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This study reanalyzes kinematically (via film) the pre- and postoperative locomotor behavior of 4 of the 10 monkeys with partial spinal cord lesions (T8) briefly described by Eidelberg, Walden, and Nguyen (1981). The behavior of the remaining 6 monkeys is qualitatively described. The analysis reveals that 5 of the animals initially exhibited unilateral hind limb stepping. Hind and forelimb cycle durations often differed postoperatively; the hind limbs commonly showed increased values, whereas forelimb cycle durations were reduced: ipsilateral interlimb phase values were usually inconsistent. A review of prior studies of primate spinal cord lesions indicates that sparing of the ventrolateral quadrant may not be essential for locomotor recovery (cf. Eidelberg, Walden, & Nguyen, 1981). Furthermore, this review as well as the kinematic analysis indicates that primates with very significant spinal lesions can stilI exhibit locomotor movements. Thus, although the primate's spinal cord seems less able than other mammals' to readily organize locomotor movements (Eidelberg, Walden, & Nguyen, 1981), the total absence of stepping in primates with completely transected cords is unexpected and warrants further research. 相似文献
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The problems caused for the NBTS by the advent of HIV are reviewed, with particular reference to the impact on blood donor numbers, the strategies adopted to minimise the risk of HIV infection through blood transfusion, and the counselling dilemmas faced by the Service in the setting of the blood donor clinic. The notification procedure for blood donors found anti-HIV positive is described, with the importance of confirmation of such results before approach to the donor emphasised. Counselling issues arising from indeterminate and false positive lest results are explored and those arising from enquiries generated by cases of possible post-transfusion HIV infection are examined. 相似文献
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The role played by reflex pathways in the production of movement has been a significant issue for motor control theorists interested in a wide variety of motor behaviors. From studies of locomotion and chewing, it appears that gains in reflex pathways can be altered so that activity in these pathways does not produce destabilizing responses during movement. In speech production, recent experimental evidence has been interpreted to suggest that autogenetic lip reflexes (perioral reflexes) are suppressed during sustained phonation or speech production. The present study was conducted to assess the effects of phonation, direction of movement, and ongoing speech production on reflex responses of lip muscles. The present results suggest, in contrast to earlier work, that this reflex pathway is not suppressed or absent because the amplitude of the observed response depends upon the activation levels of the various muscles of the lower lip and, therefore, indirectly on the nature of the gesture the subject is instructed to produce. 相似文献
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The prevalence of DSM-III conduct and adjustment disorders in two adolescent psychiatric facilities, both located near large U.S. cities, was investigated. Overall, 31.6% of the adolescent inpatients were conduct disordered while 12.5% were adjustment disordered. The conduct disorders were primarily "aggressive" subtypes suggesting that this characteristic may influence hospitalization and diagnostic decisions. Such data on prevalence assists future treatment planning, allowing anticipation of case loads. 相似文献
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Shayna Skakoon-Sparling Paolo A. Palma Adhm Zahran Trevor A. Hart David M. Moore Joseph Cox Nathan J. Lachowsky Milada Dvorakova Emerich Daroya Daniel Grace 《Social and Personality Psychology Compass》2023,17(9):e12814
In March 2020, in response to the COVID-19 pandemic, Canadian provincial governments instituted a variety of public health measures that included social distancing and isolation, which may have had unintended consequeses. According to the Loneliness and Sexual Risk Model, gay, bisexual, and other men who have sex with men (GBM) often cope with loneliness through risky sexual behaviors. Previous studies have demonstrated that COVID-19 measures such as social distancing and isolation led to increases in loneliness; thus, these measures may also have led to elevated sexual risk-taking among some GBM. Participants were recruited from an ongoing cohort study on GBM health and well-being, and were included in the current analysis if they had completed relevant study questions (n = 1134). GBM who reported lower levels of social support pre-COVID-19, were younger, and lived alone each reported greater loneliness during the first year of COVID-19. Although feelings of loneliness did not predict sexual risk-taking within the first year of COVID-19, loneliness did predict greater sexual risk-taking 6 months later. Additionally, younger GBM and those living alone were more likely to engage in sexual risk-taking at both COVID-19 data collection points. These findings offer some support of the Loneliness and Sexual Risk Model; however, it is possible that the unique circumstances of the COVID-19 pandemic resulted in a temporary suspension of this association, as many GBM took steps to protect themselves and partners in the context of COVID-19. 相似文献
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Three rhesus monkeys were trained to press either of two response keys. A response on the reinforcement key during presentation of the reinforced stimulus produced a sucrose pellet followed by an intertrial interval, but during presentation of the unreinforced stimulus produced only the intertrial interval. A response on the switching key changed the discriminative stimulus from reinforced to unreinforced or from unreinforced to reinforced. The reinforced stimulus was presented automatically on half the trials, but could be produced only by a switching response on the other half. Switching tended to occur in three distinct stages during acquisition of discriminative behavior. The first stage was identified as "nondiscriminative switching"; the second as "nonswitching"; and the third as "discriminative switching". 相似文献
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