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A tiny pale deer mouse living on a sand dune in Nebraska looks set to become an icon of biology.

Within just a few thousand years, generations of the mice have evolved a sandy-coloured coat camouflaging themselves from predators.

Most striking is that these mice acquired the mutation for pale fur naturally, then rapidly passed it on.

That makes the fast-evolving deer mouse one of the best examples yet studied of "true" natural selection in action.

Deer mice are one of the most abundant and widespread mammals in North America.

Usually the mice have a dark coat, which enables them to blend in with dark soils and avoid being seen by predators such as owls and hawks.

But at Sand Hills in Nebraska, pale-coated mice abound.

"We decided to investigate the striking contrast between mice living on the pale Sand Hills and mice living on darker soils just a few miles outside," says Dr Catherine Linnen of Harvard University in Cambridge, Massachusetts, US.

"We were also intrigued by the fact that Sand Hills had formed within the last 8,000 to 15,000 years, which implies the light colour of the Sand Hills mice became advantageous only recently."

Linnen and colleagues at Harvard and the University of California at Berkeley have now worked out exactly how the mice evolved so quickly.

They have published the details in the journal Science.

They discovered that the light coat colour is coded by a single gene, dubbed Agouti. This is expressed at a higher amount, and for longer, than the genes that code for dark hair.

Most animals known to quickly evolve new features do so by expressing a variation of a gene that already exists, rather than evolving a new type of gene altogether.

But the researchers found that the Agouti gene only appeared among wild deer mice in Sand Hills around 4,000 years ago, just a few thousand years after dark mice colonised their new home. That means it first evolved 8000 generations of mice ago.

They also ascertained that this new gene has since become very common among the Sand Hills mice.

"The light gene wasn't in existence, so the mice had to "wait" until a particular mutation occurred and then selection had to act on that new mutation," says team member Professor Hopi Hoekstra, also of Harvard University.

"It's a two part process. First the mutation has to occur and second, selection has to increase its frequency."

The researchers say it is the first time that it has been possible to document the appearance of a gene, its selection and subsequent spread through a population of wild animals.

And that has allowed them to estimate the "strength" of the natural selection pressure.

Having light coloured fur gives the paler Sand Hills mice a 0.5% survival advantage.

"It doesn't seem that much, but multiplied over thousands of individuals over hundreds of years, it makes a huge difference," says Prof Hoekstra.

"Ours is a very complete story," adds Dr Linnen.

"We've been able to connect changes at DNA level to the ability of deer mice to survive in nature."

In some respects, the dune-living deer mice are similar to the famous peppered moths of northern England.

For decades, the peppered moths (Biston betularia) have been heralded as one of the best-examples known of a wild animal adapting to its environment due to natural selection.

Originally, most peppered moths were lightly coloured, to blend with the lightly coloured bark of trees.

Due to widespread pollution caused by the Industrial Revolution, soot blackened the trees and newly conspicuous lightly coloured moths were picked off by predators, a selection pressure that triggered the rise of more dark coloured moths.

"In both species, changes in colour evolve rapidly due to selection by visually-hunting predators," says Prof Hoekstra.

But the study by Dr Linnen and Prof Hoekstra's team takes our undertaking of natural selection to a much deeper level.

The selection pressure on the moths was technically artificial, caused by pollution produced by people. Whereas the selection causing the pale mice is truly natural.

What is more, the scientists have found the gene responsible, and worked out exactly how long it took to evolve and take hold in the population.

"Despite the fact that the peppered has been an icon of 'evolution in action', we do yet know the genetic changes involved," says Prof Hoekstra.

"Once researchers find the pigmentation gene responsible for moth colour change, they can do the same types of analyses we have done. It will be really interesting to compare these estimates between mice and men."

Scientists at the University of Minnesota Medical School say that the feeling of hopelessness may make increase the risk of stroke in women.

Writing in Stroke: Journal of the American Heart Association, the researchers have revealed that even healthy middle-aged women, when feeling hopeless, seem to experience the thickening of arteries in the neck, a precursor to stroke

Linking hopelessness with negative thinking and the feeling of uselessness, they say that it affects arteries independent of clinical depression, and before women develop clinically relevant cardiovascular disease.

