. To put it in terms of absolute risk, if people in the group eating the least amount of chocolate (of whom 219 per 10,000 had a heart attack or stroke) increased their chocolate intake by six grams a day, 85 fewer heart attacks and strokes per 10,000 people could be expected to occur over a period of about ten years. If the 39% lower risk is generalised to the general population, the number of avoidable heart attacks and strokes could be higher because the absolute risk in the general population is higher."

However, he warned that it was important people ensured that eating chocolate did not increase their overall intake of calories or reduce their consumption of healthy foods. "Small amounts of chocolate may help to prevent heart disease, but only if it replaces other energy-dense food, such as snacks, in order to keep body weight stable," he said.

The people in the study were participants in the Potsdam arm of the European Prospective Investigation into Cancer (EPIC). They received medical checks, including blood pressure, height and weight measurements at the start of the study between 1994-1998, and they also answered questions about their diet, lifestyle and health. They were asked how frequently they ate a 50g bar of chocolate, and they could say whether they ate half a bar, or one, two or three bars. They were not asked about whether the chocolate was white, milk or dark chocolate; however, the researchers asked a sub-set of 1,568 participants to recall their chocolate intake over a 24-hour period and to indicate which type of chocolate they ate. This gave an indication of the proportions that might be expected in the whole study. In this sub-set, 57% ate milk chocolate, 24% dark chocolate and 2% white chocolate.

In follow-up questionnaires, sent out every two or three years until December 2006, the study participants were asked whether they had had a heart attack or stroke, information which was subsequently verified by medical records from general physicians or hospitals. Death certificates from those who had died were also used to identify heart attacks and strokes.

The researchers allocated the participants to four groups (quartiles) according to their level of chocolate consumption. Those in the top quartile, eating around 7.5g of chocolate a day, had blood pressure that was about 1mm Hg (systolic) and 0.9mm Hg (diastolic) lower than those in the bottom quartile.

"Our hypothesis was that because chocolate appears to have a pronounced effect on blood pressure, therefore chocolate consumption would lower the risk of strokes and heart attacks, with a stronger effect being seen for stroke," explained Dr Buijsse.

This is, in fact, what the study found. During the eight years there were 166 heart attacks (24 fatal) and 136 strokes (12 fatal); people in the top quartile had a 27% reduced risk of heart attacks and nearly half the risk (48%) of strokes, compared with those in the lowest quartile.

The researchers found lower blood pressure due to chocolate consumption at the start of the study explained 12% of the reduced risk of heart attacks and strokes, but even after taking this into account, those in the top quartile still had their risk reduced by a third (32%) compared to those in the bottom quartile over the duration of the study.

Although more research needs to be carried out, the researchers believe that flavanols in cocoa may be the reason why chocolate seems to be good for people's blood pressure and heart health; and since there is more cocoa in dark chocolate, dark chocolate may have a greater effect.

"Flavanols appear to be the substances in cocoa that are responsible for improving the bioavailability of nitric oxide from the cells that line the inner wall of blood vessels – vascular endothelial cells," said Dr Buijsse. "Nitric oxide is a gas that, once released, causes the smooth muscle cells of the blood vessels to relax and widen; this may contribute to lower blood pressure. Nitric oxide also improves platelet function, making the blood less sticky, and makes the vascular endothelium less attractive for white blood cells to attach and stick around."

The authors of the study conclude: "Given these and other promising health effects of cocoa, it is tempting to indulge more in chocolate. Small amounts of chocolate, however, may become part of a diet aimed to prevent CVD [cardiovascular disease] only after confirmation by other observational studies and particularly by randomized trials."

Commenting on the research on behalf of the European Society of Cardiology (ESC), Frank Ruschitzka, Professor of Cardiology, Director of Heart Failure/Transplantation at the University Hospital Zurich, Switzerland, and a Fellow of the ESC, said: "Basic science has demonstrated quite convincingly that dark chocolate particularly, with a cocoa content of at least 70%, reduces oxidative stress and improves vascular and platelet function. However, before you rush to add dark chocolate to your diet, be aware that 100g of dark chocolate contains roughly 500 calories. As such, you may want to subtract an equivalent amount of calories, by cutting back on other foods, to avoid weight gain."

