761 research outputs found

    The Shop-Locally Discourse in Jefferson County Kansas

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    Inhabitants in the villages of Jefferson County, Kansas, respond to socioeconomic changes in a variety of ways. Empirical research conducted in 2004 revealed multiple discourses that constituted such responses. The shop-locally discourse emerged in structured interviews, newspaper articles, and newspaper advertisements as an emblem of socioeconomic empowerment. Discourse was analyzed within its context and interpreted to provide some insight into residents\u27 responses to change. The discourse revealed not only nostalgia for formerly vibrant commercial districts but also the importance of economic vitality to social life. Shopping locally today, however, will not restore yesteryear\u27s social milieu. The proximity of midsize cities in adjacent counties pulls the economic lifeblood out of Jefferson County, transforming the villages into bedroom communities. If their economies are to be revitalized, inhabitants will need to become more thoughtful and creative agents of change within their own villages

    Operator Performance in Long Duration Control Operations: Switching from Low to High Task Load

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    Long duration, low task load environments are typical for nuclear power plant control rooms, where operators, after hours of operating under a low task load situation, may have to shift to a high task load situation. The effects of time-on-task and boredom due to low task load will be an important consideration for the design of new nuclear power plant control rooms, which will rely more heavily on automation. This paper describes a research study of performance in a simulated nuclear control room environment, where 36 participants responded to an alarm during a 4 hour long experiment where the alarm onset time and the availability of distractions were varied. The results indicate that operators perform better in a sterile environment and that the duration of non-active time before the alarm influences operator performance.This research was sponsored by the Nuclear Regulatory Commission

    Who benefits?: the intersection of governance and agency in farmers’ engagement with the Oklahoma Farm to School Program

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    Doctor of PhilosophyDepartment of GeographyBimal Kanti PaulFarm-to-school (FTS) programs are promoted as direct-marketing opportunities for farmers. As such, they are regarded by advocates and state and federal agencies as a pathway to rural economic development. The implementation of FTS food procurement poses significant challenges, however. Farmers make decisions regarding whether or not to market products to schools after learning about the program and considering an array of signals from multiscalar policies and governance structures. Research to date has left a gap in understanding farmers’ agency as it relates to governance structures and policy signals. This research on farmers’ engagement with the Oklahoma FTS Program contributes evidence to bridge this gap by examining the experiences not only of producers who participated in a FTS program but also of those who ceased participation or who chose not to participate. Employing a phronetic approach to social science, this explanatory, sequential, mixed-methods case study obtained quantitative and textual data from a mail survey, as well as data from two stints of qualitative fieldwork, in fall 2011 and fall 2012, which involved semistructured interviews and participant observation. Archival research completed the study methods used to gain a deeper understanding of farmers’ perspectives, practices, values, and experiences that informed their decisions to participate or not in a top-down-administered FTS program. Data collection was driven by the concept of farmers’ engagement. As such, eight categories of farmers’ engagement with the Oklahoma Farm to School Program emerged. This research answers these value-rational questions (Flyvbjerg, 2001): (1) Which farmers gain, and which farmers lose, by which mechanisms of power? (2) Is this desirable? (3) What should be done? Results provide evidence of geographically uneven development of a FTS program and incompatibilities between small- to midscale farming and the structure and governance of federal child-nutrition programs

    A Structured Grid Based Solution-Adaptive Technique for Complex Separated Flows

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    The objective of this work was to enhance the predictive capability of widely used computational fluid dynamic (CFD) codes through the use of solution adaptive gridding. Most problems of engineering interest involve multi-block grids and widely disparate length scales. Hence, it is desirable that the adaptive grid feature detection algorithm be developed to recognize flow structures of different type as well as differing intensity, and adequately address scaling and normalization across blocks. In order to study the accuracy and efficiency improvements due to the grid adaptation, it is necessary to quantify grid size and distribution requirements as well as computational times of non-adapted solutions. Flow fields about launch vehicles of practical interest often involve supersonic freestream conditions at angle of attack exhibiting large scale separate vortical flow, vortex-vortex and vortex-surface interactions, separated shear layers and multiple shocks of different intensity. In this work, a weight function and an associated mesh redistribution procedure is presented which detects and resolves these features without user intervention. Particular emphasis has been placed upon accurate resolution of expansion regions and boundary layers. Flow past a wedge at Mach=2.0 is used to illustrate the enhanced detection capabilities of this newly developed weight function

    1H, 15N, and 13C chemical shift assignments of mouse HOXA13 DNA binding domain

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    The homeobox gene (HOXA13) codes for a transcription factor protein that binds to AT-rich DNA sequences and controls expression of many important proteins during embryonic morphogenesis. We report complete NMR chemical shift assignments of the mouse HOXA13 DNA binding domain (A13DBD; BMRB no. 16252)

