544 research outputs found

    Motivation and Performance in Computer Science: Test of an Integrative Theory

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    The purpose of this study was to design and empirically test a parsimonious integrative motivation theory. The theory integrates aspects of expectancy theory, social cognitive theory, goal-setting theory, and commitment theory. The theory was tested with 170 undergraduate, students in an introductory computer science (CS) course. The study tested relationships among the following variables: CS self-efficacy, mathematics ability, affective commitment to the CS class, goal orientation, effort, and performance. The study also tested the interactive effects of effort and ability on performance. Structural equation modeling was used to test the measurement model and a series of nested structural models. Findings supported the proposed integrative motivation theory and most of the hypothesized relationships. Future directions and contributions of this research are discussed

    Work-Family Conflict Among Teleworkers: Demographic Effects and Work-Related Outcomes

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    This study examines the influence of work-family conflict (WFC) on work-related outcomes among teleworkers. Effects of work interfering with family (WIF) and family interfering with work (FIW) on telework satisfaction, affective commitment, and turnover intentions were examined in a secondary data analysis of 167 teleworkers. The effects of several demographic variables (gender, duration of the telework arrangement, number of children, and frequency of teleworking) on WFC were also examined. Structural equation modeling results support the influence of WIF on telework satisfaction and turnover intentions. The influence of FIW on the work outcomes was not supported. Analysis of the demographic variables showed that duration of the telework arrangement predicted WIF and number of children predicted FIW. This study shows that WIF is important among teleworkers. However, more research is required to adequately measure FIW and understand its impact on work outcomes. This study also shows that some demographic variables can influence WFC, but the manner in which these variables impact WFC and ways to combat the issues they present require more attention

    Dynamics and bifurcation of a model for hormonal control of the menstrual cycle with inhibin delay

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    A system of 13 ordinary differential equations with 42 parameters is presented to model hormonal regulation of the menstrual cycle. For an excellent fit to clinical data, the model requires a 36. h time delay for the effect of inhibin on the synthesis of follicle stimulating hormone. Biological and mathematical reasons for this delay are discussed. Bifurcations with respect to changes in three important parameters are examined. One parameter represents the level of estradiol adequate for significant synthesis of luteinizing hormone. Bifurcation diagrams with respect to this parameter reveal an interval of parameter values for which a unique stable periodic solution exists and this solution represents a menstrual cycle during which ovulation occurs. The second parameter measures mass transfer between the first two stages of ovarian development and is indicative of healthy follicular growth. The third parameter is the time delay. Changes in the second parameter and the time delay affect the size of the uniqueness interval defined with respect to the first parameter. Saddle-node, transcritical and degenerate Hopf bifurcations are studied. © 2011 Elsevier Inc

    Molecular Distributions in Gene Regulatory Dynamics

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    We show how one may analytically compute the stationary density of the distribution of molecular constituents in populations of cells in the presence of noise arising from either bursting transcription or translation, or noise in degradation rates arising from low numbers of molecules. We have compared our results with an analysis of the same model systems (either inducible or repressible operons) in the absence of any stochastic effects, and shown the correspondence between behaviour in the deterministic system and the stochastic analogs. We have identified key dimensionless parameters that control the appearance of one or two steady states in the deterministic case, or unimodal and bimodal densities in the stochastic systems, and detailed the analytic requirements for the occurrence of different behaviours. This approach provides, in some situations, an alternative to computationally intensive stochastic simulations. Our results indicate that, within the context of the simple models we have examined, bursting and degradation noise cannot be distinguished analytically when present alone.Comment: 14 pages, 12 figures. Conferences: "2010 Annual Meeting of The Society of Mathematical Biology", Rio de Janeiro (Brazil), 24-29/07/2010. "First International workshop on Differential and Integral Equations with Applications in Biology and Medicine", Aegean University, Karlovassi, Samos island (Greece), 6-10/09/201

    Key issues for the assessment of the allergenic potential of genetically modified foods: breakout group reports.

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    On the final afternoon of the workshop "Assessment of the Allergenic Potential of Genetically Modified Foods," held 10-12 December 2001 in Chapel Hill, North Carolina, USA, speakers and participants met in breakout groups to discuss specific questions in the areas of use of human clinical data, animal models to assess food allergy, biomarkers of exposure and effect, sensitive populations, dose-response assessment, and postmarket surveillance. Each group addressed general questions regarding allergenicity of genetically modified foods and specific questions for each subject area. This article is a brief summary of the discussions of each of the six breakout groups regarding our current state of knowledge and what information is needed to advance the field

    DNA sense-and-respond protein modules for mammalian cells

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    We generated synthetic protein components that can detect specific DNA sequences and subsequently trigger a desired intracellular response. These modular sensors exploit the programmability of zinc-finger DNA recognition to drive the intein-mediated splicing of an artificial trans-activator that signals to a genetic circuit containing a given reporter or response gene. We used the sensors to mediate sequence recognition−induced apoptosis as well as to detect and report a viral infection. This work establishes a synthetic biology framework for endowing mammalian cells with sentinel capabilities, which provides a programmable means to cull infected cells. It may also be used to identify positively transduced or transfected cells, isolate recipients of intentional genomic edits and increase the repertoire of inducible parts in synthetic biology.United States. Defense Advanced Research Projects Agency (DARPA-BAA-11-23)Defense Threat Reduction Agency (DTRA) (HDTRA1-14-1-0006)United States. Air Force Office of Scientific Research (FA9550-14-1-0060

    Assessment of allergenic potential of genetically modified foods: an agenda for future research.

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    Speakers and participants in the workshop "Assessment of the Allergenic Potential of Genetically Modified Foods" met in breakout groups to discuss a number of issues including needs for future research. These groups agreed that research should progress quickly in the area of hazard identification and that a need exists for more basic research to understand the mechanisms underlying food allergy. A list of research needs was developed

    Оценка фискальной иллюзии при налогообложении доходов физических лиц

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    Фискальная иллюзия сама по себе не является негативным явлением, она всего лишь следствие осуществляемой фискальной политики государства. Тем не менее, фискальная иллюзия нарушает представление экономических агентов о масштабах государственного влияния в перераспределении своих доходов и тем самым способствует принятию ими не самых эффективных экономических решений.Фіскальна ілюзія сама по собі не є негативним явищем, вона всього лише слідство здійснюваної фіскальної політики держави. Проте, фіскальна ілюзія порушує уявлення економічних агентів про масштаби державного впливу в перерозподілі своїх доходів і тим самим сприяє ухваленню ними не найефективніших економічних рішень
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