(Portland, OR)  --  Police say they've arrested a man who's accused in a stabbing in Southeast Portland and holing up inside a burning garage.  Authorities say after a three-hour standoff at the garage in the area of Southeast 128th and Rhone Street, 43-year-old Shawn Edward Mahan was apprehended and taken to a hospital as a precaution.  Mahan is accused of stabbing an acquaintance at the home adjacent to the garage.  The victim is expected to survive.