495 research outputs found

    Are Physical Activity and Benefits Maintained After Long-Term Telerehabilitation in COPD?

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    This study investigated whether physical activity levels and other outcomes were maintained at 1-year from completion of a 2-year telerehabilitation intervention in COPD. During the post-intervention year, nine patients with COPD (FEV1 % of pred. 42.4±19.8%; age 58.1±6 years) were encouraged to exercise on a treadmill at home and monitor daily symptoms and training sessions on a webpage as during the intervention. Participants were not provided supervision or motivational support. Physical activity levels decreased from 3,806 steps/day to 2,817 steps/day (p= 0.039). There was a decline in time spent on light physical activity (p=0.009), but not on moderate-to-vigorous activity (p=0.053). Adherence to registration of symptoms and training sessions decreased significantly. Other outcomes including health status, quality of life, anxiety and depression, self-efficacy, and healthcare utilization did not change significantly. In conclusion, provision of equipment for self-management and unsupervised home exercise might not be enough to maintain physical activity levels

    Corporate governance, market valuation and dividend policy in Brazil

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    This study investigates the effects of the corporate governance structure on market valuation and dividend payout of Brazilian companies. The empirical results indicate a high degree of ownership and control concentration. We can also note a significant difference between the voting and total capital owned by the largest shareholders, mainly through the existence of non-voting shares, pyramidal structures, and shareholding agreements. These mechanisms seem to be used by controlling shareholders to keep the firm’s control without having to own 50% of the total capital. The evidence also reveals that there is a relationship between governance structure, market valuation, and dividend policy in Brazil.Indisponível

    Synergistic cross-scale coupling of turbulence in a tokamak plasma

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    For the first time, nonlinear gyrokinetic simulations spanning both the ion and electron spatio-temporal scales have been performed with realistic electron mass ratio ((m[subscript D] [over m [subscript e])[superscript 1 over 2] = 60.0), realistic geometry, and all experimental inputs, demonstrating the coexistence and synergy of ion (k[subscript θρs] ~O(1.0)) and electron-scale (k[subscript θρe] ~O(1.0)) turbulence in the core of a tokamak plasma. All multi-scale simulations utilized the GYRO code [J. Candy and R. E. Waltz, J. Comput. Phys. 186, 545 (2003)] to study the coupling of ion and electron-scale turbulence in the core (r/a = 0.6) of an Alcator C-Mod L-mode discharge shown previously to exhibit an under-prediction of the electron heat flux when using simulations only including ion-scale turbulence. Electron-scale turbulence is found to play a dominant role in setting the electron heat flux level and radially elongated (k[subscript r] ≪ k[subscript θ]) “streamers” are found to coexist with ion-scale eddies in experimental plasma conditions. Inclusion of electron-scale turbulence in these simulations is found to increase both ion and electron heat flux levels by enhancing the transport at the ion-scale while also driving electron heat flux at sub-ρ[subscript i] scales. The combined increases in the low and high-k driven electron heat flux may explain previously observed discrepancies between simulated and experimental electron heat fluxes and indicates a complex interaction of short and long wavelength turbulence.United States. Dept. of Energy. Office of Science (Contract DE-AC02-05CH11231)United States. Dept. of Energy (Contract DE-FC02-99ER54512-CMOD)United States. Dept. of Energy. Fusion Energy Postdoctoral Research Program (Oak Ridge Institute for Science and Education

    Predictors of benefit following pulmonary rehabilitation for interstitial lung disease

