Nikkei rises for 8th day as strong U.S. data, weak yen boost mood

* Weak yen lifts index-heavy stocks but some exporters fall on profit-taking * Nikkei winning streak longest since Dec * Resistance seen at 15,500 - analyst By Ayai Tomisawa TOKYO, Aug 20 (Reuters) - Japan's Nikkei share average rose for an eighth day on Wednesday morning as the yen weakened, but gains were subdued as many investors stuck to the sidelines ahead of the U.S. Federal Reserve's annual meeting starting on Thursday. The Nikkei rose 0.2 percent to 15,478.72 in mid-