824 research outputs found

    Evolution of Subglacial Overdeepenings in Response to Sediment Redistribution and Glaciohydraulic Supercooling

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    Glaciers erode bedrock rapidly, but evacuation of sediments requires efficient subglacial drainage networks. If glaciers erode more rapidly than evacuation proceeds, a protective subglacial till layer can form to armor the bed. Where glaciers cross overdeepenings, local closed depressions, the bed slope opposes the ice surface and lowers the hydraulic potential gradient that drives water flow. Here, we present results of a dynamic, distributed model of coupled basal water flow and sediment transport to show how overdeepenings evolve over the course of a melt season. We use steady-state calculations as well as numerical simulations to understand how alluvial bed erosion alters overdeepenings. Numerical results from a modified form of the Spring-Hutter equations show behaviors that cannot be inferred from either local or steady-state calculations. In general, opposition of surface and bed slopes lessens sediment transport regardless of ice accretion from glaciohydraulic supercooling. Drainage efficiency strongly affects erosion and deposition rates. Results show characteristic behaviors of flow through overdeepenings such as overpressured water systems and accretion rates compatible with field measurements. Simulations that start with overdeepened glacier configurations progress out of a freezing regime where glaciohydraulic supercooling occurs. This progression indicates that glacier hydrology is more strongly affected by erosion and deposition than by freezing from glaciohydraulic supercooling. We discuss how this outcome affects glacier erosion and sediment transport under modern and past ice sheets

    The Changing Role of Pharmacists as Evidenced by the Strong Vocational Interest Blank

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    The Strong Vocational Interest Blank/Strong Campbell Interest Inventory-Merged Form, or simply Strong Vocational Interest Blank (SVIB), is widely used to determine the suitability of a student\u27s interests to a particular field. In the process of norming the instrument, data concerning the satisfaction of practitioners of a field and their responses on the instrument are gathered. Such data lend themselves to analysis of trends in the characteristics of those practitioners both over time and over the satisfaction spectrum. Hence changes in the field and characteristics lending themselves to satisfaction can be ascertained

    Obesity and cardiovascular diseases: implications regarding fitness, fatness, and severity in the obesity paradox

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    Obesity has been increasing in epidemic proportions, with a disproportionately higher increase in morbid or class III obesity, and obesity adversely affects cardiovascular (CV) hemodynamics, structure, and function, as well as increases the prevalence of most CV diseases. Progressive declines in physical activity over 5 decades have occurred and have primarily caused the obesity epidemic. Despite the potential adverse impact of overweight and obesity, recent epidemiological data have demonstrated an association of mild obesity and, particularly, overweight on improved survival. We review in detail the obesity paradox in CV diseases where overweight and at least mildly obese patients with most CV diseases seem to have a better prognosis than do their leaner counterparts. The implications of cardiorespiratory fitness with prognosis are discussed, along with the joint impact of fitness and adiposity on the obesity paradox. Finally, in light of the obesity paradox, the potential value of purposeful weight loss and increased physical activity to affect levels of fitness is reviewed

    Ejercicio dosis-respuesta de la pendiente V? E / V?CO 2 en mujeres posmenopáusicas en el estudio DREW

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    Purpose: Being overweight/obese, having hypertension, and being postmenopausal are risk factors for the development of congestive heart failure (CHF). A characteristic of CHF is an abnormal V?E/V?CO2 slope, which is predictive of mortality in patients with CHF. Although the V?E/V?CO2 slope is well established in CHF patients, little is known regarding interventions for 'at-risk' populations. Methods: We examined the V?E/V?CO2 slope in 401 sedentary, overweight, moderately hypertensive women randomized to 6 m of nonexercise (control) or 4 kcal·kg?1·wk?1 (KKW), 8 KKW, or 12 KKW of exercise at an intensity corresponding to 50% of baseline V?O2max. We examined trends in exercise treatment dose versus change in mean V?E/V?CO2 slope using a linear regression model (KKW vs V?E/V?CO2 slope) and a linear mixed model. Results: Regression analysis showed a significant trend for a reduction in the V?E/V?CO2 slope from baseline (mean ± SD: 32.6 ± 6.3; P < 0.004). When expressed as mean change (95% confidence interval (CI)) from baseline, we observed significant reductions in the V?E/V?CO2 slope for the 8-KKW (?1.14; 95% CI, ?1.5 to ?0.2) and 12-KKW (?1.67; 95% CI, ?2.3 to ?0.3) groups. No significant effect was noted for the 4-KKW (?0.4; 95% CI, ?1.2 to 0.15) group. Conclusion: Moderate-intensity aerobic exercise at doses of 8 KKW or greater seems to present an adequate dose of exercise to promote small but significant reductions in the V?E/V?CO2 slope in postmenopausal women who exhibit risk factors associated with the development of CHF

