Crime in Acadiana: A study of the relationship between fear levels and demographic indicators in southwest Louisiana

Demographic indicators for residents of an eight parish (county) region of Louisiana were analyzed to determine their impact on fear. Earlier studies reported a strong relationship between these indicators and high fear levels. The finding of the in‐mediate study shows a weaker relationship. Possible explanations for these results are offered.     

Symmetry in mixture experiments

Two types of symmetry can arise when the proportions of mixture components are constrained by upper and lower bounds. These two types of symmetry are shown to be useful for blocking first-order designs, as well as for finding the centroid of the experimental region. Orthogonal blocking of first-order mixture designs provides a method of including process variables in the mixture experiment, with the mixture terms orthogonal to the process factors. Symmetric regions are used to develop spherical and rotatable response surface designs for mixtures. The central composite design and designs based on the icosahedron and the dodecahedron are given for four-component mixtures. The uniform shell designs are three-level designs when applied to mixture experiments.     

A mixture of the manova and gmanova models

A mixture of the MANOVA and GMANOVA models is presented. The expected value of the response matrix in this model is the sum of two matrix components. The first component represents the GMANOVA portion and the second component represents the MANOVA portion. Maximum likelihood estimators are derived for the parameters in this model, and goodness-of-fit tests are constructed for fuller models via the likelihood ration criterion. Finally, likelihood ration tests for general liinear hypotheses are developed and a numerical example is presented.     

Comparison of bias-reducing methods for estimating the parameter in dilution series

Ten different estimators of the parameter in a limiting or serial dilution assay are compared. Eight of them are constructed to reduce the bias of the commonly used maximum likelihood estimator. Extensive Monte Carlo experiments using various designs, and practical considerations, suggest that a particular jackknife version of the maximum likelihood estimator is preferred, provided that the design is not too small.     

Practitioners’ Personal and Professional Attitudes and Behaviors Toward Religion and Spirituality

This article presents findings from a study that examined the attitudes and behaviors toward religion and spirituality held by 328 randomly selected Virginia licensed clinical social workers, psychologists, and professional counselors. Significant differences were found among the three groups, with social workers generally holding a middle position in comparison with psychologists and professional counselors. As a whole, respondents were found to value the religious or spiritual dimension in their own lives, to respect the function it serves for people in general, and to address, to some extent, religious and spiritual issues in practice. Limited professional training in this area was reported, however, with 79% (n = 259) of the respondents stating that religious or spiritual issues were rarely or never addressed during the course of their graduate education and training. Implications for social work education and practice are discussed.     

A new characterization of Elfving's method for high dimensional computation

We give a new characterization of Elfving's (1952) method for computing c-optimal designs in k dimensions which gives explicit formulae for the k unknown optimal weights and k unknown signs in Elfving's characterization. This eliminates the need to search over these parameters to compute c-optimal designs, and thus reduces the computational burden from solving a family of optimization problems to solving a single optimization problem for the optimal finite support set. We give two illustrative examples: a high dimensional polynomial regression model and a logistic regression model, the latter showing that the method can be used for locally optimal designs in nonlinear models as well.     

A control chart for variance based on squared ranks

A nonparametric control chart for variance is proposed. The chart is constructed following the change-point approach through the recursive use of the squared ranks test for variance. It is capable of detecting changes in the behaviour of individual observations with performance similar to a self-starting CUSUM chart for scale when normality is assumed, and a relatively better power when assessing nonnormal observations. A comparison is also made with two equivalent nonparametric charts based on Mood and Ansari-Bradley statistics. When dealing with symmetrical distributions, the proposed chart shows smaller (better) out-of-control average run length (ARL), and a competing performance otherwise. In addition, sensitivity to changes in mean and variance at the same time was tested. Extensive Monte Carlo simulation was used to measure performance, and a practical example is provided to illustrate how the proposed control chart can be implemented in practice.     

Cool Pose: Black Male Homicide and the Social Implications of Manhood

ABSTRACT

Black male homicide has reached crisis proportions. This study investigated homicidal incidents to assess associations of Cool Pose with Black male homicides. Cool Pose is a tradition of manhood originating in Africa. The relationship of Cool Pose and homicide was examined by analyzing with multivariate statistical techniques 721 homicide incidents that occurred in the city of Newark, New Jersey. Findings suggest that Cool Pose is linked to homicides involving Black males. Society is not irrelevant to Cool Pose homicides and therefore relevant to their resolution. Social services may contribute to said resolution by informing the social work profession.