ITEE seminar: Douglas W. Bristol, 11.00AM, Tue 08 Jul 2003

Predicting Chemical Carcinogenesis: Problem Representation Governs Model Performance

Speaker: Douglas W. Bristol, National Institute of Environmental Health Sciences

When: 11.00AM, Tuesday 08 Jul 2003

Venue: 78-420

Host: Marcus Gallagher

Abstract:

  Predictive models for chemical carcinogenesis are needed to help
  manage the safe use of over 100,000 chemical substances worldwide,
  as well as to guide decisions made during development of new
  chemicals. Three Predictive-Toxicology Challenges (PTC) have
  stimulated the development of such models over the past decade. Each
  was an open, collaborative experiment that attracted
  cross-disciplinary participants and resources. Learning sets were
  compiled from standardized chemical bioassays for carcinogenesis
  conducted in rodents by the U.S. National Toxicology Program. ROC
  convex-hull analysis was applied to evaluate the predictive
  performance of 54 individual models, within and across the three PTC
  experiments. Evaluation of model comprehensibility or the coherence
  of individual models with domain knowledge requires further
  development effort. Additionally, the three PTC experiments and
  individual models utilized three different paradigms for
  representing the nature of the problem. When classified according to
  whether a model was developed using only chemical-structure
  attributes, only biological-system attributes, or a mix of chemical
  and biological attributes, it is clear that mixed-attribute models,
  which reflect interactions between chemical and biological features,
  clearly outperform those based on only biological or chemical
  attributes. Thus, the interaction paradigm offers opportunities to
  develop predictive models with high accuracy and broad coverage,
  but, more importantly, to discover features and relationships that
  govern mechanistic pathways for chemical carcinogenesis and provide
  insight into effects, such as those that transcend species, gender,
  and route of exposure.

Biography:

  Douglas W. Bristol bristol@niehs.nih.gov, Toxicology Operations
  Branch, Environmental Toxicology Program, Division of Intramural
  Research, National Institute of Environmental Health Sciences,
  Research Triangle Park, NC 27709, USA

Contact:

Marcus Gallagher, seminar host (marcusg@itee.uq.edu.au)
or Guido Governatori (ITEE seminar co-ordinator) (guido@itee.uq.edu.au)

ITEE seminar web page: http://www.itee.uq.edu.au/~seminar

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