© The Author(s) (published by Nature Publishing Group) (Open Access Journal) Posted on January 14, 2013 by SCG DR Copyright Holders: © The Author(s) (published by Nature Publishing Group) Self-archiving policy Conditions Accepted version: √ Open Access Journal Published version: √ Open Access Journal Remarks: Scientific Reports does not require authors of original (primary) research papers to assign copyright of their published contributions. Rather, authors can choose one of three licenses: the Creative Commons Attribution 3.0 Unported license; the Attribution-NonCommercial-ShareAlike 3.0 Unported license; or the Attribution-NonCommercial-NoDerivs 3.0 Unported license. All the three licenses allow the non-commercial distribution. Verification Date: 10.01.2013 23.05.2013