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    SummaryBackgroundPulmonary rehabilitation improves functional capacity and symptoms in the interstitial lung diseases (ILDs), however there is marked variation in outcomes between individuals. The aim of this study was to establish the impact of the aetiology and severity of ILD on response to pulmonary rehabilitation.MethodsForty-four subjects with ILD, including 25 with idiopathic pulmonary fibrosis (IPF), underwent eight weeks of pulmonary rehabilitation. Relationships between disease aetiology, markers of disease severity and response to pulmonary rehabilitation were assessed after eight weeks and six months, regardless of program completion.ResultsIn IPF, greater improvements in 6-minute walk distance (6MWD) immediately following pulmonary rehabilitation were associated with larger forced vital capacity (r = 0.49, p = 0.01), less exercise-induced oxyhaemoglobin desaturation (rS = 0.43, p = 0.04) and lower right ventricular systolic pressure (r = −0.47, p = 0.1). In participants with other ILDs there was no relationship between change in 6MWD and baseline variables. Less exercise-induced oxyhaemoglobin desaturation at baseline independently predicted a larger improvement in 6MWD at six month follow-up. Fewer participants with IPF had clinically important reductions in dyspnoea at six months compared to those with other ILDs (25% vs 56%, p = 0.04). More severe dyspnoea at baseline and diagnosis other than IPF predicted greater improvement in dyspnoea at six months.ConclusionsPatients with IPF attain greater and more sustained benefits from pulmonary rehabilitation when disease is mild, whereas those with other ILDs achieve benefits regardless of disease severity. Early referral to pulmonary rehabilitation should be considered in IPF

    Impaired chronotropic response to 6-min walk test and reduced survival in interstitial lung disease

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    SummaryBackgroundReduced chronotropic response to maximal exercise has been associated with poor survival in people without respiratory disease. The contribution of chronotropic response to exercise limitation and survival in interstitial lung disease (ILD) is not well defined. This study investigated the relationships between chronotropic response during 6-min walk test, exercise capacity and survival in ILD.MethodsEligible participants had ILD, were ambulant and free of heart failure and beta blocker therapy. Chronotropic response during the 6-min walk test was defined as peak heart rate (HR) minus resting HR. Survival was recorded at four years.ResultsSixty-two participants (40 idiopathic pulmonary fibrosis) were included, with mean (SD) TLCO 50(18)% predicted and 6-min walk distance (6MWD) 377 (127) metres. A smaller chronotropic response was associated with reduced 6MWD (r = 0.65, p < 0.001). Independent predictors of 6MWD were chronotropic response, peak oxygen uptake on cardiopulmonary exercise test; right ventricular systolic pressure on echocardiogram; and age. This model explained 83% of the variance in 6MWD, with 24% of the variance attributable to chronotropic response. A chronotropic response during 6-min walk test of less than 20 beats per minute was an independent predictor of death at four years (odds ratio 10.71, 95% confidence interval 2.67–42.94) in a model that also included oxygen desaturation and forced vital capacity.ConclusionsImpaired chronotropic response to 6-min walk test is associated with reduced 6MWD and reduced survival in ILD, independent of physical fitness and pulmonary hypertension. Investigation of the mechanisms underlying attenuated HR response to exercise in ILD is warranted

    Multi-scale gyrokinetic simulations: Comparison with experiment and implications for predicting turbulence and transport

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    To better understand the role of cross-scale coupling in experimental conditions, a series of multi-scale gyrokinetic simulations were performed on Alcator C-Mod, L-mode plasmas. These simulations, performed using all experimental inputs and realistic ion to electron mass ratio ((mi/me)1∕2 = 60.0), simultaneously capture turbulence at the ion (kθρs∼(1.0)) and electron-scales (kθρe∼(1.0)). Direct comparison with experimental heat fluxes and electron profile stiffness indicates that Electron Temperature Gradient (ETG) streamers and strong cross-scale turbulence coupling likely exist in both of the experimental conditions studied. The coupling between ion and electron-scales exists in the form of energy cascades, modification of zonal flow dynamics, and the effective shearing of ETG turbulence by long wavelength, Ion Temperature Gradient (ITG) turbulence. The tightly coupled nature of ITG and ETG turbulence in these realistic plasma conditions is shown to have significant implications for the interpretation of experimental transport and fluctuations. Initial attempts are made to develop a “rule of thumb” based on linear physics, to help predict when cross-scale coupling plays an important role and to inform future modeling of experimental discharges. The details of the simulations, comparisons with experimental measurements, and implications for both modeling and experimental interpretation are discussed.United States. Department of Energy (DE-AC02-05CH11231)United States. Department of Energy (DE-FC02-99ER54512-CMOD)United States. Department of Energy (DE-SC0006957)United States. Department of Energy (DE-FG02-06ER54871
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