European Society of Cardiology

THE DAWN OF A NEW EPOCH?

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Geologists from the University of Leicester are among four scientists- including a Nobel prize-winner – who suggest that the Earth has entered a new age of geological time.

The Age of Aquarius? Not quite - It's the Anthropocene Epoch, say the scientists writing in the journal Environmental Science & Technology.

And they add that the dawning of this new epoch may include the sixth largest mass extinction in the Earth's history.

Jan Zalasiewicz and Mark Williams from the University of Leicester Department of Geology; Will Steffen, Director of the Australian National University's Climate Change Institute and Paul Crutzen the Nobel Prize-winning atmospheric chemist of Mainz University provide evidence for the scale of global change in their commentary in the American Chemical Society's' bi-weekly journal Environmental Science & Technology.

The scientists propose that, in just two centuries, humans have wrought such vast and unprecedented changes to our world that we actually might be ushering in a new geological time interval, and alter the planet for millions of years.

Zalasiewicz, Williams, Steffen and Crutzen contend that recent human activity, including stunning population growth, sprawling megacities and increased use of fossil fuels, have changed the planet to such an extent that we are entering what they call the Anthropocene (New Man) Epoch.

First proposed by Crutzen more than a decade ago, the term Anthropocene has provoked controversy. However, as more potential consequences of human activity — such as global climate change and sharp increases in plant and animal extinctions — have emerged, Crutzen's term has gained support. Currently, the worldwide geological community is formally considering whether the Anthropocene should join the Jurassic, Cambrian and other more familiar units on the Geological Time Scale.

The scientists note that getting that formal designation will likely be contentious. But they conclude, "However these debates will unfold, the Anthropocene represents a new phase in the history of both humankind and of the Earth, when natural forces and human forces became intertwined, so that the fate of one determines the fate of the other. Geologically, this is a remarkable episode in the history of this planet."

(Photo: University of Leicester)

University of Leicester

HEALTHY FOOD MAKES CONSUMERS FEEL HUNGRIER WHEN CHOICES ARE LIMITED

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If we don't have a choice in the matter, eating something that's considered healthy might simply lead us to feel hungry and eat something else, according to a new study in the Journal of Consumer Research.

Authors Stacey Finkelstein and Ayelet Fishbach (both University of Chicago) examined external controls in the domain of healthy eating—such as marketers who only offer shoppers healthy food samples or consumers who eat healthy meals in a cafeteria that only offers healthy alternatives.

"In the presence of external controls, people who eat healthily feel that they have made sufficient progress on their health goals," the authors write. "Then, they switch to the conflicting goal to satisfy their appetite: they express hunger and seek food."

In one experiment, the authors told people their job was to taste a food that was described as healthy or tasty (imposed conditions) or had people choose between the same food samples (free-choice conditions). Then participants rated their hunger.

"People who were given a food sample described as healthy rated they were hungrier than those who were given the same sample framed as tasty and delicious," the authors write. "Those who freely chose the food sample were equally hungry. Thus, only those who were given the healthy food sample (imposed consumption) became hungrier."

In another study, participants were given a sample of the same piece of bread that was described as healthy (low-fat with lots of vitamins) or tasty (delicious with a thick crust and soft center). They also asked people how much they valued watching their weight. "People given the bread described as healthy were hungrier, thus they consumed more of an available snack, than those given the same piece described as tasty," the authors write. But the effect disappeared for those who valued watching their weight; they chose to eat the healthy bread.

In addition to providing guidance to marketers, the study has policy implications. "When controlling agents take actions to help consumers meet their long-term objectives, people need to infer that they have made the choice to do so themselves. Otherwise, these efforts will backfire," the authors conclude.

University of Chicago

HYENAS' LAUGHTER SIGNALS DECIPHERED

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Acoustic analysis of the 'giggle' sound made by spotted hyenas has revealed that the animals' laughter encodes information about age, dominance and identity. Researchers writing in the open access journal BMC Ecology recorded the calls of 26 hyenas in captivity and found that variations in the giggles' pitch and timbre may help hyenas to establish social hierarchies.

