Although investors hang on every comment by Federal Reserve Chairwoman Janet Yellen to get insight on the direction of interest rates and what it means for the economy and asset prices, the real power to determine U.S. interest rates may be in the hands of China, according to Lombard Street Research. Facing an overvalued currency that is hurting corporate profits and slowing growth, China appears ready to dump its $1.3 trillion in U.S. Treasury bonds to drive U.S. interest rates up and strengthen the dollar... (snip) China tried to slow the fall of the dollar by increasing its holdings in...