(A) This represents the t-statistic (green) versus d-statistic (black) distribution; the shrinkage in the tails of the latter is due to the additional variance term. (B): This is a scatter-plot of the observed (y-axis) versus expected (x-axis) d-statistic distributions, where the open circles represent the data points. The delta (±Δ) envelope (green) defined about a d-statistic of zero, indicates a null domain – such that regions above and below the positive and negative Δ cutoff indicate up-regulation and down-regulation, respectively.
Ghosh et al. BMC Bioinformatics 2007 8:359 doi:10.1186/1471-2105-8-359