A Mixture Model for Longitudinal Partially Ranked Data

This article discusses the use of mixture models in the analysis of longitudinal partially ranked data, where respondents, for example, choose only the preferred and second preferred out of a set of items. To model such data we convert it to a set of paired comparisons. Covariates can be incorporated into the model. We use a nonparametric mixture to account for unmeasured variability in individuals over time. The resulting multi-valued mass points can be interpreted as latent classes of the items. The work is illustrated by two questions on (post)materialism in three sweeps of the British Household Panel Survey.     

A COMPARISON OF ANALYSIS METHODS FOR LATE‐STAGE VARIETY EVALUATION TRIALS

The statistical analysis of late‐stage variety evaluation trials using a mixed model is described, with one‐ or two‐stage approaches to the analysis. Two sets of trials, from Australia and the UK, were used to provide realistic scenarios for a simulation study to evaluate the different methods of analysis. This study showed that a one‐stage approach gave the most accurate predictions of variety performance overall or within each environment, across a range of models, as measured by mean squared error of prediction or realized genetic gain. A weighted two‐stage approach performed adequately for variety predictions both overall and within environments, but a two‐stage unweighted approach performed poorly in both cases. A generalized heritability measure was developed to compare methods.     

法医样本有效追踪和处理

为了配合法庭受理过程中的DNA鉴定,法医样品整个处理过程必须被记录,且在误差允许的范围内按照规定被精确执行。因此,一旦获得犯罪现场样本或参照样本,应该将它们立刻分装并保存在适当的样品库中。为了能成功、准确地检测鉴定样本中的每个成分,每个存储管必须清晰可辨,以消除不正确的样品处理机会。二维条形码是一种常见、有效地标识样本的方法。因此,对于已实施定期冻融循环或者其监管链被移动的样品,保持其二维条形码的可读性是非常重要的。     

Experimenter Presence or Absence: An Experimental Analogue with Implications for Organizational Behavior Management

Students performed a simulated bank-proofing task individually in a lab with either the experimenter present or absent. Although run rates were similar, those in the Experimenter-Absent Group were off-task twice as much during sessions. Error frequencies for both groups were low and similar while rates of responding were significantly higher (+13%) in the Experimenter-Present Group because participants were off-task less often. Most human lab experiments fail to specify whether experimenters are present or absent in the room and this extraneous variable is a potential confound that should be controlled in future studies.     

Race,Residence, and Underemployment: Fifty Years in Comparative Perspective, 1968–2017

High underemployment has been a chronic structural feature of the rural United States for decades. In this paper, we assess whether and how inequalities in underemployment between metropolitan (metro) and nonmetropolitan (nonmetro) areas have changed over the course of the last five decades. Drawing on data from the March Current Population Survey from 1968 to 2017, we analyze inequality in the prevalence of underemployment between metro and nonmetro areas of the United States, paying special attention to differences between white, black, and Hispanic workers. Our results show that the underlying risk of underemployment has increased in both metro and nonmetro areas over the last 50 years. Nonmetro workers have consistently faced greater employment hardship compared to their metro counterparts, and these differences cannot be fully explained by differences in population characteristics. Nonmetro ethnoracial minorities have experienced particularly poor labor market outcomes. The disadvantage of ethnoracial minority status and rural residence is especially pronounced for nonmetro black workers, among whom underemployment has remained persistently high with only modest convergence with other workers. Hispanic workers also face an elevated risk of underemployment, but we observe a unique convergence between metro and nonmetro workers within this population.     

Beneficiary Work: The Hidden Labor of Medicaid Users Pursuing Cross-State Moves

For users of Medicaid personal care assistance (PCA) services and their families, interstate variation in eligibility and service availability act as structural barriers to cross-state movement. However, program users desire and pursue cross-state moves. In this article, we provide a grounded theory analysis of 18 interviews with Medicaid PCA users with physical disabilities who expressed desire for or pursued cross-state moves. Our analysis identified six forms of previously unnamed and unrecognized work. As PCA users plan or pursue cross-state moves, they are also (1) assessing service ecosystems, (2) finding the right door, (3) persisting through the bureaucratic gauntlet, (4) advocating for systems cooperation, (5) reestablishing networks of support, and (6) responding to service gaps/lapses. Collectively, we describe this hidden labor as beneficiary work, the unremunerated work that program users must do in order to retain access to benefits for which they qualify. Beneficiary work, while hidden, is not optional; it is necessary for continued access to community and broadly, for survival. Identifying and describing beneficiary work expands on Feminist and interactionist perspectives on disability, poverty, and work, and highlights the need for changes to Medicaid policy that address PCA users as mobile citizens.     

Damaged Goods: Perception of Pornography Addiction as a Mediator Between Religiosity and Relationship Anxiety Surrounding Pornography Use

Recent research on pornography suggests that perception of addiction predicts negative outcomes above and beyond pornography use. Research has also suggested that religious individuals are more likely to perceive themselves to be addicted to pornography, regardless of how often they are actually using pornography. Using a sample of 686 unmarried adults, this study reconciles and expands on previous research by testing perceived addiction to pornography as a mediator between religiosity and relationship anxiety surrounding pornography. Results revealed that pornography use and religiosity were weakly associated with higher relationship anxiety surrounding pornography use, whereas perception of pornography addiction was highly associated with relationship anxiety surrounding pornography use. However, when perception of pornography addiction was inserted as a mediator in a structural equation model, pornography use had a small indirect effect on relationship anxiety surrounding pornography use, and perception of pornography addiction partially mediated the association between religiosity and relationship anxiety surrounding pornography use. By understanding how pornography use, religiosity, and perceived pornography addiction connect to relationship anxiety surrounding pornography use in the early relationship formation stages, we hope to improve the chances of couples successfully addressing the subject of pornography and mitigate difficulties in romantic relationships.