Characterization of 26 miniSTR loci for improved analysis of degraded DNA samples

An additional 20 novel mini-short tandem repeat (miniSTR) loci have been developed and characterized beyond the six previously developed by our laboratory for a total of 26 non-CODIS miniSTR markers. These new markers produce short PCR products in the target range of 50-150 base pairs (bp) by moving the primer sequences as close as possible-often directly next to the identified repeat region. These candidate loci were initially screened based on their small amplicon sizes and locations on chromosomes currently unoccupied by the 13 CODIS STR loci or at least 50 Mb away from them on the same chromosome. They were sequenced and evaluated across more than 600 samples, and their population statistics were determined. The heterozygosities of the new loci were compared with those of the 13 CODIS loci and all were found to be comparable. Only five of the new loci had lower values than the CODIS loci; however, all of these were much smaller in size. This data suggests that these 26 miniSTR loci will serve as useful complements to the CODIS loci to aid in the forensic analysis of degraded DNA, as well as missing persons work and parentage testing with limited next-of-kin reference samples.     

Pig-mentation: postmortem iris color change in the eyes of Sus scrofa

Experienced forensic pathologists and examiners may be familiar with the phenomenon of postmortem iris color change; however, only Knight, Simpson's forensic medicine, Arnold, London, 1997; Ref. 1 and Saukko and Knight, Knight's forensic pathology, 3rd ed., Arnold, London, 2004; Ref. 2 have referred to it in the literature, and to date, there have been no published scientific research studies on this taphonomic artifact. A controlled experiment was conducted of postmortem changes to isolated Sus scrofa eyes. The eyes (n = 137) were separated into three groups and each sample was observed for 3-day postmortem at a different temperature. In addition, a Sus scrofa head was obtained to observe postmortem changes of eyes in situ. All isolated blue eyes in the experiment, at room temperature and higher, changed to brown/black within 48 h. The in situ blue eye, at room temperature, turned brown/black within 72 h. If iris color consistently changes postmortem in humans, then this taphonomic artifact must be incorporated into victim identification protocol, including disaster victim identification software, and autopsy reports to prevent inaccurate victim identification and inappropriate exclusion from the identification process.     

Effects of Partner Violence and Physical Child Abuse on Child Behavior: A Study of Abused and Comparison Children

This study tests a model of the effects on child behavioral outcome of the child's exposure to partner violence and child abuse, in children who have experienced the two forms of victimization either separately or together. Recognizing that family contextual factors play an important role in influencing child outcome, an ecological model is proposed that designates family stress as the principal exogenous factor, with effects on child outcome mediated through caretaker distress, partner violence, and child abuse. The sample consists of 100 confirmed cases of physically abused New York City schoolchildren, ages 9 to 12 years, and their families, and 100 nonmaltreated classmates, matched for gender, age, and, as closely as possible, for race, ethnicity, and socioeconomic status, and their families. Child behavioral outcome is assessed by classmates for antisocial, prosocial, and withdrawn behavior and by parents and teachers for externalizing and internalizing problem behavior. Results are generally consistent with the hypothesis that partner violence and caretaker distress, both associated with family stress, increase the risk for child abuse and thereby raise the child's risk for poor outcome. Implications of differences among raters for the model's applicability, and implications of the results for clinical intervention, are discussed.