The major indices turned lower on Thursday. The Dow Jones Industrial Average closed down 49.84 points to 13,860, the NASDAQ closed down 0.18 points to 3,142 and the S&P 500 closed down 3.85 points to 1,498. The Davidson 99, which measures stocks in seven western states, including 19 in Oregon, closed down 0.71 points to 188.88. Among regional stocks posting the biggest percent changes were Planar Systems (NASDAQ: PLNR), which closed up 6.78 percent to $1.73, and TriQuint Semiconductor (NASDAQ:…