Common Searches

Sonya Bahar, Director

Sonya Bahar, PhD - “Photo by August Jennewein”

Professor of Biophysics
Director, Center for Neurodynamics

Department of Physics and Astronomy 
University of Missouri at St Louis

One University Boulevard
St. Louis MO 63121

Tel: (314) 516-7150
Fax: (314) 516-6152 

Email: bahars@umsl.edu


Editor of The Journal of Biological Physics, published by Springer.

THE ESSENTIAL TENSION: Competition, Cooperation and Multilevel Selection in Evolution

Phase transitions in yeast and bacterial populations under stress

Computational models of phase transitions in evolutionary dynamics

We are investigating the role of mutation parameters in driving speciation in evolutionary models. We have observed phase-transition-like behavior as the maximum mutation size is varied, on various types of fitness landscapes. Optimal clustering, which can be considered as an analog of speciation, occurs for an intermediate mutation parameter. Our first work on this model appeared in PLoS ONE. More recently, we have found similar behavior even on a NEUTRAL landscape, in which all simulated organisms have identical fitness. 



Recent doctoral student Daisuke Takeshita (Ph.D. 2010, now Associate Professor at the University of Tokyo) studied the synchronization of neural activity in the rat neocortex during focal seizures. Using voltage-sensitive-dye imaging, Daisuke demonstrated a sharp rise in synchronization during seizures. This study appeared in the journal Chaos, in a focus issue honoring Frank Moss.


Recent doctoral student Roxana Contreras (Ph.D. 2009), studied eye-target synchronization in normal subjects and mild traumatic-brain-injured (mTBI) patients. Her most recent work in this area appeared in Brain Research in 2011.



Recent doctoral student Nathan Dees (Ph.D. 2009), who now works at the Genome Center at Washington University in St. Louis, studied the evolution of optimal foraging behavior in various species, ranging from Daphnia to paddlefish. He also investigated how nonlinear dynamical techniques can reveal the relationship between the fMRI-BOLD signal and EEG recordings in human subjects.



In vivo imaging of seizure activity in the rat neocortex...

....and human intraoperative brain imaging (postdoctoral work with Ted Schwartz)

Neural synchronization in the crayfish caudal photoreceptor (postdoctoral work with Frank Moss)

Imaging hypoxic spreading depression in rat hippocampal slices.

Bistability and hysteresis in the response of periodically paced small pieces of bullfrog cardiac tissue. Phys. Rev. Lett. 82:2995-2998, 1999.

Spatiotemporal effects of bistability in coupled map models of cardiac dynamics(published in the Proceedings of the 5th Experimental Chaos Conference, Boca Raton, Florida, July 1999).

Control of fibrillation using nonlinear dynamics based methods in the in vivo sheep heart.

Bistability and Hysteresis in the Periodically Paced Sheep Heart

Monovalent and divalent anion transport in the band 3 and AE2 proteins with Phil Knauf

Time Delay Embeddings of IFS Attractors

Symbolic Dynamics for IFS Attractors

Apparently Chaotic Orbits Embedded in Closed Curves, written with Irene Hueter