Northwestern Events Calendar


Complex Systems Seminar: Professor Rosemary Braun: Hearing the Many Shapes of Fitness

When: Thursday, April 25, 2019
2:00 PM - 3:30 PM Central

Where: Technological Institute, F160, 2145 Sheridan Road, Evanston, IL 60208 map it

Audience: Faculty/Staff - Student - Public - Post Docs/Docs - Graduate Students

Contact: Cristian Pennington   (847) 491-3645

Group: Physics and Astronomy Complex Systems Seminars

Category: Academic


In the early 90s, Gordon, Webb, and Wolpert famously demonstrated that the answer to Mark Kac's question "Can one hear the shape of a drum?" is "no": isospectral drums -- those that sound identical despite having different shapes -- exist. Similarly, isospectral graphs -- networks that have the same Laplacian eigenspectrum despite differences in their topology -- also exist. The graph Laplacian may be thought of as a discrete form of the Laplace-Beltrami operator, and spectral differences (or lack thereof) can have profound implications for the dynamics of processes on networks. In this talk, I will show how we can extend and exploit spectral graph theory to analyze high-dimensional genomic data in the context of gene regulatory networks, with the goal of elucidating how the complex interplay of molecular interactions leads to the emergence of macroscopic phenotypes. Importantly, our approach can distinguish sets of alterations that have a cumulatively deleterious impact from those that compensate one-another to preserve the spectrum (and hence the dynamical properties) of the network. Using data from a study of acquired drug resistance, I will show how this analysis yields more reliable inferences than traditional analysis techniques, and can be used to model emergent properties of biological networks, glean insights into adaptive processes in living systems, and identify potential targets for recovering the function of damaged systems.

Professor Rosemary Braun, Northwestern University

Host: Michelle Driscoll

Keywords: Physics, Astronomy, Complex Systems

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