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991.
This study explores the determinants of labor supply patterns among Latinas in the USA. We use recent microeconomic data from the Panel Study on Income Dynamics/Latino National Political Survey (PSID-LNPS) to estimate models of labor force participation, wages, and hours worked for a sample of Cuban, Mexican, and Puerto Rican women. We estimate the same models for Anglo and Black women in order to explore ethnic differences in the impact of characteristics affecting both the reservation and the market wage. We find that differences exist in the return to characteristics, such as education, but that there are also substantial differences in the levels of those characteristics across ethnic groups. The low wage rates and labor market activity of Latinas relative to Anglo and Black women are thus likely to be the combined result of lower investments in human capital and larger family size, the greater negative impact of macroeconomic conditions, and a stronger responsiveness to wages. Among Latinas, we find that there are differences in labor market outcomes between national origin and nativity groups. We also find that age at arrival and years in the USA play a role in labor supply, and that this is particularly true for Puerto Rican women.  相似文献   
992.
Employer use of employee drugscreening procedures is widespread in the U.S. A state-by-state analysis of statutory law applicable to the drug testing issue is combined with state and industry data to isolate how drug testing laws affect workplace injury rates. Based on our data, injury rates are not statistically related to the state’s legal environment.  相似文献   
993.
The 1995 wave of the Add Health study is used to investigate the relative influence of parent gender and residence on patterns of parental involvement with adolescents. Adolescent reports (N =17,330) of shared activities, shared communication, and relationship quality with both biological parents are utilized. A multidimensional scaling analysis reveals that parent gender explains most of the variance in parent‐adolescent involvement, with residential status playing a secondary yet a fundamental role in accounting for these patterns. Resident mothers who do not live with adolescents’ biological fathers engage in the broadest range of activities with their children. Unpartnered resident fathers display patterns of parenting that are as similar to mothers as they are to other fathers.  相似文献   
994.
We examine the relationship between neighborhood structural characteristics, social organization, and the sexual partnering practices of adults. Analyses of 1990 census and 1995–1997 survey‐based data on Chicago neighborhoods and adult sexual activity reveal for men a number of neighborhood influences on sexual partnering practices. First, residential stability is negatively associated with having a short‐term sexual partner in the last year. Second, neighborhood social ties are positively associated with short‐term sexual partnering in neighborhoods with low levels of collective efficacy—the combination of cohesion and shared expectations for beneficial action among neighbors—but this effect is substantially reduced as collective efficacy increases. Moreover, neighborhood collective efficacy and social ties mediate the effect of residential stability on sexual partnering practices. Neighborhood characteristics were not associated with short‐term sexual partnering for women.  相似文献   
995.
Communication technology is a central feature of young people's lives, but its role in romantic and sexual relationships has not been thoroughly examined. This article describes how young adults use communication technology for partnering across relationship stages (formation, maintenance, and dissolution) and types (serious/casual), and proposes implications of usage in relationships. This study analyzed qualitative data from a five-week, prospective, coital diary method with related debriefing interviews (N = 70) of African American and Puerto Rican men and women aged 18 to 25 years in Hartford and Philadelphia. Cell phones, including calls, text messaging, and mobile Internet, were the most common forms of communication technology used for partnering goals. Participants reported using cell phones to pursue partnering goals across all relationship stages, including formation (meeting, screening, and getting to know new partners), maintaining existing relationships, and breaking up. Cell phone uses depended on the type of relationship (serious/casual) and the participants' intentions and desires. Results indicated that cell phones are an important element of communication among young adults in romantic and sexual relationships. Specific features of cell phone communication shape the process and context of partnering. Future research should explore emerging communication technologies and implications for psychosocial development, dating violence, and sexual behavior.  相似文献   
996.
Marital satisfaction has been psychometrically measured using many different instruments not soundly based on theory. The Revised Dyadic Adjustment Scale (RDAS), consisting of 14 items, is commonly accepted by researchers and practitioners to measure marital satisfaction but was not specifically designed to measure marital satisfaction. The Satisfaction with Married Life Scale (SWML), consisting of five items, is a short scale specifically targeted toward measuring marital satisfaction. An online sample collected from 1,187 couples throughout the United States was used to compare these instruments' correlation (r = .782), factor structures, reliability (SWML, α = .958; RDAS, α = .943), theoretical foundation, and validity. These instruments are on parity with each other when measuring marital satisfaction; however, each instrument yields implications for practitioners and researchers desiring to measure marital satisfaction.  相似文献   
997.
We present and justify a propagation algorithm to facilitate the simultaneous calculation, for every node in a probabilistic exper system of the distribution of the associated random quantity, conditional on all the evidence obtained about the remaining nodes.  相似文献   
998.
Summary.  Non-ignorable missing data, a serious problem in both clinical trials and observational studies, can lead to biased inferences. Quality-of-life measures have become increasingly popular in clinical trials. However, these measures are often incompletely observed, and investigators may suspect that missing quality-of-life data are likely to be non-ignorable. Although several recent references have addressed missing covariates in survival analysis, they all required the assumption that missingness is at random or that all covariates are discrete. We present a method for estimating the parameters in the Cox proportional hazards model when missing covariates may be non-ignorable and continuous or discrete. Our method is useful in reducing the bias and improving efficiency in the presence of missing data. The methodology clearly specifies assumptions about the missing data mechanism and, through sensitivity analysis, helps investigators to understand the potential effect of missing data on study results.  相似文献   
999.
针对平衡倒立摆这一非线性控制问题,设计了神经元控制器和控制装置,编制了实时控制程序.控制装置运行良好,成功地平衡了倒立摆.实时控制实验显示,当倒立摆的参数变化时,神经元控制器比一般的控制器具有强得多的自适应能力.  相似文献   
1000.
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