An Italian aid worker described being beaten with a rubber cable and waterboarded in harrowing testimony Thursday at the trial of a jihadist accused of being one of his Islamic State captors known as the "Beatles."Federico Motka is the first former IS hostage to testify at the trial of El Shafee Elsheikh, a former British national accused of the murders of American journalists James Foley and Steven Sotloff and aid workers Peter Kassig and Kayla Mueller.