Short tandem repeat (STR) genotyping of keratinised hair. Part 2. An optimised genomic DNA extraction procedure reveals donor dependence of STR profiles

A feasibility study of short tandem repeat (STR) genotyping of telogen phase hairs in particular, and hair shaft in general, is presented. A number of extraction procedures in common use were investigated and the quantities of nuclear DNA (nuDNA) delivered were quantified via a real-time PCR assay. The extracts were subjected to two variations on AmpFlSTR Profiler Plus PCR amplification strategies (extended cycles, two rounds of PCR) and the genotypes compared. Nuclear DNA was found to persist in human hair shafts, albeit at very low levels. Full Profiler Plus profiles consistent with the hair donor were obtained from 100 mg hair shaft samples (bleached and unbleached). These were, however, mixed profiles, indicating low copy number (LCN) contamination in the extracts. Single telogen hair clubs and single hair shafts delivered partial profiles with usually only one allele of heterozygous loci. Telogen phase hairs yielded the same amount of nuDNA (and no more) as hair shafts (either anagen or telogen). Whether hair shafts dissolved or not in lysis buffer had no effect on either the quantitated yield of DNA or on the chance of obtaining a correct genotype. These results provide evidence that genomic DNA resides on the exterior of the hair shaft and we use this information to suggest an optimal procedure for nuDNA extraction from keratinised hair samples: soaking hairs in simple digestion buffers containing Tris-HCl, a salt and a chelating agent without prior cleaning of the hair shafts. It is proposed that cleaning removes most of the recoverable DNA. This procedure was applied to obtain genotypes from 3 cm hair shafts which matched reference profiles from the donors at up to 9 out of 10 AmpFlSTR Profiler Plus STR loci. When the genotyping success was measured by counting the number of matches between the two dominant alleles at each locus for each extract with the reference DNA profile of the hair donor, the success was found to be highly dependent on the donor. The number of matching alleles varied between not less than 10 for one donor to no more than two for another donor. These results may well be linked to the environmental experience of the hairs from each donor prior to removal.     

A molecular identification system for grasses: a novel technology for forensic botany

Our present inability to rapidly, accurately and cost-effectively identify trace botanical evidence remains the major impediment to the routine application of forensic botany. Grasses are amongst the most likely plant species encountered as forensic trace evidence and have the potential to provide links between crime scenes and individuals or other vital crime scene information. We are designing a molecular DNA-based identification system for grasses consisting of several PCR assays that, like a traditional morphological taxonomic key, provide criteria that progressively identify an unknown grass sample to a given taxonomic rank. In a prior study of DNA sequences across 20 phylogenetically representative grass species, we identified a series of potentially informative indels in the grass mitochondrial genome. In this study we designed and tested five PCR assays spanning these indels and assessed the feasibility of these assays to aid identification of unknown grass samples. We confirmed that for our control set of 20 samples, on which the design of the PCR assays was based, the five primer combinations produced the expected results. Using these PCR assays in a 'blind test', we were able to identify 25 unknown grass samples with some restrictions. Species belonging to genera represented in our control set were all correctly identified to genus with one exception. Similarly, genera belonging to tribes in the control set were correctly identified to the tribal level. Finally, for those samples for which neither the tribal or genus specific PCR assays were designed, we could confidently exclude these samples from belonging to certain tribes and genera. The results confirmed the utility of the PCR assays and the feasibility of developing a robust full-scale usable grass identification system for forensic purposes.     

The Outer Limits of Copyright Law – Where Law Meets Philosophy and Culture

This article engages in a cultural critique of copyright law. The point is to explain how and why this body of law is culturally exclusive, notwithstanding the claims made by judges and others that the law is culturally open and inclusive. This involves a discussion of the relationship between philosophy and law, and of how this nexus has been misrepresented by the courts and in recent writings on the subject. Analysis centres on a discussion of Australian case law involving indigenous claims of communal ownership of copyright and the treatment of technology when it comes to attributing authorship.     

