Diana Zurco did not attend her high school graduation because she refused to receive a diploma with her birth name. At 17 and considered a boy by school officials, she grew her hair long and adopted the name Diana after the alien character on the show “V” about an extraterrestrial invasion. Now 40, she recalled her youthful rebellion while sitting in a comfortable chair in the studio of Argentina’s public television station ahead of her debut as the country’s first transgender newscaster, a milestone for an excluded community that is often the target of violence and has a life expectancy roughly half that of the rest of the population. “My presence challenges society,” she said in the smooth voice of a professional announcer that she used on Monday when she began her job as co-anchor of Public Television’s prime time evening news program.