The analysis of biological samples from crime scene for a future human DNA profile confrontation. Effects of presumptive test reagents on the ability to obtain STR profiles for human identification

Because of the increase of evidence of blood stains, that have been washed or cleaned in an attempt to mask the analysis of DNA profiles, there is also an increase in the use of presumptive tests on samples sent to laboratories. Some of the presumptive tests, used to identify blood and semen stains, could potentially affect the recovery of high molecular weight DNA from the samples, or extinguish them, especially those already present in small quantities. After the presumptive tests, often these samples are discarded. This study aimed to examine the possibility of obtaining a DNA profile from samples submitted for presumptive testing and cleaned with bleaches with and without chlorine. Two different protocols were conducted: (a) A unique sample of human blood in natura (5 μL), already typed through the DNA techniques with the genetic profile previously known (control), was distributed onto cotton fabrics and dried at room temperature. Four samples of fabric were macerated in saline solution and Coombs serum and then stored for three months (room temperature and freezer −20 °C). (b) Another sample of human blood, type A, in natura, already typed through the techniques of DNA (control) was used. Aliquots of 200 μL were distributed in: cotton, denim and synthetic fabric. The samples were dried at room temperature for 24 h. The blood stains in those fabrics (cotton, denim and synthetic) were then divided into three groups: unwashed, cleaned with chlorine bleach and cleaned with chlorine bleach and soap powder. The samples were again dried at room temperature for 24 h, before the use of luminol. The DNA were extracted with Chelex 100 and amplified with the Identifiler Kit (Applied Biosystems). The blood stains exposed to saline and Coombs serum had DNA profiles consistent with untreated samples (controls). This result shows that the experts should keep and store the samples treated with saline and Coombs serum for future DNA confrontation when necessary. Also discussed in this paper the pattern of blood stains after washing with bleaching solutions, as well as the quantity of DNA obtained from these samples.     

Longitudinal Association Between Parenting Practices and Early Sexual Risk Behaviors among Urban African American Adolescents: The Moderating Role of Gender

A sample of 274 African American families, living in impoverished neighborhoods with high HIV rates, participated in a longitudinal study of adolescent sexual development when children were in the 4th or 5th grade. Self-report and observational measures of parental warmth and parental behavioral control were collected from adolescents and parents at Time 1, and youth reported if they had initiated intercourse at Times 1 and 2. Regression analyses suggested that gender moderated associations between parental behavioral control and engagement in adolescent sexual behaviors. More generally, findings suggested that boys reared in low control/high warmth (i.e., permissive) homes and girls reared in high control/low warmth (i.e., authoritarian) homes were particularly at risk for early sexual behaviors. Clinical implications and directions for the future research are discussed.Doctoral Candidate in Clinical Psychology at Loyola University Chicago. Received her B.S. in Psychology and African & African American Studies from Duke University and her M.A. in Clinical Psychology from Loyola University Chicago. Her major research interests include the role of family and mental health factors in HIV risk exposure among urban African American adolescents.Professor, Department of Psychology, Loyola University Chicago. Received his Ph.D. in 1987 from Virginia Commonwealth University. His major research interests are family relations during adolescence, physical disabilities, pediatric psychology, developmental psychopathology, and statistical applications in psychologyAssociate Professor of Psychology in the Department of Psychiatry, Institute for Juvenile Research, University of Illinois, Chicago. Received her PhD in Child Psychology from the Institute of Child Development at the University of Minnesota in 1987. Her current research interests include developmental transitions during adolescence, as well as from pre-school to middle childhood, among typically developing children as well as children with special needs     

Satisfaction with body image for early adolescent females: The impact of pubertal timing within different school environments

