(Portland, OR)  --  A woman who's accused of poking, shoving, and spitting on TriMet bus drivers is in custody.  Thirty-year-old Eucharia Michelle Nwerem is scheduled to be arraigned today on multiple charges, including third-degree assault.  Portland police say Nwerem allegedly shoved a driver operating a northbound bus yesterday on Southeast 82nd Avenue, and reportedly poked a relief driver in the face and pushed him.  Police say Nwerem resisted arrest and assaulted officers before she was taken into custody.