Disaster victim identification: new applications for postmortem computed tomography

Abstract:  Mass fatalities can present the forensic anthropologist and forensic pathologist with a different set of challenges to those presented by a single fatality. To date radiography has played an important role in the disaster victim identification (DVI) process. The aim of this paper is to highlight the benefits of applying computed tomography (CT) technology to the DVI process. The paper begins by reviewing the extent to which sophisticated imaging techniques, specifically CT, have been increasingly used to assist in the analysis of deceased individuals. A small scale case study is then presented which describes aspects of the DVI process following a recent Australian aviation disaster involving two individuals. Having grided the scene of the disaster, a total of 41 bags of heavily disrupted human remains were collected. A postmortem examination was subsequently undertaken. Analysis of the CT images of all body parts ( n  = 162) made it possible not only to identify and side differentially preserved skeletal elements which were anatomically unrecognizable in the heavily disrupted body masses, but also to observe and record useful identifying features such as surgical implants. In this case the role of the forensic anthropologist and CT technology were paramount in facilitating a quick identification, and subsequently, an effective and timely reconciliation, of body parts. Although this case study is small scale, it illustrates the enormous potential for CT imaging to complement the existing DVI process.     

An unusual case of child head injury by coat hanger*

Traumatic brain injury is the leading cause of morbidity and mortality among children suspected of child abuse. Penetrating cranio-facial injuries are generally rare in the pediatric age group and are caused by both accidental and inflicted mechanisms. We report an unusual case of a 2-year-old female who was admitted to a pediatric emergency room with an industrial stainless steel coat hanger impaled in her skull. Pertinent clinical forensic medicine examination, coupled with home inspection and interviews by the local law enforcement, revealed a horrible episode of domestic violence.     

Supervising junior doctors and "on-call" responsibilities: Brus v Australian Capital Territory; Greater Southern Area Health Service v Angus

The recent decisions of Brus v Australian Capital Territory [2007] ACTSC 83 and Greater Southern Area Health Service v Angus [2007] NSWSC 1211 highlight different aspects of the difficulties associated with supervision of junior doctors in the present public-funded Australian public hospital system. Their facts reveal how difficult it is for senior staff to achieve the fine balance required to assist trainees by according adequate experience and responsibility on the one hand, and to ensure patient safety, on the other. In addition, these cases highlight problems with the supervision process that are likely to be exacerbated in a privatised health care setting where senior staff may have less inclination to supervise struggling juniors unless adequately remunerated for such teaching, an issue of considerable controversy given the focus on profit of those institutions.     

Value is Simple. Valuation is Complex

Value can appear so complicated that it is not only a terribly intimidating topic, but actually fruitless to pursue. That is, the concept of value is either a dead end or best left to the experts. We disagree. At the most general level, having value can be understood as having the capacity to be measured and compared against another thing (or a standard). This is consistent with Marxian concepts (which are elaborated with special reference to the capitalist value form), but it is also simple and general enough to provide a transportable frame for discussing the role of value and measurement in any context imaginable, whether it be a discussion of spiritualism, collective action, economic data, or physical science. Marx directs our attention to the political constitution of systems of measure on the very first page of Capital, and there is now a great deal of work in geography and in science and technology studies on the social constitution of systems of valuation. We believe a crucial topic deserves an accessible approach that reveals unities rather than barriers, and thus supplement them with the moral and critical political-economic critique made possible by Marxian value theory.     

Evaluation of Commercial Kits for Dual Extraction of DNA and RNA from Human Body Fluids, ,

STR typing of DNA evidence can identify the donor with a high power of discrimination but cannot identify the tissue origin of a body‐fluid stain. Using RNA to attribute a crime scene stain to a particular tissue may aid in reconstruction efforts. With blood from 10 donors, four DNA and RNA coextraction kits were evaluated by measuring yields and STR and mRNA profiles. T tests indicated some significant differences in kit performance. The Zymo Research ZR‐Duet^? kit performed best based on average DNA (41.4 ng) and mRNA (4.07 ng) yields and was the only kit to provide complete DNA/RNA profiles for all samples. The consistency of this kit was challenged by data from additional blood and saliva donors. Further testing is advised before a superior kit is unequivocally chosen. Stand‐alone DNA or RNA purification generally offers higher yield, but coextraction may still allow successful STR profiling and tissue source identification.     

Caregiving Responsibilities and Child Spanking

This study examines whether mothers who are also caregivers of elderly or dependent family members are more likely to resort to physical discipline than other mothers. Using data from the National Survey of Families and Households, we found that caregivers are more likely to spank their children than noncaregivers; however, among those who spank, caregivers are somewhat less prone to frequent spankings than noncaregivers. The data further suggest that it is primarily care for adults outside the household that is related to use and frequency of spankings.