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241.
Disaster relief involves a broad range of participants, which often results in a disjunction between actual disaster needs and the perception of appropriate strategies in relief provision. This research examines data collected through interviews with donation drive operators responding to Superstorm Sandy in 2012 and the May 2013 Oklahoma tornadoes. Using Weber's ideal types of social action to understand motivations for engaging in disaster relief, this article argues that motivations for participating in and organizing such drives influence donation strategies, and these motivations can be used to explain persistent donation of nonuseful materiel items. Findings indicate several different motivations for involvement and that donation type appeared linked to motivation. We suggest that motivation for engaging in social action is a valuable approach to better understanding donation behavior and, consequently, addressing the social problem of materiel convergence in the postdisaster environment.  相似文献   
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Faculty mentorship is a highly advantageous yet under-explored form of social capital which can grant access to co-curriculars (e.g., research assistantships), ensure strong letters of recommendation, and more. It is also typically informal and dependent on student initiative, requiring that students be skilled at engaging educational authority figures. Privileged students are most likely to have such skills as part of their dominant cultural capital, making faculty mentorship a site of social reproduction. To explore variations in this process, I compare two institution types: a small, teaching/undergraduate-focused regional university and a large, research-intensive flagship. In interviews with 68 working- and upper-middle-class students, I find that college context mediates the relationship of class background and faculty mentorship. Upper-middle-class students fostered advantageous faculty relationships at both universities, but working-class students diverged: at the flagship, they rarely approached professors in search of mentorship, while those at the regional university described close, beneficial connections with professors. I discuss working-class students’ dissimilar experiences in terms of each university’s structural and cultural characteristics (organizational habitus), particularly their institutional focus and size. I argue that through their particular organizational features, colleges can both reproduce and reduce inequalities, challenging the determinacy of precollege socialization in education.  相似文献   
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Population Research and Policy Review - There has been little examination of: (1) associations of early-life nutrition and adolescent cognitive skills, (2) if they vary by gender, (3) if...  相似文献   
244.
ABSTRACT

The optimal learner for prediction modeling varies depending on the underlying data-generating distribution. Super Learner (SL) is a generic ensemble learning algorithm that uses cross-validation to select among a ‘library’ of candidate prediction models. While SL has been widely studied in a number of settings, it has not been thoroughly evaluated in large electronic healthcare databases that are common in pharmacoepidemiology and comparative effectiveness research. In this study, we applied and evaluated the performance of SL in its ability to predict the propensity score (PS), the conditional probability of treatment assignment given baseline covariates, using three electronic healthcare databases. We considered a library of algorithms that consisted of both nonparametric and parametric models. We also proposed a novel strategy for prediction modeling that combines SL with the high-dimensional propensity score (hdPS) variable selection algorithm. Predictive performance was assessed using three metrics: the negative log-likelihood, area under the curve (AUC), and time complexity. Results showed that the best individual algorithm, in terms of predictive performance, varied across datasets. The SL was able to adapt to the given dataset and optimize predictive performance relative to any individual learner. Combining the SL with the hdPS was the most consistent prediction method and may be promising for PS estimation and prediction modeling in electronic healthcare databases.  相似文献   
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In this paper we review recent field research on teams in the workplace with the objective to help advance research about teams and their external context. We investigate contextualization by reviewing the research settings in which teams have been studied, and we investigate context theorizing by reviewing work where external context variables have been explicitly modeled. We propose guidelines to improve contextualization and avenues to explore context theorizing.  相似文献   
248.
Analyses of data from 600 households in the province of Lubin, Poland, five years after the economic transformation indicated the transfers of goods and services between households to be quite prevalent, with households with high levels of resources giving goods and services and those with low levels of resources receiving goods and services. The receipt of such transfers does not improve the living conditions of the receiving households relative to those who do not receive help; in fact, those receiving help report lower levels of satisfaction than those not receiving assistance.  相似文献   
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Obesity is increasing in the US population and seems to be disproportionately burdening disadvantaged groups. Veterans using the Veterans Healthcare System (VHS) tend to be more disadvantaged socioeconomically than the general population and in poorer health. It is important to understand how the veteran population differs from or is similar to the general population and whether the VHS is able to mediate obesity risk among veterans. This research assesses the sociodemographic, behavioral, and health risk factors for obesity in the US adult and veteran populations in 2008. We use data from the 2008 Behavioral Risk Factor Surveillance System (BRFSS) to empirically assess predictors of obesity risk. We find that women have lower odds of obesity than men once controls for sociodemographic, behavioral, and health conditions are included in our models. We also observe a veteran obesity disadvantage in the full adult sample when conducting bivariate tests, but no significant association with the odds of obesity in the logistic regression models among veterans and non-veterans. Gender specific models indicate that male veterans have increased odds of obesity compared to non-veterans, but no difference in obesity risks among veterans and non-veterans are noted for women, controlling for all variables. Further, we find no significant differences in the odds of obesity of veterans using VHS for all, some, or none of their health care needs; further no significant gender differences in obesity risk were observed among VHS usages and non-users. Based on the strong, positive association between the number of chronic health conditions and the odds of obesity, we suggest that health policy should focus efforts on weight management counseling for obese patients that have obesity related co-morbidities, and more targeted attention to male veterans would help to address the high level of obesity in this vulnerable population group.  相似文献   
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