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251.
Data collected as part of a psychosocial study of gay and bisexual men's experiences of living with HIV infection as a chronic illness were examined to investigate the psychological impact of the perceived availability of illness-related support and negative illness-related network interactions in a sample of men from this population. The sample was comprised of 144 HIV-infected non-Hispanic white, African American, and Puerto Rican men living in the New York City metropolitan area. Analyses found evidence of a conjoint (interactive) effect between perceived support and negative network interactions. There was no evidence of either perceived availability of illness-related network support buffering or negative illness-related network interactions amplifying the effect of HIV/AIDS-related physical symptomatology on depressive symptomatology.  相似文献   
252.
Maternal aggression in a Sprague-Dawley strain of laboratory rat (Charles River CD) was explored from Day 1 after mating on Day 0 through Day 24 of lactation (L0-L24). Aggression toward unfamiliar male “intruders” during 10-min tests was low among nonpregnant, nonlactating females and during the first 10 days of gestation. Frequency of attack on intruders increased moderately but significantly by Gestation Day 16 (G16; Experiment 1) or G21 (Experiment 2), a prepartum phenomenon not previously reported in laboratory rats. Levels of aggression were highest, however, during the first 9 days of lactation, when attacks averaged more than 6 per 10-min session. Attacks declined sharply in frequency after L14 and by L24 did not exceed levels observed among nonpregnant females. Experiment 3 examined the importance of the test site (home cage with nest and pups, if any, vs unfamiliar cage without nest or pups) to agonistic behavior associated with pregnancy and lactation. Late pregnant females tested in a novel cage were not aggressive; however, females tested shortly after delivering their pups were highly aggressive, averaging over four attacks per 5-min session. In novel cage tests frequency of attack remained high through L4 but declined significantly by L7. These data are consistent with the hypothesis that maternal aggression at its onset is primarily under hormonal control, but becomes increasingly dependent upon external factors, presumably pup stimulation, during the postpartum period.  相似文献   
253.
In this experiment we investigated inhibitory Pavlovian conditioning in the development of tolerance to pentobarbital-induced hypothermia. During an initial phase, one group of rats (discrimination group) received training in which, on alternate days, one conditional stimulus (CS+) was associated with administration of 30 mg/kg pentobarbital, and a different conditional stimulus (CS-) was associated with administration of physiological saline. During the phase, control groups received either exposure to both CSs but not the drug or to the drug but no CSs or to neither the CSs nor the drug. Subsequently, half the rats in each group received injections of pentobarbital in the presence of one of the CSs and the remaining half in the presence of the other CS. Rats from the discrimination group injected with pentobarbital in the presence of CS+ displayed the most tolerance (i.e., smallest drug effect), whereas rats from the discrimination group injected with pentobarbital in the presence of CS- displayed the least tolerance (i.e., greatest drug effect). The attenuation of tolerance seen in rats of the discrimination group injected in the presence of CS- provides evidence of inhibitory Pavlovian conditioning. Additional evidence of inhibitory conditioning was provided by the fact that CS2 enhanced the hypothermic effects of pentobarbital in the discrimination group, whereas CS1 attenuated these effects. Implications of the results for the nature of inhibitory conditioning are discussed.  相似文献   
254.
Japanese quail from lines bidirectionally selected for high and low male mating frequency and from the random-bred base population were observed in an ontogenetic study of aggressive-sexual behavior. Quail were reared in sex-intermingled flocks until 28 days of age at which time half of the males from each line were housed as all-male flocks and half were transferred to individual cages. At 41 days of age, individually caged males exhibited mounting behavior to win encounters with other males. By 45 days, males from the high and control lines exhibited significantly more aggressive-sexual behavior than those from the low lines. Line x Rearing Experience interactions for mounting behavior at 45 and 56 days of age were due to the individually caged high- and control-line males' winning encounters by mounts; those maintained in flocks rarely mounted. Although some low-line males won encounters by mounts, occurrence of this behavior was infrequent. Males maintained in flocks were placed in individual cages at 57 days of age. When these males were compared with those housed in individual cages from 28 days of age, at 84 days of age and older, the Line x Rearing Experience interaction observed previously disappeared, and only differences among genetic lines were evident. Genetic and rearing experience effects are discussed as influencing agonistic and sexual behaviors.  相似文献   
255.
