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81.
Social Indicators Research - The complex interplay between media and population sentiment is a well-known, yet hard to model, phenomenon. The extrema of individual sentiment (euphoria and...  相似文献   
82.
Cross‐border acquisitions are growing in volume and global economic importance, yet a considerable number end in failure. Many of these failures may be linked to people management‐related issues. We extend this stream of research by investigating the impact of the acquirer's aggregate human resource management (HRM) quality on cross‐border acquisition divestment. Our empirical analysis uses a panel database of 4128 cross‐border acquisition/year observations and an event history design. The findings confirm a curvilinear relationship and suggest that acquisition failures are not merely associated with poor HRM quality, but also with very high levels of HRM quality, that is, with both extremes. Moreover, our results show that financial slack has a significant moderating effect on the curvilinear relationship between HRM quality and the likelihood of acquisition divestment. Overall, our study reveals boundary conditions for the widely demonstrated positive relationship between HRM quality and organizational performance in an acquisition context.  相似文献   
83.
Young women’s experiences with sexual and reproductive health (SRH) stigma may contribute to unintended pregnancy. Thus, stigma interventions and rigorous measures to assess their impact are needed. Based on formative work, we generated a pool of 51 items on perceived stigma around different dimensions of adolescent SRH and family planning (sex, contraception, pregnancy, childbearing, abortion). We tested items in a survey study of 1,080 women ages 15 to 24 recruited from schools, health facilities, and universities in Ghana. Confirmatory factor analysis (CFA) identified the most conceptually and statistically relevant scale, and multivariable regression established construct validity via associations between stigma and contraceptive use. CFA provided strong support for our hypothesized Adolescent SRH Stigma Scale (chi-square p value < 0.001; root mean square error of approximation [RMSEA] = 0.07; standardized root mean square residual [SRMR] = 0.06). The final 20-item scale included three subscales: internalized stigma (six items), enacted stigma (seven items), and stigmatizing lay attitudes (seven items). The scale demonstrated good internal consistency (α = 0.74) and strong subscale correlations (α = 0.82 to 0.93). Higher SRH stigma scores were inversely associated with ever having used modern contraception (adjusted odds ratio [AOR] = 0.96, confidence interval [CI] = 0.94 to 0.99, p value = 0.006). A valid, reliable instrument for assessing SRH stigma and its impact on family planning, the Adolescent SRH Stigma Scale can inform and evaluate interventions to reduce/manage stigma and foster resilience among young women in Africa and beyond.  相似文献   
84.
An understanding of the spatial variation in the population structure of lotic fishes is vital to their conservation. Population level approaches may be more suitable than community level approaches for identifying stream fish response to urbanization. Lithophilic (clean mineral substrate) spawners are disproportionally affected by common habitat disturbances, and are thus expected to exhibit great demographic variation along gradients of disturbance. We related age distributions of six stream fishes, exhibiting four different types of lithophily (speleophily, saucer-pit nesting, gravel mound nesting, and simple broadcasting/nest association), to land cover and instream habitat variables. Fishes were collected from 18 urban or forested reaches of three 2nd-4th Strahler-order tributaries of the New River, Virginia. Individuals were assigned to age classes based on length-frequency histograms verified by sagittal otolith analysis. Chi-square tests and multiple polytomous logistic regression were used to relate population structure to land cover types and associated instream habitat variables. Age distributions of broadcast lithophils were unbalanced (containing relatively higher proportions of adults than juveniles) in urban reaches, whereas those of nest-constructing spawners were always balanced. Mixed responses were observed between the two speleophils. Differences in the directional effect of urbanization on population structure may be attributable to species?? tendency to: a) modify available substrate, b) to provide parental care to their brood, and c) life-history traits other than spawning mode (e.g. age at maturation). Although nest association may confer greater reproductive success to participants, this activity was not beneficial enough to give associates balanced age distributions in urban reaches. These results suggest that source-sink dynamics may operate to prevent populations of various fishes in urban reaches from being extirpated. Future research should focus on differences in population dynamics of stream fishes among land cover types.  相似文献   
85.
