Authors: Laurent Binet, Mathilde Bourbin, Mariem El Afrit, Didier Gourier, Yann Le Du
Presentation by Yann Le Du [i] and Mariem El Afrit [ii]
Electron Paramagnetic Resonance (EPR) is a non-destructive, non-invasive technique useful for the characterization of organic moieties in carbonaceous matter that provides unique information in exobiology . Usual EPR parameters are the peak-to-peak amplitude, the linewidth and the g factor; however, such parameters are not sufficient to fully describe a single EPR line. Combined to classic EPR parameters, we devised new constructive shape parameter that now allows a complete description of an EPR spectrum, and which turns out to be a very precise datation tool not only of carbonaceous matter, but also of any other substance characterized by a single symmetric EPR line.
With the benefit of our extensive experience with Python in scientific research , all of the data reduction, computations and analysis were done with Python and the Numpy and Cython extensions, but the real novelty lies in how we introduced a new methodology in the field of exobiology based on literate programming (LP) and reproducible research (RR): the whole study uses Sage , SageTeX , Org  and Babel . The LP/RR methodology implies that the work consists in a master file and a few data-files that in themselves allows a complete understanding of the data reduction and analysis, and a full reproducibility given the raw data. We found this tight integration to be very efficient in convincing our exobiologist collaborators that the LP/RR paradigm was a very potent tool in their research. Thanks to this tight integration, the code can evolve easily and be adapted to new datasets or even transliterated in another language: each “code chunk” can exist in different languages and yield different complete programs. The result of this study will be published in a paper to be submitted to Open Research and Computation . We would also like to share our workflow with the Scipy community: how we go from the Sage worksheet to the final Org LP/RR documents.
 Skrzypczak-Bonduelle, A and Binet, L and Delpoux, O and Vezin, H and Derenne, S and Robert, F and Gourier, D. EPR of radicals in primitive organic matter: A tool for the search of biosignatures of the most ancient traces of life. App Magn Reson - 2008