(Portland, OR)  --  Police say they've arrested a man accused of shooting a gun during a demonstration in downtown Portland.  The incident happened Saturday afternoon near Southwest 4th and Yamhill.  No one was hurt.  Police say 27-year-old Skylor Jernigan is charged with Unlawful Use of a Weapon, Menacing, Reckless Endangering and Discharging a Firearm in the City.