An analysis of single and multi-copy methods for DNA quantitation by real-time polymerase chain reaction

The goal of this paper was to examine and compare two different commercially available approaches to the determination of the relative quantities of autosomal and Y chromosomal DNA using real-time PCR. One, Quantifiler^® Duo, utilizes a TaqMan^® assay with single copy probes for both autosomal human and Y quantification. The other method, Plexor HY^® utilizes a primer quenching assay with multi-copy probes for its quantification of autosomal human and Y chromosomal DNA. To test these approaches we have utilized the NIST Human DNA Quantitation Standard Reference Material 2372, a set of three different NIST human DNA quantification standards, to examine the precision, accuracy and sensitivity of the real-time PCR assays. We also examined data from both systems utilizing casework samples. The results show that both systems produced linear estimates for DNA quantity over a broad range of input DNA. However we did observe some apparent copy number effects when comparing the three different NIST standards which we attributed to issues with sequence variations in the different standards. Overall, the single copy approach provided better accuracy while the multi-copy approach produced better sensitivity. Thus the choice of which system to use should depend upon the goals of the user.     

IPV Survivors’ Perceptions of How a Flexible Funding Housing Intervention Impacted Their Children

An estimated 15.5 million American children are exposed to intimate partner violence (IPV) every year. Such exposure negatively impacts children’s health, development and academic performance and may also be accompanied by housing instability or homelessness. Children growing up with periods of homelessness or housing instability are at risk for many of the same detrimental outcomes as children exposed to IPV. To date there are few studies examining the interrelationships among IPV, housing instability and the impact of housing interventions on children’s well-being. The current qualitative, longitudinal study examined mothers’ perceptions of how receipt of flexible funding designed to increase their housing stability may have also impacted their children’s safety, stress, mood and behavior. Forty-two mothers in the Washington, D.C. metro area were interviewed three times over a six-month period about their own safety and housing stability, as well as their children’s. Ninety-five percent of the mothers and their children were housed at the six-month interview. Mothers described improvements in children’s stability and safety, decreases in children’s stress levels, and improvements to their mood and behavior. They also discussed the symbiotic relationship between their own stress and well-being, and their children’s. The provision of flexible funding to assist domestic violence survivors with their housing also collaterally impacted their children’s safety, stress, mood and behavior.     

Nonsex offenses committed by child molesters: findings from a longitudinal study

This study, which used a prospective as well as a retrospective methodology, examined the criminal records of 30 child molesters prior to, and up to 10 years after an index event of sexual abuse for which they were convicted: 73% had convictions for other offenses, 60% had convictions for offenses other than sex offenses, 50% had convictions for property offenses, 27% had convictions for offenses involving violence, and 23% had convictions for drug offenses. Offending levels for nonsex offenses were significantly higher than the general adult male population. Any theory concerning the dynamics of sex offending against children needs to account for the level of nonsex offenses committed by child molesters.