The basic purpose of PCA is to study the hydrogeochemistry of groundwater and explain large amount variance in analytical data by a small number of key factors (Biswal et al. 2004; Dalton and Upchruch 1978; Singh et al. 2009, 2013a, b).
The observation that two very different normalization protocols yielded essentially identical results probably indicates that there is very little variance, either analytical or biological, among our samples.
There is some evidence that use of a rotary sample divider during subsampling can also reduce variance of analytical results.
Although the integral in Eqn 3 was neither solvable nor a beta distribution, its mean and variance were analytical.
2) we have defined the contributions to the overall variance of analytical, within-, between-subject variance for each of oxidative stress biomarkers in the assessment of DN and T2DM.
CV coefficient of variance, a analytical, w within-individual, ICC intra-class correlation coefficient, limbBD lower limb without the foot (from B-measure to D-measure), legBF leg volume without the foot (from the B-measure to the F-measure).
Metabolites with high analytical variance (e.g., coefficient variation > 50%) in our samples were excluded from further analyses.
Therefore, improvements in analytical variance will have a small effect on the total variance of results (Vargas et al. 2004; Whitaker et al. 2006).
All samples for all analytes will be assayed in duplicate and the analytical variance (SDA) will be calculated from the differences between the duplicate measurements.
Finally, because the temporal differences also affected the analytical variance calculation, the bootstrapping procedure is recommended.
