I have downloaded a copy of the paper. I can forward a copy to someone who wants to see it. It's a 283 kb PDF file.
The paper explains more fully why they argue the "life" signs they detected using a similar instrument to Levin's labeled release experiment are due to oxidants and not life.
Levin had argued for an update of his experiment where there were chiral versions of the organics used for any supposed microbes to metabolize and release radioactively labeled gases. The experimenters tried this in this research. They found that in the driest areas with no culturable bacteria, both chiral versions of the organics released the same amount of labeled gas. Since life is known to only metabolize left-handed amino acids and right-handed sugars, they conclude the reactions they observed could not be due to life.
In contrast, in the wetter areas where they were able to culture bacteria they found there was indeed a preference for the expected chiral mixtures.
This is a key piece of evidence against the life explanation of the Viking results. Levin had argued such chiral experiments would be a definitive test for the life hypothesis for the Viking biology results.

However, there have been discovered recently some new microbes with unusual metabolisms that I thought might provide analogues to possible life on Mars. I would like to see if these microbes could mimic the reactions seen in the Atacama experiments.
More on this soon.

Bob Clark