conditions at threshold
1threshold — 1. The point at which a stimulus first produces a sensation. 2. The lower limit of perception of a stimulus. 3. The minimal stimulus that produces excitation of any structure; e.g., the minimal stimulus eliciting a moto …
2threshold — n. (in neurology) the point at which a stimulus begins to evoke a response, and therefore a measure of the sensitivity of a system under particular conditions. A thermoreceptor that responds to an increase in temperature of only two degrees is… …
3threshold — n. 1 a strip of wood or stone forming the bottom of a doorway and crossed in entering a house or room etc. 2 a point of entry or beginning (on the threshold of a new century). 3 Physiol. & Psychol. a limit below which a stimulus causes no… …
4Flicker fusion threshold — The flicker fusion threshold (or flicker fusion rate) is a concept in the psychophysics of vision. It is defined as the frequency at which an intermittent light stimulus appears to be completely steady to the observer (this article centers around …
5Extinction threshold — is a term used in conservation biology to explain the point at which a species, population or metapopulation, experiences an abrupt change in density or number because of an important parameter, such as habitat loss. It is at this critical value… …
6Ecological threshold — can be described as the point at which a relatively small change in external conditions causes a rapid change in an ecosystem. When an ecological threshold has been passed, the ecosystem may no longer be able to return to its state. The… …
7Poverty threshold — For the term as defined in the United States, see Poverty thresholds (United States). Percentage of population living on less than $1.25 per day. UN estimates 2000 2007. The poverty threshold, or poverty line, is the minimum level of income… …
8Dark adaptation threshold — (DAT) is a vision test that measures the adjustment of the eye occurring under low levels of illumination. When light enters the eye, it ultimately reaches the rods and cones, which are two types of cells in the retina. Rods handle vision in low… …
9target threshold speed — (VAT ) The speed at which the pilot aims to cross the runway threshold when landing. Under relatively favorable conditions, it is usually the speed at a screen height of 30 ft (10 m) after a steady, stable approach at a glide slope of not less… …
10turbulent threshold — The limiting value of sub conduit size, below which water flow is essentially laminar and above which water flow includes a significant turbulent component. Sub conduit diameters between 5mm and 15mm have been suggested as the minimum for… …
