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Dual System (dual + system)
Selected AbstractsDual CD system-modified MEEKC method for the determination of clemastine and its impuritiesELECTROPHORESIS, Issue 19 2010Serena Orlandini Abstract A dual system of CDs was used for the first time in MEEKC with the aim of determining clemastine and its three main related impurities in both drug substances and tablets. The addition of methyl-,-cyclodextrin and heptakis(2,6-di- O -methyl)-,-cyclodextrin to the microemulsion pseudo-stationary phase was essential to increase the resolving power of the system to obtain a baseline separation among the compounds. The best microemulsion composition was identified by mixture design and the effects of the factors concentrations of CDs and voltage were investigated by a response surface study applying a Central Composite Design. In both cases, Derringer's desirability function made it possible to find the global optimum, which corresponded to the following combination: microemulsion, 89.8% 10,mM borate buffer pH 9.2, 1.5% n -heptane and 8.7% of SDS/n -butanol in 1:2 ratio; 18,mM methyl-,-cyclodextrin, 38,mM heptakis(2,6-di- O -methyl)-,-cyclodextrin, 17,kV. By applying these conditions, the separation was completed in about 5.5,min. The method was validated following International Conference on Harmonisation guidelines and was applied to a real sample of clemastine tablets. [source] Transgenic mice expressing a dual, CRE-inducible reporter for the analysis of axon guidance and synaptogenesis,GENESIS: THE JOURNAL OF GENETICS AND DEVELOPMENT, Issue 6 2007Aurora Badaloni Abstract Improved and modular tools are needed for the neuroanatomical dissection of CNS axonal tracts, and to study the cell-intrinsic and cell-extrinsic cues that govern their assembly and plasticity. Here we describe a general purpose transgenic tracer that can be used to visualize axonal tracts and synaptic terminals in any region of the embryonic neural tube or postnatal CNS, on any wild type or mutant genetic background. The construct permits CRE-inducible expression of a dicistronic axonal marker encoding two surface reporter proteins: a farnesylated GFP and the human Placental Alkaline Phosphatase (PLAP). Both proteins localize alongside the neuronal surface, permitting the concomitant detection of cell body, neurites, and presynaptic and postsynaptic sites in the same neuron. This provides a CRE-inducible dual system for imaging neural circuits in vivo, and to study their assembly and remodeling in cultured neurons, neural stem cells, and tissue explants derived from the reporter line. Unlike existing lines, this reporter does not encode a ubiquitously expressed, floxable LacZ gene, permitting the simultaneous analysis of beta galactosidase activity in mutant lines. genesis 45:405,412, 2007. © 2007 Wiley-Liss, Inc. [source] The Second Generation in Germany: Between School and Labor Market,INTERNATIONAL MIGRATION REVIEW, Issue 4 2003Susanne Worbs The German "mode of integration" after World War II has been to include migrants and their offspring into general societal institutions. This can be stated despite differences between federal states in some aspects of migrant integration (e.g., the educational sector). Migrant children normally attend the same schools and classes as their German age peers, they participate in the dual system of vocational training, and there are only a few limitations in labor market access. The second generation in Germany consists mainly of children of the "guestworkers" recruited in southern and southeastern European countries from the 1950s onwards. It is not easy to obtain information about their numbers and their socioeconomic position, as most statistical data distinguish only between foreigners and Germans. The achieved integration status of the second generation varies between areas: obvious problems in the educational system go along with considerable progress in the vocational training system and in the labor market. Children of Turkish migrants are the most disadvantaged group among the second generation. [source] Functional anatomy of the basal gangliaMOVEMENT DISORDERS, Issue S3 2002J. Yelnik MD Abstract Four organizational levels of the basal ganglia that could be particularly determinant in terms of functional properties are reviewed: (1) macroscopic anatomy, which is characterized by a dramatic decrease of cerebral tissue volume from the cerebral cortex to the deepest portions of the basal ganglia; (2) connectivity, which consists of both complex loops and a partition into three territories, sensorimotor, associative, and limbic (which process motor, cognitive, and emotional information, respectively); (3) neuronal morphology, characterized by a dramatic numeric and geometric convergence of striatal neurons onto pallidonigral neurons; and (4) dopaminergic innervation of the basal ganglia, which is organized as a dual system that is supposed to have opposite effects on the activity of the system. Current models of the basal ganglia are discussed. © 2002 Movement Disorder Society [source] Costs and Risks of Segregating GM Wheat in CanadaCANADIAN JOURNAL OF AGRICULTURAL ECONOMICS, Issue 3 2006William W. Wilson An analytical model was developed to explore prospective costs and risks of alternative testing strategies for a marketing system in Canada which markets both genetically modified (GM) and Non-GM wheats. The problem is solved using stochastic optimization, base case results are defined, and sensitivities conducted to evaluate impacts of selected variables. Added costs include: