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General Departmental Seminar Series

Debashis Ghosh
Department of Statistics & Huck Institute of Life Sciences,
Penn State University

Friday, September 26th, 2008
12:00 pm - 1:00 pm
5275 MSC

Genomic outlier profile analysis and multiple testing
procedures with estimated null distributions

In the statistical and scientific literature on genomic data analysis, there is now a substantive literature on methods for the analysis of differential expression between two groups. A recent example from the cancer biology literature motivates another type of gene expression pattern in which a fraction of samples show outlying differential expression with respect to the baseline group. We propose a hierarchical modelling framework for analysis in this class of problems.

We then discuss the adaptation of multiple testing procedures for the purposes of determining genes with so-called ''outlier'' profiles. Proving results about exact and asymptotic error control become more challenging in that the null distribution must be estimated from the data and is not a theoretical one. Time permitting, I will discuss application of this model to a problem of determining signficance of peptide matches in protein databases.

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