A step-by-step algorithm for combining diagnostic tests

Combining data of several tests or markers for the classification of patients according to their health status for assigning better treatments is a major issue in the study of diseases such as cancer. In order to tackle this problem, several approaches have been proposed in the literature. In this paper, a step-by-step algorithm for estimating the parameters of a linear classifier that combines several measures is considered. The optimization criterion is to maximize the area under the receiver operating characteristic curve. The algorithm is applied to different simulated data sets and its performance is evaluated. Finally, the method is illustrated with a prostate cancer staging database.     

Dimensions of ethnic identity as protective factors for substance use and sexual risk behaviors in African American college students

Objective: To examine ethnic identity and ethnic socialization as potential protective factors for risk behaviors among US college students. Participants: Participants were 398 African American and Afro-Caribbean students recruited from 30 colleges and universities during September 2008–October 2009. Methods: Data on hazardous alcohol use, substance use, sexual behaviors, ethnic identity, and ethnic/racial socialization were collected. Hierarchical linear and negative binomial regression analyses were conducted to determine the degree to which ethnic identity and ethnic/racial socialization predicted the risk behaviors. Results: Ethnic Identity affirmation, belonging, and commitment (EI-ABC) significantly predicted lower substance use and hazardous alcohol use. Ethnic/racial socialization was not a significant predictor of substance use or sexual risk behaviors. Conclusions: Components of ethnic identity are potentially protective against alcohol and substance use behaviors. Additional research is recommended to determine effective intervention strategies.     

Wage Premium in the Industrial Sector of the Spanish Economy: Empirical Evidence

Abstract. This paper presents evidence that firm-level productivity increases when the relative wage rises, or the level of unemployment rises. Both facts are consistent with the efficiency wage model. Moreover, there is support for the idea that an increase in the sector's wage with respect to the previous year also increases productivity. We obtain the empirical evidence through a double-hurdle model. We use this estimation technique because it can be established that the differences in productivity between sectors could be explained by differences in effort. It means that some of the industrial sectors of the Spanish economy may pay wage premia while others do not. We also test this implication through panel data.     

Does illegal immigration empower rightist parties?

The main goal of this paper is to analyze the political outcome in countries where the relevant issue in elections is the control of immigration. In particular, we explore the consequences on the political outcome of the fact that parties are either ideological or opportunistic with respect to this issue. To do that, we use a simple two-party political competition model in which the issues over which parties take positions are the levels of border enforcement and the way it has to be financed. We show that an ideological rather than a pure opportunistic behavior gives parties an advantage to win the election. This result may help us to understand the recent success of anti-immigrant and rightist parties in several countries.     

Digital survivance and Trickster humor: exploring visual and digital Indigenous epistemologies in the #NoDAPL movement

ABSTRACT

The decolonizing turn in the humanities and social sciences calls for scholarship that analyzes social media practices through the lens of Indigenous epistemologies. In this article, we model the ways that Indigenous epistemologies might contribute to theories of social media practices as we explore ways that the digital image can drive identification with and engagement in political acts. The article analyzes social media tropes circulated across various platforms among Indigenous communities and allies in relation to the #NoDAPL movement. We argue that attempting to analyze Native American traditions through Western theory will only work towards colonizing these Indigenous texts. Thus, whereas we employ insights from digital and visual methods of analysis (Highfield, T., & Leaver, T. (2016). Instagrammatics and digital methods: Studying visual social media, from selfies and GIFs to memes and emoji. Communication Research and Practice, 2(1), 47–62), we also highlight the strategic use of humor in the visual materials shared through various social media platforms utilizing the framework of the Trickster. We argue that the visual and digital phenomena we studied might best be understood as a form of digital survivance, drawing upon Anishinaabe scholar Gerald Vizenor [(1994). Manifest manners: Postindian warriors of survivance. Hanover, CT: Wesleyan University Press]. term ‘survivance’ as a portmanteau that combines ‘survival’ and ‘resistance’ in its characterization of Indigenous storytelling traditions. Whereas centering the Indigenous figure of the Trickster might suggest that social media has failed to live up to its promises, this epistemological approach also explains the hope that Indigenous communities hold in uniting via social media for what has been and continues to be a long-term battle for sovereignty and for the protection of the earth and all of its beings.     

Ambition gone awry: the long-term socioeconomic consequences of misaligned and uncertain ambitions in adolescence

Objective: The objective of this study was to investigate whether misaligned or uncertain ambitions in adolescence influence the process of socioeconomic attainment. Methods: Using 34 years of longitudinal data from the British Cohort Study (BCS70), we considered whether youth with (1) misaligned ambitions (i.e., those who either over- or underestimate the level of education required for their desired occupation), (2) both low occupational aspirations and educational expectations (low-aligned ambitions), and (3) uncertainty with regard to their future occupations (uncertain ambitions) at age 16 experienced more unemployment spells, lower educational attainment, and lower hourly wages in adulthood compared to youth with high occupational aspirations and educational expectations (high-aligned ambitions). Results: Youth who hold misaligned or uncertain aspirations show long-term deficits in employment stability and educational attainment, which in turn leads to lower wage attainments at age 34. Conclusion: Misaligned and uncertain ambitions in adolescence compromise the construction of life paths and the realization of long-term educational and occupational goals.     

Determinants of Household Insurance Coverage Among Low‐Income Families from Boston,Chicago, and San Antonio: Evidence from the Three‐City Study*

Objectives. In this article we examine correlates of health insurance coverage for low‐income households. Methods. Using data from the Welfare, Children, and Families Project (1999–2001), a sample of 2,402 low‐income families from Boston, Chicago, and San Antonio, we estimate two logistic regressions, one that predicts health insurance coverage for one focal child in each household and another that assesses the odds that all children in the household have coverage. Results. The children of poorly‐educated, immigrant, and Mexican‐origin parents are at an elevated risk of lacking insurance. These characteristics also increase the risk of incomplete household coverage. Mexican‐origin children and households are at particularly high risk of lacking complete coverage, a fact partially reflecting their residential concentration in states with high uninsurance rates, such as Texas. Conclusions. Serious holes in the health‐care safety net affect poor Americans differently based on their state of residence, race, ethnicity, and household structure.     

Nonparametric Estimation of the Average Availability

The average availability of a repairable system is the expected proportion of time that the system is operating in the interval [0, t]. The present article discusses the nonparametric estimation of the average availability when (i) the data on ‘n’ complete cycles of system operation are available, (ii) the data are subject to right censorship, and (iii) the process is observed upto a specified time ‘T’. In each case, a nonparametric confidence interval for the average availability is also constructed. Simulations are conducted to assess the performance of the estimators.