Origin. Macrophages come from specific white blood cells called monocytes. Monocytes are born from stem cells in the bone marrow and circulate throughout the blood stream. Once a monocyte leaves the blood, it matures into a wandering macrophage or a fixed macrophage. Wandering macrophages travel throughout both blood and lymph streams to perform their job; fixed macrophages strategically concentrate in specific areas that are more vulnerable to intruders like the lungs or the intestine.
At-large is a designation for members of a governing body who are elected or appointed to represent the whole membership of the body, rather than a subset of that membership. At-large voting is in contrast to voting by electoral districts. If an at-large election is called to choose a single candidate, a single-winner voting system must necessarily be used. If a group of seats must be covered, many electoral systems can be possible, from proportional representation methods to block voting.
noun. 1  The minimal number of officers and members of a committee or organization, usually a majority, who must be present for valid transaction of business. 2  A select group. 3  The minimal density of bacterial cells that results in altered gene expression in a population of bacteria.