Congratulations May 2005 Graduates!

05-20-2005

The Department of Statistics would like to congratulate all of our May 2005 graduates. On May 13, 2005, Purdue University and the Department of Statistics awarded degrees to the following people:

Ph.D. Graduates (Advisor) Dissertation Title

Ms. Yali Liu (Bruce Craig) Time-Dependent Covariate in the Cox Proportional Hazards Models: the LVAR Approach
Mr. John Stevens (Rebecca Doerge) Meta-Analytic Approaches for Microarray Data
Ms. Olga Vitek (Bruce Craig) An Inferential Approach to Protein Backbone Nuclear Magnetic Resonance Assignment

M.S. Graduates

Ms. Johnna Anderson
Ms. Melissa Chester
Mr. Shane Cline
Mr. Martin Gonzalo
Ms. Elsie Grace
Ms. Min-Ah Lee
Mr. Yuping Liu
Ms. Sudeshna Paul
Mr. Liang Shi
Ms. Lei Shu
Mr. Vladimiro Tobar Solano
Mr. Nikita Tuzov
Mr. Benjamin Tyner
Mr. Shih-Yi Wang
Ms. Xiaohong Wang
Ms. Xian Xiao

Graduate Certificates

Mr. Murat Kantarcioglu

Undergraduates in Statistics

Ms. Elissa Ackley
Mr. Ekarin Boonurai
Mr. Clayton Cutler
Ms. Heather Diehl
Mr. Devin Gardner
Ms. Laura Hodge
Mr. Chee-Chun Kong
Ms. Jennifer Miller
Mr. Gregory Moyer
Mr. Uzair Muhammad
Mr. Alan Saunders
Mr. Kyle Surface
Mr. Bradley S. Tank
Mr. David Weissenborn
Mr. Adam Whitehead
Ms. Zheng Ming Xu
Ms. Carla Yoder
Mr. David Young
Mr. Xiaolu (Luke) Zhang

Actuarial Science Majors

Ms. Elissa Ackley
Mr. Clayton Cutler
Ms. Heather Diehl
Mr. Devin Gardner
Ms. Laura Hodge
Ms. Jennifer Miller
Mr. Gregory Moyer
Mr. Uzair Muhammad
Mr. Kyle Surface
Mr. David Weissenborn
Mr. Adam Whitehead
Ms. Zheng Ming Xu
Ms. Carla Yoder
Mr. David Young
Mr. Xiaolu Zhang

Dr. Hongmei Jiang and Professor Rebecca Doerge

For the academic year 2004-2005, the Department of Statistics has graduated 12 Ph.D. students, 24 M.S. students, 4 Graduate Certificate students, 26 Undergraduate Statistics students and 19 Actuarial Science students.

We would like to highlight the achievements of one of the Department's Ph.D. December 2004 graduates, Hongmei Jiang. Dr. Jiang performed her Ph.D. research in the area of statisical bioinformatics under the direction of Professor Rebecca Doerge. The title of Hongmei's dissertation is: "A two-step procedure for multiple pairwise comparisons in microarray experiments."

Two major (and novel) statistical contributions resulted from Dr. Jiang's work. The first piece pertains to extending Hochberg and Benjaminis (1995) false discovery rate (FDR) to include an estimate of the proportion of true null hypotheses. Existing methods for estimating this proportion yield either large bias or large variance. Hongmei developed a simple and easy to implement method to estimate the proportion of true null hypotheses that has both small bias and small variance. The combination of Hongmei's estimate with Benjamini and Hochbergs FDR controlling procedure controls the FDR below, but extremely close to alpha. This improved approach is then implemented in the second major result from Dr. Jiang's research, a two-stage testing procedure for comparing several treatments. The purpose and motivation of this two-stage approach is to improve the power to identify differential expression for all pairwise comparisons when there are a large number of genes to be tested. Because the FDR controlling procedure is applied to a large family of pairwise comparisons, the impact is a reduction of power. To address this problem, and to improve the power of detecting differentially expressed genes, Hongmei proposed a novel two-step multiple comparison procedure. The greatest challenge in doing this is to choose the significance levels in the respective steps of the two-step procedure so that the overall FDR of the two-step procedure is controlled at a pre-specified significance level. Hongmei put forth a set of recommendations on how to choose the significance levels at each step of the two-step procedure. In turn, Hongmei's two-step procedure has more power than the typical one-step procedure in terms of detecting significant differential expression because the number of pairwise comparisons is greatly reduced in the second step.

Dr. Jiang will start as an Assistant Professor in the Department of Statistics at Northwestern University, September 2005.

Best wishes to all of our graduates. We look forward to hearing from you!