    Generic effective source for scalar self-force calculations

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    A leading approach to the modelling of extreme mass ratio inspirals involves the treatment of the smaller mass as a point particle and the computation of a regularized self-force acting on that particle. In turn, this computation requires knowledge of the regularized retarded field generated by the particle. A direct calculation of this regularized field may be achieved by replacing the point particle with an effective source and solving directly a wave equation for the regularized field. This has the advantage that all quantities are finite and require no further regularization. In this work, we present a method for computing an effective source which is finite and continuous everywhere, and which is valid for a scalar point particle in arbitrary geodesic motion in an arbitrary background spacetime. We explain in detail various technical and practical considerations that underlie its use in several numerical self-force calculations. We consider as examples the cases of a particle in a circular orbit about Schwarzschild and Kerr black holes, and also the case of a particle following a generic time-like geodesic about a highly spinning Kerr black hole. We provide numerical C code for computing an effective source for various orbital configurations about Schwarzschild and Kerr black holes.Comment: 24 pages, 7 figures, final published versio

    Generic Tracking of Multiple Apparent Horizons with Level Flow

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    We report the development of the first apparent horizon locator capable of finding multiple apparent horizons in a ``generic'' numerical black hole spacetime. We use a level-flow method which, starting from a single arbitrary initial trial surface, can undergo topology changes as it flows towards disjoint apparent horizons if they are present. The level flow method has two advantages: 1) The solution is independent of changes in the initial guess and 2) The solution can have multiple components. We illustrate our method of locating apparent horizons by tracking horizon components in a short Kerr-Schild binary black hole grazing collision.Comment: 13 pages including figures, submitted to Phys Rev

    Relativistic MHD and black hole excision: Formulation and initial tests

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    A new algorithm for solving the general relativistic MHD equations is described in this paper. We design our scheme to incorporate black hole excision with smooth boundaries, and to simplify solving the combined Einstein and MHD equations with AMR. The fluid equations are solved using a finite difference Convex ENO method. Excision is implemented using overlapping grids. Elliptic and hyperbolic divergence cleaning techniques allow for maximum flexibility in choosing coordinate systems, and we compare both methods for a standard problem. Numerical results of standard test problems are presented in two-dimensional flat space using excision, overlapping grids, and elliptic and hyperbolic divergence cleaning.Comment: 22 pages, 8 figure

    From infancy to adolescence: fifteen years of continuous treatment with hydroxyurea in sickle cell anemia

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    Despite documented laboratory and clinical benefits of hydroxyurea for children with sickle cell anemia (SCA), the drug\u27s long-term safety and efficacy remains poorly defined. The HUSOFT trial and extension study examined feasibility, toxicity, and hematological efficacy of hydroxyurea in infants with SCA.This report describes HUSOFT participants who have continued hydroxyurea therapy for 15 years. With IRB approval, medical records were reviewed for clinical, laboratory, and growth parameters.Twenty-eight infants enrolled in the original 2-year HUSOFT study received open-label liquid hydroxyurea at 20 mg/kg/day; 17 completed the extension study with dose escalation to 30 mg/kg/day. Eight of these 17 (6 girls and 2 boys, all HbSS) have continued on daily hydroxyurea for at least 15 years (median age at last follow-up 17.6 years) without interruption. All hematologic indices (Hb concentration, mean corpuscular volume (MCV), fetal hemoglobin) showed sustained effect after 15 years. The median maximum tolerated dose of hydroxyurea has decreased from 30 to 26 mg/kg/day (range 19.5-31.2); neutropenia [absolute neutrophil count (ANC) \u3c 1.0 x 10/L] prompting temporary drug discontinuation occurred a total of 10 times in 4 subjects and there was no severe neutropenia (ANC \u3c 0.5 x 10/L). Growth rates over 15 years continued at the 50th percentile for both height and weight, and puberty occurred without delay (age range 10-14 years). There were 5.1 vaso-occlusive events (pain and acute chest syndrome)/100 patient years, 7.3 packed red blood cell transfusions/100 patient years. No malignancies, strokes, or deaths occurred. At last follow up, all subjects were at appropriate grade level (10-12 grade) with no history of repeated grades.A cohort of young teenagers with SCA who initiated treatment in infancy have had sustained and continued hematological benefits for a decade and a half. Growth and sexual development are normal and comparable to the general pediatric population. Continuous hydroxyurea therapy since infancy appears safe and efficacious in SCA

    Symmetry without Symmetry: Numerical Simulation of Axisymmetric Systems using Cartesian Grids

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    We present a new technique for the numerical simulation of axisymmetric systems. This technique avoids the coordinate singularities which often arise when cylindrical or polar-spherical coordinate finite difference grids are used, particularly in simulating tensor partial differential equations like those of 3+1 numerical relativity. For a system axisymmetric about the z axis, the basic idea is to use a 3-dimensional Cartesian (x,y,z) coordinate grid which covers (say) the y=0 plane, but is only one finite-difference-molecule--width thick in the y direction. The field variables in the central y=0 grid plane can be updated using normal (x,y,z)--coordinate finite differencing, while those in the y \neq 0 grid planes can be computed from those in the central plane by using the axisymmetry assumption and interpolation. We demonstrate the effectiveness of the approach on a set of fully nonlinear test computations in 3+1 numerical general relativity, involving both black holes and collapsing gravitational waves.Comment: 17 pages, 4 figure
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