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Baptista MJ Monsanto PV Pinho Marques EG Bermejo A Avila S Castanheira AM Margalho C Barroso M Vieira DN 《Forensic science international》2002,128(1-2):66-78
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. 相似文献
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David Weil Archon Fung Mary Graham Elena Fagotto 《Journal of policy analysis and management》2006,25(1):155-181
Regulatory transparency—mandatory disclosure of information by private or public institutions with a regulatory intent—has become an important frontier of government innovation. This paper assesses the effectiveness of such transparency systems by examining the design and impact of financial disclosure, nutritional labeling, workplace hazard communication, and five other diverse systems in the United States. We argue that transparency policies are effective only when the information they produce becomes “embedded” in the everyday decision‐making routines of information users and information disclosers. This double‐sided embeddedness is the most important condition for transparency systems' effectiveness. Based on detailed case analyses, we evaluate the user and discloser embeddedness of the eight major transparency policies. We then draw on a comprehensive inventory of prior studies of regulatory effectiveness to assess whether predictions about effectiveness based on characteristics of embeddedness are consistent with those evaluations. © 2006 by the Association for Public Policy Analysis and Management 相似文献
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Mary Field 《政策研究评论》2002,19(2):33-34
This article provides an overview of factors influencing highway intermodal freight transportation planning and policy in the United States. The article provides examples of state and local initiatives to manage or balance the increasing highway transportation of freight with decreasing system capacity. It also identifies important trends in commerce affecting intermodal freight generation. It concludes with a discussion of issues facing intermodal freight transportation planning and policy making at the millennium. 相似文献
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Influences and Mediators of the Effect of Poverty on Young Adolescent Depressive Symptoms 总被引:2,自引:0,他引:2
Data from a sample of young adolescents between the ages of 10 and 12 years (N = 898) from the mother–child data set of the National Longitudinal Survey of Youth were analyzed in a study of influences that explain the relation between poverty and depressive symptoms measured 2 years later. Other variables that predicted youth depressive symptoms were also identified. Results indicated that neighborhood problems, nonparticipation in outside school and neighborhood activities, residing with mothers who exhibited depressive symptoms, and mother's use of physical punishment were partial mediators of the effect of poverty on depressive symptoms 2 years later. Youth health status, lower levels of school satisfaction, marital-partner conflict, and father's emotional support also predicted depressive symptoms. The findings indicate that youth depressive symptoms are multiply determined and that poverty can adversely affect young adolescents in many ways. 相似文献
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Our purpose is to provide empirical evidence of the relations between the quality of governmental audit services and auditor tenure and between quality and fixed fee audit contracts. Audit quality is assessed by Offices of Regional Inspectors General and is based on a review of the audit reports and supporting working papers. We test a model of quality supplied on a sample of audit engagements selected from a population of audited federal assistance programs. The empirical analysis finds that the probability of receiving a substandard audit increases with the length of the auditor-client relationship. Our analysis finds a positive relation between fixed fee contracts and the incidence of violations of professional standards among audits of federal assistance programs. Additionally, we provide evidence that the incidence of noncom-pliance with professional standards is significantly lower when the audit contract contains a provision for administrative and/or legal remedies in the event of substandard performance. 相似文献
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