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“We discuss the detection of local signals that occur at the same location in multiple one-dimensional noisy sequences, with particular attention to relatively https://www.selleckchem.com/products/bmn-673.html weak signals that may occur in only a fraction of the sequences. We propose simple scan and
segmentation algorithms based on the sum of the chi-squared statistics for each individual sample, which is equivalent to the generalized likelihood ratio for a model where the errors in each sample are independent. The simple geometry of the statistic allows us to derive accurate analytic approximations to the significance level of such scans. The formulation of the model is motivated by the biological problem of detecting recurrent DNA copy number variants in multiple samples. We show using replicates and parent-child comparisons that pooling data across samples Selonsertib Apoptosis inhibitor results in more accurate detection of copy number variants. We also apply the multisample segmentation algorithm to the analysis of a cohort of tumour samples containing complex nested and overlapping copy number aberrations, for which our method gives a sparse and intuitive cross-sample summary.”
“Background To determine the viability of using magnetic resonance imaging measurement of optic nerve morphology as an objective analysis of glaucomatous damage. Design Retrospective study conducted at Tohoku University Hospital. Participants Thirty-eight eyes of 19 patients with open-angle
glaucoma. Methods Patients were scanned with T2-weighted and 3-T diffusion tensor magnetic resonance imaging, and parameters of the optic nerve, including fractional anisotropy, apparent diffusion coefficient and cross-sectional area, were determined. Conventional parameters
of glaucomatous damage, including circumpapillary and macular retinal nerve fibre layer thickness, and mean deviation and average total deviation of the central 16 test points from the Humphrey Field Analyzer, were then compared with the magnetic resonance imaging-derived parameters. Spearman’s coefficient of correlation was calculated to determine the significance of the correlation. Main Outcome Measure Correlation coefficient between the magnetic resonance imaging parameters and the parameters of glaucomatous damage. Results Mean deviation was significantly Selleckchem VX-680 correlated with all magnetic resonance imaging parameters (fractional anisotropy: r=0.53, apparent diffusion coefficient: r=-0.44, cross-sectional area: r=0.70). Circumpapillary retinal nerve fibre layer thickness was significantly correlated with fractional anisotropy (r=0.60) and cross-sectional area (r=0.47), but not apparent diffusion coefficient (r=-0.29). Central macular function and macular retinal nerve fibre layer thickness were also significantly correlated with magnetic resonance imaging parameters. Conclusions Optic nerve magnetic resonance imaging parameters were significantly correlated to glaucomatous damage.