时间：2015年5月27日(周三)上午9:00

地点：新主C706

题目：Nonlinear Dynamics, Oscillations, Chaos and Noise in Biological Systems: From Shark Electroreceptors to Mental Disorders

主讲人：德国马尔堡大学/美国物理学会会员Braun，Hans Albert 教授作

Abstract: Biological functions typically include nonlinearities and often are organized in positive and negative feedback loops with time delays which easily can lead to oscillations and even chaotic behavior. Moreover, biological systems are notoriously noisy which can induce significant alterations of the system dynamics compared to deterministic situations. Additional randomness is introduced by the enormous diversity of the functional elements of which biological systems are composed.

These are characteristics features of life that can be found at all levels of biological functions. Examples will be given from peripheral sensory transduction [1] to neural information processing in the CNS up to the control of autonomic and mental functions [2]. Experimental and clinical data will be accomplished by computer simulations, specifically emphasizing on a flexible, biologically appropriate modeling strategy [3].

It shall be discussed to which extent such characteristic features of biological systems; especially cooperative effects between nonlinearities and noise, are the reasons why information processing in biology is often vague and imprecise but also whether these technically mostly undesired features may likewise be a source of flexibility, adaptability and creativity - not yet reached by technical artifacts.

References:

[1] Braun HA, Wissing H, Schäfer K, Hirsch MC (1994): Oscillation and noise determine signal transduction in shark multimodal sensory cells. Nature 367: 270-273.

[2] Huber MT, Braun HA and Krieg JC (2004) Recurrent affective disorders: nonlinear and

stochastic models of disease dynamics. International Journal of Bifurcation and Chaos 14:

635-652

[3] Tchaptchet A, Postnova S, Finke C, Schneider H, Huber MT, Braun HA (2013): Modeling

Neuronal Activity in Relation to Experimental Voltage-/Patch-Clamp Recordings. Brain

Res 1536: 159-167,

Biographical Sketch:

Hans Braun has been educated as electric engineer (Diploma in “Electrobiology”) and received his PD in Physiology. He has originally been hired by the University of Marburg as engineer for computer programming and the construction of stimulation and recording devices for electrophysiological experiments. In course of this work he was going to perform his own experiments with significant impact to led him install an own research group. During recent years, experimental research in the “Neurodynamics Group” was more and more supplemented by mathematical modeling studies especially in course of a big EU “Network of Excellence” about “Computer Simulations for Drug Development” (BioSim). The Neurodynamics group contributed with a Workpackage about “Sleep and Mental Disorders”. Hans Braun additionally served as member of the Steering Group and Activity Area Head of “Neural Systems”

Currently, the focus of the Neurodynamics group is laid on the elucidation of general principles of biological processes across different functional levels, also in comparison to technical artifact, and the design of biologically appropriate modeling strategies in close relation to experimental and clinical data.

Hans Braun has been honored as “Fellow” of the American Physical Society (APS) “For the discovery of noise mediated neuronal oscillators and for elucidating their nonlinear dynamical properties” and has received several awards, e.g. the “International MacWorld award for trendsetting multimedia software. Reprogramming of these teaching tools, the “Virtual Physiology” series, is currently another major task of the Marburg Neurodynamics group.

Hans Braun is member of several national and international scientific societies and is serving the scientific community as reviewer and co-editor of international journals including the organization of several international conferences.