Quantitative analysis of amplifiable DNA in tissues exposed to various environments using competitive PCR assays

Competitive PCR assays were established for the mitochondrial DNA hypervariable region I and the human amelogenin locus. Using these assays, the copy numbers of DNA participating in PCR (amplifiable DNA) were quantified in tissues exposed to different environments. Human ribs, skin and nails were left in three exposure conditions (in the open air, in soil and in water). The amounts of amplifiable DNA in these tissues were quantified during a time period of up to two months. The amount of amplifiable DNA was well preserved in hard tissues (ribs and nails) regardless of the exposure conditions, whereas the soft tissues immersed in water showed a rapid decrease in amplifiable DNA. Strong PCR inhibition was observed in the DNA extracts obtained from buried bones. This phenomenon was clearly identified from an amplification failure of the internal standards in the competitive PCR. A preliminary examination to identify the PCR inhibitor suggested that the soil itself contributed to the inhibition. In addition, the amounts of amplifiable DNA in case samples were also investigated.     

TRAJECTORIES OF CRIME AT PLACES: A LONGITUDINAL STUDY OF STREET SEGMENTS IN THE CITY OF SEATTLE*

Studies of crime at micro places have generally relied on cross‐sectional data and reported the distributions of crime statistics over short periods of time. In this paper we use official crime data to examine the distribution of crime at street segments in Seattle, Washington, over a 14‐year period. We go beyond prior research in two ways. First, we view crime trends at places over a much longer period than other studies that have examined micro places. Second, we use group‐based trajectory analysis to uncover distinctive developmental trends in our data. Our findings support the view that micro places generally have stable concentrations of crime events over time. However, we also find that a relatively small proportion of places belong to groups with steeply rising or declining crime trajectories and that these places are primarily responsible for overall city trends in crime. These findings are particularly important given the more general decline in crime rates observed in Seattle and many other American cities in the 1990s. Our study suggests that the crime drop can be understood not as a general process that occurred across the city landscape but one that was generated in a relatively small group of micro places with strong declining crime trajectories over time.     

PROFESSIONAL INTERDEPENDENCE IN DIVORCE PRACTICES

Divorce mediation is one area of the new and growing field of interpersonal mediation. Differences and similarities between divorce mediation and divorce psychotherapy are discussed in this article, and a method for teamwork between the two professions is proposed. The authors take the approach that the separate but overlapping practices of mediation and psychotherapy can be interdependent and that specific benefits to divorcing clients can result when divorce mediation and divorce psychotherapy are practiced collaboratively.     

High‐Performance Human Resource Practices and Employee Outcomes: The Mediating Role of Public Service Motivation

This article responds to recent calls for research examining the mechanisms through which high‐performance human resource practices (HPHRPs) affect employee outcomes. Using the theoretical lens of social exchange and process theories, the authors examine one such mechanism, public service motivation, through which HPHRPs influence employees’ affective commitment and organizational citizenship behaviors in public sector organizations. A sample of professionals in the Egyptian health and higher education sectors was used to test a partial mediation model using structural equation modeling. Findings show that public service motivation partially mediated the relationship between HPHRPs and employees’ affective commitment and organizational citizenship behaviors. Similar results were achieved when the system of HPHRPs was disaggregated to consider the individual effects of five human resource practices.