Femtosecond lasers could find immediate application in hospitals as a way to disinfect blood supply or biomaterialsFemtosecond laser.

Physicists in Arizona State University have designed a revolutionary laser technique which can destroy viruses and bacteria such as AIDS without damaging human cells and may also help reduce the spread of hospital infections such as MRSA. The research, published on Thursday November 1 in the Institute of Physics’ Journal of Physics: Condensed Matter, discusses how pulses from an infrared laser can be fine-tuned to discriminate between problem microorganisms and human cells, according to ScienceDaily.
Current laser treatments such as UV are indiscriminate and can cause ageing of the skin, damage to the DNA or, at worst, skin cancer, and are far from 100 per cent effective.
Femtosecond laser pulses, through a process called Impulsive Stimulated Raman Scattering (ISRS), produces lethal vibrations in the protein coat of microorganisms, thereby destroying them. The effect of the vibrations is similar to that of high-pitched noise shattering glass.
The physicists in Arizona have undertaken experiments to show that the coherent vibrations excited by infrared lasers with carefully selected wavelengths and pulse widths do no damage to human cells, most likely because of the different structural compositions in the protein coats of human cells vis a vis bacteria and viruses.
Professor K. T. Tsen from Arizona State University said, “Although it is not clear at the moment why there is a large difference in laser intensity for inactivation between human cells and microorganisms such as bacteria and viruses, the research so far suggests that ISRS will be ready for use in disinfection and could provide treatments against some of the worst, often drug-resistant, bacterial and viral pathogens.“
Femtosecond lasers could find immediate application in hospitals as a way to disinfect blood supply or biomaterials and for the treatment of blood-borne diseases such as AIDS and Hepatitis.

Spending just 10 minutes talking to another person can help improve your memory and your performance on tests, according to a University of Michigan study to be published in the February 2008 issue of the Personality and Social Psychology Bulletin.
“In our study, socializing was just as effective as more traditional kinds of mental exercise in boosting memory and intellectual performance,“ said Oscar Ybarra, a psychologist at the U-M Institute for Social Research (ISR) and a lead author of the study with ISR psychologist Eugene Burnstein and psychologist Piotr Winkielman from the University of California, San Diego, ScienceDaily said.
In the article, Ybarra, Burnstein and colleagues report on findings from two types of studies they conducted on the relationship between social interactions and mental functioning.
In one study, they examined ISR survey data to see whether there was a relationship between mental functioning and specific measures of social interaction. The survey data included information on a national, stratified area probability sample of 3,610 people between the ages of 24 and 96. Their mental function was assessed through the mini-mental exam, a widely used test that measures knowledge of personal information and current events and that also includes a simple test of working memory.
Participants’ level of social interactions was assessed by asking how often each week they talked on the phone with friends, neighbors and relatives, and how often they got together.
After controlling for a wide range of demographic variables, including age, education, race/ethnicity, gender, marital status and income, as well as for physical health and depression, the researchers looked at the connection between frequency of social contact and level of mental function on the mini-mental exam.
The higher the level of participants’ social interaction, researchers found, the better their cognitive functioning. This relationship was reliable for all age groups, from the youngest through the oldest.
In a second experiment, the researchers conducted a laboratory test to assess how social interactions and intellectual exercises affected memory and mental performance.
Participants were 76 college students, ages 18 to 21. Each student was assigned to one of three groups.
Those in the social interaction group engaged in a discussion of a social issue for 10 minutes before taking the tests. Those in the intellectual activities group completed three tasks before taking the tests.
These tasks included a reading comprehension exercise and a crossword puzzle.
Then all participants completed two different tests of intellectual performance that measured their mental processing speed and working memory.
“We found that short-term social interaction lasting for just 10 minutes boosted participants’ intellectual performance as much as engaging in so-called ’intellectual’ activities for the same amount of time,“ Ybarra said.