Frédéric Theunissen, from the University of California at Berkeley, USA, and Nicolas Mathevon, from the Université Jean Monnet, St. Etienne, France worked with a team of researchers to study the animals in a field station at Berkeley. Theunissen said, "The hyena's laugh gives receivers cues to assess the social rank of the emitting individual. This may allow hyenas to establish feeding rights and organize their food-gathering activities."

The researchers found that while the pitch of the giggle reveals a hyena's age, variations in the frequency of notes can encode information about dominant and subordinate status. These vocalizations are mainly produced during food contests by animals that are prevented from securing access to a kill, and have been considered a gesture of submission.

Theunissen and colleagues also suggest that the giggle may be a sign of frustration and that it may be intended to summon help. He said, "Lions often eat prey previously killed by hyenas. A solitary hyena has no chance when confronted by a lion, whereas a hyena group often can 'mob' one or two lions and get their food back. Giggles could therefore allow the recruitment of allies. Cooperation and competition are everyday components of a hyena's life. When hearing a giggling individual, clan-mate hyenas could receive information about who is getting frustrated (in terms of individual identity, age, status) and decide to join the giggler, or conversely to ignore it or move away". The researchers plan to further test these hypotheses with playback experiments in the field.

(Photo: Theunissen et al., BMC Ecology)

BMC

GOOD NEWS FOR ELDERLY SLEEP APNEA SUFFERERS

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Findings from the Technion-Israel Institute of Technology could provide good news for elderly patients who suffer from sleep apnea. The research results from noted sleep researcher (and current Technion President) Professor Peretz Lavie and his wife, Dr. Lena Lavie of the Technion Faculty of Medicine show that elderly patients with moderate sleep apnea live longer than their counterparts in the general population.

In an article published in the December 2009 issue of the Journal of Sleep Research, the researchers hypothesize that the intermittent lack of oxygen (hypoxia) that occurs with sleep apnea actually provides protection to elderly patients’ cardiovascular systems. This would explain, they say, why elderly patients with moderate sleep apnea show significantly lower mortality rate compared with the general population. The findings were based on a study of 611 individuals with a media age of 70, and a five-year follow-up period.

Behind this phenomenon, say the Lavies, is a protein in the blood known as VEGF (vascular endothelial growth factor), which is created during hypoxia, and which is responsible for the growth of new blood vessels. The study found that the ability of individuals to produce VEGF varied widely among patients, and individuals who could produce a large amount when exposed to hypoxia had more blood vessels around their hearts when compared to individuals who could not. The resulting reservoir of blood, they believe, provides protection in the case of heart attack.

Researchers at Heinrich Heine University in Dusseldorf, Germany recently confirmed the Lavies’ hypothesis. In the most recent issue of Chest, the Journal of the American College of Chest Physicians, Stephan Steiner and colleagues from the Department of Cardiology reported that patients with sleep apnea had significantly more blood vessels around their hearts than patients without sleep apnea – even though there were no differences between the groups in age, weight, heart condition or use of medication.

“If confirmed, these findings may have important clinical implications regarding treatment of sleep apnea syndrome,” say Prof. and Dr. Lavie in an editorial that accompanied the Chest article. “Moreover, such findings, if combined with individual gene analysis, may provide new treatment strategies for cardiovascular protection.”

Sleep apnea is characterized by interruptions in breathing during sleep that last 10 seconds or more, at least five times per hour. They cause repeated interruptions of sleep and decreased oxygen levels in the blood, and have been linked with cardiovascular diseases, especially hypertension. The condition affects up to 10 percent of adult men, who in most cases are not aware that their breathing stops during sleep but who complain of chronic fatigue, excessive sleepiness, tendency to doze off during the day and loud, intermittent snoring.

(Photo: ATS)

American Technion Society

ANCIENT SNAKES LIVING ON MADAGASCAR

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"Blindsnakes are not very pretty, are rarely noticed, and are often mistaken for earthworms," admits Blair Hedges, professor of biology at Penn State University. "Nonetheless, they tell a very interesting evolutionary story." Hedges and Nicolas Vidal, of the Muséum National d'Histoire Naturelle in Paris, are co-leaders of the team that discovered that blindsnakes are one of the few groups of organisms that inhabited Madagascar when it broke from India about 100 million years ago and are still living today.

