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Numerical Experiments in compuGUT

By, Andrew Mueller in collaboration with Professor Melara

and Dr. A. J. Kearsley (NIST)

Program created by Dr. Arun Moorthy under advisement of Professor Eberl

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Background of compuGUT:

  • Created by Dr. Arun Moorthy under the advisement of Professor Eberl for his thesis project.
  • Dr. A. J. Kearsley and others at NIST continue to improve upon it
  • CompuGUT simulates fermentation & digestion process
    • Mathematical models
  • Intended to study bacteria and other microorganisms

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compuGUT Parameters

  • Basic Parameters
    • Allows for user-friendly adjustment of parameters
    • Include: operations, diet, inocula (initial conditions), and reaction parameters
  • Advanced parameters
    • Requires editing C source code
    • More difficult

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Complete Mathematical Model:

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Closeup of Basic Irregular Diet

Lumen Environment

Biomaterials in Lumen Environment

Mucus Environment:

Biomaterials in Mucus Environment

Location in Colon [m]

Total Mass of Particulates [g]

Total Mass of Particulates [g]

Concentration of

Compounds[g/L]

Location in Colon [m]

Location in Colon [m]

Location in Colon [m]

Concentration of

Compounds[g/L]

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Perturbing Parameter Values

  • Inocula (Initial conditions)
    • Initial mucus
    • Initial biomasses
  • ADM1 Parameters:
    • Only the yield coefficients
    • Helps to focus the research

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Modified Program:

ADM1

Inocula (IC)

Diet

Parameters (Text Files [.txt])

Operation Instructions

compuGUT - Integration (C code [.c])

Results (Text Files [.txt])

ccm_r####

PreColon

Time Values

Sim Summary

Sim Parameters

Interactive Results (R Markdown File [.RMD])

Plot of Results (HTML File [.html])

Interactive Error Results (R Markdown file [.RMD])

Plot of Error (HTML File [.html])

Run (Bash Script [.sh])

Perturb Parameters (Bash Script [.sh])

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Sensitivity by perturbing parameters by 0.001:

p0 + 0.001:

p9 + 0.001:

Lumen Environment

Lumen Environment

Lumen Environment

Lumen Environment

Mucus Environment

Mucus Environment

Mucus Environment

Mucus Environment

Total Mass of Particulates [g]

Mass of Particulates

Total Mass of Particulates [g]

Total Mass of Particulates [g]

Concentration of

Compounds[g/L]

Concentration of

Compounds[g/L]

Concentration of

Compounds[g/L]

Location in Colon [m]

Location in Colon [m]

Location in Colon [m]

Location in Colon [m]

Location in Colon [m]

Location in Colon [m]

Location in Colon [m]

Location in Colon [m]

Concentration of

Compounds[g/L]

p26 + 0.001:

Lumen Environment

Total Mass of Particulates [g]

Location in Colon [m]

Mucus Environment

Total Mass of Particulates [g]

Location in Colon [m]

Concentration of

Compounds[g/L]

Location in Colon [m]

Lumen Environment

Mucus Environment

Concentration of

Compounds[g/L]

Location in Colon [m]

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Conclusions

  • Inocula (initial condition) parameters are less sensitive
  • Yield Coefficients tend to be more sensitive
    • p9 does not behave well when perturbed
    • p26 performs similarly to inocula parameters
  • Why?
    • Yield coefficients have more concrete bounds
    • Inocula (initial conditions) deal with varying amounts of mucus and biomasses
  • Continuing Research