This is command-line utility for the inverse modelling of OECD 308 experiments with Bayesian parameter inference.

Details about the applied models and calculation procedure can be found in: Honti M. & Fenner K. (submitted to ES&T) Deriving persistence indicators from regulatory water-sediment studies – Opportunities and limitations in OECD 308 data.

• Windows

  Supports Microsoft Windows 7 and above (64 bit versions only)

• Mac OS X

  Supports Mac OS X 10.8 and above

Installation

The utility does not require installation. Just extract the contents of the zip archive to anywhere on your computer.

Preparing data

The results of the OECD 308 experiment should be converted to the format specified by the example data provided with the software (sample_input.txt).

Notation:

• Pw: Parent compound in water
• Ps: Parent compound in sediment
• Mw: Pooled metabolites in water
• Ms: Pooled metabolites in sediment
• C: CO₂
• N: NER

Place the file of experimental data into the directory/folder of the utility.

Update priors.txt to contain your desired values for the means and standard deviations (sd) for the lognormal prior distribution.

Running

1. Open a command prompt/terminal and navigate to the directory/folder of the tool with cd.

2. type:

   308util.bat [version] [inputfilename] [outputfilename] on Windows

   ./308util.sh [version] [inputfilename] [outputfilename] on Mac OS X

   where [version] is the model version to be fit (A/B/C/D), [inputfilename] is the name of the file containing the experimental data and [outputfilename] is the name of the result file to be created.

3. The produced output file will contain the posterior sample of model parameters. Each parameter has its dedicated column in the file. The values in the column form a proper statistical sample of the posterior marginal distribution. Due to the necessary adaptation phase of the Markov-Chain Monte Carlo sampler rows having burn_in=0 should be discarded.