Staff Sgt. Christopher Costa,10th Intelligence Squadron link systems supervisor, demonstrates a self-defense move to Maria Atahualpa, 633d Logistics Readiness Squadron receiving apprentice, during a personal safety class at Langley Air Force Base, Va., April 20, 2011. Joint Base Langley-Eustis is celebrating Sexual Assault Prevention Month throughout April with a variety of seminars, demonstrations and classes to increase awareness of sexual assault and honor survivors. (U.S. Air Force photo by Airman 1st Class Camilla Elizeu/Released)