U.S. Army Spc. Tyler Beck, medic, and Spc. Roberto Arias, supply, assigned to Charlie Company, 407th Brigade Support Battalion, Fort Bragg, N.C., install a protective concertina wire barrier in support of a field exercise at Joint Readiness Training Center, Fort Polk, La., Oct. 13, 2012. JRTC 13-01 is designed to prepare and educate U.S. military service members in a simulated combat environment.