It has come to our attention that the Academic Editor who handled this manuscript, Dr Jose Calbet, had co-authored publications with two of the authors of the article in the five years before the submission of this work.
In line with the PLOS ONE competing interests policy (http://www.plosone.org/st...), we consider this as a potential conflict of interest. Dr Calbet was invited by PLOS ONE to act as Academic Editor for this manuscript and we acknowledge that the journal should not have approached him to handle this manuscript.
We have therefore asked an independent Academic Editor, Makoto Kanzaki, to carefully evaluate the peer review process of this article. Dr Kanzaki has confirmed that he is satisfied that the decision for publication was adequate.