    Developing a framework for the analysis of power through depotentia

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    Stakeholder participation in tourism policy-making is usually perceived as providing a means of empowerment. However participatory processes drawing upon stakeholders from traditionally empowered backgrounds may provide the means of removing empowerment from stakeholders. Such an outcome would be in contradiction to the claims that participatory processes improve both inclusivity and sustainability. In order to form an understanding of the sources through which empowerment may be removed, an analytical perspective has been developed deriving from Lukes�s views of power dating from 1974. This perspective considers the concept of depotentia as the removal of �power to� without speculating upon the underlying intent and also provides for the multidimensionality of power to be examined within a single study. The application of this analytical perspective has been tested upon findings of the government-commissioned report of the Countryside and Community Research Unit in 2005. The survey and report investigated the progress of Local Access Forums in England created in response to the Countryside and Rights of Way Act 2000. Consideration of the data from this perspective permits the classification of individual sources of depotentia which can each be addressed and potentially enable stakeholder groups to reverse loss of empowerment where it has occurred

    Associations Between Cardiorespiratory Fitness and C-Reactive Protein in Men

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    Objective - This study examined the association between cardiorespiratory fitness and C-reactive protein (CRP), with adjustment for weight and within weight categories. Methods and Results - We calculated median and adjusted geometric mean CRP levels, percentages of individuals with an elevated CRP (≥2.00 mg/L), and odds ratios of elevated CRP across 5 levels of cardiorespiratory fitness for 722 men. CRP values were adjusted for age, body mass index, vitamin use, statin medication use, aspirin use, the presence of inflammatory disease, cardiovascular disease, and diabetes, and smoking habit. We found an inverse association of CRP across fitness levels (P for trend\u3c0.001), with the highest adjusted CRP value in the lowest fitness quintile (1.64 [1.27 to 2.11] mg/L) and the lowest adjusted CRP value in the highest fitness quintile (0.70 [0.60 to 0.80] mg/L). Similar results were found for the prevalence of elevated CRP across fitness quintiles. We used logistic regression to model the adjusted odds for elevated CRP and found that compared with the referent first quintile, the second (odds ratio [OR] 0.43, 95% CI 0.22 to 0.85), third (OR 0.33, 95% CI 0.17 to 0.65), fourth (OR 0.23, 95% CI 0.12 to 0.47), and fifth (OR 0.17, 95% CI 0.08 to 0.37) quintiles of fitness had significantly lower odds of elevated CRP. Similar results were found when examining the CRP-fitness relation within categories of body fatness (normal weight, overweight, and obese) and waist girth (\u3c102 or ≥102 cm). Conclusions - Cardiorespiratory fitness levels were inversely associated with CRP values and the prevalence of elevated CRP values in this sample of men from the Aerobics Center Longitudinal Study

    Heart Rate Variability and Exercise in Aging Women

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    Background: Our group has shown a positive dose-response in maximal cardiorespiratory exercise capacity (VO2max) and heart rate variability (HRV) to 6 months of exercise training but no improvement in VO2max for women ≥60 years. Here, we examine the HRV response to exercise training in postmenopausal women younger and older than 60 years. Methods: We examined 365 sedentary, overweight, hypertensive, postmenopausal women randomly assigned to sedentary control or exercise groups exercising at 50% (4 kcal/kg/week, [KKW]), 100% (8 KKW) and 150% (12 KKW) of the National Institute of Health (NIH) Consensus Development Panel physical activity guidelines. Primary outcomes included time and frequency domain indices of HRV. Results: Overall, our analysis demonstrated a significant improvement in parasympathetic tone (rMSSD and high frequency power) for both age strata at 8 KKW and 12 KKW. For rMSSD, the age-stratified responses were: control, \u3c60 years, 0.20 ms, 95% confidence interval (CI) - 2.40, 2.81; ≥60 years, 0.07 ms, 95% CI - 3.64, 3.79; 4 KKW, \u3c60 years, 3.67 ms, 95% CI 1.55, 5.79; ≥60 years, 1.20 ms, 95% CI - 1.82, 4.22; 8-KKW, \u3c60 years, 3.61 ms, 95% CI 0.88, 6.34; ≥60 years, 5.75 ms, 95% CI 1.89, 9.61; and 12-KKW, \u3c60 years, 5.07 ms, 95% CI 2.53, 7.60; ≥60 years, 4.28 ms, 95% CI 0.42, 8.14. Conclusions: VO2max and HRV are independent risk factors for cardiovascular disease (CVD) mortality. Despite no improvement in VO2max, parasympathetic indices of HRV increased in women ≥60 years. This is clinically important, as HRV has important VCD risk and neurovisceral implications beyond cardiorespiratory function
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