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<?xml version='1.0' encoding='utf-8'?>
<!-- FILE : wilkins_model_1998.xml

CREATED : 27th March 2004

LAST MODIFIED : 27th March 2004

AUTHOR : Catherine Lloyd
         Bioengineering Instute
         The University of Auckland
         
MODEL STATUS : This model conforms to the CellML 1.0 Specification released on
10th August 2001, and the 16/01/2002 CellML Metadata 1.0 Specification.

DESCRIPTION : This file contains a CellML description of Wilkins and Sneyd's 1998 mathematical model of intercellular spiral waves of calcium. 
-->

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  <title>Intercellular spiral waves of calcium</title>
  <author>
    <firstname>Catherine</firstname>
          <surname>Lloyd</surname>
    <affiliation>
      <shortaffil>Auckland Bioengineering Institute, The University of Auckland</shortaffil>
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            This model contains partial differentials and as such can not currently be solved by existing CellML tools.
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  <sect1 id="sec_structure">
<title>Model Structure</title>

<para>
ABSTRACT: Intercellular calcium waves have been observed in a large number of cell types, and are known to result from a variety of stimuli, including mechanical or hormonal stimulation. Recently, spiral intercellular waves of calcium have been observed in slices of hippocampal tissue. We use an existing model to study the properties of spiral intercellular calcium waves. Although intercellular spiral waves are well known in the context of cardiac muscle, due to the small value of the calcium diffusion coefficient intercellular calcium waves have fundamentally different properties. We show that homogenisation techniques give a good estimate for the plane wave speed, but do not describe spiral behaviour well. Using an expression for the effective diffusion coefficient we estimate the intercellular calcium permeability in liver. For the bistable equation, we derive an analytic estimate for the value of the intercellular permeability at which wave propagation fails. In the calcium wave model, we show numerically that the spiral period is first a decreasing, then an increasing, function of the intercellular permeability. We hypothesise that this is because the curvature of the spiral core is unimportant at low permeability, the period being approximately set instead by the speed of a plane wave along a line of coupled cells in one dimension.
</para>

<para>
The original paper reference is cited below:
</para>

<para>
Intercellular Spiral Waves of Calcium, Matthew Wilkins and James Sneyd, 1998,<emphasis>Journal of Theoretical Biology</emphasis>, 191, 299-308. <ulink url="http://www.ncbi.nlm.nih.gov/pubmed/9631570">PubMed ID: 9631570</ulink>
</para>

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                <title>reaction diagram</title>
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            <caption>Schematic diagram showing the transmembrane calcium fluxes which are described by the mathematical model.</caption>
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</sect1>
</article>
</documentation>
  
  
  
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        Wilkins and Sneyd's 1998 mathematical model of intercellular spiral waves of calcium.
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