Effects of stimulant medication (methylphenidate) on levels (feature, name, semantic) of word processing by the left and right hemisphere were assessed in 31 attention- deficit- disordered children. In a double-blind procedure, same- different decisions were made to tachistoscopically presented word pairs under medication and placebo. Analysis of manual response times failed to show any negative effects of medication. Feature decisions were faster than name decisions, which were faster than semantic decisions. Methylphenidate induced a right visual field advantage (left hemisphere) for the name decision, which was interpreted as a normalization effect. The results suggest that (1) methylphenidate may selectively improve the phonological level of word processing and (2) methylphenidate's favorable therapeutic effect is produced through inhibition of excessive right hemisphere activity in response to task demands that engage the left hemisphere.This research is based in part upon a doctoral thesis completed by the first author in the Department of Education, University of Toronto. The authors thank Dr. William Logan and Dr. Wendy Roberts of the Hospital for Sick Children for permitting testing of patients in the Child Development Clinic. This research was supported in part by a doctoral fellowship from the Social Sciences and Humanities Research Council to the first author.  相似文献   
256.
Do the reformulated model of learned helplessness and the self-control model apply to clinically depressed children? Are the related cognitive patterns specific to depression? Are the cognitive deficits associated with depression learned from one's parents? To address these questions this investigation examined three groups of children (ages 8–12) and their parents: nonclinic (n =25),nondepressed clinic (n=22),and depressed clinic (n=15).Children were diagnosed depressed on the basis of Kiddie-SADS interview data. Depressed clinic children self-reported more depression, had a more depressive attributional style, and had more self-control problems. There were more depressed mothers in the clinic than in the nonclinic sample. Depressed clinic children had more depressed mothers than did nondepressed clinic children. There were no differences among the three groups of parents in their cognitive patterns. No relationship was found between the attributional style and self-control behavior of children and their parents.  相似文献   
257.
A pocket computer is described that can be used by subjects to self-administer cognitive tests in field situations. Two cognitive tests, a vigilance and an encoding task, were developed for this computer and used to test cognitive performance during a 30-day military field exercise.  相似文献   
258.
A sequence of theoretical models is constructed as an extension to Leszek Nowak's theory of socialist society to explain important characteristics of the violent party purges in Soviet Stalinism. According to these models, purges are a regular and systemic feature of a socialist system during a certain phase of development (modelled as the phase of social enslavement). Contrary to traditional conceptions which interpret the purges essentially as resulting from the actions of an almost omnipotent, and partly irrational, despot, the models presented here provide an explanation which does not need to conceive Stalin as the architect of terror (Robert Conquest), i.e. as the long-term planner of the terror. However, the concepts presented here preserve the vital arguments of the traditional approach, thereby contradicting the revisionist pattern of interpretation. In particular the models seek to provide a theoretical base for an explanation of the moderation of inner-party terror from 1938. This moderation is interpreted as resulting from a modification of the then existing ideology (and corresponding habits of the party's leadership); a modification which in itself had been stimulated by the disastrous effects of the great purge in 1937/38. This modification can be theoretically conceived as a process of ideological learning. The historical fact that the post-war purges (i.e. the Leningrad affair in 1949 and the Mingrelian affair 1951/52) did not reach such an enormous extent as the purges of the late 1930s may thus be attributed to a process of ideological learning.  相似文献   
259.
Picture and word triads were tested in a Brown-Peterson short-term retention task at varying delay intervals (3, 10, or 30 sec) and under acoustic and simultaneous acoustic and visual distraction. Pictures were superior to words at all delay intervals under single acoustic distraction. Dual distraction consistently reduced picture retention while simultaneously facilitating word retention. The results were interpreted in terms of the dual coding hypothesis with modality-specific interference effects in the visual and acoustic processing systems. The differential effects of dual distraction were related to the introduction of visual interference and differential levels of functional acoustic interference across dual and single distraction tasks. The latter was supported by a constant 2/1 ratio in the backward counting rates of the acoustic vs. dual distraction tasks. The results further suggest that retention may not depend on total processing load of the distraction task, per se, but rather that processing load operates within modalities.  相似文献   
260.
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