Forensic Discrimination of Dyed Hair Color: II. Multivariate Statistical Analysis*,†

Abstract: This research is intended to assess the ability of UV–visible microspectrophotometry to successfully discriminate the color of dyed hair. Fifty‐five red hair dyes were analyzed and evaluated using multivariate statistical techniques including agglomerative hierarchical clustering (AHC), principal component analysis (PCA), and discriminant analysis (DA). The spectra were grouped into three classes, which were visually consistent with different shades of red. A two‐dimensional PCA observations plot was constructed, describing 78.6% of the overall variance. The wavelength regions associated with the absorbance of hair and dye were highly correlated. Principal components were selected to represent 95% of the overall variance for analysis with DA. A classification accuracy of 89% was observed for the comprehensive dye set, while external validation using 20 of the dyes resulted in a prediction accuracy of 75%. Significant color loss from successive washing of hair samples was estimated to occur within 3 weeks of dye application.     

Political and Civic Engagement and Participation: Towards an Integrative Perspective

Abstract

This article presents an overview of current understandings in the study of political and civic engagement and participation, drawing in particular on innovations which have emerged from the Processes Influencing Democratic Ownership and Participation (PIDOP) project. For the purposes of the article, ‘engagement’ is defined as having an interest in, paying attention to, or having knowledge, beliefs, opinions, attitudes, or feelings about either political or civic matters, whereas ‘participation’ is defined in terms of political and civic participatory behaviours. The different forms that political and civic engagement and participation can take are outlined, and the factors that are related to different patterns of engagement and participation are reviewed. These factors operate at different levels, and include distal macro contextual factors, demographic factors, proximal social factors, and endogenous psychological factors. An integrative model covering all four levels of factors is outlined. Some findings from the secondary analysis of existing data-sets (including the European Social Survey and the International Social Survey Programme) in the PIDOP project are also reported. These findings show that engagement and participation vary as a function of complex interactions between macro, demographic, and psychological factors. It is argued that multi-level integrative theories, such as the one proposed in the current article, are required to understand the drivers of political and civic engagement and participation, and that policies and interventions aimed at enhancing citizens' levels of engagement and participation need to take this multi-level complexity into account.     

How Accurate is Food-for-Work Self-Targeting in the Presence of Imperfect Factor Markets? Evidence from Ethiopia

Effective targeting of transfers is a key issue in public policy to combat poverty. Much faith is presently placed in self-targeting mechanisms such as public employment schemes supported by food-for-work transfers. Where targeting errors have been observed, these are usually attributed to mismanagement of key operational details, such as the project's wage rate. Using a unique data set from rural Ethiopia, we demonstrate that targeting errors may also have structural causes in some low-income countries. We hypothesise that imperfect factor markets generate a predictable dispersion across households in reservation wage rates that breaks down the unconditionally positive relation between income and shadow wages on which the theory of self-targeting public employment programmes rests. Our results confirm that the inaccuracy of FFW targeting stems from the fact that, in rural Ethiopia, higher income households are endowed with more labour per unit of land or animal. Due to poor factor markets in land and livestock these labour-abundant households have lower marginal labour productivity on farm, thereby depressing the reservation wage rates they find acceptable for FFW participation.     

Enhanced elution of sperm from cotton swabs via enzymatic digestion for rape kit analysis

This report describes development of a method for enhanced cell elution from cotton swabs. The method exploits an enzyme mixture for digestion of the cotton to remove intact cells, and can be utilized in conjunction with or to circumvent conventional differential extraction (DE). Samples digested with Aspergillus niger cellulase yielded sperm cell recoveries (18+/-3.5%) similar to conventional DE buffer (23+/-7.8%) while providing intact epithelial cells. Storage time affected the concentration of enzyme required for optimal sperm cell recovery, with longer times requiring increased cellulase concentrations. Cellulase from A. niger yielded a twofold enhancement in sperm cell elution over buffer alone, and preliminary testing of higher activity cellulases from Trichoderma reesei and Trichoderma viride showed even greater enhancement. These results indicate that cellulose-digesting enzymes enhance the release of sperm and epithelial cells from a cotton swab over buffer alone, providing for efficient DNA analysis.     

Improvisation and Mediation: Balancing Acts

Improvisation can be an important element of mediation practice, and there are several ways in which mediation practice correlates to improvisational performance. In this article, two mediation experts and two skilled jazz musicians explore the improvisational aspects of mediation. Two central themes emerge: (1) mediators often use improvisational techniques, and (2) by being improvisational, mediators can create environments that would encourage the parties themselves to be improvisational. We argue that practitioners can enhance their effectiveness as mediators by mastering improvisational skills.