Inferring ancestral origin using a single multiplex assay of ancestry-informative marker SNPs

Tests that infer the ancestral origin of a DNA sample have considerable potential in the development of forensic tools that can help to guide crime investigation. We have developed a single-tube 34-plex SNP assay for the assignment of ancestral origin by choosing ancestry-informative markers (AIMs) exhibiting highly contrasting allele frequency distributions between the three major population-groups. To predict ancestral origin from the profiles obtained, a classification algorithm was developed based on maximum likelihood. Sampling of two populations each from African, European and East Asian groups provided training sets for the algorithm and this was tested using the CEPH Human Genome Diversity Panel. We detected negligible theoretical and practical error for assignments to one of the three groups analyzed with consistently high classification probabilities, even when using reduced subsets of SNPs. This study shows that by choosing SNPs exhibiting marked allele frequency differences between population-groups a practical forensic test for assigning the most likely ancestry can be achieved from a single multiplexed assay.     

Identifying a suitable mounting medium for use in forensic fibre examination.

As the result of a previous study many laboratories have used XAM neutral medium-improved white mounting medium in textile fibre examination for more than 20 years. Due to European Directive 98/79/EC, XAM is no longer available and an alternative needed to be found. A list of desirable properties was formulated and a number of mounting media were tested against this. Entellan New was identified as the best mounting medium, and performed similarly to XAM in all aspects.     

Guantánamo Bay: Towards Legality?

This article outlines the US Supreme Court's approach to the habeas corpus entitlements of suspected terrorists detained in Guantánamo Bay and argues for the extension of constitutional habeas corpus rights to them. The article considers two ways in which the Supreme Court might carry out this task: first, 'the territorial approach' (based on domestic legal principles of 'unincorporated territories' and principles of leasehold), and secondly, 'the extraterritorial approach' (based on international purposive approaches to the reach of human rights treaties exemplified by the European Court of Human Rights' Article 1 jurisprudence). For reasons of effectiveness of protection, the Article expresses a clear preference for the latter. The House of Lords decision in R (Al-Skeini) v Secretary of State for Defence (2007) is proposed as a template for such a development. Finally the article refutes arguments rejecting such a development based on the 'trade-off thesis' and perceptions of judicial competence.     

The analysis and comparison of blue wool fibre populations found at random on clothing.

Fifty-eight garments were taped and searched for mid to dark blue wool fibres. These were then removed from the tapings, mounted on slides and examined using a high-power microscope (400x). A total of 2,740 blue wool fibres were identified and visible range microspectrophotometry (MSP) was performed on them. Three hundred independent blue wool populations were identified on 56 of the 58 garments searched. The lack of control fibres meant the spectral range of each population was unknown. The number of populations may have been underestimated by grouping together the fibres that had broad single peaks and a lack of distinguishing features in the spectra. Although blue wool is considered to be a common fibre type, 300 unique spectral shapes were identified by the use of microspectrophotometry alone. This demonstrates that the dyes used in the dyeing of blue wool are variable. Showing that many different populations of blue wool occur on a range of garments should ensure that the forensic scientist does not underestimate or understate the strength of evidence in cases where blue wool is found. Hopefully this work will enlighten scientists and enable them to also assess the true value of their findings when other commonly occurring fibres are encountered.     

Allele frequency distribution for 21 autosomal STR loci in Bhutan

We studied the allele frequency distribution of 21 autosomal STR loci contained in the AmpFlSTR^® Identifiler™ (Applied Biosystems), the Powerplex^®16 (Promega) and the FFFL (Promega) multiplex PCR kits among 936 individuals from the Royal Kingdom of Bhutan. As such these are the first published autosomal DNA results from this country.