Officials say legislation will begin a paradigm shift in how college campuses in California prevent and investigate sexual assaultsThe governor of California, Jerry Brown, has signed a bill that makes the state the first in the United States to define when yes means yes and adopt requirements for colleges to follow when investigating sexual assault reports.State lawmakers last month approved a bill by Senator Kevin de Leon, a Los Angeles Democrat, as states and universities across the US are under pressure to change how they handle rape allegations.