The results of their study were published in the 31 March 2010 issue of the Royal Society journal Biology Letters.

Blindsnakes comprise about 260 different species and form the largest group of the world's worm-like snakes -- scolecophidians. These burrowing animals typically are found in southern continents and tropical islands, but occur on all continents except Antarctica. They have reduced vision -- which is why they are called "blind" -- and they feed on social insects including termites and ants. Because there are almost no known fossil blindsnakes, their evolution has been difficult to piece together. Also, because of their underground lifestyle, scientists have long wondered how they managed to spread from continent to continent.

In this study, the team investigated the evolution of blindsnakes by examining the genetics of living species. They extracted five nuclear genes, which code for proteins, from 96 different species of worm-like snakes to reconstruct the branching pattern of their evolution and allow the team to estimate the times of divergence of different lineages within blindsnakes using molecular clocks. "Our findings show that continental drift had a huge impact on blindsnake evolution," explains Vidal, "by separating populations from each other as continents moved apart."

Mutations in the genes record the history of these blurry-eyed serpents. The genetic research reveals that the original stock of worm-like snakes arose on Gondwana, the ancient southern supercontinent. The initial split occurred about 155 million years ago as Gondwana divided into East Gondwana (the landmasses of Antarctica, India, Madagascar, and Australia) and West Gondwana (the landmasses of South America and Africa). The residents of East Gondwana -- the blindsnakes -- then diverged into several lineages including a new family named in this study and found only on Madagascar. Later, East Gondwana further divided into a new paleolandmass -- called by the researchers "Indigascar" (India plus Madagascar) -- and another comprised of Australia and Antarctica. The research suggests that the new family on Madagascar arose as a result of the break-up of the Indigascar landmass about 94 million years ago.

Madagascar's long isolation has led to the evolution of many unique endemic animals including this family of blindsnakes, various lemurs, and other rare mammals. Unfortunately, both the animals and plants of Madagascar are now endangered by habitat loss. Says team member Miguel Vences, a professor at the Technical University of Braunschweig, Germany, and authority on the biodiversity of Madagascar, "Finding such ancient roots for a group of animals in Madagascar gives us even more reason to protect their rapidly declining habitat."

If blindsnakes got their start on Indigascar, leaving an endemic living family as evidence on Madagascar, how did they get to all of those other places in the world that they occupy today -- Europe, Asia, Australia, Africa, and the Americas?

The phylogeny constructed by the Hedges and Vidal team shows a series of diversifications within the blindsnakes, outside of Madagascar, that occurred between 63 and 59 million years ago. The period of greatest diversification coincided with a time of low sea levels, when connections between continents were forming and the dispersal of such unlikely animals by floating on flotsam was easier. Blindsnakes must have moved either out of Africa via Europe and Asia -- the ancient northern supercontinent Laurasia -- or out of India and then from southeast Asia to Australia at about 28 million years ago. Since there were no land connections between Asia and Australia at this time, these blindsnakes could have reached Australia only by crossing the ocean on floating flotsam. After that point, the splits within the blindsnakes probably occurred because they were following the evolution and spread of their prey -- ants and termites -- in various geographic regions.

Floating across oceans seems an unlikely mechanism for a burrowing animal to spread to new continents, but there is a second instance of ocean crossing by blindsnakes among the groups left on West Gondwana: West Gondwana broke up about 100 million years ago, making Africa and South America separate continents, but the genetic split between African and South American blindsnakes occurred only at about 63 million years ago. This finding shows that blindsnakes probably were confined to Africa when West Gondwana broke up and only later traveled to South America -- and still later to the West Indies -- by floating across the Atlantic from east to west.

This journey has rarely been documented. Only six or seven other vertebrates are thought to have crossed the Atlantic in a westward direction. However, the crossing would have taken no more than six months and might not have been too difficult for blindsnakes, which have a relatively low need for food and may have been floating on vegetation rafts along with their insect prey.

"Some scientists have argued that oceanic dispersal is an unlikely way for burrowing organisms to become distributed around the world," observes Hedges. "Our data now reinforce the message that such 'unlikely' events nonetheless happened in evolutionary history."

