There was substantial intrasubject systematic variability in CBF of gray matter ROIs corresponding to a range of standard deviations = [39 168] (ml/(100 g min)).
Further, systematic variability like influence of the image scanner settings on the dye intensity measurements have now been robustly handled by applying various normalization techniques [ 83- 86].
By means of a reanalysis of published data (Schreuder & Baayen, 1997), using random regression models, we present a proof of existence of systematic variability between participants that is ignored in the standard psycholinguistic analytical procedures.
Since we could not increase the precision of the immunomodulatory gene expression data with the reference genes, and we had alternatively controlled for appreciable amounts of systematic variability through study design, the strategy of normalization to reference genes was abandoned.
However, this pattern is sensitive to censoring and other sources of systematic variability, such as general increases in the recording of medical events around the time of prescription, possibly reflecting follow-up visits, or the increased rates of abnormal lab test results sometimes observed because of closer monitoring of treated patients [ 16].
Traditional analyses of our experiment, whose design affords control over a range of confounds and allows us to disentangle the three effects, affirms all three as fundamental causes of systematic variability in recognition accuracy.
Redundancy analysis [40] was used to decompose multivariate chromatographic profiles into their constituent sources of systematic variability corresponding to MHC, Diet, and MHC×Diet to determine which contributes most to overall variability.
Systematic variability in the proportion of successful assignment across geographical units would pose some doubts about underlying bias.
Several aspects of our study led us to conclude that reference gene normalization was introducing several sources of systematic variability into the data.
In addition, these methods allowed us to quantify the proportion of total and systematic variability in peripheral blood DNAm explained by estimated immune cell composition.
