Mark Smith of Des Moines, a longtime leader of the Iowa Federation of Labor and an outspoken advocate for working men and women, died Thursday,DesMoinesRegister.com reported. Smith, who was 71, became secretary-treasurer of the federation, which represents about 50,000 union members statewide, in 1979. He was president for 10 years until he retired in 2007.         In recent years, he had held the title of president emeritus. Read his obituaryonline.