Multimodal Simulation of the Phage-λ
          Decision Cycle


            Ryan Imms
Biomedical Simulation




 What is Biomedical Simulation?

 Why should we use it?

 What benefits does it offer?
Viral Reproduction




                         Two methods of reproduction for
                          viral cells after initial infection

                         Depending on the virus,
                          environmental conditions can be
                          critical




Wikipedia
Phage-λ




          Myers, 2007
Modelling Stages


             Intention is to reduce
             simulation time without a loss
             of accuracy.

             Refinements in modelling
             techniques allow marked
             improvements to be made

             Each of these techniques is
             probabilistic, requiring
             multiple simulation runs to
             acquire an accurate set of
             data.
Model Purpose

 Recreate the work outlined in “Engineering
  Genetic Circuits” by Myers using non-
  specialist packages.

 Lay the groundwork for further biological
  modelling using these same packages.

 Open the field of biological modelling to an
  increased range of individuals.
Model Realisation
Model Parameterisation




Surface plot showing activity of a specific promoter at varying levels of expression of
two proteins.

Modelled in MATLAB to determine threshold values used to control expression in the
finite state machine.
Results




Results from simulation of the Phage-λ stochastic Finite State Machine.

Reasonable at low phage inputs, loses accuracy at higher initial concentrations.

Likely to be caused by a combination of incorrectly chosen boundary conditions.
Model Limitations

 Explicit knowledge required for exact
  replication of real world.

 Assumptions may severely reduce accuracy
  or validity of results.

 More complex systems can still require
  excessive amounts of time to simulate.
Further Applications



 Genetic Disorders

 Congenital Disease

 Virology Studies
Thank You for Listening

Imms phage lambda_2011

  • 1.
    Multimodal Simulation ofthe Phage-λ Decision Cycle Ryan Imms
  • 2.
    Biomedical Simulation  Whatis Biomedical Simulation?  Why should we use it?  What benefits does it offer?
  • 3.
    Viral Reproduction  Two methods of reproduction for viral cells after initial infection  Depending on the virus, environmental conditions can be critical Wikipedia
  • 4.
    Phage-λ Myers, 2007
  • 5.
    Modelling Stages Intention is to reduce simulation time without a loss of accuracy. Refinements in modelling techniques allow marked improvements to be made Each of these techniques is probabilistic, requiring multiple simulation runs to acquire an accurate set of data.
  • 6.
    Model Purpose  Recreatethe work outlined in “Engineering Genetic Circuits” by Myers using non- specialist packages.  Lay the groundwork for further biological modelling using these same packages.  Open the field of biological modelling to an increased range of individuals.
  • 7.
  • 8.
    Model Parameterisation Surface plotshowing activity of a specific promoter at varying levels of expression of two proteins. Modelled in MATLAB to determine threshold values used to control expression in the finite state machine.
  • 9.
    Results Results from simulationof the Phage-λ stochastic Finite State Machine. Reasonable at low phage inputs, loses accuracy at higher initial concentrations. Likely to be caused by a combination of incorrectly chosen boundary conditions.
  • 10.
    Model Limitations  Explicitknowledge required for exact replication of real world.  Assumptions may severely reduce accuracy or validity of results.  More complex systems can still require excessive amounts of time to simulate.
  • 11.
    Further Applications  GeneticDisorders  Congenital Disease  Virology Studies
  • 12.
    Thank You forListening