138 research outputs found
Analyzing Power for He-4(n-],N)he-4 Elastic-Scattering at 50.4 Mev
Journals published by the American Physical Society can be found at http://publish.aps.org
Discriminative and reinforcing effects of brotizolam in rhesus monkeys
The reinforcing and discriminative stimulus effects of brotizolam, a benzodiazepine-hypnotic, were evaluated in rhesus monkeys. In one experiment, separate groups of monkeys ( N =3/group) were trained to discriminate pentobarbital (10 mg/kg, IG) or d -amphetamine (0.56β1.0 mg/kg, IG) from saline, in a discrete-trials avoidance/escape paradigm. Pentobarbital (5.6β10 mg/kg), diazepam (1.0β1.7 mg/kg), and brotizolam (0.3β1.7 mg/kg) resulted in 100% drug-lever responding in all three pentobarbital-trained monkeys. In d -amphetamine-trained monkeys brotizolam administration resulted only in saline-lever responding. In another experiment, monkeys were surgically prepared with indwelling intravenous catheters and lever pressing resulted in an injection of 0.1 mg/kg/injection sodium methohexital under a fixed-ratio 10 (FR 10) schedule. Pentobarbital (0.01β0.3 mg/kg/injection) and diazepam (0.003β0.10 mg/kg/injection) maintained responding above saline control levels when substituted for methohexital. Brotizolam (0.001β0.01 mg/kg/injection) resulted in more injections received compared to saline, but fewer injections compared to pentobarbital or diazepam. Thus, results from the present experiment suggest that brotizolam would have pentobarbital-like subjective effects. However, the abuse liability of brotizolam may be lower than that for diazepam.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/46334/1/213_2005_Article_BF02244198.pd
Polarization Transfer in N-P Scattering at 50 Mev
Journals published by the American Physical Society can be found at http://publish.aps.org
Measurement of the H-1(d-],N-])Pp Transverse Polarization Transfer-Coefficient at 42.8 Mev
Journals published by the American Physical Society can be found at http://publish.aps.org
Evidence for Habitual and Goal-Directed Behavior Following Devaluation of Cocaine: A Multifaceted Interpretation of Relapse
BACKGROUND:Cocaine addiction is characterized as a chronically relapsing disorder. It is believed that cues present during self-administration become learned and increase the probability that relapse will occur when they are confronted during abstinence. However, the way in which relapse-inducing cues are interpreted by the user has remained elusive. Recent theories of addiction posit that relapse-inducing cues cause relapse habitually or automatically, bypassing processing information related to the consequences of relapse. Alternatively, other theories hypothesize that relapse-inducing cues produce an expectation of the drug's consequences, designated as goal-directed relapse. Discrete discriminative stimuli signaling the availability of cocaine produce robust cue-induced responding after thirty days of abstinence. However, it is not known whether cue-induced responding is a goal-directed action or habit. METHODOLOGY/PRINCIPAL FINDINGS:We tested whether cue-induced responding is a goal-directed action or habit by explicitly pairing or unpairing cocaine with LiCl-induced sickness (n = 7/group), thereby decreasing or not altering the value of cocaine, respectively. Following thirty days of abstinence, no difference in responding between groups was found when animals were reintroduced to the self-administration environment alone, indicating habitual behavior. However, upon discriminative stimulus presentations, cocaine-sickness paired animals exhibited decreased cue-induced responding relative to unpaired controls, indicating goal-directed behavior. In spite of the difference between groups revealed during abstinent testing, no differences were found between groups when animals were under the influence of cocaine. CONCLUSIONS/SIGNIFICANCE:Unexpectedly, both habitual and goal-directed responding occurred during abstinent testing. Furthermore, habitual or goal-directed responding may have been induced by cues that differed in their correlation with the cocaine infusion. Non-discriminative stimulus cues were weak correlates of the infusion, which failed to evoke a representation of the value of cocaine and led to habitual behavior. However, the discriminative stimulus-nearly perfectly correlated with the infusion-likely evoked a representation of the value of the infusion and led to goal-directed behavior. These data indicate that abstinent cue-induced responding is multifaceted, dynamically engendering habitual or goal-directed behavior. Moreover, since goal-directed behavior terminated habitual behavior during testing, therapeutic approaches aimed at reducing the perceived value of cocaine in addicted individuals may reduce the capacity of cues to induce relapse
np elastic spin-transfer measurements at 485 and 635 MeV
Journals published by the American Physical Society can be found at http://publish.aps.org/We have measured the spin-transfer parameters K(LL), K(SL), K(LS) and K(SS) at 635 MeV from 50-degrees to 178-degrees c.m. and at 485 MeV from 74-degrees to 176-degrees c.m. These new data have a significant impact on the phase-shift analyses. There are now sufficient data near these energies to overdetermine the elastic nucleon-nucleon amplitudes
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