(Photo: Frank Glaw)

Penn State University

OPTIMISM BOOSTS THE IMMUNE SYSTEM

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Feeling better about the future might help you feel better for real. In a new study, psychological scientists Suzanne Segerstrom of the University of Kentucky and Sandra Sephton of the University of Louisville studied how law students' expectations about the future affected their immune response. Their conclusions: Optimism may be good for your health.

Other studies have found that people who are optimistic about their health tend to do better. For example, people who are optimistic about heart transplant surgery recover better from that grueling operation. But it's not clear how optimism affects your health — or whether pessimism makes you less healthy.

For this study, reported in Psychological Science, a journal of the Association for Psychological Science, the researchers recruited first-year law students by sending them a packet during the summer before classes started. The 124 students that participated in the research were studied at five times over six months. Each time, they answered questions about how optimistic they felt about law school. Then they were injected with material that should summon an immune response and two days later, they came back to have the injection site measured. A larger bump in the skin means a stronger immune response. Immune systems are many-faceted; this test only measures the strength of the part that is responsible for fighting viral infections and some bacterial infections.

The students' general outlook on life — whether they had an optimistic disposition — didn't account for the differences in immune responses between students. But as each student's expectations about law school waxed and waned, their immune response followed along. At more optimistic times, they'd have bigger immune responses; at a more pessimistic time, a more sluggish immune response. So, being optimistic about success in a specific, important domain may promote better immunity against some infections.

Of course, the law students often have good reason to be optimistic or pessimistic; by a few months into the first semester, they've gotten some grades back and started to figure out if they're good or bad at law school. "I don't think that I would advise people that they should revise their expectations to be unrealistic," says Segerstrom. "But if people have slightly more positive views of the future than is actually true, that's adaptive."

Association for Psychological Science

A SYSTEM THAT’S WORTH ITS SALT

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Potable water is often in high demand and short supply following a natural disaster like the Haiti earthquake or Hurricane Katrina. In both of those instances, the disaster zones were near the sea, but converting salty seawater to potable fresh water usually requires a large amount of dependable electrical power and large-scale desalination plants — neither of which were available in the disaster areas.

A new approach to desalination being developed by researchers at MIT and in Korea could lead to small, portable units that could be powered by solar cells or batteries and could deliver enough fresh water to supply the needs of a family or small village. As an added bonus, the system would also remove many contaminants, viruses and bacteria at the same time.

The new approach, called ion concentration polarization, is described in a paper by Postdoctoral Associate Sung Jae Kim and Associate Professor Jongyoon Han, both in MIT’s Department of Electrical Engineering and Computer Science, and colleagues in Korea. The paper was published on March 21 in the journal Nature Nanotechnology.

One of the leading desalination methods, called reverse osmosis, uses membranes that filter out the salt, but these require strong pumps to maintain the high pressure needed to push the water through the membrane, and are subject to fouling and blockage of the pores in the membrane by salt and contaminants. The new system separates salts and microbes from the water by electrostatically repelling them away from the ion-selective membrane in the system — so the flowing water never needs to pass through a membrane. That should eliminate the need for high pressure and the problems of fouling, the researchers say.

The system works at a microscopic scale, using fabrication methods developed for microfluidics devices — similar to the manufacture of microchips, but using materials such as silicone (synthetic rubber). Each individual device would only process minute amounts of water, but a large number of them — the researchers envision an array with 1,600 units fabricated on an 8-inch-diameter wafer — could produce about 15 liters of water per hour, enough to provide drinking water for several people. The whole unit could be self-contained and driven by gravity — salt water would be poured in at the top, and fresh water and concentrated brine collected from two outlets at the bottom.

That small size could actually be an advantage for some applications, Kim explains. For example, in an emergency situation like Haiti’s earthquake aftermath, the delivery infrastructure to get fresh water to the people who need it was largely lacking, so small, portable units that individuals could carry would have been especially useful.

So far, the researchers have successfully tested a single unit, using seawater they collected from a Massachusetts beach. The water was then deliberately contaminated with small plastic particles, protein and human blood. The unit removed more than 99 percent of the salt and other contaminants. “We clearly demonstrated that we can do it at the unit chip level,” says Kim. The work was primarily funded by a grant from the National Science Foundation, as well as a SMART Innovation Centre grant

While the amount of electricity required by this method is actually slightly more than for present large-scale methods such as reverse osmosis, there is no other method that can produce small-scale desalination with anywhere near this level of efficiency, the researchers say. If properly engineered, the proposed system would only use about as much power as a conventional lightbulb.

