4,628 research outputs found

    A Proportion Method for Sampling Spittlebug Populations

    Get PDF
    Author Institution: Department of Entomology, Ohio Agricultural Experiment Station, Wooster, and Department of Mathematics, The Ohio State University, Columbus 1

    Families of Graphs With Chromatic Zeros Lying on Circles

    Full text link
    We define an infinite set of families of graphs, which we call pp-wheels and denote (Wh)n(p)(Wh)^{(p)}_n, that generalize the wheel (p=1p=1) and biwheel (p=2p=2) graphs. The chromatic polynomial for (Wh)n(p)(Wh)^{(p)}_n is calculated, and remarkably simple properties of the chromatic zeros are found: (i) the real zeros occur at q=0,1,...p+1q=0,1,...p+1 for npn-p even and q=0,1,...p+2q=0,1,...p+2 for npn-p odd; and (ii) the complex zeros all lie, equally spaced, on the unit circle q(p+1)=1|q-(p+1)|=1 in the complex qq plane. In the nn \to \infty limit, the zeros on this circle merge to form a boundary curve separating two regions where the limiting function W({(Wh)(p)},q)W(\{(Wh)^{(p)}\},q) is analytic, viz., the exterior and interior of the above circle. Connections with statistical mechanics are noted.Comment: 8 pages, Late

    Plasma Physics

    Get PDF
    Contains reports on three research projects.U. S. Atomic Energy Commission (Contract AT(30-1)-1842)U. S. Air Force (Electronic Systems Division) under Contract AF19(604)-599

    A Motivational Climate Intervention and Exercise-Related Outcomes: A Longitudinal Perspective

    Get PDF
    While researchers have suggested that the social context in exercise settings is linked to individuals’ physical activity motivation and potential exercise-related outcomes, few research designs have examined the nuance of those relationships. Moreover, interventions targeting the social context of exercise settings are sparse, so the potential impact of staff training on members’ motivation to exercise are not well known. Drawing from two major motivation theories, achievement goal perspective theory and self-determination theory, this study considered an intervention with fitness center staff from the members’ perspectives. Members completed a survey before and after an intervention designed to help staff create a high caring, task-involving, and low ego-involving motivational climate. Using a half-longitudinal structural equation model, participants’ perceptions of the motivational climate, basic psychological needs, exercise motivation, and exercise experiences (including commitment to exercise, life satisfaction, body image) were modeled pre-post intervention. The model revealed significant latent mean differences for post-intervention constructs, with participants experiencing a more positive motivational climate, higher competence and relatedness, intrinsic motivation, commitment, life satisfaction, and body image. The final mediation model demonstrated tenable fit, with perceptions of climate having significant, direct and indirect effects on commitment, life satisfaction, and body image. Our study supports that the motivational climate contributes to an optimal social context for exercise where basic psychological needs are nurtured, intrinsic motivation is fostered, and individuals experience well-being benefits, including increased life satisfaction. Further, short and targeted training meetings with fitness center staff can result in members’ perceiving a significant change in the motivational climate

    Situating implementation science (IS) in res(IS)tance: A conceptual frame toward the integration of scholarship from the black radical tradition

    Get PDF
    This manuscript undertakes a disciplinary self-critique of the field of implementation science, a field which attempts to bridge the gap between evidence-based interventions and their practical application. Despite the heightened emphasis on health equity and racial disparities, the field\u27s current discourse is limited by key epistemic shortcomings. First, even though prevalence of implementation gaps between racialized groups in the United States necessitates a comprehensive understanding of the systems perpetuating these disparities, the field does not operate with a general explanation for disparities not as a failure of systems, but a system historically and structural designed to produce disparities. Second, the field has attempted to address disparities without adequate dialog with a broad tradition of anti-racist and anti-colonial sociology, history and epistemology, and therefore risks a decontextualized analysis of disparities and under-informed approaches to achieving equity. Fortunately, scholarship from the Black radical tradition (BRT), such as the Public Health Critical Race Praxis (PHCRP), Critical Race Theory (CRT), and more broadly conceptual frameworks from post-modern, anti-colonial, Black feminist studies and social epistemology can offer to implementation science frameworks that center power dynamics and racialized oppression. This epistemic re-alignment of implementation research to center at the margins can enable the field of implementation science to more critically examine and dismantle systems that perpetuate racial inequalities in access to and utilization of health interventions. For example, normalization and dynamic fit, which are thought to be key mechanisms of implementation, are revealed in the light of this tradition of scholarship to be potentially problematic acquiescence to oppressive systems. Drawing from the concept of resistance anchored in the scholarship of the Black radical tradition as well as contemporary social epistemology such as the work of José Medina and Maria Fricker about epistemic justice, the authors further advance that implementation science could make more substantial contributions to the dismantling of racialized systems and actively work toward health justice through the transdisciplinary lens of resistance. This is a call to action for integrating implementation science with critical philosophical and theoretical perspectives rooted in Black studies and related insights, which have been acquired through the struggle for social justice, to inform the design of implementation strategies and research projects that improve health services and health outcomes for health disparity populations

    Psychometric Properties of the Abbreviated Perceived Motivational Climate in Exercise Questionnaire

    Get PDF
    The purpose of this study was to develop an abbreviated version of the Perceived Motivational Climate in Exercise Questionnaire (PMCEQ-A) to provide a more practical instrument for use in applied exercise settings. In the calibration step, 2 shortened versions’ measurement and latent model values were compared to each other and the original PMCEQ using a 3-group CFA invariance testing approach with previously collected exercise setting data (N = 5,427). Based on the model fit and reliability values, the 12-item version performed better than the 17-item version. The resultant 12-item PMCEQ-A’s CFA model estimates were then compared to the PMCEQ’s model values for 2 different, previously conducted studies of exercise settings (N = 414 and 770). The more parsimonious 12-item PMCEQ-A can be used by exercise psychology researchers to gain insight into members’ perspectives on the motivational climate and may lead to developing effective strategies to enhance members’ experiences and commitment

    Plasma Physics

    Get PDF
    Contains reports on two research projects.United States Atomic Energy Commission (Contract AT(30-1)-1842)United States Air Force, Electronic Systems Division (Contract AF19(604)-5992)National Science Foundation (Grant G-24073
    corecore