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51.
Population Research and Policy Review - Well-documented, large-scale abortion underreporting on U.S. surveys raises questions about the use of abortion self-reports for statistical inference. This... 相似文献
52.
We describe a new Monte Carlo algorithm for the consistent and unbiased estimation of multidimensional integrals and the efficient
sampling from multidimensional densities. The algorithm is inspired by the classical splitting method and can be applied to
general static simulation models. We provide examples from rare-event probability estimation, counting, and sampling, demonstrating
that the proposed method can outperform existing Markov chain sampling methods in terms of convergence speed and accuracy. 相似文献
53.
K. Hoelzer Y. Chen S. Dennis P. Evans R. Pouillot B. J. Silk I. Walls 《Risk analysis》2013,33(9):1568-1581
Listeria monocytogenes is a leading cause of hospitalization, fetal loss, and death due to foodborne illnesses in the United States. A quantitative assessment of the relative risk of listeriosis associated with the consumption of 23 selected categories of ready‐to‐eat foods, published by the U.S. Department of Health and Human Services and the U.S. Department of Agriculture in 2003, has been instrumental in identifying the food products and practices that pose the greatest listeriosis risk and has guided the evaluation of potential intervention strategies. Dose‐response models, which quantify the relationship between an exposure dose and the probability of adverse health outcomes, were essential components of the risk assessment. However, because of data gaps and limitations in the available data and modeling approaches, considerable uncertainty existed. Since publication of the risk assessment, new data have become available for modeling L. monocytogenes dose‐response. At the same time, recent advances in the understanding of L. monocytogenes pathophysiology and strain diversity have warranted a critical reevaluation of the published dose‐response models. To discuss strategies for modeling L. monocytogenes dose‐response, the Interagency Risk Assessment Consortium (IRAC) and the Joint Institute for Food Safety and Applied Nutrition (JIFSAN) held a scientific workshop in 2011 (details available at http://foodrisk.org/irac/events/ ). The main findings of the workshop and the most current and relevant data identified during the workshop are summarized and presented in the context of L. monocytogenes dose‐response. This article also discusses new insights on dose‐response modeling for L. monocytogenes and research opportunities to meet future needs. 相似文献
54.
We investigated associations between retrospectively assessed timing of pubertal development, interpersonal interactions, and hypothalamic–pituitary–adrenal axis reactivity to an interpersonal stress task in 110 young adult women. Participants provided salivary cortisol samples at points prior and subsequent to a video‐taped conflict discussion with their romantic partner. Participants also provided subjective global ratings of their discussion on dimensions of conflict and support. For earlier developing girls, higher levels of interpersonal conflict were associated with greater physiological stress in anticipation of the discussion task and less physiological recovery following the discussion. In contrast, for later developing girls, low levels of conflict were associated with greater anticipatory stress and less physiological recovery. These findings have implications for understanding the influence of off‐time pubertal development on the lifetime development of young women. 相似文献
55.
R.I. Woods 《Population studies》2013,67(2):283-311
The secular decline of marital fertility which took place in late nineteenth and early twentieth-century England and Wales is considered by using a number of approaches. Among the theoretical approaches considered are those of transition models, and social diffusion. The former overemphasises the role of industrialization and urbanization; the latter is inappropriate when dealing with the development of a small-family ideal in Victorian society. Explanations of fertility decline using ecological and time-series analysis are considered. The registration districts of England and Wales provide the framework for analyses of spatial variations in marital fertility and its correlates in 1861, 1891 and 1911. A time-series analysis attempts to establish the sequential nature of social, economic and demographic changes during the sixty years preceding the First World War. The following points are emphasised in conclusion. The Victorian fertility transition was not directly related to the development of an urban-industrial society, the social diffusion of family ideals or the use of appliance methods of contraception. But its immediate cause was probably linked to the substantial increase in family planning literature available from the 1870s, and the challenge that this posed to the tradition of unlimited marital fertility. This critical change in social attitudes to family planning was facilitated both by developments in mass education and, ultimately by the decline of infant mortality. 相似文献
56.
The life-course origins of mastery among older people 总被引:1,自引:0,他引:1
In this article, we aim to identify the sources of mastery--the understanding that individuals hold about their ability to control the circumstances of their lives. The sample for our inquiry was drawn from the Medicare beneficiary files of people 65 and older living in Washington, DC, and two adjoining Maryland counties. We find that past circumstances, particularly those reflecting status attainment and early exposure to intractable hardships, converge with stressors experienced in late life to influence elders' level of mastery. The impact of past conditions, however, does not necessarily directly affect the current mastery of older people. Instead, the effect of prior experiences on current mastery is mediated by what we refer to as life-course mastery: one's belief that one has directed and managed the trajectories that connect one's past to the present. Our analyses show that life-course mastery largely serves as the mediating channel through which individuals connect their past to their present. 相似文献
57.
In recent years, a variety of regression models, including zero-inflated and hurdle versions, have been proposed to explain the case of a dependent variable with respect to exogenous covariates. Apart from the classical Poisson, negative binomial and generalised Poisson distributions, many proposals have appeared in the statistical literature, perhaps in response to the new possibilities offered by advanced software that now enables researchers to implement numerous special functions in a relatively simple way. However, we believe that a significant research gap remains, since very little attention has been paid to the quasi-binomial distribution, which was first proposed over fifty years ago. We believe this distribution might constitute a valid alternative to existing regression models, in situations in which the variable has bounded support. Therefore, in this paper we present a zero-inflated regression model based on the quasi-binomial distribution, taking into account the moments and maximum likelihood estimators, and perform a score test to compare the zero-inflated quasi-binomial distribution with the zero-inflated binomial distribution, and the zero-inflated model with the homogeneous model (the model in which covariates are not considered). This analysis is illustrated with two data sets that are well known in the statistical literature and which contain a large number of zeros. 相似文献
58.
A laboratory experiment examined the effects of applying decision support system (DSS) technology to decision making in ill-structured problem environments under varying information conditions. Marketing executives participated in the experiment which investigated the effects of DSS availability, DSS training, and data availability on dependent variables that included: (1) the number of alternatives considered by a subject during decision making, (2) the period of time spent by a subject to complete the decision-making process, (3) the subject's perceived confidence in the decisions he or she had made, (4) the amount of data considered by a subject's during decision making, (5) the individual subject's decision processing, and (6) the subject's performance overall. Our results indicate that all three factors significantly affect the number of alternatives considered by subjects during the decision-making process. We therefore suggest that DSS training be coordinated with decision training in order to realize the potential of DSSs as described in the DSS literature. 相似文献
59.
Hani I. Mesak 《决策科学》1985,16(1):25-42
Based on empirical findings in the literature, sales response to advertising pulsing policy (APP) is modeled mathematically. The implications for APP are discussed. This policy is compared with an alternative policy of uniform expenditures (UAP), a commonly used strategy. The results of the research indicate that substantial savings in advertising budget or an increase in sales revenues may be achieved for a firm using APP. 相似文献
60.
Decision support for managers and policy makers, such as required in planning and evaluation efforts, often requires ad hoc behavioral modeling to account for context-specific phenomena and to handle data limitations. This paper introduces a systematic approach useful for meeting these requirements in which time-varying parameter estimation plays an important role. A case study evaluating the impacts of public policy actions on residential natural gas conservation illustrates the approach. 相似文献