Fixing design bugs and wrong wire connections in computer chips after they’ve been fabricated in silicon is a tedious, trial-and-error process that often costs companies millions of dollars and months of time-to-market.
According to Physorg.com, engineering researchers at the University of Michigan say it doesn’t have to be that way. They’ve developed a new technology to automate “post-silicon debugging.“
“Today’s silicon technology has reached such levels of small-scale fabrication and of sheer complexity that it is almost impossible to produce computer chips that work correctly under all scenarios,“ said Valeria Bertacco, assistant professor of electrical engineering and computer science and co-investigator in the new technology.
FogClear, as the new method is called, uses puzzle-solving search algorithms to diagnose problems early on and automatically adjust the blueprint for the chip. It reduces parts of the process from days to hours.
“Practically all complicated chips have bugs and finding all bugs is intractable,“ said Igor Markov, associate professor of computer science and electrical engineering and another of FogClear’s developers. “Today, manufacturers are producing chips that must work for almost all applications, from e-mail to chess, but they cannot be validated for every possible condition. It’s physically impossible.“
In the current system, a chip design is first validated in simulations. Then a draft is cast in silicon, and this first prototype undergoes additional verification with more realistic applications. If a bug is detected at this stage, an engineer must narrow down the cause of the problem and then craft a fix that does not disrupt the delicate balance of all other components of the system. This can take several days. Engineers then produce new prototypes incorporating all the fixes. This process repeats until they arrive at a prototype that is free of bugs. For modern chips, the process of making sure a chip is free of bugs takes as much time as production.
“Bugs found post-silicon are often very difficult to diagnose and repair because it is difficult to monitor and control the signals that are buried inside a silicon die, or chip. Up until now engineers have handled post-silicon debugging more as an art than a science,“ said Kai-Hui Chang, a recent doctoral graduate who will present a paper on FogClear.
FogClear automates this debugging process. The computer-aided design tool can catch subtle errors that several months of simulations would still miss. Some bugs might take days or weeks before causing any miscomputation, and they might only do so under very rare circumstances, such as operating at high temperature. The new application searches for and finds the simplest way to fix a bug, the one that has the least impact on the working parts of the chip. The solution usually requires reconnecting certain wires, and does not affect transistors.

A protein in the pancreas of mice may offer insight into the mechanism behind gestational diabetes, a condition that affects about 4 percent of all pregnant women, researchers said.
Researchers at Stanford University found the protein menin acts as a natural brake in the pancreas, controlling the production of cells needed to make insulin, which helps the body convert sugar into energy, Reuters said.
Pregnant mice genetically engineered to produce too much menin were unable to make enough insulin-producing islet cells and developed signs of gestational diabetes.
“We think our work raises new possibilities, including possibilities about how gestational diabetes and other forms of type 2 diabetes arise,“ said Dr. Seung Kim, associate professor of developmental biology at Stanford, whose study appears in the journal Science.
Gestational diabetes occurs when a woman previously free of diabetes is unable to make and use all the insulin she needs for pregnancy.
Other researchers have found that the hormone prolactin, found in abundance during pregnancy, triggers the production of insulin-producing islet cells during pregnancy.
The mechanism behind this process was not understood, but Kim and other researchers thought menin might play a role. Menin has already been shown to help prevent cancer in the pancreas by blocking cell growth.
When Kim and colleagues gave prolactin to mice that were not pregnant, menin levels dropped and the pancreas grew in size, mimicking what happens during pregnancy.
The researchers think prolactin depresses menin levels during pregnancy, allowing the body to make more insulin-producing cells to support fetal growth.
“We think it likely that one reason for developing gestational diabetes is an impaired ability of islet cells to respond to growth signals like prolactin,“ he said in e-mailed comments.
He said the finding, if correct, may lead to new tests to predict the likelihood of developing diabetes during pregnancy.
It may also lead to new ways to stimulate islet cell growth in people with diabetes who do not have enough islet cells to meet their body’s demands, he said.

