CHICAGO Using a fan to circulate air seemed to lower the risk of sudden infant death syndrome in a study of nearly 500 babies, researchers reported Monday. Placing babies on their backs to sleep is the best advice for preventing SIDS, a still mysterious cause of death.

ANCHORAGE, Alaska The federal government will designate "critical habitat" for polar bears off Alaska's coast, a decision that could add restrictions to future offshore petroleum exploration or drilling.

PHILADELPHIA Most people over 75 should stop getting routine colon cancer tests, according to a government health task force that also rejected the latest X-ray screening technology.

SAO PAULO, Brazil More than 370 penguins that mysteriously washed up on Brazil's equatorial beaches were flown south on a huge air force cargo plane and released closer to the frigid waters they call home, animal advocates said Monday.

WASHINGTON A small asteroid was headed for a fiery but harmless dive into Earth's atmosphere early Tuesday morning over Africa, astronomers said in a first of its kind advance warning.

STOCKHOLM, Sweden Two French scientists who discovered the AIDS virus and a German who defied convention in showing a viral cause for cervical cancer shared the Nobel Prize in medicine Monday for breakthroughs that have led to lifesaving drugs and a vaccine.

GENEVA A bad electrical connection likely caused the malfunction that sidelined the world's largest atom smasher days after it was launched with great fanfare, a senior scientist said Monday.

The awarding of the Nobel Prize in medicine on Monday writes a postscript to a bitter scientific dispute in the 1980s over who deserved credit for discovering HIV and the resulting test to screen blood for it.

WASHINGTON One in 75 patients who gets a knee or hip replaced must get it replaced again within three years, new research finds, although the studies underscore a question: Just how much pounding can a new joint take if you want it to last?

HILTON HEAD, S.C. Forget wind.

Who knew? Women, it turns out, sleep better than men, says Wichita sleep medicine specialist Thomas Bloxham. Left to our own devices, we sleep longer and deeper, with fewer problems such as narcolepsy or sleep apnea.

Cynthia Reilly, director of the practice development division of the American Society of Health-Systems Pharmacists, offers advice for shopping online:

So much has been written about breast cancer it's hard to imagine there's anything new to say about a topic that will directly affect more than 182,000 women this year in the United States.

TRENTON, N.J. An injected Johnson & Johnson biologic drug used to treat several immune diseases controlled Crohn's disease, a difficult-to-treat bowel disorder, better than a widely used pill, a study found.

WASHINGTON Conservationists have taken the first detailed look at the world's mammals in more than a decade, and the news isn't good.

STOCKHOLM, Sweden Three European scientists shared the 2008 Nobel Prize in medicine on Monday for separate discoveries of viruses that cause AIDS and cervical cancer, breakthroughs that helped doctors fight the deadly diseases.

CHICAGO Warning: young children should not keep hedgehogs as pets - or hamsters, baby chicks, lizards and turtles, for that matter - because of risks for disease.

GREEN SWAMP PRESERVE, N.C. Laura Gadd pauses at the edge of a pristine savanna, delicately lifting her feet to avoid trampling any venus flytraps hidden underfoot.

CHICAGO More children have died from flu because they also had staph infections, according to a new government report that urges parents to have their kids get the flu shot.

SALT LAKE CITY Rattlesnakes aren't to be trifled with, but if you're trying to collect the sound of every creature in the West that slithers, hops, flies or flops, distance isn't a luxury you can afford.

Recent winners of the Nobel Prize in physiology or medicine, and their research, according to the Nobel Foundation:

WASHINGTON The government is urging consumers to thoroughly cook frozen chicken dinners after 32 people in 12 states were sickened with salmonella poisoning.

SUZHOU, China She's around 80 years old. He's 100. Breathless scientists watched as the world's most endangered turtles successfully mated.

GILCHRIST, Texas One of North America's renowned bird migration and bird watching areas is strangely silent.

NEW YORK Federal health officials have issued a public health warning against rabies after an Iraqi puppy with the disease arrived in the United States.

WASHINGTON Tiny traces of melamine, the chemical that has set off a global food safety scare, are not harmful in most foods, except baby formula, government experts said Friday.

