Lactate accumulation following isometric exercise training and its relationship with reduced resting blood pressure     

Devereux GR  Coleman D  Wiles JD  Swaine I 《Journal of sports sciences》2012,30(11):1141-1148

The purpose of this study was (a) to assess lactate accumulation during isometric exercise, and to quantify the shifts in accumulation following isometric training; and (b) to relate any training-induced changes in lactate accumulation to reductions in resting blood pressure. Eleven male participants undertook isometric training for a 4-week period using bilateral-leg exercise. Training caused reductions in systolic, diastolic, and mean arterial resting blood pressure (of -4.9 ± 6.3 mmHg, P = 0.01; -2.6 ± 3.0 mmHg, P = 0.01; and -2.6 ± 2.3 mmHg, P = 0.001 respectively; mean ± s). These were accompanied by changes in muscle activity, taken as electromyographic activity to reach a given lactate concentration (from 114 ± 22 to 131 ± 27 mV and from 136 ± 25 to 155 ± 34 mV for 3 and 4 mmol · L(-1) respectively. Training intensity expressed relative to peak lactate was correlated with reduced resting systolic and mean arterial blood pressure. Training caused significant shifts in lactate accumulation, and reductions in resting blood pressure are strongly related to training intensity, when expressed relative to pre-training peak lactate. This suggests that higher levels of local muscle anaerobiosis may promote the training-induced reductions in resting blood pressure.  相似文献   

Bidirectional cross-sectional and prospective associations between physical activity and body composition in adolescence: birth cohort study     

Hallal PC  Reichert FF  Ekelund U  Dumith SC  Menezes AM  Victora CG  Wells J 《Journal of sports sciences》2012,30(2):183-190

The aim of this study was to investigate the cross-sectional and prospective associations between physical activity and body composition in adolescence. This is a prospective study, including 4,103 adolescents belonging to the Pelotas (Brazil) 1993 birth cohort, who were followed up at the mean ages of 11.3 and 14.7 years. Subsample analyses included 511 individuals with accelerometry and deuterium dilution data at 13.3 years. Sum of skinfolds at age 11.3 years was highly correlated with skinfolds at age 14.7 years (rho = 0.74, P < 0.001). More than 85% of participants remained in the same quintile or changed by not more than one quintile during the 3.4 year period. Tracking of physical activity was considerably lower, although still significant; the correlation was 0.24 (P < 0.001) and 61.4% of the adolescents moved one or less quintiles. In fully-adjusted models, no significant cross-sectional or longitudinal associations were found between physical activity and body composition, neither in boys nor in girls. These null results were confirmed in the 511 individuals with accelerometry and deuterium data. We provide evidence of tracking of physical activity and particularly body composition during adolescence. Our results do not support the hypothesis that physical activity and fatness are strongly related in adolescents.  相似文献   

Up in the air: Are airlines following the new DOT rules on equal pricing for people with disabilities when websites are inaccessible?     

Jonathan Lazar  Paul T. Jaeger  Anthony Adams  Anthony Angelozzi  John Manohar  James Marciniak  Justin Murphy  Pouria Norasteh  Charles Olsen  Evangelos Poneres  Tiffany Scott  Naresh Vaidya  James Walsh 《Government Information Quarterly》2010

This paper details the findings from a study of airline compliance with Department of Transportation (DOT) regulations requiring that persons with disabilities not be discriminated against in the pricing of airline travel. These regulations mandate that if an airline website is inaccessible for persons with disabilities, the airline must charge the same price that is available on the website and may not charge a fee for purchasing tickets over the phone. To evaluate compliance, the websites of leading airlines were examined for accessibility in terms of the ability to check flight schedules and order tickets. Among the four airlines with barriers to accessibility on their websites, a series of phone calls were made by researchers to assess whether the DOT regulations would be followed. Two of the airlines, USAirways and United, practiced discriminatory pricing, even after being made aware of the regulations, in over one-third of the phone calls. This paper details the findings from the study and analyzes the data in terms of website accessibility, civil rights for travelers with disabilities, and policy implications.  相似文献   

Response to Kelly Near and Ann Duesing’s letter: “Informatics Training for Public Health Practitioners”     

Jonathan D. Eldredge  Richard D. Carr  David Broudy  Ronald E. Voorhees 《Journal of the Medical Library Association》2010,98(1):4-5

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Foreword     

Jonathan D. Fife 《ASHE Higher Education Report》1983,12(5):V-VI

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Foreword     

Jonathan O. Fife 《ASHE Higher Education Report》1982,11(6):V-V

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Foreword     

Jonathan D. Fife 《ASHE Higher Education Report》1982,11(9):i-ii

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Foreword     

Jonathan D. Fife 《ASHE Higher Education Report》1984,13(1):VII-VII

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Foreword     

Jonathan D. Fife 《ASHE Higher Education Report》1989,18(7):xvii-xviii

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Foreword     

Jonathan D. Fife 《ASHE Higher Education Report》1985,14(8):xv-xvi

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