[cellml-discussion] Looping Cell Cycle Models

[Catherine Lloyd]

Thank you Nicolas.

I thought that this might have been the case.  I believe we can mimic  
your events as you describe them below in CellML by using piecewise  
equations.

Just out of interest, where did you get these descriptions from?  The  
original paper?  Correspondence with the authors?  Or did you come up  
with them yourselves?

We will attempt to implement these equations in the CellML models and  
I will let you know if we are successful.

Best wishes
Catherine


On 29/12/2008, at 10:35 AM, Nicolas Le novère wrote:

> Catherine Lloyd wrote:
>
>> Looking at the equations in the papers we can't find any function  
>> which would cause the models to loop.  Indeed, even where we have  
>> access to the author's original XPP code, we are struggling to find  
>> the "loop function" (although, we confess this may be due to our  
>> misinterpretation of the XPP!).
>> In SBML is it possible that an event is used to get the model to  
>> repeat? (My apologies for my ignorance here!).
>
> Indeed, the events are responsible of the cycling. For Novak and  
> Tyson 1997, they are described in Table 1, in the section  
> "switches". There are two events:
>
> S-Phase Start
> =============
>
> When SPF becomes superior or equal to 0.1
>  after 60 seconds kp = kp / 2
>
> Cell division
> =============
>
> When UbE becomes inferior or equal to 0.1
>  immediately      kp = 2 * kp
>                   Mass = Mass / 2
>
> -- 
> Nicolas LE NOVERE, Computational Neurobiology, EMBL-EBI, Wellcome- 
> Trust
> Genome Campus, Hinxton CB101SD UK, Mob:+447833147074, Tel: 
> +441223494521
> Fax:468, Skype:n.lenovere, AIM:nlenovere, MSN:nlenovere at hotmail.com
> http://www.ebi.ac.uk/~lenov/, http://www.ebi.ac.uk/compneur/
>
>
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