How closely have you been following the latest nutritional research? Here's a true/false quiz to test yourself:

WASHINGTON The largest study of U.S. children ever performed - aiming to track 100,000 from conception to age 21 - will start recruiting mothers-to-be in North Carolina and New York in January.

WASHINGTON Talk about going out with a win.

MIAMI Phylicia Rashad's father died more than 20 years ago of a heart attack, but she has recently wondered if that needed to be the case.

MIAMI Our worries.

MIAMI Norma Maynard, a 59-year-old Hialeah, Fla., grandmother, died twice in the last six weeks.

Bone loss commonly occurs as we age, especially for women. Until recently, women were routinely prescribed estrogen after menopause to prevent bone loss and fractures.

CHICAGO The economy isn't the only thing that's sagging - so are faces, breasts and bellies as would-be cosmetic surgery patients increasingly opt against costly nips and tucks because of tough financial times.

BOSTON Deborah Anderson had heard the urban legends about the contraceptive effectiveness of Coca-Cola products for years. So she and her colleagues decided to put the soft drink to the test. In the lab, that is.

The 2008 Ig Nobel winners, awarded Thursday at Harvard University by the Annals of Improbable Research magazine:

WASHINGTON A top government health official Thursday rejected pediatricians' calls for an immediate ban on over-the-counter cough and cold medicines for young children, saying it might cause unintended harm.

TORONTO Public health officials in Canada announced Thursday that they are looking for 27 people who may have been exposed to tuberculosis from an infectious passenger during a bus trip in late August.

WASHINGTON Bluefin tuna from both sides of the Atlantic get together as juveniles, a discovery that could affect how the tuna fishery is managed. While North American and Mediterranean bluefin return home to spawn, a study published in Friday's edition of the journal Science reveals that as youngsters the fish travel long distances to intermix.

Finally, after six years of waiting, country-of-origin labeling has arrived.

PORTLAND, Maine A ferocious-looking denizen of the deep that can gobble up whole urchins and crabs in a few swift chomps needs protection, according to a petition filed with the federal government.

NEW YORK A computer is as good as a second pair of eyes for helping a radiologist spot breast cancer on a mammogram, one of the largest and most rigorous tests of computer-aided detection found.

WASHINGTON If there ever is another anthrax attack, the letter carrier may deliver your antibiotics. Federal health officials are beginning a project in Minneapolis-St. Paul to let letter carriers stockpile a personal supply of emergency antibiotics so they are protected and ready to deliver aid to the rest of the city at a moment's notice.

NEW YORK The AIDS virus has been circulating among people for about 100 years, decades longer than scientists had thought, a new study suggests. Genetic analysis pushes the estimated origin of HIV back to between 1884 and 1924, with a more focused estimate at 1908.

WALNUT CREEK, Calif. Four years ago, Jessica Soske of Berkeley, Calif., was diagnosed with a rare neuro-endocrine disease that affects the use of her muscles. She had a tough time coping and coming to terms with her body's changes. Soske, a former attorney, tends to get stuck in her analytical mind, so traditional psychotherapy didn't help, she says.

ATLANTA The government approved a new genetic test for the flu virus Tuesday that will allow labs across the country to identify flu strains within four hours instead of four days.

HONOLULU The federal government took a new, ecosystem-based approach to the endangered species list on Tuesday, proposing an all-at-once addition of 48 species, including plants, two birds and a fly, that live only on the Hawaiian island of Kauai.

HELENA, Mont. Environmental groups sued the federal government Tuesday to protect wolverines under the Endangered Species Act, saying the Interior Department disregarded scientific conclusions that the species was in jeopardy.

CHICAGO Could voting for president be hazardous to your health? An analysis of Election Day traffic deaths dating back to Jimmy Carter's 1976 win suggests yes, but the authors say that's no reason not to go to the polls.

JOHANNESBURG, South Africa Making tests and treatment for malaria free dramatically increases the number of people who seek treatment for the disease that kills 1 million people a year, an international medical aid group said Tuesday.