Donald Trump takes part in a CNN town hall event in Milwaukee on Tuesday. Darren Hauck/Getty Images hide caption

Dirk van der Maelen, a Social Democratic member of Belgium's Federal Parliament, defends the country's motto, seen here: "Unity makes strength." He think Belgium needs to remain unified, now more than ever. But there are also renewed calls for the country to split into two. Melissa Block/NPR hide caption

Joe Castro with Louis Armstrong and Teddy Wilson, backstage at Basin Street in 1956. Whitestone Photo /Courtesy of James Castro hide caption

Tunisian soldiers patrol the outskirts of Ben Guerdane, in southern Tunisia, on March 8. Islamic State extremists crossed over from nearby Libya on March 7. They were beaten back, but the episode raised concerns that Libya's chaos could spread to Tunisia. AP hide caption

Fatty plaque (shown here in yellow) blocks about 60 percent of this coronary artery's width. The increasing thickness of artery walls is just one factor that can increase vulnerability to a heart attack or stroke. Prof. P.M. Motta/G. Macchiarelli, S.A. Nottola/Science Source hide caption