Methods for ensuring the highest DNA concentration and yield in future and retrospective trace DNA extracts

In forensic laboratories, increased extraction efficiency of trace evidence is paramount because analytical success is intrinsically dependent on the quantity of DNA recovered. Moreover, highly concentrated nucleic acids are vital for effective downstream analysis and high quality results. This study investigated the efficiency of extraction with the Qiagen® QIAamp® DNA Investigator kit, and explored improvements to the methodology that would maximise the recovery of low concentration forensic samples. Controlled amounts of starting cellular material were used to mimic trace (or low level) DNA deposits prior to DNA extraction with the Investigator kit. Addition of the provided carrier RNA along with conducting two successive elutions of 50 µL improved the net recovery of DNA to 95%. Concentration with centrifugal filters post-extraction were able to concentrate DNA but a large net loss was observed. For the concentration of historic, retrospectively extracted DNA, centrifugal methods are able to concentrate DNA extracts previously too dilute for analysis. These concentrated volumes, however are small, allowing for minimal downstream analysis attempts before the sample is exhausted.     

Theorising noncitizenship: concepts,debates and challenges

Abstract

Existing political theory, particularly which deals with justice and/or rights, has long assumed citizenship as a core concept. Noncitizenship, if it is considered at all, is generally defined merely as the negation or deprivation of citizenship. As such, it is difficult to examine successfully the status of noncitizens, obligations towards them, and the nature of their role in political systems. This article addresses this critical gap by defining the theoretical problem that noncitizenship presents and demonstrating why it is an urgent concern. It surveys the contributions to the special issue for which the article is an introduction, drawing on cross-cutting themes and debates to highlight the importance of theorising noncitizenship due to both the problematic gap that exists in the theoretical literature, and the real world problems created as a result of noncitizenship which are not currently successfully addressed. Finally, the article discusses key future directions for the theorisation of noncitizenship.     

MEDIATION IN CHILD PROTECTION IN BRITISH COLUMBIA

The child protection mediation or case conference–implemented under the new Child, Family, and Community Services Act–is a mandatory conference in British Columbia that attempts to provide a plan of care for the apprehended child or children through a combined cooperative effort of parents, social workers, their respective counsel, parties that have an interest in the child's welfare, and the mediation judge. It is also a process that undertakes to counter the adversarial effects of trial where the potential for conflict is great and seeks to achieve the spirit of building solutions through cooperation for the continued care of the child. A year later, the results look encouraging, as two thirds of cases settle and, in British Columbia, unlike any other province, the case conference is made available in every community where court is held.     

Youth and the forbidden fruit: Experiences with changes in legal drinking age in North America

The effects of changes in the minimum drinking ages in various North American jurisdictions are reviewed. The research suggests that although most teenagers have experimented with alcohol, the rates of alcohol consumption and alcohol-related traffic collisions can be increased and decreased with the drinking age control legislation.     

Forensic analysis of bicomponent fibers using infrared chemical imaging

The application of infrared chemical imaging to the analysis of bicomponent fibers was evaluated. Eleven nominally bicomponent fibers were examined either side-on or in cross-section. In six of the 11 samples, infrared chemical imaging was able to spatially resolve two spectroscopically distinct regions when the fibers were examined side-on. As well as yielding characteristic infrared spectra of each component, the technique also provided images that clearly illustrated the side-by-side configuration of these components in the fiber. In one case it was possible to prepare and image a cross-section of the fiber, but in general the preparation of fiber cross-sections proved very difficult. In five of the 11 samples, the infrared spectra could be used to identify the overall chemical composition of the fibers, according to a published classification scheme, but the fiber components could not be spatially resolved. Difficulties that are inherent to conventional "single-point" infrared spectroscopy, such as interference fringing and sloping baselines, particularly when analyzing acrylic type fibers, were also encountered in the infrared chemical image analysis of bicomponent fibers. A number of infrared sampling techniques were investigated to overcome these problems, and recommendations for the best sampling technique are given. Chemical imaging results were compared with those obtained using conventional fiber microscopy techniques.