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141.
Hoffman Howard S.; Ratner Alan M.; Eiserer Leonard A. 《Canadian Metallurgical Quarterly》1972,81(3):399
Conducted 2 experiments with a total of 36 1-11 day old Khaki Campbell ducklings, to assess the suppression of distress vocalization by 2 distinctive stimuli before and after Ss were imprinted to 1 of the stimuli. In Exp. I, both stimuli strongly suppressed distress calls initially. At 5 days of age, however, only the stimulus involved in imprinting suppressed the calls. Results suggest that the loss of control by the nonimprinted stimulus was age-related and represented the development of fear to insufficiently-familiar stimuli. In Exp. II, 5-11 day old Ss were permitted lengthy exposure to a novel imprinting-type stimulus. Under these circumstances, distress vocalization eventually came under stimulus control. The overall pattern of results suggests that through imprinting, stimuli that innately evoke filial behavior become familiar and thus are prevented from later evoking novelty-induced fear. (16 ref.) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
142.
Evaluated 40 schizophrenics and 20 normals on a social communication task and on an individual cognitive task, both designed to reveal decentering deficits. It was hypothesized that the processes underlying the schizophrenic's thought disorder are formally similar to the processes involved in his deviant organization of social situations, specifically social communication, with both deficits to be interpreted in terms of faulty decentering. Schizophrenics manifested a decentering deficit on both the social communication (p 相似文献
143.
The cost of managing 114 adult haemophiliacs in the west of Scotland was assessed for the period 1 March 1971 to 28 February 1974. Altogether 23 of them (20%) accounted for 80% of the resources used. The cost of hospital treatment of these patients during the period was compared with the predicted cost of home treatment, given the availability of freeze-dried factor VIII concentrate in sufficient amounts. We calculate that adequate on-demand home treatment would cost only 16% more than the present treatment, which is substantially less efficient. 相似文献
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The object of this paper is to present a mathematical model capable of determining the optimum amount of time that semiconductor devices, which have specified life characteristics, must be placed on burn-in to obtain maximum performance versus total cost. To make the model operational and realistic, the traditional assumption of an exponential (more recently, Weibull) distribution of life is omitted in favor of the generalized gamma distribution (GGD). This is done because the GGD includes, as special cases, such distributions as the normal, Rayleigh, Maxwell, chi, chi2, Weibull, exponential, ordinary gamma, etc. The use of the greater representational capability of the GGD is justified in the results of the studies showing that (other things being equal) small changes in parametric values of life characteristics can cause vast differences in the optimum burn-in time and maximum system effectiveness. The physical performance sector of the model incorporates system effectiveness that includes such factors as availability, expected time to repair, mission reliability, system use coefficient, storage survival probability, and operational readiness. The costs considered are those due to burn-in operation, production, and sales. The model has been studied by use of computer runs from the standpoint of critical analysis and parametric sensitivity analysis. 相似文献
148.
JW Taylor AJ McLean RG Leonard TM Ludden U Clibon BP du Souich SC Harris D Lalka RL Talbert N Vicuna CA Walton JL McNay 《Canadian Metallurgical Quarterly》1979,19(1):1-7
International statistics indicate that there is a close correlation between the consumption of saturated fats (dairy fats and meat fats) and the mortality from coronary heart disease (CHD), and this conception has been confirmed by many epidemiological studies. Such studies alone, however, cannot prove the existence of a cause-and-effect relationship between these two variables; dietary intervention trials are needed. The Finnish Mental Hospital Study was such a trial, conducted in two hospitals near Helsinki in 1959--1971. Practically total replacement of dairy fats by vegetable oils in the diets of these hospitals was followed by a substantial reduction in the mortality of men from CHD. Total mortality also appeared to be reduced. As to the causes of death other than CHD, none was significantly influenced by dietary change. This was also true for malignant neoplasms. To alleviate the burden of CHD on public health, many investigators have recommended important changes in the quantity and quality of dietary fats. 相似文献
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In vivo characterisation of a novel bioresorbable poly(lactide-co-glycolide) tubular foam scaffold for tissue engineering applications 总被引:2,自引:0,他引:2
Day RM Boccaccini AR Maquet V Shurey S Forbes A Gabe SM Jérôme R 《Journal of materials science. Materials in medicine》2004,15(6):729-734
Polylactide-co-glycolide (PLGA) foams of tubular shape were assessed for their use as soft-tissue engineering scaffolds in vitro and in vivo. Porous membranes were fabricated by a thermally induced phase separation process of PLGA solutions in dimethylcarbonate. The parameters investigated were the PLGA concentration and the casting volume of solution. Membranes produced from 5 wt/v % polymer solutions and a 6 ml casting volume of polymer solution were selected for fabricating tubes of 3 mm diameter, 20 mm length and a nominal wall thickness of 1.5 mm. Scanning electron microscopy revealed that the structure of the tubular foams consisted of radially oriented and highly interconnected pores with a large size distribution (50-300 microm). Selected tubes were implanted subcutaneously into adult male Lewis rats. Although the lumen of the tubes collapsed within one week of implantation, histological examination of the implanted scaffolds revealed that the foam tubes were well tolerated. Cellular infiltration into the foams, consisting mainly of fibrovascular tissue, was evident after two weeks and complete within eight weeks of implantation. The polymer was still evident in the scaffolds after eight weeks of implantation. The results from this study demonstrate that the PLGA tubular foams may be useful as soft-tissue engineering scaffolds with modification holding promise for the regeneration of tissues requiring a tubular shape scaffold such as intestine. 相似文献