During adolescence dramatic physical changes take place which the individual must incorporate into his or her evolving body image. The impact of different school environments on this incorporation process is explored using data on 225 White females from a longitudinal study. Differences in physical characteristics between early, middle, and late developers were assessed each year. The effects of pubertal timing on satisfaction with body image dimensions and self-esteem were then explored for sixth- and seventh-graders within different school environments. Reference group theory was used to examine three alternative hypotheses. Early versus late onset of menarche had different effects on certain aspects of satisfaction with body image, depending on the school environment. Results support the strength of the cultural ideal of thinness for women, but no other hypothesis had consistent support. The findings indicated the need to consider a multiplicity of factors in relation to specific body image dimensions.This study has been funded by NIMH grant R01 MH-30739 and a grant from the William T. Grant Foundation. In addition, the work of the second author has been supported by a Research Development Award from the National Institute of Mental Health, #2 K02 MH-41688.Received his Ph.D. from the University of Minnesota. Current research interests include stress and coping in adolescence, the role of social relationships in problem behavior, and the effects of different school contexts.Received her Ph.D. from Columbia University. Research interests include the social and psychological effects of puberty and sex differences in adolescence.Received M. A. in clinical child psychology from Ohio State University. Main interests are developmental aspects of body-image and research on personality disorders.     

Voltammetric analysis of luminescent markers in gunshot residues

Currently, SEM-EDS is used to detect gunshot residue (GSR) from the presence of Ba, Pb, and Sb in the sample. However, the development of new nontoxic ammunition (NTA) has prevented conventional metals from being found. In this work, we aim to determine the presence of an inorganic luminescent chemical marker based on rare earth in gunshot residues using the technique of squarewave voltammetry (SWV). After firing, the luminescent complex [(Eu₂Zr)(btc)₃(Hbtc)_0.5.6H₂O], which is used as a chemical marker, can be detected under a UV lamp. An aqueous solution with 0.1 mol L⁻¹ KCl as supporting electrolyte can be easily collected on carbon paste electrode surfaces for SWV analysis A = 100 mV, f = 10 Hz, and step potential of 5 mV are required. The luminescent marker incorporated into the carbon paste electrode showed two anodic peak currents in the region of 0.4 V (vs Ag/AgCl) and at 0.75 V (vs Ag/AgCl) and also a cathodic one in 0.4 V (vs Ag/AgCl). SEM-EDS was able to analyze the same voltammetric results for conventional and nontoxic ammunition containing the luminescent marker. Therefore, voltammetry and SEM-EDS are valid for detecting the new residue marker in GSR. Despite this, the electrochemical method is still more advantageous because of its low cost and lack of expensive equipment and supplies in forensic laboratories.     

The Gendered Face of Partisan Politics: Consequences of Facial Sex Typicality for Vote Choice

Facial cues are consequential for voters’ behavior at the polls. Yet the facial cues that are associated with vote choice remain under-examined. We predicted that vote choice judgments rely, in part, on the sex typicality of facial cues (i.e., the degree of facial masculinity and femininity) that vary as a function of candidate gender and partisan identification. Stimuli included image pairs of winners and runners-up in the elections for the 111th U.S. House of Representatives. In Study 1, we found that female Republican candidates who appeared relatively more feminine and male Republican candidates who looked relatively less masculine in their appearance were more likely to win their election. Democratic candidates’ electoral success was not related to their sex typicality. In Study 2, we found that relatively masculine-appearing Democrats and feminine-appearing Republicans were more likely to be selected in a hypothetical vote choice task. Implications for U.S. partisan politics are discussed.     

A step towards improving workflow practices for volume crime investigations: outcomes of a 90-day trial in South Australia

The provision of forensic science services in volume crime investigations works most successfully as a partnership between police agencies and external forensic laboratories as opposed to a client/provider model where unlimited demand ignores finite resources. The principles of Lean Six Sigma have been applied in various laboratories to improve workflow through identification of wasteful work practices. These strategies are aimed at process optimisation through the application of triaging, a concept that has rarely been studied yet referenced strongly in the literature. The South Australia End to End 90-Day Trial: facilitating quicker justice through timely evidence processing, is a collaborative approach between South Australia Police and Forensic Science South Australia. This trial applied evidence-based policing principles, a law enforcement philosophy that uses research undertaken with scientific processes to inform law-enforcement decision-making. The results demonstrate how a review of processes and the removal of non-value adding activities can improve service delivery while not exhausting those ‘finite resources’.