Repeat trial vs. breath averaging: Evidence to support recommendations in conducting research of the VO2 kinetics of exercise transitions to steady state

2017 ◽  
Vol 20 ◽  
pp. e119-e120
Author(s):  
C. McNulty ◽  
R. Robergs
Keyword(s):  
Steady State ◽  
Repeat Trial ◽  
Vo2 Kinetics ◽  
Exercise Transitions ◽  
Conducting Research ◽  
Kinetics Of

scholarly journals Repeat trial and breath averaging: Recommendations for research of VO2 kinetics of exercise transitions to steady-state

2019 ◽  
pp. 37-44 ◽  
Author(s):  
Craig Ryan McNulty ◽  
Robert Andrew Robergs
Keyword(s):  
Steady State ◽  
Total Error ◽  
Exponential Model ◽  
Oxygen Uptake Kinetics ◽  
Ventilation Threshold ◽  
Vo2 Kinetics ◽  
Exercise Transitions ◽  
Well Data ◽  
Kinetics Of ◽  
Male Subjects

Multiple-breath and multiple-trial averaging have been used extensively in research of oxygen uptake kinetics to steady-state. However, specific guidelines outlining correct levels of averaging have not been discussed. The aim of this study was to assess error differences using multiple-trial and multiple-breath averaging systems, and make recommendations for future VO2 kinetics research. Eight male subjects were recruited for this study. Following a maximal cycle test to ascertain each subject’s ventilation threshold, eight identical repetition cycling exercise bouts were administered. The bouts consisted of 6-minute at 85% of the subject’s ventilation threshold. Firstly, multiple-trial and multiple-breath data were processed using traditional methods. As well, data were fit using a mono-exponential model to derive tau. Data for all levels of multiple-trial and multiple-breath methods were compared to an 8-trial and 13-breath average, respectively. Reduction in error from the 3-trial average and a 3-breath average represented ∼68% and ∼70% of total error reduction, respectively. Tau tended to increase with increasing breath averaging and decrease with increasing trial averaging. There is negligible benefit to averaging more than 3 repeat trials in VO2 kinetics research. Breath averaging beyond 3-breaths artificially increases tau.

Kinetic analysis of mechanism of intestinal Na+-dependent sugar transport

1985 ◽  
Vol 248 (5) ◽  
pp. C498-C509 ◽  
Author(s):  
D. Restrepo ◽  
G. A. Kimmich
Keyword(s):  
Experimental Data ◽  
Steady State ◽  
Sugar Transport ◽  
Enzyme Kinetic ◽  
Steady State Distribution ◽  
State Distribution ◽  
Least Squares Fit ◽  
Coupling Stoichiometry ◽  
Rate Limiting ◽  
Kinetics Of

Zero-trans kinetics of Na+-sugar cotransport were investigated. Sugar influx was measured at various sodium and sugar concentrations in K+-loaded cells treated with rotenone and valinomycin. Sugar influx follows Michaelis-Menten kinetics as a function of sugar concentration but not as a function of Na+ concentration. Nine models with 1:1 or 2:1 sodium:sugar stoichiometry were considered. The flux equations for these models were solved assuming steady-state distribution of carrier forms and that translocation across the membrane is rate limiting. Classical enzyme kinetic methods and a least-squares fit of flux equations to the experimental data were used to assess the fit of the different models. Four models can be discarded on this basis. Of the remaining models, we discard two on the basis of the trans sodium dependence and the coupling stoichiometry [G. A. Kimmich and J. Randles, Am. J. Physiol. 247 (Cell Physiol. 16): C74-C82, 1984]. The remaining models are terter ordered mechanisms with sodium debinding first at the trans side. If transfer across the membrane is rate limiting, the binding order can be determined to be sodium:sugar:sodium.

scholarly journals Kinetics of Biofilm Detachment

1992 ◽  
Vol 26 (9-11) ◽  
pp. 1995-1998 ◽  
Author(s):  
B. M. Peyton ◽  
W. G. Characklis
Keyword(s):  
Steady State ◽  
Utilization Rate ◽  
Carbon Utilization ◽  
Biofilm Thickness ◽  
First Order ◽  
Detachment Rate ◽  
Biofilm Detachment ◽  
Biofilm Modeling ◽  
Kinetics Of ◽  
Sensitive Variable

In predictive biofilm modeling, the detachment rate coefficient may be the most sensitive variable affecting both the predicted rate and the extent of biofilm accumulation. At steady state the detachment rate must be equal to the net growth rate in the biofilm. In systems where organic carbon is growth-limiting, the substrate carbon utilization rate determines the net biomass production rate and, therefore, the steady state biomass detachment rate. Detachment rates, first order with biofilm thickness, fit the experimental data well, but are not predictive since the coefficients must be determined experimentally.

Steady-state kinetics of valproic acid in epileptic patients

1978 ◽  
Vol 24 (3) ◽  
pp. 324-332 ◽  
Author(s):  
J. Bruni ◽  
B. J. Wilder ◽  
L. J. Willmore ◽  
R. J. Perchalski ◽  
H. J. Villarreal
Keyword(s):  
Valproic Acid ◽  
Steady State ◽  
Steady State Kinetics ◽  
Epileptic Patients ◽  
Kinetics Of
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