Nearly half of first marriages break up within 20 years, a new government study finds. With those odds, you might wonder: Would we be better off living together first?

The new research, part of a marriage survey of 22,000 men and women, suggests times have changed from the days when living together signaled poor chances for a successful marriage later.

Michael Bloomberg, the billionaire who has made reducing smoking one of his signature causes as mayor of New York City, is committing $220 million to his charity to go toward reducing tobacco use in countries that are home to millions of smokers.

He announced his four-year commitment to Bloomberg Philanthropies at the 15th World Conference on Tobacco or Health in Singapore on Thursday. The new commitment will bring the total amount he has directed to his eponymous charity to over $600 million for anti-smoking efforts since 2007.

Police in the southern Russian province of Dagestan said Friday that a Muslim cleric, who criticized radical Islamists, has been killed by a powerful explosion.

Gitinmagomed Abdulgapurov, an imam in a mosque in the central city of Buinaksk, became the fifth Muslim cleric in the restive province killed in the past two years.

Scientists analyzing the surface of a giant asteroid are puzzling over bright spots that represent some of the purest materials seen so far by a NASA spacecraft.

NASA on Wednesday released new images of the asteroid Vesta taken by the orbiting Dawn spacecraft that show some places on the surface twice as bright as others.

A run of poor economic figures weighed on markets Thursday in what is turning out to be one of the worst weeks for stocks this year.

Disappointing figures out of China and the 17-country eurozone have prompted investors to cash out of stocks, following a strong run in previous weeks. Many traders are wary of further pushing up indexes, many of which recently hit multi-month highs.

"CSI" creator Anthony Zuiker is making a movie destined for the small screen.

The creator of the hit CBS television show plans to debut the as-yet-unfinished feature, "Cybergeddon," on Yahoo in installments this fall. His latest foray into online storytelling follows his partnership on a horror series for YouTube.

Beware the new iPad, not because it's an inferior product, but because it's a superior one. Using one is like living the life of a millionaire for a day, then getting dumped back in your regular life. Your eyes are now opened to how miserable your existence is.

The big culprit here is its stunner screen. It has four times the resolution of the previous models. That's a big, big jump, which makes text and high-resolution images look amazingly sharp and clear. High-definition movies look amazingly detailed.

Ferrari driver Felipe Massa has shrugged off mounting speculation the team is preparing to replace him, saying he is accustomed to premature reports of the end of his Formula One career.

Massa's poor performance in last weekend's season-opening Australian Grand Prix had heightened expectations that Ferrari will fire him, with Italian media already speculating upon a replacement.

Allergy season has come early and hit with a wheezing vengeance in parts of the South and Midwest this year, thanks largely to an unusually warm winter. Abundant pollen is causing watery eyes, sniffles and sneezing.

Doctors say the spring misery stretches from Mississippi to Ohio and from Georgia to Texas, where drought conditions have exacerbated the problem. Forecasters and allergists blame the unseasonably warm weather, and few cold snaps, for causing plants to bloom weeks early and release the allergy-causing particles.

Too often, people pass a cardiac checkup only to collapse with a heart attack days later. Now scientists have found a clue that one day may help doctors determine if a heart attack is imminent, in hopes of preventing it.

Most heart attacks happen when fatty deposits in an artery burst open, and a blood clot then forms to seal the break. If the clot is too big, it blocks off blood flow.