Coglunch - January 26, 2006

"Context in computational linguistics and gene expression"
Sean O Nuallain
CSLI, Stanford University and MCB, Berkeley
The categorical failure to solve the general problem of natural language processing (nlp) by computer will be postulated as prognostic of the future of gene expression work. After what seemed like a promising start, the field was stalled by an inability to handle, or even define coherently, "contextual" factors. Currently, the field is gradually being taken over by Bayesian "methods" that simply look for the statistical incidence of co-occurrence of lexical items in the source (analogous to gene) and target (analogous to protein) languages. Contextual factors in the case of gene expression include the bioenergetic status of the cell, a status that can be assessed properly only with painstaking work; yet it determines what genes are being turned on and off at any particular moment.

This seminar begins by looking at how context might be defined in a way that does justice to both disciplines and both sets of problems. Paradigms in genetic expression will be looked at through the prism supplied by nlp. The simplistic "one gene, one protein" notion that characterised the HGP's publicity will be seen as analogous to template matching in nlp, a technique whose limitations have long been apparent to the linguistics community. The phenomenon of alternative splicing demands at the very least a concept analogous to that of compositional semantics in nlp. Yet more sophisticated linguists use different techniques that combine syntax and semantics in different ways depending on the degree of restriction of context, and the task involved. The seminar ends with speculation about biological counterparts of this impetus toward diversity.

Ast, G. (2004) "How did alternative splicing evolve?" Nature Reviews Genetics, Vol. 5, Pp. 773-782

O Nuallain, Sean (forthcoming) Subjects and Objects; from metaphysics to context-specification. Biosemiotics.

O Nuallain, Sean (2003) The Search for Mind; third edition. Exeter: England

Pattee, H. (2001) "The physics of symbols: bridging the epistemic cut" Biosystems Volume 60, Issues 1-3, May 2001, Pages 5-21

Strohman, R. (2000) "Organization becomes cause in the matter" Nature biotechnology, June 2000, Vol. 18, Pp. 575-576

Strohman, R. (2003) "Thermodynamics- old laws in medicine and complex disease" Nature Biotech, May 2003, Vol 21, Pp. 477-78

Veech, R.L., B. Chance, Y. Kashiwaya, H. Lardy, and G. Cahill "Ketone Bodies, potential therapeutic uses" IUMB Life 51:241-247


Last modified: Fri Feb 10 11:17:44 PST 2006 by emma@csli.stanford.edu