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621.
We present a validated method for the simultaneous analysis of basic drugs which comprises a sample clean-up step, using mixed-mode solid-phase extraction (SPE), followed by LC-MS/MS analysis. Deuterated analogues for all of the analytes of interest were used for quantitation. The applied HPLC gradient ensured the elution of all the drugs examined within 14 min and produced chromatographic peaks of acceptable symmetry. Selectivity of the method was achieved by a combination of retention time, and two precursor-product ion transitions for the non-deuterated analogues. Oral fluid was collected with the Intercept, a FDA approved sampling device that is used on a large scale in the US for workplace drug testing. However, this collection system contains some ingredients (stabilizers and preservatives) that can cause substantial interferences, e.g. ion suppression or enhancement during LC-MS/MS analysis, in the absence of suitable sample pre-treatment. The use of the SPE was demonstrated to be highly effective and led to significant decreases in the interferences. Extraction was found to be both reproducible and efficient with recoveries >76% for all of the analytes. Furthermore, the processed samples were demonstrated to be stable for 48 h, except for cocaine and benzoylecgonine, where a slight negative trend was observed, but did not compromise the quantitation. In all cases the method was linear over the range investigated (2-200 microg/L) with an excellent intra-assay and inter-assay precision (coefficients of variation <10% in most cases) for QC samples spiked at a concentration of 4, 12 and 100 microg/L. Limits of quantitation were estimated to be at 2 microg/L with limits of detection ranging from 0.2 to 0.5 microg/L, which meets the requirements of SAMHSA for oral fluid testing in the workplace. The method was subsequently applied to the analysis of Intercept samples collected at the roadside by the police, and to determine MDMA and MDA levels in oral fluid samples from a controlled study.  相似文献   
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The present research investigated differences in levels of impulsivity among early-onset, late-onset, and non-offending adolescents. 129 adolescents (114 males, 15 females), of whom 86 were institutionalised (M age=15.52 years) and 43 were regular school students (M age=15.40 years) participated. Each participant completed the Adapted Self-Report Delinquency Scale, Stroop Colour and Word Test, Time Perception task, Accuracy Game, Risk-Taking Game, and the Eysenck Impulsiveness Questionnaire. Results suggest that adolescents who display rapid cognitive tempo, poor mental inhibitory control, and high impulsivity are more likely to be early-onset offenders. Offender and non-offender groups showed significant differences on several measures of impulsivity, which may suggest that late-onset offenders acquire or exacerbate impulse-related problems through social mimicry of early-onset offender peers. Potentially important implications for our understanding of delinquency and the design and provision of prevention programs are highlighted.Senior Lecturer in Educational Psychology at the School of Education, The University of Queensland, Brisbane, Australia. She received her PhD in educational psychology from The University of Western Australia. Her major research interests include at-risk behaviours of children and adolescents, self-regulation and goal setting, and developmental trajectories of antisocial and aggressive behaviours School of Education, The University of Queensland, Brisbane Q 4072 AustraliaDoctor of Clinical Psychology student within the School of Psychology at The University of Queensland, Brisbane, Australia. Her research interests include at-risk children and adolescents, mental health in adolescents and adults, cognitive-behavioural interventions, and self-regulationMaster of Philosophy student within the School of Education, The University of Queensland, Brisbane, Australia. Her research interests include self-regulation, youth at-risk, Indigenous youth issues, and prevention and intervention approachesProfessor of Education and Head of the School of Education, The University of Queensland, Brisbane, Australia. He received his PhD in educational psychology from the University of Alberta, Canada. His research interests include cognitive educational psychology, classroom-based instruction, strategy training, problem solving, and at-risk youthProfessor of Education and Director, Centre for Attention and Related Disorders at the Graduate School of Education, The University of Western Australia. He received his PhD in educational psychology from the University of Birmingham, UK. His research interests include attentional disorders, severe antisociality in children and adolescents, emotion regulation, complex information processing and cognitive processes of at-risk adolescents Graduate School of Education, The University of Western, AustraliaProfessor of Psychology in the Department of Psychology, University of Strathclyde, United Kingdom. He received his PhD in developmental psychology, specialising in cognitive and communicative development in childhood and adolescence from Cambridge University, UK. His research interests include developmental psychology, at-risk children and adolescents, and the impact of media on children’s behaviour  相似文献   
