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.
The five levels of DEFCON. The DEFense readiness CONdition (DEFCON) is an alert state used by the United States Armed Forces. The DEFCON system was developed by the Joint Chiefs of Staff (JCS) and unified and specified combatant commands. It prescribes five graduated levels of readiness (or states of alert) for the U.S. military.