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951.
The paper explores the outcomes of permanent family placement for children of minority ethnic origin, using a sample of 254 placements drawn, in the main, from a cohort of 1165 British children placed between 1980 and 1985. Statistical techniques are used to explore the relationship between 'success' (defined, for the purposes of this paper, as the placement not known to have broken down) and a range of variables, including the characteristics of the child, the birth parents and the adoptive parents, and the type of placement. In most respects, the findings are consistent with those of similar studies. Age at placement is found to have an important effect, with success least likely for children placed in the middle age range. Lack of problem behaviours in the children at the time of placement is also found to be associated with success. Variables which are found to have no effect on the probability of success include ethnic origin of the child, whether it is an adoptive or permanent foster placement, and whether contact with birth parents continued after placement. There was an interesting gender effect in that boys did better in 'transracial' than in 'matched' placements, but the opposite was the case for girls.  相似文献   
952.
It has become a commonplace to argue that in the face of a discredited Marxism, socialism must find an alternative basis for a renewed project. This article investigates two of these claims by Gerald Cohen and Bob Fitch. It does so with particular reference to the attempt by these authors to re-invoke, both wittingly and unwittingly, David Ricardo, John Stuart Mill, Henry George, and Auguste Comte among others as the source of a renewed left project. It takes as its special concern the way in which the supposed need to revivify "industry" in the late twentieth century parallels the often voiced need to revivify "agriculture" in the late nineteenth century as a means of staving off "underdevelopment."  相似文献   
953.
P D Kurtz 《Child welfare》1979,58(3):165-176
Early identification of handicapping conditions in children greatly enhances the possibility of treatment that may limit malfunctioning. Social work has responsibility and an opportunity to become more active in early identification.  相似文献   
954.
本文建立了火焰原子吸收光谱法测定硫酸中铁和锌的方法。确定了最佳仪器工作条件和样品处理方法。在选择好的实验条件下,测定铁的特征浓度为0.014μg/mL/1%吸收;测定锌的特征浓度为0.002μg/mL/1%吸收。回收率分别为铁98.8%—103.4%,锌92.5%—98.6%。  相似文献   
955.
Yu (1995) provides a novel convergence diagnostic for Markov chain Monte Carlo (MCMC) which provides a qualitative measure of mixing for Markov chains via a cusum path plot for univariate parameters of interest. The method is based upon the output of a single replication of an MCMC sampler and is therefore widely applicable and simple to use. One criticism of the method is that it is subjective in its interpretation, since it is based upon a graphical comparison of two cusum path plots. In this paper, we develop a quantitative measure of smoothness which we can associate with any given cusum path, and show how we can use this measure to obtain a quantitative measure of mixing. In particular, we derive the large sample distribution of this smoothness measure, so that objective inference is possible. In addition, we show how this quantitative measure may also be used to provide an estimate of the burn-in length for any given sampler. We discuss the utility of this quantitative approach, and highlight a problem which may occur if the chain is able to remain in any one state for some period of time. We provide a more general implementation of the method to overcome the problem in such cases.  相似文献   
956.
957.
The hypothesis that polygyny is associated with higher fertility than monogamy was evaluated. An assessment of previous studies and of the results of a 1966-1967 study comparing the fertility levels of polygynously and monogamously married women in a rural and an urban population in Nigeria lead to the conclusion that the hypothesis was useless. The hypothesis was judged to be useless because 1) fertility rates are the product of multiple influences; 2) it is too difficult to separate out these multiple influences, given the variability involved in polygynous practices and the inadequates of the data; and 3) the influence of polygyny on fertility is too slight to take into account. In the Nigerian study, the fertility of 2742 monogamously married women was compared with the fertility of 1261 polygynously married women. Preliminary analysis revealed that the fertility rate was higher for polygynously married women; however, when marriage duration was controlled, there was no significant differences between the fertility rates observed for the polygynously and monogamously married women living in rural areas nor those living in urban area.  相似文献   
958.
Received: December 30, 1999; revised version: July 19, 2000  相似文献   
959.
When Shannon entropy is used as a criterion in the optimal design of experiments, advantage can be taken of the classical identity representing the joint entropy of parameters and observations as the sum of the marginal entropy of the observations and the preposterior conditional entropy of the parameters. Following previous work in which this idea was used in spatial sampling, the method is applied to standard parameterized Bayesian optimal experimental design. Under suitable conditions, which include non-linear as well as linear regression models, it is shown in a few steps that maximizing the marginal entropy of the sample is equivalent to minimizing the preposterior entropy, the usual Bayesian criterion, thus avoiding the use of conditional distributions. It is shown using this marginal formulation that under normality assumptions every standard model which has a two-point prior distribution on the parameters gives an optimal design supported on a single point. Other results include a new asymptotic formula which applies as the error variance is large and bounds on support size.  相似文献   
960.
Resumen

Dentro del estudio de los procesos sociocognitivos implicados en la conducta de salud, el objetivo de este estudio es obtener la percepción de rol de las personas implicadas en la relación del profesional de la salud con el paciente. Así como su asociación con el cumplimiento terapéutico del paciente. Cien pacientes de hipertensión arterial esencial y cien profesionales de la salud (médicos y de enfermería) respondieron a los cuestionarios especialmente elaborados para este trabajo.

El cumplimiento terapéutico lo valoramos mediante una medida combinada de autoinforme y consecución de los objetivos terapéuticos. Los resultados mostraron que el rol del paciente podría evaluarse por los profesionales sanitarios en función de tres dimensiones fundamentales (obediencia/resistencia hacia la asistencia sanitaria; confianza/desconfianza hacia los profesionales sanitarios y cumplimiento/incumplimiento hacia los tratamientos terapéuticos). El rol de médico percibido por los pacientes se definió de forma más amplia y exigente que el rol de la enfermera. Y por último, observamos diferencias entre los pacientes cumplidores y los incumplidores respecto a algunas características atribuidas al rol del médico.  相似文献   
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