(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.
Treadle
Definition:
(n.) The part of a foot lathe, or other machine, which is pressed or moved by the foot.
(n.) The chalaza of a bird's egg; the tread.
Example Sentences:
(1) Three coyotes were operantly conditioned to depress one of two foot treadles, left or right, depending on the condition of the stimulus light.
(2) Ashden Outstanding Achievement Award International Development Enterprises India (IDEI) - for a simple treadle pump that has lifted more than 750,000 farmers out of poverty.
(3) Groups of pigeons were trained to depress a treadle in the presence of a compound stimulus consisting of a tone and a red houselight (a) to avoid electric shock, or (b) to obtain grain.
(4) The facilitative effect was equal in four cases: (i) making no response (NR), (ii) finger abduction (FA), (iii) noninvolved muscle (NIM), and (iv) involved muscle during treadle pressing (IM).
(5) The effects of promazine on treadle pressing to postpone the presentation of electric shock were studied in three pigeons.
(6) In Experiment 2 eight pigeons learned a treadle-press response to avoid or escape shock on a signaled free-operant schedule.
(7) Rates of responding changed systematically across sessions for rats pressing levers and keys and for pigeons pressing treadles and pecking keys.
(8) After performance had stabilized, the degree to which each element controlled treadle pressing was determined.
(9) Selected doses of both promazine and chlorpromazine increased the rates of treadle pressing in all birds.
(10) Two experiments investigated free-operant avoidance responding with pigeons using a treadle-pressing response.
(11) The response-rate increases produced by promazine and chlorpromazine were due to increased conditional probabilities of treadle pressing both before and during the preshock stimulus.
(12) Effective doses of apomorphine caused dose-dependent decreases on treadle-pressing rates in all animals.
(13) Appropriate doses of amphetamine caused rate-increasing effects on key-pecking as well as treadle-pressing rates of all pigeons.
(14) Frame-by-frame analysis of videotape records of E21 rat fetuses revealed that tactile contact with the artificial nipple elicited mouthing, licking directed at the nipple, forelimb treadling, and grasping of the nipple.
(15) Pigeons were trained to depress and hold a foot treadle until a stimulus change occurred.
(16) Each treadle press postponed electric shock for 20 sec and presentation of a preshock stimulus for 14 sec.
(17) Key-pecking and treadle-pressing behavior were maintained in five pigeons by a mult.
(18) For example, Climate Care is helping to fund simple 'treadle' water pumps for farmers in India, to give them the freedom to irrigate their crops without relying on expensive, polluting diesel pumps.
(19) This will take over 2000 years to make the same carbon savings as the treadle pump project will make in a single year with the same investment.