Hair analysis for delta(9)-THC,delta(9)-THC-COOH,CBN and CBD,by GC/MS-EI. Comparison with GC/MS-NCI for delta(9)-THC-COOH

A sensitive analytical method was developed for quantitative analysis of delta(9)-tetrahydrocannabinol (delta(9)-THC), 11-nor-delta(9)-tetrahydrocannabinol-carboxylic acid (delta(9)-THC-COOH), cannabinol (CBN) and cannabidiol (CBD) in human hair. The identification of delta(9)-THC-COOH in hair would document Cannabis use more effectively than the detection of parent drug (delta(9)-THC) which might have come from environmental exposure. Ketamine was added to hair samples as internal standard for CBN and CBD. Ketoprofen was added to hair samples as internal standard for the other compounds. Samples were hydrolyzed with beta-glucuronidase/arylsulfatase for 2h at 40 degrees C. After cooling, samples were extracted with a liquid-liquid extraction procedure (with chloroform/isopropyl alcohol, after alkalinization, and n-hexane/ethyl acetate, after acidification), which was developed in our laboratory. The extracts were analysed before and after derivatization with pentafluoropropionic anhydride (PFPA) and pentafluoropropanol (PFPOH) using a Hewlett Packard gas chromatographer/mass spectrometer detector, in electron impact mode (GC/MS-EI). Derivatized delta(9)-THC-COOH was also analysed using a Hewlett Packard gas chromatographer/mass spectrometer detector, in negative ion chemical ionization mode (GC/MS-NCI) using methane as the reagent gas. Responses were linear ranging from 0.10 to 5.00 ng/mg hair for delta(9)-THC and CBN, 0.10-10.00 ng/mg hair for CBD, 0.01-5.00 ng/mg for delta(9)-THC-COOH (r(2)>0.99). The intra-assay precisions ranged from <0.01 to 12.40%. Extraction recoveries ranged from 80.9 to 104.0% for delta(9)-THC, 85.9-100.0% for delta(9)-THC-COOH, 76.7-95.8% for CBN and 71.0-94.0% for CBD. The analytical method was applied to 87 human hair samples, obtained from individuals who testified in court of having committed drug related crimes. Quantification of delta(9)-THC-COOH using GC/MS-NCI was found to be more convenient than GC/MS-EI. The latter may give rise to false negatives due to the detection limit.     

Analysis of the CODIS autosomal STR loci in four main Colombian regions

Genotype polymorphism studies at the 13 loci STRs included in the combined DNA index system [CODIS and PCR-based short tandem repeat loci, in: Proceedings of the Second European Symposium on Human Identification, Promega Corporation, Madison, WI, 1998, pp. 73-88; J. Forensic Sci. 46 (2001) 453] (CODIS: D3S1358, HUMvWA31, HUMFGA, D8S1179 D21S11, D18S51, D5S818, D13S317, D7S820, HUMTH01, HUMTPOX, HUMCSF1PO and D16S539) were carried out in a sample of 1429 unrelated Colombian individuals belonging to 25 different departments. As many other countries in Latino-America, Colombia shows an important admixture component, basically integrated by Amerindians, European-descendants and African-descendants. Due to the fact that only partial population analyses have been carried out in the country, the main aim of the present analysis is to establish a database of forensic interest based on the widely used CODIS systems covering the main Colombian regions.     

Homeless Youth Seeking Health and Life-Meaning Through Popular Culture and the Arts

This pilot study demonstrates the roles of popular culture, media and the arts in the health and self-esteem of homeless youth. Reflecting focus group findings from a representative sample of street and sheltered youth, this article provides a qualitative assessment of what they advocated as an effective intervention that would promote the receipt of health services within their vulnerable community. Unlike alienating disease models where adverse health behaviors and outcomes determine intervention success or failure, a culturally-sensitive approach which provided skills mentoring and engaged the youth as health advocates seemed likely to produce important recovery incentives and enhanced health outcomes.     

A "politically robust" experimental design for public policy evaluation, with application to the Mexican universal health insurance program.

We develop an approach to conducting large-scale randomized public policy experiments intended to be more robust to the political interventions that have ruined some or all parts of many similar previous efforts. Our proposed design is insulated from selection bias in some circumstances even if we lose observations; our inferences can still be unbiased even if politics disrupts any two of the three steps in our analytical procedures; and other empirical checks are available to validate the overall design. We illustrate with a design and empirical validation of an evaluation of the Mexican Seguro Popular de Salud (Universal Health Insurance)program we are conducting. Seguro Popular, which is intended to grow to provide medical care, drugs, preventative services, and financial health protection to the 50 million Mexicans without health insurance, is one of the largest health reforms of any country in the last two decades. The evaluation is also large scale, constituting one of the largest policy experiments to date and what may be the largest randomized health policy experiment ever.     

Climbing off the Back Burner: Lyndon Johnson's Soft Power Approach to Africa

The general historiography of United States–African relations in the 1960s holds that the policies of Lyndon Johnson towards this continent were a failure. Johnson, most historians suggest, generally ignored Africa and, in doing so, squandered the good feelings that many Africans had developed towards his more charming and polished predecessor. However, such views do a disservice to the Johnson Administration, which in fact embarked on a quiet African programme rooted in American cultural and economic power, and which proved to be more successful than is generally believed. Two factors lay at the heart of Johnson's decision to rely on a soft power policy in Africa: the domestic political constraints of the civil rights movement at home; and the belief in modernisation theory that had emerged as a guiding principle for many of his advisors. Johnson, to put it simply, may have lacked his predecessor's style but he compensated with a substantive and imaginative policy that quietly produced a superior method of advancing both American and African interests.     

Pre-Election Polling and the Rational Voter: Evidence from State Panel Data (1986–1998)

This study examines the role of pre-election perceptions of race closeness, by way of newspaper polls, in motivating citizens to vote on a specific contest while in the voting booth. Results from an error components model (random effects), employing state panel data of concurrent gubernatorial and Senate elections for the period 1986 to 1998, fail to bolster the rational voter hypothesis that perceived closeness matters. The extent to which pre-election perception matters is shown to depend directly on how one measures the likelihood of a close contest. In contrast, few long-standing variables, inherent to the voting literature, have any impact on “within-booth” voting behavior. The majority of within-booth abstention is left unexplained; furthering the notion of Matsusaka and Palda (1999) that the act of voting, indeed, may be random.