Stability of hemoglobin mass over 100 days in active men

The purpose of this study was to investigate the suggestion in a recent meta-analysis that variability in hemoglobin mass increases when time between measurements increases from days to months. Hemoglobin mass of six active men was measured with the carbon monoxide method every 1–6 days for 100–114 days (42 ± 3 measurements, mean ± SD). Measurement error for each individual's series was estimated from the standard deviation of consecutive pairwise changes and compared with his total error (standard deviation of all values). Linear trends and periodicities in each series were quantified by regression and spectral analysis. Series with known random error and periodicity were also simulated and analyzed. There were clear differences in the pairwise error of measurement between subjects (range 1.4–2.7%). For five men, there was little difference between the total and pairwise errors; their mean ratio (1.06, 90% confidence limits 0.96–1.17) was less than ratios for simulated sinusoidal series with random error of 2%, amplitude of 2%, and periods of 20–100 days (ratios 1.13–1.21). Spectral analysis clearly revealed such periodicities in the simulated series but not in the series of these subjects. The sixth man, who had donated blood 12 days before commencing measurements, showed errors, trend, and periodicity consistent with gradual restoration of hemoglobin mass. Measurement error of hemoglobin mass does not increase over 100 days. Consequently, hemoglobin mass may be suitable for long-term monitoring of small changes that might occur with training or erythropoietin abuse, taking into consideration the small differences between athletes in errors and trends.

Stochastic Properties of the Solution Vector of Parameters for the Model of the Partially Mobile Adsorption of a Single Gas on an Energetically Heterogeneous Microporous Adsorbent

For the previously formulated model of single gas adsorption on energetically heterogeneous microporous solids, two adsorption isotherms were generated — one for each distribution function of the localization energy dividing two neighbouring adsorption sites. Using numeric methods, a mass measurement error was ascribed to each point generated for both adsorption isotherms and an analysis of the influence of the normal distribution of this error on the type of distribution of the optimized parameter values was undertaken. The hypothesis regarding the agreement of the distributions of the parameter values for both energy distribution functions was verified. The work described was carried out for three arbitrary assumed values of the variation coefficients of the adsorbate mass measurement error.