Point Estimates of Test Sensitivity and Specificity from Sample Means and Variances

In a wide variety of biomedical and clinical research studies, sample statistics from diagnostic marker measurements are presented as a means of distinguishing between two populations, such as with and without disease. Intuitively, a larger difference between the mean values of a marker for the two populations, and a smaller spread of values within each population, should lead to more reliable classification rules based on this marker. We formalize this intuitive notion by deriving practical, new, closed-form expressions for the sensitivity and specificity of three different discriminant tests defined in terms of the sample means and standard deviations of diagnostic marker measurements. The three discriminant tests evaluated are based, respectively, on the Euclidean distance and the Mahalanobis distance between means, and a likelihood ratio analysis. Expressions for the effects of measurement error are also presented. Our final expressions assume that the diagnostic markers follow independent normal distributions for the two populations, although it will be clear that other known distributions may be similarly analyzed. We then discuss applications drawn from the medical literature, although the formalism is clearly not restricted to that application.     

Household time activities,food waste,and diet quality: the impact of non-marginal changes due to COVID-19

Review of Economics of the Household - In early 2020, a novel coronavirus quickly spread across the globe. In response to the rapidly increasing number of confirmed U.S. cases, state and local...     

Conditional covariance penalties for mixed models

The prediction error for mixed models can have a conditional or a marginal perspective depending on the research focus. We introduce a novel conditional version of the optimism theorem for mixed models linking the conditional prediction error to covariance penalties for mixed models. Different possibilities for estimating these conditional covariance penalties are introduced. These are bootstrap methods, cross-validation, and a direct approach called Steinian. The behavior of the different estimation techniques is assessed in a simulation study for the binomial-, the t-, and the gamma distribution and for different kinds of prediction error. Furthermore, the impact of the estimation techniques on the prediction error is discussed based on an application to undernutrition in Zambia.     

The (Conditional) Resource Dilution Model: State- and Community-Level Modifications

Demography - One of the most consistent patterns in the social sciences is the relationship between sibship size and educational outcomes: those with fewer siblings outperform those with many. The...     

Mastery,Homeownership, and Adult Roles During the Transition to Adulthood

We investigate the relationship between homeownership and personal sense of mastery in the transition to adulthood and examine whether three important adult transitions (employment, marriage/cohabitation, and parenthood) moderate the impact of homeownership on mastery. Utilizing the National Longitudinal Survey of Youth—Young Adult Sample (N = 1,609), we estimate change models to assess the direct effects of homeownership on mastery as well as whether this impact is modified by the transition to adult roles. Homeownership increases the sense of mastery among young adults. Homeowners who are unemployed paradoxically receive a boost to mastery not experienced by those who are employed, and homeowners who are parents experience increased mastery, compared to those who do not have children. Owning a home has a positive influence on young adults' sense of mastery during a period when their mastery is in flux and they are accumulating new roles.     

The Mediating Role of Emotion Dysregulation in the Relation Between Adult Attachment Insecurity and Depression Among Young Gay and Bisexual Men

Objectives: Attachment insecurity may be more pronounced among young gay and bisexual men (YGBM). Further, attachment insecurity is associated with dysregulated patterns of emotion regulation, which can lead to depression. However, pathways linking attachment insecurity to depression are underexplored among YGBM. Methods: This study used pilot data from N?=?67 YGBM to examine if emotion dysregulation mediated the association between attachment insecurity and depression. Results: Results supported the study hypotheses. Attachment insecurity was associated with emotion dysregulation, which was associated with depression. Conclusion: Findings provide preliminary evidence that emotion regulation training may be a useful approach for addressing depression among YGBM.     

The urban background to public health changes in England and Wales, 1900–50

The history of public health changes is taken forward from 1900 to 1950. This was a period of important development in a population in which most ofthe adult members had at the outset of the period experienced compulsory primary education; when the full effects of industrial development had made their mark on the nation's health and, at last, on the public conscience; when the force of social and economic factors in producing and perpetuating disease was becoming appreciated; and when community responsibility for the health and welfare ofthe individual was becoming accepted. Not surprisingly, great improvements were made in the scope of preventive and curative services and in their accessibility. But the most important factor in the improvement of the national health was the steady rise in the level of living of the population, especially during the last two decades of the period.     

Revolutionary Horizons: Past and Present in Bolivian Politics

Revolutionary Horizons, by Forrest Hylton and Sinclair Thomson,is a highly readable work that contributes to understandingthe recent events that have placed Bolivia, once erased fromthe map by Queen Victoria following the expulsion of her emissaryin the nineteenth century, in the spotlight of observers ofprogressive movements around the world. With an insightful introductionby Adolfo Gilly, the book provides an accessible analysis ofthe events that led to the inauguration of Evo Morales, thefirst indigenous president in Bolivian history, in January 2006,ending the epoch of Andean apartheid. More than a simple recounting,     

Georges Bataille's base materialism

Abstract

The French intellectual Georges Bataille (1897–1962) developed base materialism in his work during the late 1920s and early 1930s as an attempt to break with all existing materialism. This essay is an explication of base materialism and its radical implications for contemporary theory. Bataille argues for the concept of an active base matter that disrupts the opposition of high and low and destabilises all foundations. Then he attempts to use this to develop a radical libertarian Marxism, opposed to both Stalinism and fascism. Although it provided a critique of the emphasis in Marxism on production, the active flux of base matter could not be contained in a political discourse. This means that Bataille's thought has an impact beyond the political and into the wider domain of theory. One example of this is the influence of base materialism on Derrida's deconstruction, and both share the attempt to destabilise philosophical oppositions by means of an unstable ‘third term’. This explains why Bataille's materialism does not appear as conventionally materialist, and why it has had little impact within contemporary materialism. Despite attempts to force base materialism into the mold of a new form of materialism it disrupts conventional materialism and the ‘radical’ politics that often goes with it. Bataille destroys the promise of liberated spaces and offers a more radical and disorienting freedom which inscribes instability into all discourses. It is this that defines the importance and necessity of Bataille's base materialism today.     

Bounding Optimal Expected Revenues for Assortment Optimization under Mixtures of Multinomial Logits

We consider assortment problems under a mixture of multinomial logit models. There is a fixed revenue associated with each product. There are multiple customer types. Customers of different types choose according to different multinomial logit models whose parameters depend on the type of the customer. The goal is to find a set of products to offer so as to maximize the expected revenue obtained over all customer types. This assortment problem under the multinomial logit model with multiple customer types is NP‐complete. Although there are heuristics to find good assortments, it is difficult to verify the optimality gap of the heuristics. In this study, motivated by the difficulty of finding optimal solutions and verifying the optimality gap of heuristics, we develop an approach to construct an upper bound on the optimal expected revenue. Our approach can quickly provide upper bounds and these upper bounds can be quite tight. In our computational experiments, over a large set of randomly generated problem instances, the upper bounds provided by our approach deviate from the optimal expected revenues by 0.15% on average and by less than one percent in the worst case. By using our upper bounds, we are able to verify the optimality gaps of a greedy heuristic accurately, even when optimal solutions are not available.