Blog Posts by Lylah M. Alphonse, Senior Editor, Yahoo! Shine

PFCs may make certain vaccines less effective. Is your child at risk?Certain vaccines may be much less effective for kids who have been exposed to high levels of perfluorinated compounds (PFCs), a group of chemicals used to make materials stain-, water-, wrinkle- and flame-resistant, a new study shows.

Given that the chemicals are found in many common household goods -- including pizza boxes, carpets, and non-stick pans -- more children than expected may be at risk.

The study, which was published last week in the Journal of the American Medical Association, found that children with high amounts of PFCs in their bloodstreams produced fewer antibodies after receiving vaccines for Diphtheria and Tetanus -- so few that they could be at risk for getting those diseases, in spite of the vaccinations.

"When the PFC concentration increases in the body, the immune system gets more sluggish and is less capable of maintaining a defense mechanism against microorganisms," the study's lead researcher, Dr. Philippe Grandjean of the Harvard School of Public Health in

Makayla Hayes, 14, won the international grand prize in the 2011 National Geographic Kids photo contest for this cool under-water shot.Kids have an interesting perspective on just about everything, and when you hand a kid a camera you can get a glimpse into her world. This year's winners in the Fifth Annual National Geographic Kids International Photo Contest captured humorous quips, quirky sights, and poignant moments that may be impossible to see without a view finder.

Judges sifted through more than 12,000 images submitted by kids in the United States and Canada, Bulgaria, Egypt, Hungary, Indonesia, Lithuania, Slovenia, South Africa, Turkey, and the United Kingdom. Winners were chosen from each region, but the international grand prize went to 14-year-old Makayla Hayes of Marion, Illinois, for her eerie underwater self-portrait.

We've pulled together a slideshow (above) of the top shots from this year's contest; you can check out the 2010 winners and 2009 winners at National Geographic Kids.

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How do you celebrate Valentine's Day?
Valentine's Day falls on a Tuesday this year -- guys, take note! -- and some people have been orchestrating for the perfect romantic night far in advance.



Not everyone has an elaborate Ultimate Proposal in the works, of course, but there are still plenty of planners out there. According to a survey of 3,000 people by OpenTable.com, 53 percent of respondents make their reservations at least a week in advance, and some a saving spots and more than one romantic restaurant.

Related: Single? 5 ways to actually enjoy Valentine's Day

"About half of diners surveyed anticipate booking a romantic evening on the 14th, while another 26 percent are choosing to celebrate on Saturday night, February 11," Caroline Potter, Chief Dining Officer for OpenTable.com, said in a statement. "Regardless of which night diners plan to celebrate, Valentine's Day promises to be a bustling day for romantic hot spots."

Seventy-five percent of those surveyed say wine or champagne makes them feel more romantic,

A new study shows that men are more likely to experience memory loss as they age.Is your husband or boyfriend tuning you out, or did they actually just forget what you said? A new study shows that men are more likely than women to develop mild memory loss as they get older, leading to dementia and Alzhimer's disease.

Related: How to prevent memory loss

According to "The Incidence of MCI Differs by Subtype and is Higher in Men," published Wednesday in the journal "Neurology," researchers from the Mayo Clinic followed 1,450 senior citizens for three years. Participants took memory tests every 15 months, and by the end of the trial 7.2 percent of men and 5.7 percent of women had developed Mild Cognitive Impairment, or MCI.

"The condition appears to affect men and those who only have a high school education more than women and those who have completed some higher education," a Mayo Clinic report said.

But that doesn't mean that women aren't out of the woods when it comes to memory loss. "Women may develop risk factors for MCI at a later age, but the effects may be

Is the man bun sexy?Here's another thing to add to the growing list of Things for Men That Used to Be for Women: The bun. As in one's hair, wound into a knot at the back or top of one's head.

Yes, the 'do that many movie directors use to indicate "this girl is a geek" is now the hot hair trend for hipster guys -- mainly in Brooklyn, though we've heard rumors that the librarian look is catching on with men in other cities as well.

Long-haired celebrities have rocked the man bun for years (think Bush frontman Gavin Rossdale, actor Orlando Bloom, Patriots playerTom Brady, and comedian John Belushi as the Samurai Deli guy on SNL). And in other cultures, men routinely bundle their locks up to get them out of the way. Ponytails used to be the way to go, but now, guys in the know say, invoke images of "Steven Seagal, hippie uncles and the like," Sam Anderson, a 30-year-old bartender in Brooklyn, told the New York Times.

The man bun isn't very complicated, which may be it's biggest plus; unlike the careful

undefinedProject Runway star and mentor Tim Gunn says that he hasn't had sex in nearly three decades -- and he's totally fine with that.

Related: Yahoo! Shine interviews "Project Runway" mentor Tim Gunn!

The 58-year-old fashion icon joined the co-hosts of ABC's "The Revolution," on Tuesday, where he told the audience: "I haven't had sex in 29 years. Do I feel like less of a person for it? No. Not even remotely."

"I'm a perfectly happy, fulfilled individual," he added. "And I have feelings. It's not as though I'm some barren forest."

He's stayed celibate for so long, he says, because he was wounded by an old relationship. "It's very personal," he said, choosing his words carefully and getting a bit emotional. "I was in a very intense relationship for a long time. And my partner ended it, saying that, quite frankly, he was impatient with my sexual performance." The AIDS epidemic was just starting, Gunn added, which was an added concern. "I'm happy to be healthy and alive, quite frankly."

He