Recurrent events involve the occurrences of the same type of event repeatedly over time and are commonly encountered in longitudinal studies. Examples include seizures in epileptic studies or occurrence of cancer tumors. In such studies, interest lies in the number of events that occur over a fixed period of time. One considerable challenge in analyzing such data arises when a large proportion of patients discontinues before the end of the study, for example, because of adverse events, leading to partially observed data. In this situation, data are often modeled using a negative binomial distribution with time‐in‐study as offset. Such an analysis assumes that data are missing at random (MAR). As we cannot test the adequacy of MAR, sensitivity analyses that assess the robustness of conclusions across a range of different assumptions need to be performed. Sophisticated sensitivity analyses for continuous data are being frequently performed. However, this is less the case for recurrent event or count data. We will present a flexible approach to perform clinically interpretable sensitivity analyses for recurrent event data. Our approach fits into the framework of reference‐based imputations, where information from reference arms can be borrowed to impute post‐discontinuation data. Different assumptions about the future behavior of dropouts dependent on reasons for dropout and received treatment can be made. The imputation model is based on a flexible model that allows for time‐varying baseline intensities. We assess the performance in a simulation study and provide an illustration with a clinical trial in patients who suffer from bladder cancer. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   
86.
Emmanuel Caron 《Statistics》2019,53(4):885-902
In this paper, we consider the usual linear regression model in the case where the error process is assumed strictly stationary. We use a result from Hannan (Central limit theorems for time series regression. Probab Theory Relat Fields. 1973;26(2):157–170), who proved a Central Limit Theorem for the usual least squares estimator under general conditions on the design and on the error process. Whatever the design satisfying Hannan's conditions, we define an estimator of the covariance matrix and we prove its consistency under very mild conditions. As an application, we show how to modify the usual tests on the linear model in this dependent context, in such a way that the type-I error rate remains asymptotically correct, and we illustrate the performance of this procedure through different sets of simulations.  相似文献   
87.
Social Indicators Research - The literature on inequality in Tanzania has been dependent on limited rounds of methodologically different household budget surveys. The literature in question...  相似文献   
88.
Multimedia modelers from the United States Environmental Protection Agency (EPA) and the United States Department of Energy (DOE) collaborated to conduct a detailed and quantitative benchmarking analysis of three multimedia models. The three models—RESRAD (DOE), MMSOILS (EPA), and MEPAS (DOE)—represent analytically-based tools that are used by the respective agencies for performing human exposure and health risk assessments. The study is performed by individuals who participate directly in the ongoing design, development, and application of the models. Model form and function are compared by applying the models to a series of hypothetical problems, first isolating individual modules (e.g., atmospheric, surface water, groundwater) and then simulating multimedia-based risk resulting from contaminant release from a single source to multiple environmental media. Study results show that the models differ with respect to environmental processes included (i.e., model features) and the mathematical formulation and assumptions related to the implementation of solutions. Depending on the application, numerical estimates resulting from the models may vary over several orders-of-magnitude. On the other hand, two or more differences may offset each other such that model predictions are virtually equal. The conclusion from these results is that multimedia models are complex due to the integration of the many components of a risk assessment and this complexity must be fully appreciated during each step of the modeling process (i.e., model selection, problem conceptualization, model application, and interpretation of results).  相似文献   
89.
A new discrimination procedure based on the measurement of visual orientation latency to speech stimuli is introduced. Each participant listens to a series of short familiarization test trials. In each trial, 5 to 7 centrally‐presented familiarization stimuli are followed by laterally‐presented test stimuli. Infants were found to orient faster to different‐category than to same‐category test stimuli. This result was found despite a high degree of prosodic variability in the familiarization and test stimuli introduced by changes in talker and speaking rate. The combination of a multitrial design with use of acoustic and prosodic variability seems suitable for studying the representation of phonological categories.  相似文献   
90.
The crisis which Cameroon has been going through since 1986 has affected the various sectors of its economic and social life. For the first time since its establishment, the social security system administered by the National Social Insurance Fund is experiencing serious difficulties. After a period of financial surplus during which it accumulated substantial reserves, the product of the Fund's contributions has not covered its expenditure since the 1988/89 financial year, thereby obliging it to draw upon its reserves to balance its budget. After examining the fundamental criteria which have to be followed in the investment of social security assets, in accordance with the objectives and principles governing the financing of the system, the author of this article looks at the various types of investment undertaken by the Fund during its period of prosperity. "he resulting assessment leads to a series of recommendations for the formulation of a sound investment policy and the rational management of social security investment portfolios".  相似文献   
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