Mark A. Shannon of the Center of Advanced Materials for the Purification of Water with Systems at the University of Illinois at Urbana-Champaign, who was not involved in this work, agrees with that assessment. In a News & Views piece that accompanies the Nature Nanotechnology paper, he writes that the new system achieves “perhaps the lowest energy ever for desalinating microliters of water,” and when many of these micro-units are combined in parallel, as Kim and his co-authors propose, “it could be used to supply liters of water per hour using only a battery and gravity flow of water.” That meets a significant need, he says, since at present there are few efficient methods for small-scale desalination, both for emergencies and for use in remote areas in poor countries.

Alex Iles, a research scientist at the University of Hull in Britain, says that while further testing must be done to establish long-term stability and fabrication techniques, “This is an elegant new concept for water desalination.” He says it is likely to produce a low-cost, low-maintenance system that could be “ideal for applications such as disaster relief.” When it was initially presented at a conference he attended last year, Iles says, “I thought it was probably the most significant new work at the entire conference, even though it was only a poster.”

The basic principle that makes the system possible, called ion concentration polarization, is a ubiquitous phenomenon that occurs near ion-selective materials (such as Nafion, often used in fuel cells) or electrodes, and this team and other researchers have been applying the phenomenon for other applications such as biomolecule preconcentration. This application to water purification has not been attempted before, however.

Since the separation occurs electrostatically, it doesn’t work for removing contaminants that have no electric charge. To take care of these remaining particles — mostly industrial pollutants — the researchers suggest the unit could be combined with a conventional charcoal filter system, thus achieving pure, safe drinking water through a single simple device.

Having proved the principle in a single-unit device, Kim and Han plan to produce a 100-unit device to demonstrate the scaling-up of the process, followed by a 10,000-unit system. They expect it will take about two years before the system will be ready to develop as a product.

“After that,” says Kim, “we’ll know if it’s possible” for this to work as a robust, portable system, “and what problems might need to be worked on.”

(Photo: Patrick Gillooly)

Massachusetts Institute of Technology

JENNIFER SMITH HELPS SOLVE 'BLUE' MYSTERY

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Jennifer Smith, PhD, associate professor of earth and planetary sciences in Arts & Sciences at Washington University in St. Louis, was belly crawling her way to the end of a long, narrow tunnel. The tunnel was carved in the rock at a desert oasis by Egyptians who lived in the time of the pharaohs.

“I was crawling along when suddenly I felt stabbed in the chest,” Smith says. “I looked down and saw that I was pressing against the broken end of a long bone. That freaked me out because at first I thought I was crawling over bodies, but I looked up and saw a sheep skull not too far away, so I calmed down. At least the bones weren’t human.”

What was she doing in the tunnel?

The answer: seeking an uncontaminated sample of a mineral that might have been the key ingredient in the blue used to decorate “blue painted pottery” popular among the Egyptian elite during the New Kingdom (1550-1079 BC).

Colleague Colin A. Hope, PhD, an expert in blue painted pottery, had asked if she wouldn’t help him pin down the source of the blue pigment by sampling and analyzing material from the mine.

Hope and Smith, together with Paul Kucera, a doctoral student at Monash University in Australia who first identified the mines, describe the pottery, the mines and the mineral in a chapter of Beyond the Horizon, a festschrift for the Egyptologist Barry A. Kemp,

In the wastes of the eastern Sahara, nestled against the limestone escarpment that separates the desert from the Nile Valley, lies the Dakhleh Oasis. This fortunate spot, where deep water is able to reach the surface along fractures and faults under its own pressure, has been continuously inhabited for a very long time — perhaps as long as 400,000 years.

During that period, there were roughly four glacial cycles and, although Egypt itself was ice-free, the local climate oscillated from hyperarid to semi arid as the Earth's orbital position drove changes in the location of the tropical rainfall belts.

Smith studies the impact of these climate fluctuations on ancient oasis dwellers.

