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Figure 5 | BMC Bioinformatics

Figure 5

From: Correlation analysis of two-dimensional gel electrophoretic protein patterns and biological variables

Figure 5

Intra-image testing for verification whether a combination of opposing or similar correlations relates to the external variable. When the correlation analysis reveals opposing or similar correlation in two areas, the relation between those two areas might correlate towards the external variable. Two examples are given. (A) shows that the α-area correlates negatively and the δ-area correlates positively. Does the intensity difference between the α-area and δ-area correlate with the external parameter ? To answer this, one first calculates for every image the total intensity in areas with the size of the bounding boxes of α and δ. (Their sizes are designated sx α , sy α , sx δ and sy δ ). Thereafter, the images are slided over each other (the red arrow, translation dx, dy) and subtracted prior to correlation. (B) The result shows no correlation at observation point o1, indicating that the difference between α and δ does not relate to the AML differentiation stage. (C) Given the positive correlation in the δ-region and negative correlation in the sub-δ region, we want to determine whether a mass change relates to the AML differentiation stage. Image preprocessing consists of shifting the image upwards (along the red arrow, which is parallel to the mass axis) and subtracting, it from the original prior to correlation. (D) The result at observation point o2 indicates that a mass change of p53-δ strongly correlates to AML differentiation.

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