The space-time permutation model is susceptible to population shift bias, whereby shifts in the background population distribution may create an interaction in space and time that is not related to increased disease risk [ 43].
Therefore, the MISCORE-based over-representation score ORS r for a motif S can be given using Eq (18) as, (19) O R S r (M S ) = c f (M S, S b g ) c f (M S, S f g ), where S bg and S fg are the sets of all k-mers produced by window shifting in the background and in the foreground regions, respectively.
Our results suggest a minor shift in the spectrum of background nucleotide substitution in saltans/willistoni group relative to that found in D. melanogaster.
One explanation for the concomitant shifts in GC content of codon and noncoding sequences is a genome-wide shift in the pattern of background substitutions [ 15] in favor of lower GC content in the saltans/willistoni group [ 22, 25, 28].
Here tonal shifts in the black background make it seem as if the pattern is drifting in and out of a black fog that changes as you move; the pattern shifts from black-on-gray to gray-on-black.
We walk through the windswept ruins at Sabratha while the sea shifts and shimmers in the background, the sun glinting off mosaics that have seen off two thousand years of winds, salt and sea.
The researchers then showed a second set of videos that incorporated subtle shifts of movement in the background to give more information on the walker's direction.
One proposed solution is the dynamic shift-share analysis mentioned in the "Background" section.2 Instead of conducting shift-share analysis over a long period, the dynamic version conducts shift-share analysis over a short period in each year and aggregates the values for each year (Barff and Knight [13]).
Higher R values are more prone to shift in the absolute zero of the background level.
It can be seen that a ~30%% down shift in the position of absolute background value can be accepted before the disparity between the resulting Rwith downshift and Rno downshift values exceeds 21%% for R = 2.
