2,781 research outputs found

    Abnormalities of the ventilatory equivalent for carbon dioxide in patients with chronic heart failure

    Get PDF
    Introduction. The relation between minute ventilation (VE) and carbon dioxide production (VCO2) can be characterised by the instantaneous ratio of ventilation to carbon dioxide production, the ventilatory equivalent for CO2 (VEqCO2). We hypothesised that the time taken to achieve the lowest VEqCO2 (time to VEqCO2 nadir) may be a prognostic marker in patients with chronic heart failure (CHF). Methods. Patients and healthy controls underwent a symptom-limited, cardiopulmonary exercise test (CPET) on a treadmill to volitional exhaustion. Results. 423 patients with CHF (mean age 63±12 years; 80% males) and 78 healthy controls (62% males; age 61±11 years) were recruited. Time to VEqCO2 nadir was shorter in patients than controls (327±204 s versus 514±187 s; P=0.0001). Univariable predictors of all-cause mortality included peak oxygen uptake (X 2 =53.0), VEqCO2 nadir (X 2 =47.9), and time to VEqCO2 nadir (X 2 =24.0). In an adjusted Cox multivariable proportional hazards model, peak oxygen uptake (X 2 =16.7) and VEqCO2 nadir (X 2 =17.9) were the most significant independent predictors of all-cause mortality. Conclusion. The time to VEqCO2 nadir was shorter in patients with CHF than in normal subjects and was a predictor of subsequent mortality. © 2012 Lee Ingle et al

    A Functional Analysis of Non-Presidential Primary Debates

    Get PDF
    Despite the fact that political debates are increasingly common at all levels of government, relatively little work investigates the content of non-presidential debates (and work on primary debates is even less common). This study breaks new ground by analyzing four non-presidential primary debates. Two Democratic gubernatorial debates, one Republican U.S. Senate debate, and one Republican U.S. House debate were content analyzed using the framework of the functional theory of political campaign discourse. Overall, these debates were mainly positive, with 71% acclaims, 22% attacks, and 7% defenses. The Democratic (and gubernatorial) debates had more attacks and defenses and fewer defenses than the Republican (congressional) debates. Overall, these campaign messages focused more on policy (60%) than character (40%). The Democratic (gubernatorial) debates emphasized policy even more (65% to 55%), and character less (35% to 45%), than the Republican (congressional) debates

    A Phase Space Approach to Gravitational Enropy

    Get PDF
    We examine the definition S = ln Omega as a candidate "gravitational entropy" function. We calculate its behavior for gravitationl and density perturbations in closed, open and flat cosmologies and find that in all cases it increases monotonically. Using the formalism to calculate the gravitational entropy produced during inflation gives the canonical answer. We compare the behavior of S with the behavior of the square of the Weyl tensor. Applying the formalism to black holes has proven more problematical.Comment: Talk delivered at South African Relativistic Cosmology Symposium, Feb 1999. Some new results over Rothman and Anninos 97. To appear in GRG, 17 page

    Newspaper Coverage of the 2008 General Election Presidential Campaigns

    Get PDF
    News coverage of political campaigns is very important to the political campaign process. Some voters pay little attention to debates or other sources of information about the candidates and their policies. The news is one important source of this information. Newspapers can also supplement and reinforce the information possessed by voters who do attend to campaign messages. This study content analyzed news coverage of the 2008 general election presidential campaign (New York Times, Washington Post, USA Today). Horse race coverage was most common topic (45%), followed by themes about character (32%), and policy (23%). The tone of newspaper coverage was more positive (51%) than negative (39%; 9% of themes reported the candidates‘ defenses)

    Simulation and flight evaluation of a head-up landing aid for general aviation

    Get PDF
    A head-up general aviation landing aid called a landing site indicator (LASI) was tested in a fixed-base, visual simulator and in an airplane to determine the effectiveness of the LASI. The display, which had a simplified format and method of implementation, presented to the pilot in his line of sight through the windshield a graphic representation of the airplane's velocity vector. In each testing model (simulation of flight), each of 4 pilots made 20 landing approaches with the LASI and 20 approaches without it. The standard deviations of approach and touchdown parameters were considered an indication of pilot consistency. Use of the LASI improved consistency and also reduced elevator, aileron, and rudder control activity. Pilots' comments indicated that the LASI reduced work load. An appendix is included with a discussion of the simulator effectiveness for visual flight tasks