testing, rejection, and a risk premium which is required for handlers to be indifferent between the current and the proposed dual system. Protocols would require testing at the point of loading at the primary elevator, and export elevator, and supplementing this information with some form of grower variety declaration. There are several sources of inherent risks in such a system. For buyers, the cumulative impact of these is the risk of receiving GM content in a Non-GM shipment. For sellers, it is the risk of having a Non-GM shipment rejected. For sellers, the risk of rejection was typically less than 2%, and for buyers, the risk was typically less than 0.02%. Nous avons élaboré un modèle analytique pour explorer les coûts et les risques potentiels de la mise en place de nouvelles stratégies pour analyser le grain si le Canada décidait de commercialiser du blé génétiquement modifié (GM) et du blé non génétiquement modifié (NGM). Le problème est résolu à l'aide d'une optimisation stochastique; des scénarios de référence sont définis et des tests de sensitivité sont effectués pour évaluer l'impact de variables sélectionnées. Les coûts supplémentaires comprennent les coûts d'analyses, les coûts liés au rejet ainsi qu'une prime de risque exigée pour que les manutentionnaires demeurent indifférents entre le système actuel et le système double proposé. Les protocoles obligeraient la tenue d'analyses au point de chargement du silo primaire ainsi qu'au silo terminal, auxquelles s'ajouterait une certaine forme de déclaration du céréaliculteur sur la variété. Ce genre de système comporte plusieurs sources de risques inhérents. Pour les acheteurs, l'impact cumulatif est le risque de recevoir un chargement de blé NGM contenant du blé GM. Pour les vendeurs, c'est le risque qu'un chargement de blé NGM soit rejeté. Pour les vendeurs, le risque de rejet était généralement inférieur à 2%, et pour les acheteurs, le risque était généralement inférieur à 0.02%. [source] Youth Transitions and Employment in GermanyINTERNATIONAL SOCIAL SCIENCE JOURNAL, Issue 164 2000Walter R. Heinz In the 1990s, the timing and duration of youth transitions has become variable because of cultural modernisation and the declining stability of careers. In particular, the German ,dual system' of Vocational Education and Training (VET) has come under pressure of globalisation and labour market deregulation. Despite economic turbulence, the main features of the VET have been maintained. The apprenticeship route is still highly accepted-two-thirds of the cohort of school-leavers are passing through it. It continues to provide standardised occupational qualifications and a context for socialisation. It supplies a skilled labour force and keeps youth unemployment low-despite shortcomings in standards of social equality and a slow pace in adapting to changes in technology and work. For the future, the ,left modernisers' strategy of upgrading skills remains possible, by reforming the apprenticeship system and main-taining the 'high-skills, route for transition from education to work. In transition studies structural analysis should be combined with research on institutional regulations, transition pathways, and individual agency. [source] A dual systems model of adolescent risk-taking,DEVELOPMENTAL PSYCHOBIOLOGY, Issue 3 2010Laurence Steinberg Abstract It has been hypothesized that reward-seeking and impulsivity develop along different timetables and have different neural underpinnings, and that the difference in their timetables helps account for heightened risk-taking during adolescence. In order to test these propositions, age differences in reward-seeking and impulsivity were examined in a socioeconomically and ethnically diverse sample of 935 individuals between the ages of 10 and 30, using self-report and behavioral measures of each construct. Consistent with predictions, age differences in reward-seeking follow a curvilinear pattern, increasing between preadolescence and mid-adolescence, and declining thereafter. In contrast, age differences in impulsivity follow a linear pattern, with impulsivity declining steadily from age 10 on. Heightened vulnerability to risk-taking in middle adolescence may be due to the combination of relatively higher inclinations to seek rewards and still maturing capacities for self-control. © 2010 Wiley Periodicals, Inc. Dev Psychobiol 52: 216,224, 2010 [source] Enantiomeric separation of aminoglutethimide by capillary electrophoresis using native cyclodextrins in single and dual systemsJOURNAL OF SEPARATION SCIENCE, JSS, Issue 6-7 2003Adel M. Abushoffa Abstract Aminoglutethimide (AGT) is one of the few examples of chiral drugs that can be enantioseparated by capillary electrophoresis using any of the three native cyclodextrins: ,-, ,-, or ,-CD. A complete resolution of the enantiomers of this compound in cationic form could be achieved with each of the three CDs, using a pH 3 phosphoric acid-triethanolamine buffer. Affinity constants for AGT enantiomers with the three native CDs were determined, confirming that the highest selectivity was given by ,-CD while the strongest complexation was obtained with ,-CD. However, an opposite affinity pattern was observed with the latter. Selectivity was lower for AGT enantiomers in dual CD systems, compared to that obtained with a single selector at its optimal concentration, which confirms that dual systems are of more limited interest when the two selectors have a similar effect on the analyte mobility. These results are in good agreement with those predicted using recently developed mathematical models. [source] | |||||||||||||