Raoul Wallenberg is credited with saving thousands of Jews in Budapest during the Nazi occupation by giving them Swedish travel papers or moving them to safe houses. The Swedish diplomat was arrested by the Soviet Red Army more than six decades ago. His fate has been a mystery ever since.

On Monday, the chief archivist of Russia's counterintelligence service said the agency will continue searching for clues about his fate.

As part of a new tech segment, we're occasionally going to be looking at a concept, invention or tool that's altered the way the world works. To start things off, we asked Doug Wilson, director of Linotype: The Film, to tell us about — what else? — the linotype.

Headphones or earbuds are becoming common in the workplace. Not just for listening to music on a break, they allow people to tune out their co-workers all day long. But in many cases, those same co-workers are still communicating — online.

Melissa Gore, a project manager at Huge, a Brooklyn, N.Y., digital branding agency, works side-by-side at long tables with hundreds of others. But she doesn't hear the chatter and commotion.

"I just have some headphones on," she says. "I get in the zone with Spotify and sometimes people have to wave their hand in front of me."

On Memorial Day, many of us flip burgers, spear hot dogs, and whack a ketchup bottle trying to coax a stubborn glob of the stuff out and onto the bun. Now, a team of scientists at MIT has decided that this ketchup-to-bottle adhesion is a problem that must be fixed. Melissa Block talks with doctoral MIT student Adam Paxson about a solution some researchers have developed.

Millions of men and their doctors are trying to understand a federal task force's recommendation against routine use of a prostate cancer test called the PSA.

The guidance, which came out last week, raises basic questions about how to interpret medical evidence. And what role expert panels should play in how doctors practice.