| suburban population | The inhabitants of peripheral or adjacent areas of a city or town. (12 Dec 1998) |
|---|---|
| synchronous cell population | <cell culture> A culture of cells that all divide in synchrony. Particularly useful for certain studies of the cell cycle, cells can be made synchronous by depriving them of essential molecules, which are then restored. Synchronisation breaks down after a few cycles, however, as individual cells have unique division rates. (19 Jan 1998) |
| q in population genetics | The frequency of the less common of two different alternative (allelic) versions of a gene. (the frequency of the more common allele is p). (12 Dec 1998) |
| topotypical population | <zoology> Population occurring at the type locality from which the type specimen was taken. (09 Jan 1998) |
| urban population | The inhabitants of a city or town, including metropolitan areas and suburban areas. (12 Dec 1998) |
| action current | An electrical current induced in muscle fibres when they are effectively stimulated; normally it is followed by contraction. (05 Mar 2000) |
| alternating current | Electrical current which alternates direction periodically. (For instance, household electric current is AC alternating at 60 oscillations/sec (60 Hertz) in the United States, and 50 Hertz in many other countries.) Acronym: AC (09 Oct 1997) |
| anodal current | A current produced in tissues under the anode when the circuit is closed. (05 Mar 2000) |
| ascending current | The direction of current flow in a nerve when the anode is placed peripheral to the cathode, in contrast to descending current; the convention used is that current flows from positive to negative. Synonym: centripetal current. (05 Mar 2000) |
| axial current | The central rapidly moving portion of the bloodstream in an artery. (05 Mar 2000) |
| bootstrap current | <radiobiology> Currents driven in toroidal devices by neo-classical diffusion. They may amount to a substantial fraction of the net current in a tokamak reactor, thus lengthening the pulse time or decreasing the power needed for current drive. (09 Oct 1997) |
| calcium current | Inflow of calcium ions through specific calcium channels. Critically important in release of transmitter substance from presynaptic terminals. (18 Nov 1997) |
| galvanic current | See: direct current, galvanism. (05 Mar 2000) |
| radio frequency current drive | <radiobiology> Plasma waves in the radio-frequency range can be used to push plasma particles in such a way that current forms in the plasma, this is a method of non-inductive current drive which would allow for steady-state fusion reactors to operate. (09 Oct 1997) |
| gating current | <physiology> Small currents in the membrane just prior to the increase in ionic permeability, due to the movement of charged particles within the membrane. So called because they open the gates for current flow through ion channels. (20 Mar 1998) |