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191.
Validity of heart rate, pedometry, and accelerometry for predicting the energy cost of children's activities 总被引:5,自引:0,他引:5
Eston Roger G.; Rowlands Ann V.; Ingledew David K. 《Journal of applied physiology》1998,84(1):362-371
Eston, Roger G., Ann V. Rowlands, and David K. Ingledew.Validity of heart rate, pedometry, and accelerometry forpredicting the energy cost of children's activities.J. Appl. Physiol. 84(1): 362-371, 1998.Heart rate telemetry is frequently used to estimate dailyactivity in children and to validate other methods. This study comparedthe accuracy of heart rate monitoring, pedometry, triaxialaccelerometry, and uniaxial accelerometry for estimating oxygenconsumption during typical children's activities. Thirty Welshchildren (mean age 9.2 ± 0.8 yr) walked (4 and 6 km/h) and ran (8 and 10 km/h) on a treadmill, played catch, played hopscotch, and satand crayoned. Heart rate, body accelerations in three axes, pedometrycounts, and oxygen uptake were measured continuously during each 4-minactivity. Oxygen uptake was expressed as a ratio of body mass raised tothe power of 0.75 [scaled oxygen uptake (sO2)]. All measurescorrelated significantly (P < 0.001)with sO2. Amultiple-regression equation that included triaxial accelerometry counts and heart rate predictedsO2 better than any measure alone (R2 = 0.85, standard error of the estimate = 9.7 ml · kg0.75 · min1).The best of the single measures was triaxial accelerometry (R2 = 0.83, standard error of the estimate = 10.3 ml · kg0.75 · min1).It is concluded that a triaxial accelerometer provides the bestassessment of activity. Pedometry offers potential for large populationstudies. 相似文献
192.
Lysine added to grain mashes under nitrogen-limiting conditions (as in most industrial fermentations) inhibited growth of Saccharomyces cerevisiae. This inhibition was relieved by raising the assimilable nitrogen content. Lysine-induced inhibition is not mediated through accumulation of -oxoadipic acid, an intermediate of lysine metabolism which accumulates by a back up of intermediates in de novo synthesis. Lysine degradation is regulated by the synthesis of L-lysine -aminotransferase, an enzyme that catalyses the first step in one of three possible routes of lysine degradation (not previously reported in S. cerevisiae). Synthesis is repressed under nitrogenlimiting conditions, but derepressed when excess assimilable nitrogen is available. Derepression results in degradation of lysine and decreases inhibitory effects on growth. The toxic compound appears to be lysine itself.The authors are with the Department of Applied Microbiology and Food Science, University of Saskatchewan, Saskatoon, Saskatchewan, S7N 0W0. Canada 相似文献
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Hester van der Vaart Dirkje S Postma Wim Timens Machteld N Hylkema Brigitte WM Willemse H Marike Boezen Judith M Vonk Dorothea M de Reus Henk F Kauffman Nick HT ten Hacken 《Respiratory research》2005,6(1):22
Background
Chronic smoking is the main risk factor for chronic obstructive pulmonary disease. Knowledge on the response to the initial smoke exposures might enhance the understanding of changes due to chronic smoking, since repetitive acute smoke effects may cumulate and lead to irreversible lung damage.Methods
We investigated acute effects of smoking on inflammation in 16 healthy intermittent smokers in an open randomised cross-over study. We compared effects of smoking of two cigarettes on inflammatory markers in exhaled air, induced sputum, blood and urine at 0, 1, 3, 6, 12, 24, 48, 96 and 192 hours and outcomes without smoking. All sputum and blood parameters were log transformed and analysed using a linear mixed effect model.Results
Significant findings were: Smoking increased exhaled carbon monoxide between 0 and 1 hour, and induced a greater decrease in blood eosinophils and sputum lymphocytes between 0 and 3 hours compared to non-smoking. Compared to non-smoking, smoking induced a greater interleukin-8 release from stimulated blood cells between 0 and 3 hours, and a greater increase in sputum lymphocytes and neutrophils between 3 and 12 hours.Conclusion
We conclude that besides an increase in inflammation, as known from chronic smoking, there is also a suppressive effect of smoking two cigarettes on particular inflammatory parameters. 相似文献198.
Brigitte WM Willemse Nick HT ten Hacken Bea Rutgers Dirkje S Postma Wim Timens 《Respiratory research》2005,6(1):38
Background
Inflammation in the airways and lung parenchyma underlies fixed airway obstruction in chronic obstructive pulmonary disease. The exact role of smoking as promoting factor of inflammation in chronic obstructive pulmonary disease is not clear, partly because studies often do not distinguish between current and ex-smokers.Methods
We investigated airway inflammation in sputum and bronchial biopsies of 34 smokers with chronic obstructive pulmonary disease (9 Global initiative for Chronic Obstructive Lung Disease stage 0, 9 stage I, 10 stage II and 6 stage III) and 26 asymptomatic smokers, and its relationship with past and present smoking habits and airway obstruction.Results
Neutrophil percentage, interleukin-8 and eosinophilic-cationic-protein levels in sputum were higher in chronic obstructive pulmonary disease (stage I-III) than asymptomatic smokers. Inflammatory cell numbers in bronchial biopsies were similar in both groups. Current smoking correlated positively with macrophages: in bronchial biopsies in both groups, and in sputum in chronic obstructive pulmonary disease. Pack-years smoking correlated positively with biopsy macrophages only in chronic obstructive pulmonary disease.Conclusion
Inflammatory effects of current smoking may mask the underlying ongoing inflammatory process pertinent to chronic obstructive pulmonary disease. This may have implications for future studies, which should avoid including mixed populations of smokers and ex-smokers. 相似文献199.
Growth rates determined by linear regression analysis revealed that Saccharomyces cerevisiae consistently grew more rapidly than Brettanomyces yeasts under a wide array of batch fermentative conditions, including acetic acid stress, in normal gravity (ca. 20°Plato) mashes made from ground corn. Brettanomyces yeasts only grew more rapidly than S. cerevisiae when acetic acid concentrations were elevated to industrially irrelevant levels (>0.45%, w/v). Furthermore, the three Brettanomyces isolates used in this study failed to produce significant quantities of acetic acid under pure culture fermentative conditions. In fact, the small amounts of acetic acid which accumulated in pure culture fermentations of whole corn mash were below the concentration required to inhibit the growth and metabolism of S. cerevisiae. Acetic acid concentrations in pure culture Brettanomyces fermentations exceeded 0.05% (w/v) only in media containing low levels of glucose (<4%, w/v) or when aeration rates were elevated to at least 0.03 vol. air vol.–1 mash min–1. Consequently, it was concluded that Brettanomyces yeasts would not be capable of competing with S. cerevisiae in industrial batch fermentations of whole corn mash based solely on growth rates, nor would they be capable of producing inhibitory concentrations of acetic acid in such fermentations. 相似文献
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