For their study, the researchers looked at 559 healthy women—average age 50, 62 percent white, 38 percent African American—who did not show any signs of clinical cardiovascular disease.

They measured hopelessness with a two-item questionnaire assessing expectancies regarding future and personal goals. Depressive symptoms were measured with a 20-item Center for Epidemiologic Studies Depression Scale. Thickness of neck arteries was assessed using ultrasound.

The researchers found consistent, progressive, and linear association between increasing neck artery thickness and rising levels of hopelessness.

They say that the overall difference in arterial thickening between women with higher versus lower hopelessness scores, about .02 millimetres (mm), was equal to about one year of thickening.

Those with the highest hopelessness scores had an average .06 mm greater thickening than those in the lowest group — a clinically significant difference. This correlation remained after adjusting for any influence of age, race, income, cardiovascular risk factors, and depression.

"Previous studies have shown that hopelessness is associated with cardiovascular disease outcomes in men and also in women with documented heart disease. However, this is the first study to suggest that hopelessness may be related to subclinical cardiovascular disease in women without clinical symptoms of heart disease and who are generally healthy," said Dr. Susan A. Everson-Rose, principal investigator of the study, associate director of the Program in Health Disparities Research, and associate professor of medicine.

"These findings suggest that women who experience feelings of hopelessness may have greater risk for future heart disease and stroke. In fact, our data indicate that hopelessness may be uniquely related to cardiovascular disease risk. We did not see similar relations when looking at global depressive symptoms," Everson-Rose said

The researchers used data from Chicago and Pittsburgh sites of the Study of Women's Health Across the Nation (SWAN) to examine associations of hopelessness, and depressive symptoms with carotid IMT, an early marker of atherosclerosis.

"The findings we observed are based on cross-sectional data — a snapshot in time — so we look forward to examining the longitudinal relations between hopelessness and heart disease risk in women," Everson-Rose said.

Source TOI

Circumcision, which has helped prevent AIDS among heterosexual men in Africa, doesn't help protect gay men from the virus, according to the largest U.S. study to look at the question.

The research, presented at a conference Tuesday, is expected to influence the government's first guidance on circumcision.

Circumcision ``is not considered beneficial'' in stopping the spread of HIV through gay sex, said Dr. Peter Kilmarx, of the U.S. Centers for Disease Control and Prevention.

However, the CDC is still considering recommending it for other groups, including baby boys and high-risk heterosexual men.

UNAIDS and other international health organizations promote circumcision, the cutting away of the foreskin, as an important strategy for reducing the spread of the AIDS virus. There hasn't been the same kind of push for circumcision in the United States.

For one thing, nearly 80 percent of American men are already circumcised _ a much higher proportion than most other countries. Worldwide, the male circumcision rate is estimated at about 30 percent.

Also, while HIV spreads primarily through heterosexual sex in Africa and some other parts of the world, in the United States it has mainly infected gay men. Only about 4 percent of U.S. men are gay, according to preliminary CDC estimates released at the conference this week. But they account for more than half of the new HIV infections each year.

Previous research has suggested circumcision doesn't make a difference when anal sex is involved. The latest study, by CDC researchers, looked at nearly 4,900 men who had anal sex with an HIV-infected partner and found the infection rate, about 3.5 percent, was approximately the same whether the men were circumcised or not.

Government recommendations on circumcision are still being written and may not be final until next year, following public comment. CDC doctors and many experts believe there is a good argument for recommending that baby boys and heterosexual men at a higher risk for HIV be circumcised.

The definition of ``high risk'' is still being discussed, said Kilmarx, chief of the epidemiology branch in the CDC's HIV division.

Circumcision is a sensitive issue laden with cultural and religious meaning, particularly when babies are involved, Kilmarx acknowledged.

``It's seen by many as more than just as medical procedure,'' he said. It's possible the government would just recommend better education for doctors and parents about the procedure's benefits and risks, he added.

The prospect of the government promoting circumcision of infants has already drawn fire from an advocacy group called Intact America. The organization, based in Tarrytown, New York, parked a motorized billboard this week outside the hotel hosting the HIV conference, displaying the message: ``Tell the CDC that circumcising babies doesn't prevent HIV.''

``It's removing healthy, functioning, sexual and protective tissue from a person who cannot consent. You're mutilating a child,'' said Georgeanne Chapin, the group's executive director.

