Liudmila Yafremava

General Interest - understanding the means of decision making and survival by integrating knowledge about intracellular processes, cellular interactions, organism behavior and population fitness through experimentation, detailed modeling and construction of artificial organisms.  Click for Research: behavioral study of turning or modeling of feeding network

Education

• 1999-2007 PhD in Biophysics and Computational Biology, University of Illinois, Urbana, Illinois, USA. Neural substrates of decision in foraging by a predatory marine mollusk, Pleurobranchaea californica.
• 1995-1997 undergraduate student at the Department of Law, Belarus State University, Minsk, Belarus.
• 1994-1999 Diploma (B.S.) Department of Physics, specialization - biophysics, Belarus State University, Minsk, Belarus. Optimization of the training procedure for multilayer perceptrons using vector quantization.

Research

• Behavioral study of turning in the marine mollusk Pleurobranchaea californica to investigate the relationships between the slug’s turn angle and the site of application of the chemotactile stimulus which caused the turn. The study encompassed both orienting and avoidance turning in response to a variety of chemical stimulants presented at different concentrations. Responses to distributed stimuli were also investigated.

• To better understand the neuronal mechanisms underlying turn behavior in Pleurobranchaea, I investigated the functionality of the slug’s chemosensory oral veil by performing electrophysiological recordings from sensory nerves originating in it.

• To integrate the available electrophysiological data on the structure and function of neural networks mediating swimming, turning and feeding behavior in Pleurobranchaea, I constructed a computer simulation of those networks. This simulation explains how behavioral decisions could arise from the interplay between the animal’s internal state and experience through competition for arousal between neural networks.

• Cost-benefit analysis model to investigate decision making of Pleurobranchaea. The model explained Pleurobranchaea feeding thresholds through interaction of the slug’s internal state with its physical environment.

• To understand the role of serotonin in regulation of Pleurobranchaea turn behavior through internal state, I performed immunocytochemical analysis of serotonin content in multi-function serotonergic cells of the turn neural network. I applied a two-step fluorescent antibody staining to the slug’s brain to qualitatively assess the relationship between serotonin content in the neurons and the slug’s satiation state.

• In collaboration with Dr. N. Hatcher I constructed a data-driven model of cAMP diffusion and phosphodiesterase kinetics in a giant MCG cell of Pleurobranchaea. The model allowed computation of the kinetic parameters of phosphodiesterase present in the MCG of this mollusk.

• I helped with electrophysiological recordings in Dr. S. Boppart’s group in Beckman Institute to help develop a non-invasive neuronal spike detection technique by means of optical coherence tomography. Results were presented at the Optical Society of America Topical Meeting on Optical Techniques in Neuroscience.

Teaching

Teaching assistant at the University of Illinois in the courses:

• Spring 2005 Developmental biology
• Fall 2004 Cell and Membrane Physiology lab
• Fall 2001-Spring 2002 Plant and Animal Physiology lab

Conference abstracts

• L. S. Yafremava, R. Gillette (2006) Sensory Perception context for functioning of serotonergic As cells in the brain of Pleurobranchaea californica. Society for Integrative and Comparative Biology Annual Meeting, January 4-8 2006
• L.S. Yafremava, R. Gillette (2004) Neural network simulation of switching between multiple behaviors based on hunger state and learning. Proceedings of the Society for Neuroscience 34^th Annual Meeting.
• A. Bowonder, C. Vinegoni, L. Yafremava, R. Gillette, S.A. Boppart Optical coherence tomography of neural activity. Poster presentation, Chicago Universities Bioengineering Industry Consortium (CUBIC). Chicago, IL, January 29-30, 2004.
• L.S.Yafremava, C.W.Anthony, L.Lane, R.Gillette (2003) Orienting and avoidance turning in the predatory sea-slug Pleurobranchaea. Proceedings of the Society for Neuroscience 33^rd Annual Meeting.
• L. S. Yafremava, T. J. Anastasio, R. Gillette (2001) Utility Theory And Neural Network Modeling Of Cost-Benefit Decision-Making In A Predatory Foraging Marine Snail. Proceedings of the year 2001 Computational Neuroscience Conference.
• N.G.Hatcher, L.L.Moroz, K.Potgieter, J.V.Sweedler, L.S.Yafremava, X.Zhang, R.Gillette (2001) A model of feeding regulation by neuronal 5-HT and NO in the sea-slug Pleurobranchaea. The Sixth International Congress of Neuroethology, Bonn, Germany.
• L.S.Yafremava, R.Gillette (2001) Mechanisms of decision-making: a neural network simulation. Proceedings of the Society for Neuroscience 31^st Annual Meeting.
• K.Potgieter, F. Angenstein, L.Yafremava, X. Zhang, N.Hatcher, L. Moroz, J.Sweedler, R. Gillette (2001) Serotonin as an arousal factor determining appetite n the feeding network of Pleurobranchaea. Proceedings of the Society for Neuroscience 31^st Annual Meeting.
• J.K.Wenzel, Yafremava, R.Gillette (2001) Precise computation in orienting turning by the predatory snail Pleurobranchaea. Proceedings of the Society for Neuroscience 31^st Annual Meeting.
• R. Gillette, L.S. Yafremava (2000) Towards A Computational Neural Network Model Of Behavioral Choice In Pleurobranchaea. Proceedings of the Society for Neuroscience’s 30^th Annual Meeting.
• L.S. Yafremava, T.J. Anastasio, R. Gillette (2000) Probabilistic Utility-Theory Model Of Foraging Behavior In The Predatory Marine Slug Pleurobranchaea Californica. Proceedings of the Society for Neuroscience’s 30^th Annual Meeting.
• L. S. Yafremava, A.T.Vlassov. (1999) Optimization of the training procedure for multilayer perceptrons using vector quantization. Proceedings of 55^th student conference at Belarus State University, BSU press, Minsk, Belarus.
• L. S. Yafremava, A.T.Vlassov (1998) Using the Liapunov Function for the Investigation the Memory Processes and Pattern Recognition in Neural Networks. Proceedings of 54^th student conference at Belarus State University, BSU press, Minsk, Belarus.

Awards

• 2002 John G. and Evelyn Hartman Heiligenstein Outstanding teaching assistant in biology 121 award
• 2002 Graduate teaching certificate from the University of Illinois at Urbana-Champaign
• 2001 Francis M. and Harlie M. Clark research support grant, School of Life Science at University of Illinois.
• 2000 Francis M. and Harlie M. Clark research support grant, School of Life Science at University of Illinois.
• 1994 Soros Stipend by International Soros Science Education Program.

Advisors

• A.T. Vlassov (undergraduate thesis advisor) Belarus State University
• R. Gillette (thesis advisor) University of Illinois

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