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BP: Fachverband Biologische Physik
BP 7: Coupled Problems in Biological Systems (Focus Session)
BP 7.6: Talk
Monday, March 7, 2016, 12:45–13:00, H45
The effect of model rescaling and normalization on sensitivity analysis on an example of a MAPK pathway model — Jakob Kirch, Caterina Thomaseth, Antje Jensch, and •Nicole Radde — Institute for Systems Theory and Automatic Control, University of Stuttgart, Stuttgart, Germany
The description of intracellular processes based on chemical reaction kinetics has become a standard approach, and parameter estimation poses several challenges. Sensitivity analysis can aid model calibration in various ways. Results can for example be used to simplify the model. However, models are usually subject to rescaling and normalization, which changes the variance of the output and hence also influences results of sensitivity analyses.
We investigate the effect of model rescaling and normalization to a reference experiment on the outcome of local and global sensitivity analyses. Results are exemplified on a model for the MAPK pathway. Results for differently scaled and normalized model versions are compared. We show that sensitivity analyses are invariant under simple rescaling of variables and parameters. By contrast, normalization to a reference experiment that also depends on parameters has a large impact on any sensitivity analysis, and in particular makes an interpretation difficult. This dependency should be taken into account when working with normalized model versions.