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Fig. 3 | BMC Bioinformatics

Fig. 3

From: Statistical image processing quantifies the changes in cytoplasmic texture associated with aging in Caenorhabditis elegans oocytes

Fig. 3

Second-order statistical analysis of the age-associated changes in the cytoplasmic texture of C. elegans oocytes. a Algorithm for calculating the Gray Level Co-occurrence Matrix (GLCM). First, we define a spatial relationship by using the parameters distance (d) and angle (θ). We then calculate the second-order joint probability P(i, j | d, θ) of two pixels with gray levels i and j (0 ≤ i < G, 0 ≤ j < G). To calculate P(i, j | d, θ), we sum the number of pixels with paired intensities (i and j) in the defined spatial relationship. For example, when d is 1 pixel and the θ is 90°, the calculated number of pixels with i = 1 and j = 2 or i = 2 and j = 1 is 2. The co-occurrence matrix defined is symmetric. be Effect of oocyte age on Correlation (COR). Curves of mean COR as a function of distance d for Day 1, Day 2, and Day 3 oocytes are shown for θ set at b 0, c 45, d 90, and e 135°. Data are means ± SEM (n = 12 animals in each age group, pooled from two experiments). Symbols indicate significant difference (Tukey–Kramer test) in COR between Day 1 and Day 3 oocytes (*P < 0.05; **P < 0.01) or Day 2 and Day 3 oocytes (P < 0.05, ††P < 0.01). fh Effect of θ on COR. Curves of mean COR as a function of distance d when θ is set at 0°, 45°, 90°, or 135° are shown for f Day 1, g Day 2, and h Day 3 oocytes. Data are means ± SEM (n = 12 animals in each age group, pooled from two experiments). Symbols indicate significant difference (Tukey–Kramer test) in COR between 0° and 135° (*P < 0.05; **P < 0.01), 45° and 135° (P < 0.05; ††P < 0.01), or 90° and 135° (§P < 0.05; §§P < 0.01)

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