The Prevalence of Uncorrected Refractive Errors in Adolescents Incarcerated in a Youth Detention Center

The purpose of this study was to determine the number of residents requiring corrective lenses in a youth detention center for juveniles from 12 to 18 years old over a 2-year period. A greater number of adolescents incarcerated for criminal activity in a detention center had uncorrected refractive errors (34.87 %) as compared to a comparable population in the public school system (22 %). The prevalence of significant refractive errors among incarcerated adolescents in this study is significantly higher than has been reported previously. The current study found a refractive error rate of almost 35 %. This difference can be explained by a number of factors in their social environments and identifies an area for potential intervention to reduce antisocial behavior in this population.     

$$D_s$$-optimality in copula models

Optimum experimental design theory has recently been extended for parameter estimation in copula models. The use of these models allows one to gain in flexibility by considering the model parameter set split into marginal and dependence parameters. However, this separation also leads to the natural issue of estimating only a subset of all model parameters. In this work, we treat this problem with the application of the \(D_s\)-optimality to copula models. First, we provide an extension of the corresponding equivalence theory. Then, we analyze a wide range of flexible copula models to highlight the usefulness of \(D_s\)-optimality in many possible scenarios. Finally, we discuss how the usage of the introduced design criterion also relates to the more general issue of copula selection and optimal design for model discrimination.     

Improved model selection criteria for SETAR time series models

The purpose of this paper is threefold. First, we obtain the asymptotic properties of the modified model selection criteria proposed by Hurvich et al. (1990. Improved estimators of Kullback-Leibler information for autoregressive model selection in small samples. Biometrika 77, 709–719) for autoregressive models. Second, we provide some highlights on the better performance of this modified criteria. Third, we extend the modification introduced by these authors to model selection criteria commonly used in the class of self-exciting threshold autoregressive (SETAR) time series models. We show the improvements of the modified criteria in their finite sample performance. In particular, for small and medium sample size the frequency of selecting the true model improves for the consistent criteria and the root mean square error (RMSE) of prediction improves for the efficient criteria. These results are illustrated via simulation with SETAR models in which we assume that the threshold and the parameters are unknown.     

A Multilevel Analysis of Hispanic Youth,Exposure to the United States,and Retail Theft

Panel data in the National Longitudinal Survey of Youth (NLSY97) provide an excellent opportunity to examine the relationship between Hispanic immigration, assimilation, and retail theft. This study examines the relationship between length of time Hispanic youth have spent in America, with the probability of stealing from a store. After controlling for traditional predictors of crime that are correlated with adolescence and immigrant status, random effects logistic regression models indicate that immigrants are less likely to steal than non-immigrants. However, calculating the marginal effects of time spent in the United States reveals that their probability increases with assimilation. Supplementary analyses specify that Hispanic youth who enter the United States within their first 5 years of age will have higher odds of engaging in retail theft. Supportive parenting and a structured home environment is a consistent protective factor in the models. Policies targeting pro-family and social identification are likely to benefit immigrant youth as they acculturate to America.     

Financial Strain,Negative Interaction,Coping Styles,and Mental Health Among Low-Income Latinos

This study examines the relationship between financial strain and depressive symptoms in later life, and potential psychosocial mediators of this relationship. Drawing on a sample of 214 low-income Latino older adults, we used structural equation modeling to test the direct effect of chronic financial strain on depressive symptomatology, and the indirect effects via social support, negative interaction, and coping styles. Findings indicated that financial strain increased the level of depressive symptoms among this sample. Avoidance and approach-related coping styles emerged as independent determinants of depressive symptoms albeit in opposite directions; higher levels of avoidance coping was associated with higher levels of depressive symptoms. Contrary to previous findings on the general population, findings from the current study indicate that social support and negative interaction were not directly associated with depressive symptoms. Financial strain mediated the effect of sociocultural (nativity status, years of U.S. residence) and social status factors (age, education) on depressive symptoms. This study highlights the differential impact of financial strain and coping styles on psychological well-being, and the potential psychosocial targets of interventions for older adults with chronic health care conditions.     

On the distance paired domination of generalized Petersen graphs <Emphasis Type="Italic">P</Emphasis>(<Emphasis Type="Italic">n</Emphasis>,1) and <Emphasis Type="Italic">P</Emphasis>(<Emphasis Type="Italic">n</Emphasis>,2)

Let G=(V,E) be a graph without an isolated vertex. A set D⊆V(G) is a k -distance paired dominating set of G if D is a k-distance dominating set of G and the induced subgraph 〈D〉 has a perfect matching. The minimum cardinality of a k-distance paired dominating set for graph G is the k -distance paired domination number, denoted by γ _p ^k (G). In this paper, we determine the exact k-distance paired domination number of generalized Petersen graphs P(n,1) and P(n,2) for all k≥1.     

A new random permutation test in ANOVA models

This paper developed an exact method of random permutations when testing both interaction and main effects in the two-way ANOVA model. The method of this paper can be regarded as a much improved model when compared with those of the previous studies such as Still and White (1981) and ter Braak (1992). We further conducted a simulation experiment in order to check the statistical performance of the proposed method. The proposed method works relatively well for small sample sizes compare with the existing methods. This work was supported by Korea Science and Engineering Foundation Grant (R14-2003-002-0100)     

Street lamps,alleys, ratio analysis,and nonprofit organizations

This article offers an accounting‐based framework for evaluating the efficiency of nonprofit organizations using four factors. Separately, these factors reflect (1) the proportion of revenues actually used in the current year, (2) the proportion of the expenditures allocated to programs, (3) the units of output produced from that spending, and (4) the value of the units produced, expressed in terms of an index value. Combined, these four factors measure the value of units produced per dollar of revenue received, an accounting measure of overall efficiency. Using this framework provides insight into both the appropriateness and the limitations of employing solely financial measures to judge nonprofit organizations and also identifies conceptual areas absent from currently available evaluation tools.     

Association of educational level and child sex ratio in rural and urban India

Utilizing data from the Census of India, this study compared child sex ratio in rural and urban regions of India and analyzed whether the child sex ratio was associated with mother’s education level. The child sex ratios in the rural and urban regions throughout India were analyzed using the two-sample and paired Student’s t-test. Further, the Chi-square test for trend in binomial proportions was used to assess the association between child sex ratios and mother’s education levels in rural and urban areas. Analysis of the data showed that there was a significant difference between the child sex ratios in rural areas versus urban areas. In addition, the Chi-square test for trend showed that there was a significant association of the child sex ratio and the educational levels of their mothers. This trend occurred in both rural and urban areas.     

Extreme Copulas and the Comparison of Ordered Lists

We introduce two extreme methods to pairwisely compare ordered lists of the same length, viz. the comonotonic and the countermonotonic comparison method, and show that these methods are, respectively, related to the copula T _M (the minimum operator) and the Ł ukasiewicz copula T _L used to join marginal cumulative distribution functions into bivariate cumulative distribution functions. Given a collection of ordered lists of the same length, we generate by means of T _M and T _L two probabilistic relations Q ^M and Q ^L and identify their type of transitivity. Finally, it is shown that any probabilistic relation with rational elements on a 3-dimensional space of alternatives which possesses one of these types of transitivity, can be generated by three ordered lists and at least one of the two extreme comparison methods.