Conditioning reinforcer positive

Amphetamine given systemically or infused in the nucleus accumbens facilitates responding with conditioned reinforcement and this effect can be prevented by doses of neuroleptics or by 6-OHDA lesions that per se do not impair normal responding (Hill, 1970 Robbins, 1975 Beninger et al., 1983 Taylor and Robbins, 1984 Kelley and Delfs, 1991). This effect has been explained to be due to the positive motivational properties of amphetamine (Hill, 1970) or to its activational properties (Robbins et al., 1983). 

Resorcinol (1,3-dihydroxybenzene) is more reactive to formaldehyde than phenol itself, the two hydroxyl groups reinforcing each other in activating the o-and p-positions. This allows faster reactions to occur than with phenol, when compared at the same temperature, and under appropriate conditions curing can occur at normal room temperatures. 

Ongoing experiments with methylenedioxymethamphetamine (MDMA) show a systematic dose-dependent decrease in attack and threat behavior in mice confronting an intruder into their homecage (Miczek et al., unpublished observations). The decrement in aggressive behavior appears to be behaviorally specific it is obtained at MDMA doses (0.3, 1, 3 mg/kg) that are lower than those necessary to decrease measures of conditioned performance under the control of schedules of positive reinforcement. Because of species-dependent neurotoxicity, MDMA s effects on aggressive behavior need to be explored in other species, including primates. 

Under conditions of internal restraint, the expansion produced is proportional to the ratio of steel to concrete and the dosage of the admixture. Special care should be taken to ensure that reinforcement is located in its proper position during placement and consolidation so that adequate restraint and good bond to steel is obtained. Restrained expansion increases the density of the matrix and produces concrete or mortar with a lower coefficient of permeability than that of corresponding Portland cement concretes and mortar. 

A two-factor theory requires appetites (or visceral factors) to be qualitatively distinct from reward-seeking mental processes, a distinction that does not stand up on close examination. Ultimately, there is no line that divides rewards from the stimuli that reinforce classical conditioning. The only reason that a separate conditioning principle has seemed necessary—to explain the imposition of negative visceral factors and the restraint of positive ones—can be removed by the hyperbolic shape of discounting the future. 

According to Ref 2, booster cavity forming tools should be maintained in a polished condition and should be handled to prevent marring their, surfaces. Ammo items contg expls may be drilled either while in a vertical or horizontal position. Vertical drilling is preferred, since withdrawal of expl chips dust is easier, and proper drill alignment is mote easily attained maintained in such a position. To protect adjacent operators, HE s should be drilled, faced, milled, sawed or otherwise machined within rooms or cubicles having safety approved specified reinforced concrete wails... 

More complex procedures for unmasking drug dependence liability could involve assessment of acquired positive reinforcing effects as a result of repeated treatment. Induction of conditioned place preference (see below) has been reported with different substances, for example nicotine (Shoaib et al. 1994), after the animals have been pre-exposed to repeated treatment with the substance, whereas no conditioned place preference can be induced with the same substances in the absence of pretreatment. 

Conditioned place preference appears to provide a fairly simple indication of whether a test substance exerts positive reinforcing effects. The existence of conditioned place preference with a novel substance therefore represents a clear first sign of abuse potential. 

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