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This paper asks: what is the relationship between the mainstream media and blog agendas? To be more precise, this paper tracks media coverage and blog discussion of 35 issues during the 2004 presidential campaign to test the hypothesis that the mainstream media agenda exerts a substantial impact on the blog agenda against the increasingly popular hypothesis that the blog agenda exerts a strong influence on the mainstream media agenda. Using a computer‐assisted, quantitative content analysis of ten randomly selected A‐list political blogs and 50 randomly selected, less popular political blogs over the five‐month period from July 1 to November 30, 2004, the author finds that on the vast majority of issues there was a complex, bidirectional relationship between mainstream media coverage and blog discussion rather than a unidirectional media or blog agenda‐setting effect.  相似文献   
626.
The connections between body image disturbance and psychological functioning have been well established in samples of older adolescent girls and young women. Little is known, however, about body image in younger children. In particular, little is known about possible gender differences in preadolescent children. The current study explored self-reported body image disturbance and psychological functioning in relation to peer and parental influences in 141 elementary school-aged girls and boys aged 8–11. Results suggest that girls are more concerned about dieting and are more preoccupied with their weight than are boys. Girls also reported a greater drive for thinness and a higher level of family history of eating concerns than did boys. Correlations suggested that girls' experiences of body image concerns (body dissatisfaction, bulimia, and drive for thinness) were related to a number of factors (such as family history of eating concerns, peer influences, teasing, depression, and global self-worth) whereas boys' experiences of body image concerns were related to fewer factors. On the basis of these findings, the assessment and treatment of body image concerns in preadolescent children (especially girls) are of great importance. Implications for intervention and prevention programs are discussed.  相似文献   
627.
The federal government subsidizes lending to a number of borrowers—notably students, farmers, and homeowners. Government‐sponsored enterprises issue the securities that channel capital to many of these privileged borrowers. One of the largest of these enterprises, the Student Loan Marketing Association (Sallie Mae), is scheduled to be wholly privatized by September 30, 2008. What explains the privatization of this enterprise? To identify distinctive features of Sallie Mae that permitted or abetted privatization, we investigate the structure, related capital market innovations, and growth of three government‐sponsored enterprises. We conclude that a unique structural feature of Sallie Mae may explain the pace of privatization. The core asset of Sallie Mae, the student loan, is guaranteed and subsidized by the government. The case of Sallie Mae is an instructive yet poorly understood example of how the federal government can leverage private‐sector assets and incentives to achieve public policy missions.  相似文献   
628.
Thirty adolescents and their parents participated in a study of family interaction and optimal experience. Family members completed questionnaires, and discussed 7 topics for approximately 30 minutes while being videotaped. The audio portion of the tape was replayed after the discussion, with pauses after each topic segment to allow family members an opportunity to complete a modified form of the Experience Sampling Method. Family interaction was coded by independent observers, and compared to family members' experiential reports. Results showed that family communication complexity (i.e., interaction characterized jointly by integrating and differentiating responses) was associated with family members' reports of more optimal experience (i.e., feelings of interest and/or flow experience). Segment-to-segment analyses added that increases and descreases in family members' interest were associated with upward and downward changes in communication complexity, respectively. These findings, and the novel methodological approach, are discussed in terms of their relevance for studying adolescent development in the family.  相似文献   
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630.
Book Reviews     
Mac and Supermac

Alistair Horne, Macmillan, 1894–1956 : Volume I of the Official Biography. (London: Macmillan, 1988. £16.95. ISBN 0 333 27691)

Paul Kennedy, The Rise and Fall of the Great Powers: Economic Change and Military Conflict from 1500–2000 (London and Sydney, 1988)

Edward N. Luttwak, Strategy: The Logic of War and Peace (Harvard University Press, 1987)

Henry Butterfield Ryan, The Vision of Anglo‐America: The US‐UK Alliance and the Emerging Cold War, 1943–1946 (Cambridge University Press, 1987)  相似文献   

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