One of the biggest stumbling blocks to securing a massive free trade agreement between the United States and Europe is a sharp disagreement on genetically modified foods. Much of the corn, soybean, sugar beets and cotton cultivated in the United States today contains plants whose DNA was manipulated in labs to resist disease and drought, ward off insects and boost the food supply. Though common in the U.S., they are largely banned in the 28-nation European Union. Washington wants Europe to ease restrictions on imports of GMO foods, but the EU is skeptical they are safe. Intense emotions on both sides of the divide make it difficult to separate between strongly held belief and science. Here is a look at key points in the debate.

SAFE OR UNSAFE?

The U.S. Senate easily confirmed President Barack Obama's selection for ambassador to the United Nations on Thursday.

The Irish-born Samantha Power, a former Obama foreign policy adviser and outspoken human rights advocate, moves into the job formerly held by Susan Rice, who is now Obama's national security adviser.

A $60 million research ship funded by a Google executive is setting sail from San Francisco to study a so-called "dead zone" in the Pacific Ocean and other mysteries of the sea.

The San Francisco Chronicle reports the 272-foot (83-meter) vessel called Falkor was scheduled to leave port Thursday.

It's been so hot in China that people are grilling shrimp on manhole covers, eggs are hatching without incubators and a highway billboard has mysteriously caught fire by itself.

The heat wave — the worst in at least 140 years in some parts — has left dozens of people dead and pushed thermometers above 40 degrees C (104 F) in at least 40 cities and counties, mostly in the south and east. Authorities for the first time have declared the heat a "level 2" weather emergency— a label normally invoked for typhoons and flooding.

A big new study says as the world gets warmer, people are more prone to get hot under the collar. Scientists found that aggressive acts like violent crimes and wars become more likely with each added degree.

The research analyzed 60 studies of such things as the historic collapses of empires, recent wars and violent crime rates in the United States. They found a common thread: Extreme weather — hot or dry — means more violence.

The British government has stepped in to stop singer Kelly Clarkson from taking a ring once owned by author Jane Austen out of the country.

The "American Idol" winner bought the gold and turquoise ring at auction last year for just over 150,000 pounds ($228,000).

One Direction singer Louis Tomlinson's career in heading in a new direction.

The boy band star signed up to play a game for English football club Doncaster, a team that plays in the second-tier League Championship.

Charlie Chaplin's cane, costumes from the "Sound of Music" and a jacket worn by Steve McQueen in "Bullitt" have sold for several million dollars at an auction of Hollywood memorabilia.

The Los Angeles Times reported that a cane from Chaplin's "Modern Times" went for $420,000 at the auction held Sunday and Monday. That includes auction house fees.

Russian Sports Minister Vitaly Mutko says a new law cracking down on gay rights activism will be enforced during the 2014 Olympics in Sochi.

Mutko's statement on Thursday follows assurances from the International Olympic Committee that neither athletes nor visitors to the games would be subject to discrimination under the law.

Uruguay's unprecedented plan to put the government at the center of a legal marijuana industry has made it halfway through congress, giving President Jose Mujica a long-sought victory in his effort to explore alternatives to the global war on drugs.

All 50 members of the governing Broad Front coalition approved the proposal in a party line vote just before midnight Wednesday, keeping a narrow majority of the 96 lawmakers present after more than 13 hours of passionate debate.