BLOOMINGTON, Indiana — A 56-year-old woman has been charged after an 18-year-old Indiana University student repeatedly was stabbed in the head on a public bus in an attack the school says was because the victim is Asian. The victim told investigators she was standing and waiting for the exit doors to open on a Bloomington Transit bus Wednesday afternoon when another passenger began striking her in the head, Bloomington police said in a release. A witness who also was riding the bus followed the woman’s attacker and contacted police, who later arrested Billie R. Davis of Bloomington.