Isotope ratio mass spectrometry as a tool for forensic investigation (examples from recent studies).

The versatility of isotope ratio mass spectrometry is demonstrated by reference to diverse case studies. Variations in the natural isotopic composition of non-biological, organic materials are compared as a means by which samples may be associated or discriminated. These techniques may be used to augment or compliment conventional forensic methodologies. delta13C analysis was used to demonstrate that different masking tape had been recovered in two, apparently similar cases, involving the smuggling of money. Visually similar ecstasy tablets were compared by consideration of the delta13C and delta15N composition of MDMA extracted from the tablets. Although only a limited number of tablets were analysed, the isotopic similarity between two different seizures was sufficient to induce a guilty plea from a person suspected of possessing both. A combination of delta2H, delta13C, delta15N and delta18O together with GC-MS analyses were applied to small samples of seized heroin. Although GC-MS analysis indicated differences between the chemical composition of two of the heroin samples, isotopic analysis suggested similarities, which were confirmed by further delta2H, delta13C and delta18O isotopic analysis of the clingfilm in which the samples were wrapped.     

Drowning of a Friedreich's ataxia patient

We here report an unusual, apparently accidental death, in which weakness associated with a progressive neuromuscular disease, Friedreich's ataxia, apparently resulted in the drowning of the deceased. The possibility of neuromuscular disease as a rare cause of drownings should not be overlooked.     

Correlations on radioimmunoassay, fluorescence polarization immunoassay, and enzyme immunoassay of cannabis metabolites with gas chromatography/mass spectrometry analysis of 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid in urine specimens.

Results obtained from three commercial immunoassay kits, Abuscreen, TDx, and EMIT, commonly used for the initial test of urine cannabinoids (and metabolites) were correlated with the 11-nor-delta 9-tetrahydrocannabinol-9-carboxylic acid (9-THC-COOH) concentration as determined by GC/MS. Correlation coefficients obtained based on 26 (out of 1359 total sample population) highly relevant samples, are 0.601 and 0.438 for Abuscreen and TDx. Correlation coefficients obtained from a parallel study on a different set of 47 (out of 5070 total sample population) highly relevant specimens are 0.658 and 0.575 for Abuscreen and Emit. The immunoassay concentration levels, that correspond to the commonly used 15 ng/ml GC/MS cutoff value for 9-THC-COOH, as calculated from the regression equations are 82 ng/ml and 75 ng/ml for TDx and EMIT and 120 ng/ml and 72 ng/ml for Abuscreen manufactured at two different time periods. The difference of these calculated corresponding concentrations provides quantitative evidence of the reagent specificity differences.     

Accredited to Africa: British diplomatic representation and African experience, c. 1960-95

How justified is the complaint sometimes voiced by British businessmen and other UK visitors to contemporary Africa that, compared to 'the [good old] colonial days', Britain's FCO representatives have no experience of Africa and little idea about who's who and what's going on in their bailiwick? The aim of this article is to construct a professional profile of Britain's Heads of Mission assigned to newly independent African states over the past 35 years, with a view to assessing the extent of their African experience. This period also neatly coincides with what in one sense can be interpreted as a single FO generation, in that the mean entry age into the Diplomatic Service is around 25 and the maximum retiring age is a strict 60. The statistical biodata on which the argument is premised are presented in the 19 Mission Tables appended. The article concludes with an examination of the major issues surrounding the question of 'African experience' among those Heads of Mission.     

New identification criteria for the Chilean population: Estimation of sex and stature

In the analysis of human skeletal or otherwise unidentifiable remains the assessment of sex is an initial vital element when rendering a biological profile. As such other aspects of the biological profile are sex-specific (e.g. stature and age) and cannot be successfully determined without this preliminary assessment. In addition, the estimation of stature is an essential parameter of the biological profile, which is often used to confirm or exclude presumptive identifications.The purpose of this study is to present newly developed local identification criteria for the estimation of sex from the postcrania and stature for Chileans. Linear discriminant functions were derived for the humerus and femur. Sexing accuracies of 87%, 86%, and 82% were achieved. Furthermore, new univariate predictive stature equations are presented using a Bayesian approach for the humerus, femur and tibia.