(Portland, OR)  --  A registered sex offender in Portland is accused of taking sexually explicit photos of a teenage girl.  Luis Tryborn was arrested Wednesday and is being held on one-million-dollars bail at the Multnomah County Jail.  In court yesterday, he pled not guilty to four counts of using a child in a display of sexually explicit conduct.  Tryborn, the director of the Portland Soccer Academy, is a registered sex offender for a 1997 conviction for third-degree sex abuse.