    Enhancing IS Education with Flexible Teaching and Learning

    Get PDF
    Flexible teaching and learning is not a new concept, but it is one that we, as educators, do not focus on enough. Designing and delivering innovative, exciting and relevant learning experiences is needed if we are to make our classes good learning experiences. Information systems (IS) educators deal with technology every day, yet we are sometimes the first ones to forget how to use it in the classroom. Educators must recognize the importance of increasing student control over and active participation in their own learning. This Special Issue of the Journal of Information Systems Education looks at flexible teaching and learning in the IS classroom. We present eight papers on flexible teaching and learning, dealing with both the face-to-face and online classroom environments. We hope that the ideas presented in these papers will foster your thinking in using flexible teaching techniques. In the end, flexible teaching and learning focuses on improving student learning, a goal that we all aspire to in our classrooms

    On the evolution of a large class of inhomogeneous scalar field cosmologies

    Get PDF
    The asymptotic behaviour of a family of inhomogeneous scalar field cosmologies with exponential potential is studied. By introducing new variables we can perform an almost complete analysis of the evolution of these cosmologies. Unlike the homogeneous case (Bianchi type solutions), when k^2<2 the models do not isotropize due to the presence of the inhomogeneitiesComment: 23 pages, 1 figure. Submitted to Classical and Quantum Gravit

    EB1 directly regulates APC-mediated actin nucleation

    Get PDF
    EB1 was discovered 25 years ago as a binding partner of the tumor suppressor Adenomatous Polyposis Coli (APC) [1]; however, the significance of EB1-APC interactions has remained poorly understood. EB1 functions at the center of a network of microtubule end-tracking proteins (+TIPs) [2–5], and APC binding to EB1 promotes EB1 association with microtubule ends and microtubule stabilization [6, 7]. Whether or not EB1 interactions govern functions of APC beyond microtubule regulation has not been explored. The C-terminal Basic domain of APC (APC-B) directly nucleates actin assembly, and this activity is required in vivo for directed cell migration and for maintaining normal levels of F-actin [8–10]. Here, we show that EB1 binds APC-B and inhibits its actin nucleation function by blocking actin monomer recruitment. Consistent with these biochemical observations, knocking down EB1 increases F-actin levels in cells, and this can be rescued by disrupting APC-mediated actin nucleation. Conversely, overexpressing EB1 decreases F-actin levels and impairs directed cell migration, without altering microtubule organization and independent of its direct binding interactions with microtubules. Overall, our results define a new function for EB1 in negatively regulating APC-mediated actin assembly. Combining these findings with other recent studies showing that APC interactions regulate EB1-dependent effects on microtubule dynamics [7], we propose that EB1-APC interactions govern bidirectional cytoskeletal crosstalk by coordinating microtubule and actin dynamics

    Isotropic cosmological singularities: other matter models

    Get PDF
    Isotropic cosmological singularities are singularities which can be removed by rescaling the metric. In some cases already studied (gr-qc/9903008, gr-qc/9903009, gr-qc/9903018) existence and uniqueness of cosmological models with data at the singularity has been established. These were cosmologies with, as source, either perfect fluids with linear equations of state or massless, collisionless particles. In this article we consider how to extend these results to a variety of other matter models. These are scalar fields, massive collisionless matter, the Yang-Mills plasma of Choquet-Bruhat, or matter satisfying the Einstein-Boltzmann equation.Comment: LaTeX, 19 pages, no figure

    Pilot-Scale Denitrification Bioreactors for Replicated Field Research

    Get PDF
    Carbon-based denitrification bioreactors are designed to intercept tile drainage and are a promising technology for reducing NO3- export to surface water. While these systems have been tested extensively in the laboratory, the ability to study in-field bioreactors under controlled conditions with statistical replicates has been limited. Nine pilot-scale bioreactors (5.79 x 1.05 x 1.07 m) were designed and installed for systematic field testing, allowing for variation in retention time, fill material, and influent water quality parameters. Each bioreactor is constructed from a concrete trench in-line with influent flow control, dosing port, flow diffusion, and effluent water level control. Sampling ports are installed at two points in each bioreactor for access to water samples or fill materials. A potassium bromide (KBr) tracer study was conducted and Morrill Dispersion Index (MDI) values averaged 2.8 ± 0.3, indicating plug flow characteristics. The average tracer residence time () was 2.3 ± 0.3 h, in close agreement with the estimated hydraulic retention time (HRT) value of 2.1 ± 0.3 h, which was calculated using a porosity value of 0.70. Hydraulic efficiency was good (λ = 0.78 ± 0.03) and there was no evidence of short circuiting (S = 0.73 ± 0.03). This system is expected to provide useful insight regarding design for improved field performance of denitrification bioreactors
    corecore