(n.) A rigid piece which is capable of turning about one point, or axis (the fulcrum), and in which are two or more other points where forces are applied; -- used for transmitting and modifying force and motion. Specif., a bar of metal, wood, or other rigid substance, used to exert a pressure, or sustain a weight, at one point of its length, by receiving a force or power at a second, and turning at a third on a fixed point called a fulcrum. It is usually named as the first of the six mechanical powers, and is of three kinds, according as either the fulcrum F, the weight W, or the power P, respectively, is situated between the other two, as in the figures.
(n.) A bar, as a capstan bar, applied to a rotatory piece to turn it.
(n.) An arm on a rock shaft, to give motion to the shaft or to obtain motion from it.
Example Sentences:
(1) In this experiment animals were trained to lever press in two distinctive contexts.
(2) Orientation and lever responding were not functionally related.
(3) In older stages, the cervical joints rotate according to geometric and lever arm principles.
(4) In EastEnders , the mystery surrounding the identity of Kat's secret squeeze continues amid the grinding of narrative levers and the death rattle of overflogged script-horses.
(5) Cats were trained to press a lever for 0.5--1.0 ml of milk reward both in the presence and absence of ambient light.
(6) Setting out how Britain would have a lever over the rest of the EU to demand repatriation of UK competences, Cameron said: "What's happening in Europe right now is massive change being driven by the existence of the euro.
(7) When lever pressing was established, the 2-kHz signal was presented through a speaker adjacent to the response lever according to a different set of variable intertrial intervals.
(8) Officials said the changes to the planning rules will mean it is possible to lever in billions of private sector development in low-cost housing.
(9) Rats were allowed to bar press on either of two levers (left and right).
(10) Knee flexion is synchronized with ankle dorsiflexion by a synchronizer rod and lever.
(11) In order to study the interactions between serotonergic mechanism and electrical stimulation of the mesencephalic central gray substance, rats were trained to lever-press for terminating aversive electric stimuli applied at the Periaqueductal gray and adjoining tectum of the mesencephalon.
(12) Rats were trained to press a lever to obtain a brief burst of pulses to the lateral hypothalamus.
(13) But its original meaning is the practice of using the levers of the state and of government to get difficult things done that otherwise wouldn't happen.
(14) Intact rats and rats bearing lesions of the suprachiasmatic nuclei (SCNX rats) were trained to obtain food by pressing either of two levers located on opposite sides of a cylindrical cage.
(15) We found that attenuation of lever-pressing and water intake by raclopride were not more separated in dose than after, for example, haloperidol.
(16) Young rats weaned at 16 days were taught to press a lever by shaping at 18 days and trained for 11 days (from 20 to 30 days of age) on a fixed-interval 60-sec schedule, at a rate of 5 half-hour sessions per day.
(17) In contrast, the selective norepinephrine uptake inhibitors, desipramine and talsupram, and the selective serotonin uptake inhibitor, citalopram, occasioned averages of only 13 to 19% drug-lever responding.
(18) When reinforcement was not available, each lever response produced a 0.5-sec green light on the key.
(19) Rats implanted with placebo pellets and given access to morphine reestablished lever pressing, while those given access to isotonic saline extinguished their lever pressing.
(20) Levels of acetylcholine were significantly elevated in the telencephalon and diencephalon + mesencephalon of rats killed by near-freezing during conditioned suppression of food-reinforced lever pressing, whereas levels of serotonin, dopamine, and norepinephrine were not altered.