Barr body. Definition. noun. The small, dark-staining mass of inactive X chromosome within the nucleus of non-dividing cell. Supplement. Barr bodies are previously used as the basis for sex determination especially during the Olympics (see Barr test). Word origin: named after its discoverer Murray Llewellyn Barr, a Canadian anatomist who first identified the particle in the nucleus of neurons of female cats. Synonym: sex chromatin.
As of September 2011, there are nine Unified Combatant Commands as specified in Title 10 and the latest annual UCP. Six have regional responsibilities, and three have functional responsibilities.
When the numbered air forces that function as the service components of geographic combatant commands (such as the 9th Air Force for CENTCOM) execute contingencies, they request and receive a DM4--A and a tailored AMD from the Air Mobility Command.