The alleged mastermind of the Sept.11 attacks, Khalid Sheikh Mohammed, and four other defendants appeared in a military courtroom at Guantanamo Bay, Cuba, over the weekend to answer a roster of charges filed against them. The hearing was supposed to be a straightforward arraignment, but nothing went according to plan.

Graduation is supposed to in part be about celebrating the future, but last year in Joplin, Mo., shortly after the high school graduation ceremony, an EF-5 tornado — the highest-strength rating — destroyed one-third of the city and killed 161 people, including one teen who had received his diploma that day.

Across the U.S., 40 percent of children are now born to unmarried parents. This demographic shift, primarily among younger, low-income parents, can pose a challenge to a child support system designed chiefly to extract money from paychecks.

A court in Minneapolis is now trying a new approach, one that's about more than just the money as it attempts to keep both parents involved in the lives of their kids.

Very soon, Facebook will go public. That means anyone will be able to buy shares of the social networking giant on the Nasdaq exchange. But sophisticated investors have already been buying pieces of Facebook and many other hot tech stocks, on private exchanges.

And now it seems that trading in private company shares is poised to grow, thanks to recent changes in the law.

Endurance athletes sometimes say they're "addicted" to exercise. In fact, scientists have shown that rhythmic, continuous exercise — aerobic exercise — can in fact produce narcoticlike chemicals in the body.

Now researchers suggest that those chemicals may have helped turn humans, as well as other animals, into long-distance runners.

The man behind the research is University of Arizona anthropologist David Raichlen, a runner himself. He does about 25 miles a week.

When it comes to walking, the easy part is understanding the benefits: Regular, brisk walks can strengthen our bones, help control blood sugar, help lower blood pressure and cholesterol, and the list goes on. The hard part is finding the time to fit it in.

Engineering physical activity back into Americans' daily lives is the goal of an educational campaign launched by Kaiser Permanente,an Oakland, Calif.-based health plan.

Somewhere on the path to the White House this year, a powerful set of ideas began to creep into the mainstream debate over which direction the country will take.

These are ideas that not too long ago were written off as marginal, or even worse, a little kooky. They come from Libertarians: free and open markets and extremely limited government. Those ideals are now becoming more mainstream and are influencing the Republican Party.

According to exit polls, angry Greek voters have overwhelmingly punished the two major parties that endorsed draconian international loan agreements.

There is no front-runner in sight, but the fringe parties on the left and the right that strongly oppose the bailout terms have benefited the most.

The socialist PASOK and the conservative New Democracy parties that have alternated for four decades — and uneasily co-governed for the last six months — are imploding.

The end of Republican Sen. Richard Lugar's 35-year career representing Indiana in the U.S. Senate could be imminent.

A new Howey/DePauw Indiana Battleground Poll shows the octogenarian trailing State Treasurer Richard Mourdock by 10 percentage points ahead of Tuesday's GOP Senate primary. The survey also finds that the venerable Lugar is increasingly viewed by home-state voters in a negative light.