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981.
982.
The significance of a helicopter patrol procedure directed toward prevention of home burglaries was evaluated from experimental and cost-benefit perspectives. The helicopter patrolled one city zone from 9 a.m. to 5 p.m. for two 12-day periods. Each 12-day period was separated by a baseline period in which only normal patrol-car levels were maintained. Significantly reduced burglary levels during the intervention periods, compared to baseline periods, documented the experimental significance of the helicopter procedure. The cash costs of implementing the patrol procedure were compared to two estimates of the resulting cash benefits. This latter cost-benefit analysis was supplemented by a discussion of the intangible costs and benefits of the helicopter procedure. Taken together, these analyses documented that the marginal costs of the helicopter intervention were exceeded by all estimates of benefits.  相似文献   
983.
The current studies were designed to investigate the influence of variations in type of school setting on the development of role-taking skills and ethnic identity. We were interested in groups of school children in grades 1 to 5 inclusive from three different types of language programs: (1) instruction in the native language (English in this case); (2) total instruction in a second language (French); and (3) partial instruction in a second language (French). All children were native-English speaking, and came from perdominantly middle class families with monolingual English-speaking parents. The children from each program were equated at each grade level on age, and verbal and non-verbal I.Q. It was expected that (1) children in the second language programs would develop identity with their native language reference group later and less consistently than children in the native language programs; because (2) the second language children would identify more with the second language ethnic group; (3) the second language children would be able to understand at an earlier grade level than the native language group the principle of reciprocity in role-taking; and (4) these difference would be more pronounced for the totally than for the partially immersed second language children. The children were required to rate a number of ethnic dolls on a 20 point rating scale according to (1) how much each would be desired as a personal friend, (2) how much each would be desired as a friend for a member of another specific ethnic group, and (3) how similar each doll was to the child. The results indicated general support for hypotheses (1), (2) and (4), particularly among the primary school samples (1, 2), but a lack of support for hypothesis (3). These results demonstrate the influence of socio-cultural factors on the development of ethnic identity and ethnic role-taking skills.  相似文献   
984.
J W Tiller 《Family process》1978,17(2):217-223
This paper reports the success of brief analytically oriented outpatient family therapy exclusively in treating an eight-year old girl presenting with a short history of multiple tics involving facial, thoracic, and upper limb musculature, with associated hoarse coughing and grunting. Diagnostic features are reviewed. No medicines were used, and the patient remained asymptomatic nine months after ceasing family therapy. Tentative indications for family therapy for tiqueurs are proposed.  相似文献   
985.
The fluorescence intensity of the catecholamine cell bodies of the A2 group--as determined by microfluorimetry--increased significantly due to exposure of the rats to the following environmental events: placement of a rat from the colony cage into a cold (4 degree C) room for a period of 10 min, isolation of a rat from the colony for 6--7 days, and satiation of gouped rats by allowing them access to sweetened milk for 15 min. The following events failed to affect the intensity of the cells of A2: reduction of the group colony size from eight to three rats per colony for 6--7 days and presentation of water instead of milk after the rats had experienced 6--7 days of milk satiation. These results indicate that aversive as well as rewarding environmental events activate the catecholamine cells of A2.  相似文献   
986.
987.
This study compared black and white children on the Behavior Problem Checklist. Data on 1,162 white and 614 black children were obtained from school records and from teachers and were analyzed using multiple regression analysis of variance. Blacks were judged to have a greater frequency of behavior disorders than whites. A number of interactions of race with other variables were found, and their meanings were discussed.  相似文献   
988.
989.
Pigeons received equal variable-interval reinforcement during presentations of two line-orientation stimuli while five other orientations appeared in extinction. Component duration was 30 seconds for all orientations and the sequence was arranged so that each orientation preceded itself and each other orientation equally often. The duration of one component (0°) was shortened to 10 seconds and the other (90°) was lengthened to 50 seconds. All animals showed large increases in response rate in the shortened component and this increase was recoverable after an interpolated condition in which all components were again 30 seconds in duration. This effect was replicated in a second experiment in which component duration was changed from 150 seconds to 50 seconds and 250 seconds. An examination of local contrast effects during the first experiment showed that the shortened component produced local contrast during subsequent presentations of the lengthened component, just as would a component associated with more frequent reinforcement. When the presentation sequence was changed so that the lengthened component was always followed by the shortened component, response rates generally increased during the lengthened component. When the sequence was arranged so that the shortened component always preceded the longer component, response rate decreased in the former. These effects, as well as the increases in response rate following change in component length, seem not to be the product of local contrast effects among components.  相似文献   
990.
The performance of pigeons was studied under conditions in which the completion of a fixed-ratio requirement was not contiguous with the presentation of a reinforcer. Timein and timeout periods alternated throughout the experimental sessions. Responses made by an experimental bird during the timein period were accumulated, and when a fixed-ratio requirement had been met, grain was presented to the experimental bird and a yoked control following their first response in the next timein period. Across most manipulations of the fixed-ratio requirement and of the duration of the timeout period, the response rates of the experimental birds were considerably higher than those of their controls, suggesting that the response-reinforcer dependency controlled the behavior of the experimental bird in the absence of a close temporal association between responding on the ratio schedule and reinforcer presentations.  相似文献   
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