Real-time forensic DNA analysis at a crime scene using a portable microchip analyzer

An integrated lab-on-a-chip system has been developed and successfully utilized for real-time forensic short tandem repeat (STR) analysis. The microdevice comprises a 160-nL polymerase chain reaction reactor with an on-chip heater and a temperature sensor for thermal cycling, microvalves for fluidic manipulation, a co-injector for sizing standard injection, and a 7-cm-long separation channel for capillary electrophoretic analysis. A 9-plex autosomal STR typing system consisting of amelogenin and eight combined DNA index system (CODIS) core STR loci has been constructed and optimized for this real-time human identification study. Reproducible STR profiles of control DNA samples are obtained in 2 h and 30 min with ≤0.8 bp allele typing accuracy. The minimal amount of DNA required for a complete DNA profile is 100 copies. To critically evaluate the capabilities of our portable microsystem as well as its compatibility with crime scene investigation processes, real-time STR analyses were carried out at a mock crime scene prepared by the Palm Beach County Sheriff's Office (PBSO). Blood stain sample collection, DNA extraction, and STR analyses on the portable microsystem were conducted in the field, and a successful “mock” CODIS hit was generated on the suspect's sample within 6 h. This demonstration of on-site STR analysis establishes the feasibility of real-time DNA typing to identify the contributor of probative biological evidence at a crime scene and for real-time human identification.     

Evaluation of age estimation technique: testing traits of the acetabulum to estimate age at death in adult males

This study evaluates the accuracy and precision of a skeletal age estimation method, using the acetabulum of 100 male ossa coxae from the Grant Collection (GRO) at the University of Toronto, Canada. Age at death was obtained using Bayesian inference and a computational application (IDADE2) that requires a reference population, close in geographic and temporal distribution to the target case, to calibrate age ranges from scores generated by the technique. The inaccuracy of this method is 8 years. The direction of bias indicates the acetabulum technique tends to underestimate age. The categories 46-65 and 76-90 years exhibit the smallest inaccuracy (0.2), suggesting that this method may be appropriate for individuals over 40 years. Eighty-three percent of age estimates were ±12 years of known age; 79% were ±10 years of known age; and 62% were ±5 years of known age. Identifying a suitable reference population is the most significant limitation of this technique for forensic applications.     

Determination of an effective housekeeping gene for the quantification of mRNA for forensic applications

The potential application of mRNA for the identification of biological fluids using molecular techniques has been a recent development in forensic serology. Constitutively expressed housekeeping genes can assess the amount of mRNA recovered from a sample, establish its suitability for downstream applications, and provide a reference point to corroborate the identity of the fluid. qPCR was utilized to compare the expression levels of housekeeping genes from forensic-like body fluid stains to establish the most appropriate assessment of human mRNA quantity prior to profiling. Although variability was observed between fluids and individuals, results indicated that beta-2 microglobulin exhibited the highest expression for all body fluids examined and across donors. A one-way analysis of variance was performed for housekeeping gene variability between donors (at the α, 0.05, significance level), and the results indicated significant differences for semen, vaginal secretions, and menstrual blood.     

The effect of body coverings on the formation of adipocere in an aqueous environment

Adipocere is a postmortem decomposition product that consists of a mixture of fatty acids. The rate of formation of adipocere from pig adipose tissue in an aqueous environment has been monitored. The effect of various clothing and carpet material types on the process was investigated. The fatty acid composition of the adipocere was determined at regular intervals using gas chromatography-mass spectrometry. Examination of the changes to fatty acid concentrations allowed the degree of adipocere formation in the different environments to be estimated. The study demonstrated that the rate at which adipocere forms is particularly accelerated by the presence of coverings produced from natural materials. Elemental analysis by inductively coupled plasma-mass spectrometry revealed, for the most part, little change to the cations present in the adipocere formed. However, an increase in Ca concentration was observed for tissue wrapped in acrylic carpet, which was associated with a CaCO(3) additive used in the carpet manufacture.     

The relationship between marijuana use and intimate partner violence in a nationally representative, longitudinal sample

Intimate partner violence is a significant public health problem, as these behaviors have been associated with a number of negative health outcomes including illicit drug use, physical injury, chronic pain, sexually transmitted diseases, depression, and posttraumatic stress disorder. The current study examined the association between marijuana use and intimate partner violence using a longitudinal survey of adolescents and young adults ages 15 to 26 years. Data were obtained from 9,421 adolescents in the National Longitudinal Study of Adolescent Health (Add Health) Waves 1 through 4 (1995-2008). Marijuana use was measured in the past year at each wave and participants were categorized as "users" or "nonusers." Partner violence was constructed using six items (three pertaining to victimization and three concerning perpetration) from Wave 4 (2007-2008). Using these six items, participants were categorized as "victims only," "perpetrators only," or "victims and perpetrators." Survey multinomial regression was used to examine the relationship between marijuana use and intimate partner violence. Consistent use of marijuana during adolescence was most predictive of intimate partner violence (OR = 2.08, p < .001). Consistent marijuana use (OR = 1.85, p < .05) was related to an increased risk of intimate partner violence perpetration. Adolescent marijuana use, particularly consistent use throughout adolescence, is associated with perpetration or both perpetration of and victimization by intimate partner violence in early adulthood. These findings have implications for intimate partner violence prevention efforts, as marijuana use should be considered as a target of early intimate partner violence intervention and treatment programming.     

IN SEARCH OF PERMANENCY

President Clinton signed the Adoption and Safe Families Act (ASFA) into law on November 19, 1997. ASFA is designed to prevent children in foster care from being returned to unsafe homes and to find safe homes for children who are not able to return to their families. Some critics say that ASFA is too extensive and intrusive; others feel it does not go far enough. The author focuses on the practical issues of what ASFA has done so far and how various communities can still use it to ameliorate some of their child welfare problems. She begins with the history of child welfare in the United States, followed by an extensive discussion of ASFA's provisions. The author then addresses criticisms of some of ASFA's key components. A discussion of the ways the states have implemented ASFA follows. The author concludes that ASFA could be a powerful and important tool in aiding the child welfare system.