(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.
Rigid
Definition:
(a.) Firm; stiff; unyielding; not pliant; not flexible.
(a.) Hence, not lax or indulgent; severe; inflexible; strict; as, a rigid father or master; rigid discipline; rigid criticism; a rigid sentence.
Example Sentences:
(1) By the 1860s, French designs were using larger front wheels and steel frames, which although lighter were more rigid, leading to its nickname of “boneshaker”.
(2) Diphenoxylate-induced hypoxia was the major problem and was associated with slow or fast respirations, hypotonia or rigidity, cardiac arrest, and in 3 cases cerebral edema and death.
(3) Pitlike surface structures seen in negatively stained whole cells and thin sections were correlated with periodically spaced perforations of the rigid sacculus.
(4) Rigidly fixing the pubic symphysis stiffened the model and resulted in principal stress patterns that did not reflect trabecular density or orientations as well as those of the deformable pubic symphysis model.
(5) The fracture can be treated arthroscopically by rigid internal fixation, while at the same time treating possible associated lesions.
(6) This study examined the extent to which normal learners identified as cognitively rigid could use alternate strategies when instructed to do so.
(7) In some patients stimulation can reduce rigidity and coactivation of muscles immediately or slowly over days or months.
(8) Major alleviation of the rigidity and bradykinesia with chronic oral l-dopa therapy was not accompanied by any change in the silent period.
(9) At clinically achievable concentrations, the combination of nafcillin plus gentamicin produced enhanced killing against 13 of 14 strains of enterococci and was synergistic (by very rigid criteria) against 10 of 14 strains.
(10) Low-temperature NMR studies indicate that 5 is more rigid than tamoxifen; interconversion between enantiomeric conformers is slow on the NMR time scale at -75 degrees C.
(11) Global 'abnormality', hunching (rigid arching of back), hindlimb abduction, forepaw myoclonus, stereotyped lateral head movements, backing, and immobility occurred significantly only in drug-treated rats.
(12) A study was made of twelve cases with uveitis, glaucoma and hyphema (UGH) caused by rigid intraocular posterior chamber implants.
(13) Eight alpha-helices behave as relatively rigid bodies and corner regions are more flexible, showing larger fluctuations.
(14) This modification allows for precision of movement, ease of repositioning, and adaptation of rigid skeletal stabilization of mobilized osseous segments in the chin.
(15) The pedicle screw systems were always the most rigid.
(16) Lactate dehydrogenase (LDH) levels and subunit isozyme patterns in cornea were monitored in 36 albino rabbits wearing thick, rigid, gas-permeable contact lenses for periods of 24 h, 2 and 7 days, and 1 and 3 months.
(17) The prevalence of sleep apnea, apnea index, duration of the longest episode of apnea, and penile rigidity were tabulated.
(18) During the last 21 months, 12 additional children have been managed with a more stringent protocol combining neck immobilization in a rigid cervical brace for 3 months and restriction of both contact and noncontact sports, together with a major emphasis on patient compliance.
(19) In the second placebo controlled experiment 150 mg im testosterone enanthate administration was associated with enhanced rigidity of NPT but with no effect on frequency or circumference change of NPT and no effect on frequency of REM.
(20) The whole isolator system included two rigid supply isolators, too.