Characterization of surface organic components of human hair by on-line supercritical fluid extraction-gas chromatography/mass spectrometry: a feasibility study and comparison with human identification using mitochondrial DNA sequences

This paper discusses results of a supercritical fluid extraction-gas chromatography/mass spectrometry (SFE-GC/MS) study of small samples ( 100 microg to 1 mg) of human scalp hair. The method offers a number of benefits including greater sensitivity than liquid extraction methods because the entire extractable mass is transferred to the analytical system, compared with only a few percent from a conventional liquid extraction/injection. The project's goals were to determine if SFE-GC/MS analyses of the surface-extractable components of an individual's hair yield consistent chemical profiles and to investigate if the profiles are sufficiently different to distinguish them from those of other individuals. In addition, the mtDNA sequences from ten of the same individuals used in the SFE-GC/MS study from four family units were determined, and, while the families were distinguishable, the maternal relations yielded identical sequences. In tandem, SFE-GC/MS and mtDNA techniques may provide valuable complementary data from forensic hair samples.     

Violence and the U.S. prohibitions of drugs and alcohol

This paper examines the relation between prohibitions and violence,using the historical behavior of the homicide rate in the UnitedStates. The results document that increases in enforcement ofdrug and alcohol prohibition have been associated with increasesin the homicide rate, and auxiliary evidence suggests this positivecorrelation reflects a causal effect of prohibition enforcementon homicide. Controlling for other potential determinants ofthe homicide rate does not alter the conclusion that drug andalcohol prohibition have substantially raised the homicide ratein the U.S. over much of the past 100 years.