(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.
Torsion
Definition:
(n.) The act of turning or twisting, or the state of being twisted; the twisting or wrenching of a body by the exertion of a lateral force tending to turn one end or part of it about a longitudinal axis, while the other is held fast or turned in the opposite direction.
(n.) That force with which a thread, wire, or rod of any material, returns, or tends to return, to a state of rest after it has been twisted; torsibility.
Example Sentences:
(1) Prompt diagnosis, in which timely diagnostic laparoscopy and ultrasound evaluation of the pelvis may be helpful, provides the opportunity for prompt laparotomy with untwisting of the torsion and stabilization of the adnexa by suture and cystectomy, if possible, extirpation if not.
(2) In testing the contribution of the long, curved stem to the torsional stability of uncemented prostheses by comparing it with other stems, the long, curved stem was the most stable, followed by a shorter straight stem, and a short, proximally curved stem.
(3) The importance of prompt diagnosis of torsion is emphasized.
(4) In this paper, we develop functions suggested by and regression fit to crystallographic data which allow three of these torsion angles, alpha (O3'-P-O5'-C5'), delta (C5'-C4'-C3'-O3') and epsilon (C4'-C3'-O3'-P), to be calculated as dependent variables of those remaining.
(5) An alternative explanation, that there may be a pre-existing defect in spermatogenesis, was tested in 20 post-pubertal males with acute torsion.
(6) We measured the stiffness of comparable configurations (1 or 2 bars) under axial compression, four-point-bending in two planes, and torsion.
(7) (4) The spine becomes less flexible in the presence of preload when it is subjected to axial tension or axial torsion.
(8) On celiotomy, peritoneal effusion was present secondary to torsion of a 10 x 6 cm right ovarian cyst.
(9) Since some of these patients closely resembled cases of idiopathic torsion dystonia, the prior occurrence of asphyxia should be used as a criterion of exclusion for that diagnosis.
(10) These sequences adopt cruciform geometry when the DNA helix is torsionally strained by negative supercoiling.
(11) Gastric volvulus is an uncommon condition in which an acquired torsion of the stomach results in acute or chronic gastrointestinal symptoms.
(12) The adenine moiety is nearly planar and the torsional angle of the glycosidic linkage O(4')-C(1')-N(3)-C(4) is -161.5 degrees.
(13) Using the single criterion of presence or absence of identifiable intratesticular flow, the authors found that color Doppler was 86% sensitive, 100% specific, and 97% accurate in the diagnosis of torsion and ischemia in the painful scrotum.
(14) A single nucleotide structure having an anti adenine-ribose glycosidic torsional angle of -114 degrees was found to satisfy the experimental distance constraints.
(15) In group I (torsion maintained), unilateral torsion of the spermatic cord was maintained until the day of sacrifice; in group II (torsion and untwist), torsion of the spermatic cord was maintained for 8 to 12 hours, then the spermatic cord was untwisted and the testis was retained until the day of sacrifice.
(16) Values for helical torsional angles phi and psi assume a much wider range than anticipated.
(17) We report the clinical findings, diagnostic problems and treatment of a 1-year-old Coloured child (with classic 'prune belly syndrome') in whom the spleen had undergone torsion, thus simulating an intra-abdominal abscess.
(18) Idiopathic torsion dystonia (ITD) is characterized by sustained, involuntary muscle contractions, frequently causing twisting and repetitive movements or abnormal postures.
(19) The effect of increasing torsional stress on the conformation of the composing elements was determined by analysis of the sensitivity to the single strand-specific S1 endonuclease and it was observed that the sites of conformational alterations correspond to the positions relevant for promoter function (upstream activator sequence, TATA sequence, and RNA initiation site).
(20) Intranucleotide proton-proton distances combined with the knowledge of sugar puckers have been used to fix the glycosidic bond torsion angle (chi).