In the cities of Najaf and Karbala, home to two of Shiite Islam’s holiest sites, hundreds of thousands attended commemorations for Ayatollah Ali Khamenei, who extended Iran’s influence in Iraq.

The I.M.F. projected world output would fall to 3 percent for the year, a number pushed down by high commodity prices.

Behind closed doors, millions of Americans are stepping into one of the hardest roles they’ll ever take on: caring for their aging parents.