NEW DELHI: Angry over delay in payment of their salaries by cash-strapped Air India management, over 20,000 members of airlines' employee's unions have decided to go on a three-day hunger strike from Tuesday.

"Over 20,000 members of Aviation Industry Employees Guild (AIEG) and Air Corporation Employees Union (ACEU) and some other unions from across the nation have decided to go on hunger strike from today, as the management is rigid over payment of our salaries," J B Kadian, General secretary ACEU said.

The employees threatened that they would again strike work on August 31 if their negotiations with the management fail.

"For the past two months, we have been working for betterment of the airlines, but the management is adamant on the 50 per cent cut in our salaries. It is not acceptable to us," Kadian said, adding "salary is our right and it is government's duty to pay us and no CMD or Minister can unilaterally decide on a cut".

Some airports in the country could face disruption in movement of the flights due to the strike.

Earlier, in July the employees had gone on a strike for two hours and staged demonstrations over the issue.

The meeting of the unions with the Air India CMD last Friday at the Air India headquarters in Mumbai failed and the next round of meeting is scheduled here in the afternoon.

(CNN) -- South Korea will try again Tuesday to get its first space rocket into orbit, state media reported.A series of delays have kept the rocket and its satellite payload earthbound, including a technical glitch that halted Wednesday's countdown less than eight minutes before blastoff.

The Korea Space Launch Vehicle-1 is scheduled to launch from the Naro Space Center on the southern coast about 5 p.m. (4 a.m. ET) Tuesday.

South Korea spent 502 billion won (US $402 million) on the rocket, which is part of an ambitious plan to jump-start the country's space program, South Korea's Yonhap News Agency reported.

Officials plan another rocket launch in April.

The long-term goal is to create an unmanned space probe that can reach the moon by 2025, the agency reported.

The rocket was originally scheduled to be launched in late 2005, before being pushed back to October 2007 and then 2008 due to "administrative and diplomatic reasons," Yonhap reported.

South Korea's space program suffered a blow Tuesday after a satellite launched from its first space rocket failed to reach proper orbit, a science official said.

"All aspects of the launch were normal, but the satellite exceeded its planned orbit and reached an altitude of 360 kilometers," said Ahn Byung-man, the minister of science and technology. The satellite should have separated at about 302 kilometers, according to South Korea's Yonhap news agency.

The cause of the failure was not immediately known. Korean experts were working with Russian scientists, who provided the technology for launch, to determine the reason, Ahn said.

The Korea Space Launch Vehicle-1 lifted off from the Naro Space Center on the southern coast about 5 p.m. (4 a.m. ET) Tuesday.

A series of delays had kept the rocket and its satellite payload earthbound for nearly four years, including a technical glitch that halted last week's countdown less than eight minutes before blastoff.

South Korea spent 502 billion won (US $402 million) on the rocket, which is part of an ambitious plan to jump-start the country's space program, Yonhap reported.

Officials plan another rocket launch in April. The long-term goal is to create an unmanned space probe that can reach the moon by 2025, the agency reported.

The rocket was originally scheduled to be launched in late 2005, before being pushed back to October 2007 and then 2008 due to "administrative and diplomatic reasons," Yonhap reported.

Please Be Extremely Careful especially if you are using internet mail such as Yahoo, Hotmail, AOL and so on…....

This information arrived this morning direct from both Microsoft and Norton. Please send it to everybody you know who has access to the Internet. You may receive an apparently harmless email with a Power Point presentation 'Life is beautiful.'If you receive it DO NOT OPEN THE FILE UNDER ANY CIRCUMSTANCE and delete it immediately.

If you open this file, a message will appear on your screen saying: 'It is too late now, your life is no longer beautiful.' Subsequently you will LOSE EVERYTHING IN YOUR PC and the person who sent it to you will gain access to your name, e-mail and password. This is a new virus which started to circulate on Tuesday afternoon. AOL has already confirmed the severity and the antivirus software's are not capable of destroying it.

The virus has been created by a hacker who calls himself 'life owner.'

This is Emial What i resived form one of my friend..

But i find that it is fack mail and here is the proof :http://en.wikipedia.org/wiki/Life_is_beautiful_virus_hoax