But Smith also is the “generic geologist,” as she puts it, for the Dakhleh Oasis Project, a long-term study of the oasis that covers the entire stretch of Dakhleh history, from the Neolithic through the Pharaonic, Roman, Islamic and modern settlements, and employs — off and on — more than 50 specialists.

“The dig house is open from November until March,” Smith says.

As generic geologist, Smith was asked to help with a material-sourcing puzzle that she says was “way outside her period.” During the 2007 season, Hope, associate professor and director of the Center for Archaeology and Ancient History at Monash University, asked her whether a mineral found at the oasis could have been used to color the blue painted pottery.

It was a small question, but an intriguing one.

Most Egyptian pottery is undecorated, but during the New Kingdom, the period when Egypt was at the zenith of its power, a variety of pottery was elegantly decorated in a distinctive pale blue.

The pottery has been found at many sites in Egypt and also in the Middle East and in Sudan.

The largest deposits, however, were found at New Kingdom sites in Egypt, including Malqata (the palace complex of Amenhotep III), Amarna (the remains of the city built by the Akenaten, the famous pharaoh who moved the capital from Thebes and established his own religion), the cemetery at Deir el-Medineh (the village where artisans who worked on the tombs in the Valley of the Kings during the New Kingdom lived), and the Great Temple of Amun (patron of kingship during the New Kingdom).

“Walking over some sites, it is only a matter of minutes before several shards of blue painted pottery or cobalt blue glass or faience can be collected,” Hope, who has written extensively about the pottery, says.

Given the restricted use to which the pigment was put and the archeological sites where remnants were found, Hope believes it probably was available only to artisans associated with major royal residences.

The pale blue is distinguishable at a glance from the brilliant blues and blue-greens of the faience glazes common from 3,000 BC onward. Faience, probably most familiar in the form of the small statue of a hippo nicknamed William that is now in the collection of the Metropolitan Museum of Art in New York, was made by adding ground copper to ground quartz to create what ceramists today call Egyptian paste.

But it is difficult to create durable patterns with copper pigment on pottery, Hope says. "Copper-based pigments must be applied in thick layers and were added after firing, so they tended to flake off when an object was handled. Instead of copper, the colorant used on most of the blue painted pottery is cobalt, which was fired onto the pots.

Where did the cobalt-bearing mineral come from? Analysis of the paint showed that the cobalt was accompanied by trace amounts of zinc, nickel and manganese, a mixture of elements distinctive enough to serve as a chemical fingerprint.

At the height of its power, the Egyptian administration of the Nile Valley sponsored mineral exploitation of the valley and surrounding desert regions. As early as 1980, it was suggested that the cobalt might have come from the desert oases at Dakhleh and Kharga.

In the lower foothills of the oasis escarpment at the western end of Dakhleh, four mine shafts were meticulously hand-cut into the rock. Steps carved along the shafts allowed a safe descent. The shafts provided access to horizontal galleries, some as long as 15 meters, that followed horizontal veins of the mineral alum.

A few centimeters thick, the alum veins are fibrous, pale gray to pink in color and slightly astringent.

Alum is both the term for a specific compound and for a class of compounds, all of which contain two negatively charged sulfate groups and two chemical elements or groups bearing a positive charge. The specific compound is hydrated aluminum potassium sulfate but many other elements or groups can substitute for the aluminum and potassium, and cobalt is one of these.

Alum was probably exploited for a variety of purposes in ancient times, some having nothing to do with color. The Egyptians, for example, used alum both to whiten skins during tanning and to prepare cloth to absorb dye.

Alum is still used today in styptic pencils to stem bleeding and in recipes for pickling cucumbers. More recently, it has been in vogue as a "crystal deodorant" that is sold as more natural than older deodorant products.

Was the Dakhleh Oasis alum used as a general-purpose astringent, or did it have the same chemical fingerprint as the blue paint on the pottery?

To find out, Smith needed to sample the alum and analyze its composition.

“I wanted to get relatively unaltered samples,” she says, “which is why I was crawling to the end of a gallery. The galleries were small enough you couldn’t really crawl on your hand and knees: You had to belly crawl.”

