Natural images contain many low and high-order correlations (Geisler, 2008), and this implies that the fly brain could in principle use a wide array of correlations for visual motion estimation (Appendix figure 1).
Despite these and similar complications that arise from a wide array of correlations, such analyses illustrated the ability to address questions that could not have been resolved in the pre-genomic era.
This procedure calculates standard variance components and an array of haplotypic correlation measures for population structure, referred to as Φ-statistics.
Though samples taken from different muscles could add variability to the results of the expression array analysis, correlation of the results with the quantitative RT-PCR results gave strength to the findings.
We cross-validated gene array by the mean of correlation index of 12 genes present in two or more different arrays (signal transduction vs apoptosis: r = 0.956; apoptosis vs DNA-damage: r = 0.986; signal transduction vs DNA-damage: r = 0.999).
The microarray data for analysis of the 70-gene prognosis profile were obtained with the use of the same 25,000-element oligonucleotide array; the correlation coefficient of the expression of these 70 genes with the good prognosis profile was calculated as reported previously [ 22].
For hierarchical clustering of array experiment correlation coefficients the CLUSTER program was used to organise experiments into self organising maps, subsequently complete linkage hierarchical cluster using an uncentered correlation metric was applied.
The correlation array of detailed exposures by time windows (preconception, pregnancy, postnatal) showed low to moderate correlations (r ranged from 0.16 to 0.64), except for petroleum solvent exposure during preconception period and pregnancy (r = 0.80, p < 0.001).
However, these numbers are in-line with the previous study on miRNA arrays that compared several platforms to TaqMan arrays, and found a range of correlation coefficients from 0.44 to 0.86 (including 0.85 for Agilent and 0.67 for Exiqon) [ 11].
However, the differences observed in metabotropic glutamate receptor 7 gene expression is more difficult to interpret due to the lack of correlation between array and qPCR results.
