A novel histological technique for distinguishing between epithelial cells in forensic casework

There are a number of forensic cases in which the identification of the epithelial cell type from which DNA originated would provide important probative evidence. This study aimed to develop a technique using histological staining of fixed cells to distinguish between skin, buccal and vaginal epithelium. First, 11 different stains were screened on formalin-fixed, wax-embedded cells from five women. Samples were analysed qualitatively by examining staining patterns (colour) and morphology (absence or presence of nuclei). Three of the staining methods – Dane's, Csaba's and Ayoub-Shklar – were successful in distinguishing skin epithelial cells from buccal and vaginal. Second, cells were smeared directly onto slides, fixed with one of five fixatives and stained with one of the three stains mentioned above. Methanol fixation, coupled with the Dane's staining method, specific to keratin, was the only technique that distinguished between all three cell types. Skin cells stained magenta, red and orange and lacked nuclei; buccal cells stained predominantly orange–pink with red nuclei; while vaginal cells stained bright orange with orange nuclei and a blue extracellular hue. This staining pattern in vaginal cells was consistent in samples collected from 50 women aged between 18 and 67. Identification of cell type from unlabelled micrographs by 10 trained observers showed a mean success rate of 95%. The results of this study demonstrate that histological staining may provide forensic scientists with a technique for distinguishing between skin, buccal and vaginal epithelial cells and thus would enable more conclusive analyses when investigating sexual assault cases.     

Race-Based Peremptory Challenges: An Empirical Analysis of Litigation from the U.S. Court of Appeals, 2002–2006

This paper examines race-based peremptory challenges. Such challenges occur during the voir dire jury selection process. The process allows both the defense and the prosecution to strike jurors who they believe will not decide cases fairly. However, in the case of Batson v. Kentucky 476 U.S. 79 (1986), the Supreme Court ruled that race could not be used as a factor in eliminating prospective jurors. This paper examines federal litigation for five years in which it was alleged that race was used as a factor in removing a juror. An examination of the cases revealed that most of the cases involved sole male litigants who allege that there were multiple race-based peremptory challenges used in their cases. Moreover, most of the cases that led to the allegations involved violent offenses. Other case characteristics are noted, but of most significance was the finding that most appellants lost their cases. As such, the courts felt that most of the challenges were, in fact, race neutral. The implications of this research are discussed. This study was funded by an undergraduate research grant from Penn State University.     

The “Science of Science Policy”: reflections on the important questions and the challenges they present

Developing the “Science of Science Policy” will require data collection and analysis related to the processes of innovation and technological change, and the effects of government policy on those processes. There has been much work on these topics in the last three decades, but there remain difficult problems of finding proxies for subtle concepts, endogeneity, distinguishing private and social returns, untangling cumulative effects, measuring the impact of government programs in a true “but for” sense, and sorting out national and global effects. I offer observations on how to think about these issues. This paper was presented as the Keynote Address at the NSF Workshop on Advancing Measures of Innovation: Knowledge Flows, Business Metrics, and Measurement Strategies, Arlington, VA, June 2006.     

THE FIFTH WORLD CONGRESS ON FAMILY LAW AND THE RIGHTS OF CHILDREN AND YOUTH

Editor's note on the 5^th World Congress on Family Law and Children's Rights held in Halifax Nova Scotia, August 23–26, 2009