Smith brought the samples she collected back to WUSTL, where she ran them through a variety of sophisticated analytical instruments. “When we characterize a natural mineral,” she says, “we want to know two things: its chemical composition and then how the elements that make it up are arranged, or its crystal structure.”

In the case of the Dakhleh alum, the crystal structure was of little use because it would have been destroyed in preparing the paint. Only the composition could connect the alum to the pottery.

Smith’s results showed that the alum did contain cobalt, although they weren’t particularly rich in this element. The cobalt, however, was accompanied by trace amounts of manganese, nickel and zinc, the same mixture of elements found in the blue paint.

Surprised by the low concentration of cobalt, Smith wondered if the ancient artisans hadn’t found a way to concentrate it on site. One sample she collected, a crust at the edge of a partially flooded mine shaft, had a higher cobalt content than the others. Because sulphate dissolves easily and the mines were much more likely to have been flooded in the past, she wondered whether the cobalt was mined not by chipping it out of the rock but instead by ladling water out of the mines and collecting the sediment left over when the water evaporated.

“But this is wild arm waving given the amount of data,” Smith says.

This small exercise in archeological problem-solving left her with a deep respect for the long-vanished miners.

“I look at all these different veins of sulfate, and I don’t know which are useful for which purposes without doing analyses, but they must have had ways of telling from observable properties which ones to mine. That’s impressive,” she says.

(Photo: Colin A. Hope/ Monash University)

Washington University in St. Louis

(ULTRA)SOUNDING OUT A NEW WAY TO TREAT CHRONIC PAIN

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Imagine that after long day tending to patients, a middle-aged nurse feels a burning pain in her knees so intense she can barely walk. For millions of people who suffer from arthritis or other chronic joint pain, this is a familiar story. Right now there are few day-to-day therapies available for these patients, and many involve strong medications that can be harmful over time.

If George K. Lewis, a biomedical engineering graduate student at Cornell University has his way, there may soon be another option. Lewis and his colleagues have created a miniaturized ultrasound device that would allow patients to apply ultrasound therapy to inflamed joints at home, work, or even while going about their day.

Most of us are familiar with the amazing powers of diagnostic ultrasound technologies in modern medicine, which allow doctors to tell us the gender of a child prior to birth or the condition of our internal organs without exploratory surgery. Doctors have also used ultrasound therapeutically to effectively treat joint pain from arthritis and other ailments without the use of drugs. The drawback to these current treatments, however, is that they can only be administered in a doctor's office or clinic, since the ultrasound devices available are bulky and expensive.

Enter Lewis, who, with funding from the National Science Foundation, has spent his time at Cornell focusing on creating smaller and more accessible ultrasound devices for use in medicine. His portable ultrasound device for joint pain, which is now entering clinical trials in association with Weill Cornell Medical College geriatrician Dr. Cary Reid, is about the size of an iPod, and can provide pain relief for several hours without being tethered to a doctor's office. After receiving instructions from their doctor, patients can apply the device themselves and adjust the level of ultrasound intensity as needed.

The key to Lewis's success in miniaturizing ultrasound devices is increasing their efficiency. Conventional devices lose about half the electricity used to create sound waves. Lewis has found a way to convert 95 percent of the device's electricity into sound waves.

So how do sound waves reduce joint pain? A knee, for example, is surrounded by an area called the synovial sac. Think of this sac as a sponge. Osteoarthritis causes that ‘sponge' to become swollen with excess fluid and the knee to be painfully inflamed. Ultrasound penetrates the joint and the surrounding tissue, and its waves both stimulate the synovial sac ‘sponge' and increase its permeability, which helps it lose the excess fluid. Once the ‘sponge' is wrung out, swelling subsides, and the body can deliver nutrients to the joint that help repair it.

Lewis says there are other potential uses for his small ultrasound devices, including treatment of glioblastoma, a type of brain cancer. During surgery, Lewis explains, a surgeon could remove a tumor and replace it with a dissolving drug wafer, which ultrasound waves would then help spread to kill off any cancer cells left behind.

For now, the device has demonstrated its effectiveness in pain relief when used on animals, and if clinical trials with humans are successful, it could become an important tool to treat chronic pain without the use of drugs.

(Photo: Zina Deretsky, National Science Foundation)

National Science Foundation

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