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171.
McCoy Clyde B. Metsch Lisa R. McCoy H. Virginia Lai Shenghan 《Population research and policy review》1999,18(1-2):71-87
Despite the central role of women drug users in escalating AIDS statistics, there is still a limited number of studies that examine the roles of gender and drug use type in HIV seroprevalence. This lacuna in the research literature has led to significant gaps in researchers' understanding of how and to what extent women may differ in their drug-using and HIV risk behaviors compared to their better-studied male counterparts. This study, derived from a sample of 3,555 out-of-treatment drug users residing in three South Florida urban and rural communities, attempts to compare the drug usage and needle and sexual risk behaviors of male and female drug users that put them at risk for HIV infection. The overall seropositivity rate for women drug users was 26.5% compared to 19.5% for their male counterparts. Results of multivariate analyses indicate that females compared to males were 1.4 times more likely to be HIV seropositive. Risk behaviors associated with this elevated seropositivity include living arrangements, homeless status, drug use, sexual trading behaviors, and history of STDs. Furthermore, there was a strong linear relationship between drug use type and HIV seroprevalence among women drug users. Compared to those who were neither crack smokers nor injectors of illicit drugs, those who were crack smokers only were 2 times more likely to be HIV seropositive, while those who were both crack smokers and injectors were 5 times more likely to be HIV seropositive, and those who were injectors only were 6 times more likely to be HIV seropositive. These findings indicate that among women, drug abuse and its associated risk behaviors, increase the vulnerability of this population for HIV and thus render them an extremely important priority population on which to focus HIV prevention and public health efforts and programs. 相似文献
172.
Leaving school prematurely is often claimed to be among the most negative consequences of early marriage and pregnancy for girls in less developed countries. However, an analysis of the relative frequency with which these events actually occur or are named as reasons for leaving school reveals that, at least in the case of francophone Africa, they explain no more than 20 per cent of dropouts. To the extent that demographic events trump school or family factors as determinants of school-leaving, our data indicate that it is union formation--defined by the DHS as first marriage or cohabitation--rather than childbirth that is more likely to have this effect. 'Schoolgirl pregnancy' typically accounts for only between 5 and 10 per cent of girls' departures from school. Furthermore, the risks of leaving school because of pregnancy or marriage have declined over time with the decline in rates of early marriage and childbearing. 相似文献
173.
王德 《内蒙古民族大学学报(社会科学版)》2006,32(3):67-70
本文根据洪堡特的《论人类语言结构的差异性及其对人类精神发展的影响》,从语言的界定与民族精神、语言的认识与世界观、语言的系统性与思维方式、语言的分类与创新等方面对汉语的形成和发展进行了剖析,并由此阐明了汉语在今后发展以及创新的见解。 相似文献
174.
Reply 总被引:2,自引:0,他引:2
175.
The critical path in a PERT/CPM network is determined in various textbooks by finding the path with associated minimal slack for the network arcs or by finding the path with associated minimal slack for the network nodes. This paper points out that the use of nodes can result in a network path being incorrectly identified as a path of maximum length. 相似文献
176.
A branch and bound algorithm is presented for determining the minimum number of telephone operators, and their shift schedules, required to meet demand that varies over a 24 hour operating period. An integer linear programming formulation is used, and the algorithm is described in terms of its separation, relaxation, fathoming, and branching procedures. Computational results are provided, using actual operating data. The results indicate that practical sized problems can be solved by the algorithm, involving as many as 100 different shift type variables and demand profiles typical of those encountered in many telephone traffic exchanges. 相似文献
177.
叶明德 《浙江大学学报(人文社会科学版)》2002,32(6):5-10
注重人口质量是马寅初人口思想对马尔萨斯人口论的实质性超越.马寅初关于人口质量的观点主要体现于:人口质量与人口数量是对立的统一;在新时代,人不在乎多,而在乎精;人口质量的提高是德、智、体全面的提高和全民的提高;提高人口质量不能离开本国国情.在现代化进程中我们重温马寅初关于提高人口质量方面的有关观点和主张,有助于我们处理好提高人口质量与稳定低生育水平、保护资源环境、提高农民收入等方面的关系. 相似文献
178.
B.J. Hicks S.J. Culley C.A. McMahon P. Powell 《Journal of Engineering and Technology Management》2010,27(1-2):52-73
The benefits of integrated enterprise-wide information systems (IS), such as Enterprise Resource Planning (ERP) systems, are widely accepted. The implementation of such systems in large organisations is established with many in their second or third generation. However, in small to medium-sized enterprises (SMEs) the maturity and extent of their IS infrastructure is less clear. In engineering SMEs, this infrastructure needs to support not only business processes but also the activities of design and manufacture.In this case study, our goal is to provide a better understanding of current IS infrastructure, the functional elements of IS infrastructure, integration and expenditures are explored in ten engineering SMEs. A model of IS functionality is developed and used to identify and classify functional elements within the firms and to compare and contrast the IS infrastructures. The findings are contrasted with the SME literature and conclusions and implications developed. 相似文献
179.
This article is based on a quantitative risk assessment (QRA) that was performed on a radioactive waste disposal area within the Western New York Nuclear Service Center in western New York State. The QRA results were instrumental in the decision by the New York State Energy Research and Development Authority to support a strategy of in‐place management of the disposal area for another decade. The QRA methodology adopted for this first of a kind application was a scenario‐based approach in the framework of the triplet definition of risk (scenarios, likelihoods, consequences). The measure of risk is the frequency of occurrence of different levels of radiation dose to humans at prescribed locations. The risk from each scenario is determined by (1) the frequency of disruptive events or natural processes that cause a release of radioactive materials from the disposal area; (2) the physical form, quantity, and radionuclide content of the material that is released during each scenario; (3) distribution, dilution, and deposition of the released materials throughout the environment surrounding the disposal area; and (4) public exposure to the distributed material and the accumulated radiation dose from that exposure. The risks of the individual scenarios are assembled into a representation of the risk from the disposal area. In addition to quantifying the total risk to the public, the analysis ranks the importance of each contributing scenario, which facilitates taking corrective actions and implementing effective risk management. Perhaps most importantly, quantification of the uncertainties is an intrinsic part of the risk results. This approach to safety analysis has demonstrated many advantages of applying QRA principles to assessing the risk of facilities involving hazardous materials. 相似文献
180.
Miranda Witvliet Tjeert Olthof Jan B. Hoeksma Frits A. Goossens Marieke S. I. Smits Hans M. Koot 《Social Development》2010,19(2):285-303
To understand children's peer group affiliation, this study examined to what extent children in naturally occurring groups resemble each other on bullying, likeability, and perceived popularity. Participants were fourth‐ to sixth‐grade pupils (N = 461). Peer groups were identified using the social cognitive map procedure. Resemblance on bullying, likeability, and perceived popularity was evaluated by means of variance components models. Resemblance in peer groups was strongest for perceived popularity, followed by bullying and likeability. Moreover, resemblance on bullying could for a large part be attributed to the high‐perceived popularity of the group, and to a lesser extent, to the low likeability of the group. It is concluded that children showing bullying seem to affiliate with each other most of all to attain or maintain their position in a perceived popular peer group. Results stress the importance of considering the functionality of bullying from a group perspective. 相似文献