Evaluating the discriminating power of amino acid ratios on distinguishing dark colored hair samples

Human hairs are one of the most commonly encountered items of trace evidence. Currently, conventional methods for hair analysis include microscopic comparison and DNA analysis (nuclear and mitochondrial). Each approach has its own drawbacks. Hair proteins are stable and offer an alternative to DNA testing, as demonstrated with proteomics for distinguishing humans. However, proteomics is complicated and requires identifying peptides to remain intact following harsh sample preparation methods. Alternatively, the actual amino acid content of a hair sample may also offer important identifying information and actually requires proteins and peptides to be broken down completely rather than remaining intact. This study evaluated the discriminating power of using hair amino acid ratios to differentiate hair samples from 10 unrelated individuals with dark colored hair. Hair proteins were digested, derivatized, and analyzed using gas chromatography–mass spectrometry. Amino acid ratios were calculated for each individual and comparisons using ANOVA and post-hoc pairwise t-test with Bonferroni correction were made with amino acid ratios for individuals. Overall, out of the 45 possible pairwise comparisons between all hair samples, 38 (84%) were differentiable. Out of the 36 possible pairwise comparisons between brown haired individuals, 32 (89%) were considered differentiable using univariate statistics. Multivariate statistics were also attempted but, overall, univariate models were sufficient for exclusionary purposes. These results indicate that amino acid ratio analysis can potentially be used as an exclusionary method using hair if DNA analysis cannot be performed, or to corroborate conclusions made following microscopic analysis.     

Pathways to Sexual Risk Taking Among Female Adolescent Detainees

Sexual risk taking among female delinquents represents a significant public health problem. Research is needed to understand the pathways leading to sexual risk taking among this population. This study sought to address this issue by identifying and testing two pathways from child maltreatment to non-condom use among 329 White and 484 African American female adolescent detainees: a relational pathway and a substance use coping pathway. The relational pathway indicated that child maltreatment would be related to non-condom use via depressive self-concept and condom use self-efficacy. The substance use coping pathway suggested that depressive self-concept and alcohol-based expectancies for sexual enhancement would mediate the relationship between child maltreatment and non-condom use. As hypothesized, the relational pathway variables were associated with one another in the expected directions; however, evidence of mediation was not found. Support for mediation was found for the substance use coping pathway. Exploratory across group comparison analysis indicated that the relational pathway was significant for White girls whereas the substance use coping pathway was significant for African American girls. Limitations and implications for future research are discussed.     

How Stable is the Condition of Family Homelessness?

Although research has documented the majority of homelessness experienced by individuals and families in the US to be transitional rather than chronic, the mechanisms by which some families successfully escape homelessness while other do not remains relatively unclear. To provide more information to this area of inquiry, this study analyzed the transitional nature of homelessness for a sample of families with school-aged children who were homeless under the McKinney-Vento definition. By conducting a survey with over 1000 homeless families with children enrolled in two public school systems in Central Florida, we find that over a quarter of families exit homelessness in less than six months. We compare these families to those that remained homeless to examine the potential importance of demographic differences and other potential barriers to securing housing. Many of the commonly assumed barriers were not significant predictors of continued homelessness; the most salient difference between the groups was income underscoring the importance of employment opportunities for families to allow them to exit homelessness.     

More than Risk? Longitudinal Changes in Friendship Support with Serious Adolescent Offenders

Journal of Youth and Adolescence - Research on the friendships of adolescents who offend has overwhelmingly focused on delinquency, despite developmental evidence that friendships are a large...     

A media campaign prevention program for child sexual abuse: community members' perspectives

This study examines the face validity and feasibility of materials included in a multimedia child sexual abuse (CSA) prevention campaign. A quantitative survey method assessed participants' comfort level, knowledge gain, and likelihood of behavioral change in response to the media campaign. Furthermore, a focus group method explored participants' attitudes and opinions regarding the campaign and the unique effects of ethnic or cultural norms on participants' acceptance of the media materials. Six groups, established based on participant ethnicity (i.e., three Caucasian groups, two African American groups, one Hispanic group), met at two sites in the Charleston, South Carolina, area. Quantitative data suggest that participants reported increased CSA knowledge and low levels of discomfort or anxiety related to exposure to the materials. Focus group results suggest that study participants, regardless of ethnic background, agreed that the media campaign can have a positive impact on public knowledge of CSA. Implications and directions for future research are discussed.     

Mass Reentry,Neighborhood Context and Recidivism: Examining How the Distribution of Parolees Within and Across Neighborhoods Impacts Recidivism

Recent scholarship focuses on the role neighborhood context plays in reoffending. These studies lack an examination of how the size of the parolee population at the neighborhood-level impacts individual recidivism. We examine how the size and clustering of parolee populations within and across neighborhoods impacts individual-level recidivism. Using data from parolees returning to three Ohio cities from 2000 to 2009, we examine how concentrations of parolees in neighborhoods and in the surrounding neighborhoods impact the likelihood of reoffending. We also examine whether parolee clustering conditions the relationship between neighborhood-level characteristics and recidivism. Results show concentrated reentry increases recidivism, while parolees in stable neighborhoods are less likely to recidivate. Also, the positive effect of parolee concentration is tempered when parolees return to stable neighborhoods. These findings suggest that augmenting resources available in neighborhoods saturated by parolees, as well as bolstering residential stability in these same neighborhoods might reduce reoffending.     

How Economic Stress Impacts Risky Sex among African American Adolescents

Journal of Youth and Adolescence - Given the potential for unintended pregnancy and exposure to sexually transmitted infections, both of which can have long-term deleterious health consequences,...     

Evaluation of police recruit training involving psychology

Abstract

Claims have been made that critical thinking is a necessary skill for constructing accurate offender profiles. However, in studies purporting to demonstrate this, critical thinking ability amongst participants has never been adequately assessed, making it impossible to draw any valid conclusions about the importance of this skill for profiling. In order to empirically examine the relationship between critical thinking ability and profile accuracy, participants (n=36) in the current study completed a mock profiling exercise and the Watson–Glaser Critical Thinking Appraisal – Form S (WGCTA-S). Profile accuracy scores were calculated for each participant and correlated with his or her scores on the WGCTA-S. Although the majority of participants were found to be adequate critical thinkers, no significant relationship was found between critical thinking ability and profile accuracy. Potential explanations for this finding are discussed.