Yap Von Bing's Homepage

Yap Von Bing's Homepage

S16 06-105
Department of Statistics and Applied Probability
National University of Singapore
6 Science Dr 2
Singapore 117546
Tel (65) 6874 7143
Fax (65) 6872 3919
email: stayapvb@nus.edu.sg


Teaching

Current

Semester 2 2004/05 Biostatistics for Basic Research MDG5108 webpage

Past

Semester 1 2004/05 Biostatistics for Basic Research MDG5108 webpage
Gifted Education Programme Annual Meeting 2004 Presentation
Presentation


Research Interests

My primary focus is on the statistical aspects of biological sequence analysis, molecular evolution and phylogenetics. Examples are: What kind of Markov process should be used to model substitutions, and for what purpose (to infer the phylogeny or to infer substitution rates)? Which estimation method should be used (parsimony, distance, maximum likelihood, Bayesian, or a mixture)? How can the results be verified (simulations, well-known tree topology from other kinds of data)? What kind of stochastic process is good for making sense of insertions or deletions? How can these techniques be usefully applied to real problems in, e.g., ecology, population genetics, infectious diseases, etc.?

A succinct list of references (under construction):

1. Molecular studies of evolution: A source of novel statistical problems. J Neyman. in Statistical Decision Theory and Related Topics ed SS Gupta and J Yackel, 1--27, Academic Press, New York (1971).
2. Inferring Phylogenies J Felsenstein, Sinauer Associates, Inc. (2004).

I am also developing interests in statistics education and health policies. How can statistics be taught effectively to students of different levels? How much mathematics should be included (roughly speaking, enough to make arguments sharp, but not so much as to obscure the conceptual subtleties)? How can the administration of healthcare, in particular, prescription drugs, be improved, so that it produces better clinical outcomes at lower financial costs?

A succinct list of references (under construction):

1. Statistics, 3e D Freedman, R Pisani and R Purves, WW Norton & Company, Inc (1997).
2. Powerful Medicines: the benifits, risks, and costs of prescription drugs J Avorn, AA Knorf (2004).


Publications

1. Matrix extension and biorthogonal multiwavelet construction. SS Goh and VB Yap. Linear Algebra and its Applications, 269:139--157 (1998).

2. Association between divergence and interspersed repeats in mammalian noncoding genomic DNA. F Chiaromonte, S Yang, L Elnitski, VB Yap, W Miller and RC Hardison. Proceedings of the National Academy of Sciences of the USA, 98:14503--14508 (2001).

3. Scoring pairwise genomic sequence alignments. F Chiaromonte, VB Yap and W Miller. Proceedings of the Pacific Symposium on Biocomputing, 115--126 (2002).

4. Modeling genomic DNA base substitution. VB Yap and TP Speed. Proceedings of the American Statistical Association, 3855--3864 (2002).

5. Modeling DNA base substitution in large genomic regions from two organisms. VB Yap and TP Speed. Journal of Molecular Evolution, 58:12--18 (2004).

6. Identification of evolutionary hotspots in the rodent genomes. VB Yap and L Pachter. Genome Research, 14:574--579 (2004).

7. Genome sequence of the brown Norway rat yields insights into mammalian evolution. The Rat Genome Sequencing Consortium. Nature, 428:493--521 (2004).

8. Comparative immunopeptidomics of humans and their pathogens. S Istrail, L Florea, BV Halldorsson, O Kohlbacher, RS Schwartz, VB Yap, JW Yewdell and SL Hoffman Proceedings of the National Academy of Sciences of the USA, 101:13268--13272 (2004).

9. Rooting a phylogenetic tree with nonreversible substitution models. VB Yap and TP Speed. BMC Evolutionary Biology, 5:2 (2005).

10. Estimating substitution matrices. VB Yap and TP Speed. To appear in Statistical Methods in Molecular Evolution, edited by Rasmus Nielsen.


Work in progress

1. Exploration of the most general Markov process for phylogenetic inference.

2. Developing a complete phylogenetics package with nonreversible substitution processes.

3. I am also interested in methods to incorporate gaps into various activities in molecular evolution, e.g., the estimation of distances, and of rates of evolution, and phylogenetic analysis. Some notes on the birth-and-death process are collected here.