Nucleated red blood cell Nucleated red blood cell All vertebrate organisms have hemoglobin-containing cells in their blood and with the exception of mammals, all of these red blood cells contain a nucleus. Mammals represent ~5,500 named species out of ~66,000 vertebrate species, and within this ~8% subgroup, red blood cells are known as erythrocytes or RBCs and lack a cell nucleus in mature organisms. In contrast, a nucleated red blood cell (NRBC), also known by several other names, is a mammalian RBC that contains a cell nucleus. NRBCs occur in normal development as progenitor cells in the erythropoietic lineage and in pathological states. Normally,
Under a Blood Red Sky Under a Blood Red Sky Under a Blood Red Sky is a live album by Irish rock band U2, produced by Jimmy Iovine and released on 21 November 1983. Along with its companion concert film, "", the release helped establish U2's reputation globally as a live act. The album consists of live recordings from three shows on the band's War Tour, from Colorado and Boston in the US and from Germany. An accompanying concert video entitled "U2 Live at Red Rocks: Under a Blood Red Sky" was released the following year. The film was recorded entirely at the outdoor Red