@article {2553, title = {Pseudospectral method of solution of the Fitzhugh-Nagumo equation}, journal = {Mathematics and Computers in Simulation}, volume = {79}, number = {7}, year = {2009}, note = {ISI Document Delivery No.: 429KBTimes Cited: 3Cited Reference Count: 41Olmos, Daniel Shizgal, Bernie D.}, month = {Mar}, pages = {2258-2278}, type = {Article}, abstract = {We present a study of the convergence of different numerical schemes in the solution of the Fitzhugh-Nagumo equations in the form of two coupled reaction diffusion equations for activator and inhibitor variables. The diffusion coefficient for the inhibitor is taken to be zero. The Fitzhugh-Nagumo equations, have spatial and temporal dynamics in two different scales and the solutions exhibit shock-like waves. The numerical schemes employed are a Chebyshev multidomain method, a finite difference method and the method developed by Barkley [D. Barkley, A model for fast computer simulation of excitable media, Physica D, 49 (1991) 61-70]. We consider two different models for the local dynamics. We present results for plane wave propagation in one dimension and spiral waves for two dimensions. We use an operator splitting method with the Chebyshev multidomain approach in order to reduce the computational time. Zero flux boundary conditions are imposed on the solutions. (C) 2009 IMACS. Published by Elsevier B.V. All rights reserved.}, keywords = {3-DIMENSIONAL EXCITABLE MEDIA, Chebyshev multidomain, Convergence, DYNAMICS, Fitzhugh-Nagumo equations, MECHANISM, MODEL, REACTION-DIFFUSION-SYSTEMS, SELECTION, Spiral waves, SPIRAL-WAVE, TRANSITION}, isbn = {0378-4754}, url = {://000264918200021}, author = {Olmos, D. and Shizgal, B. D.} } @article {1007, title = {High affinity DNAzyme-based ligands for transition metal cations - a prototype sensor for Hg2+}, journal = {Organic \& Biomolecular Chemistry}, volume = {2}, number = {3}, year = {2004}, note = {ISI Document Delivery No.: 776YCTimes Cited: 32Cited Reference Count: 47}, month = {Feb}, pages = {307-312}, type = {Article}, abstract = {Inspired by recent interest in DNAzymes as transition metal ion sensors, a survey of the effects of various transition metals on the intramolecular cleavage rate of an imidazole modified, M2+-independent, self-cleaving "9(25)-11" DNA is reported. In particular, 9(25)-11 activity was strongly inhibited by Hg2+ (K-d(APP) = 110 +/- 9 nM). It is postulated that the affinity and selectivity of 9(25)-11 for Hg2+ stems from the fact that this synthetically modified DNAzyme contains imidazoles. This study demonstrates the utility of modified nucleotides in developing DNAzyme sensors for metals ions, especially those for which unmodified nucleic acids might not serve as inherently good ligands.}, keywords = {2-STEP MECHANISM, BIOSENSOR, CATALYTIC REPERTOIRE, CLEAVING DNA ENZYME, IMIDAZOLYL FUNCTIONALITIES, MERCURIC ION, MERCURY(II), NUCLEIC-ACIDS, NUCLEOSIDES, SELECTION}, isbn = {1477-0520}, url = {://000189146100008}, author = {Thomas, J. M. and Ting, R. and Perrin,David M.} }