Scientific Reports 6: Article number: 33087; published online: 26 September 2016; updated: 21 October 2016

The original version of this Article contained a typographical error in Affiliation 2. The affiliation:

Centre National de la Recherche Scientifique, CNRS UMR7104, Paris, France.

Now reads:

Centre National de la Recherche Scientifique, CNRS UMR8104, Paris, France.

This has been corrected in the HTML and PDF versions of this Article.