A new government study suggests a lot of teenage girls are clueless about their chances of getting pregnant.

In a survey of thousands of teenage mothers who had unintended pregnancies, about a third who didn't use birth control said the reason was they didn't believe they could pregnant.

Twitter has acquired Summify, a Vancouver-based social news aggregator.

"We're extremely excited to announce that Summify has been acquired by Twitter!" Summify announced on its website on Thursday.

The director of Interpol says there is no specific intelligence the Olympics will be targeted.

Ron Noble, secretary-general of the international police agency based in France, also said Thursday that Britain does a good job of screening identification documents against the Interpol database as part of its security procedures.

An international group seeking to preserve the legacy of Winston Churchill is announcing plans Thursday to create the first U.S. research center devoted to the longtime British leader.

The new National Churchill Library and Center will be established between 2013 and 2015 at George Washington University in Washington, D.C., with an $8 million (€6.23 million) pledge from the Chicago-based Churchill Centre.

It's high noon for the humble leap second.

After ten years of talks, governments are headed for a showdown vote this week on an issue that pits technological precision against nature's whims.

Russia will look into the possibility that a U.S. radar station could have inadvertently interfered with the failed Mars moon probe that plummeted to Earth, Russian media reported Tuesday, but experts argued that any such claims were far-fetched.

NASA spokesman Bob Jacobs also said the U.S. space agency was not using the military radar equipment in question at the time of the Russian equipment failure, but instead was using radar in the Mojave desert in the western United States and in Puerto Rico.

If a day without Wikipedia was a bother, think bigger. In this plugged-in world, we would barely be able to cope if the entire Internet went down in a city, state or country for a day or a week.

Sure, we'd survive. People have done it. Countries have, as Egypt did last year during the anti-government protests. And most of civilization went along until the 1990s without the Internet. But now we're so intertwined socially, financially and industrially that suddenly going back to the 1980s would hit the world as hard as a natural disaster, experts say.

Even though Jennifer Hudson has dropped more than 80 pounds (36 kilograms), the singer and actress said she would have no problem gaining weight for Hollywood if the proper movie role comes her way.

"When I do films, it has to be led by something through me — like my passion for it," Hudson said before a book signing in suburban Atlanta on Wednesday. "I just don't want to hop into anything. So if I commit myself to something, than it'll be worth it no matter what character it is."

YouTube is launching a film festival that will play out online and ultimately send 10 finalists to the Venice Film Festival.

The Google Inc.-owned video site announced Thursday that Your Film Festival will take submissions of short films up to 15 minutes in length between Feb. 2 and March 31. Fifty semi-finalists will be selected by Scott Free Productions, Ridley and Tony Scott's production company.

A former Israeli military intelligence chief said Iran has all the components to build a nuclear bomb, an Israeli newspaper reported Thursday.

It was not clear whether Amos Yadlin, who retired in November 2010, was referring to the mechanical elements of a bomb or implying the Iranians have sufficient weapons-grade uranium, a critical ingredient for bombmaking.