Artist's impression of the new alien worlds

Britain’s leading team of planet-hunters says it has found three new alien worlds that lie beyond our solar system, boosting confidence that Earth-like worlds are waiting to be discovered.
The discovery of the planets will be announced by the Wide Area Search for Planets (WASP) project this week at an international conference in Suzhou, China, and have been called WASP-3, WASP-4 and WASP-5, according to Telegraph.co.uk.
The WASP project is the most ambitious in the world designed to discover large planets and relies on “super cameras“ that monitor millions of stars in the sky.
Prof Andrew Cameron, of St Andrews University says the new finds add to two alien planets found by the team last year: “All three planets are similar to Jupiter, but are orbiting their stars so closely that their ’year’ lasts less than two days. These are among the shortest orbital periods yet discovered“.
Being so close to their star, the surface of the newly-found planets will be more than 2000 degrees centigrade, so it is unlikely that life as we know it could survive there. “But the finding of Jupiter-mass planets around other stars supports the idea that there are also many Earth-sized planets waiting to be discovered as astronomers’ technology improves,“ he says.
These new planets were detected as they pass in front of, or ’transit,’ their host star. This blocks some starlight and causes a small dip in the brightness of the star. The WASP cameras monitor myriad stars, looking for these tell-tale dips. Dr Coel Hellier, of Keele University, comments: “When we see a transit we can deduce the size and mass of the planet and also what it is made of, so we can use these planets to study how solar systems form.“
Over 200 extra-solar planets (those that orbit other stars, rather than our Sun) are currently known to astronomers. WASP-4 and WASP-5 are the first planets discovered by the WASP project’s cameras in South Africa, and were confirmed by Swiss and French astronomers. “These two are now the brightest transiting planets in the Southern hemisphere“ said Dr Hellier.
WASP-3 is the third planet that the team has found in the North, using the SuperWASP camera sited in the Canary Islands. Dr Don Pollacco, of Queen’s University Belfast, said “We are the only team to have found transiting planets in both the Northern and Southern hemispheres; for the first time we have both SuperWASP cameras running, giving complete coverage of the whole sky“.

People who suffer from anxiety from stressful life situations may be more likely to experience sleep disturbances for at least the first six months after the event, according to a new study.
The study, authored by Jussi Vahtera, MD, of the Finnish Institute of Occupational Health in Helsinki, Finland, focused on a population sample of 16,627 men and women with undisturbed sleep and 2,572 with disturbed sleep, all of whom participated in a five-year longitudinal observational cohort study, Bio-medicine.org reported.
A measurement of each person’s liability to anxiety, as determined by a general feeling of stressfulness and symptoms of hyperactivity, was assessed at the onset. The occurrence of post-onset life events (i.e., death or illness in the family, divorce, financial difficulty and violence) and sleep disturbances was measured at follow-up five years later.
According to the results, both liability to anxiety and exposure to negative life events were strongly associated with sleep disturbances. Among the men liable to anxiety, the odds of sleep disturbances were 3.11 times higher for those who had experienced a severe life event within six months than for the others. The men not liable to anxiety had odds of only 1.13 for sleep disturbances. For the men and women liable to anxiety, the odds ratio for sleep disturbance zero to six months after divorce was 2.05, with the corresponding ratio being 1.47 for those not liable to anxiety.
“This five-year follow-up showed that exposure to severe stressful events can trigger sleep disturbances in people with undisturbed sleep before the event. Those liable to anxiety before the event seemed to be at a higher risk of post-event sleep disturbances compared with those not liable to anxiety.

Active ingredient in rosemary, known as carnosic acid, can protect the brain from stroke and neurodegeneration.

Rosemary may be one answer to preventing dementia and the effects of aging, says a team of US and Japanese researchers.
Researchers led by Dr. Stuart Lipton of Burnham Institute in La Jolla, Calif., and Dr. Takumi Satoh of Iwate University in Japan say the herb rosemary contains an ingredient that fights off free radical damage in the brain, UPI said.
The researchers say the active ingredient in rosemary, known as carnosic acid, can protect the brain from stroke and neurodegeneration due to injurious free radicals. These free radicals are believed to contribute not only to stroke and neurodegenerative conditions such as Alzheimer’s, but also to the ill effects of normal aging on the brain, the researchers say.
“This works through a mechanism known as redox chemistry in which electrons are transferred from one molecule to another in order to activate the body’s own defense system,“ Lipton says in a statement.