1) Minor Essential Revisions: line 90: "The data were reduced to approximately 42.15 Gb 91 after filtering, removing approximately 4% of the data." should read "The data were reduced to approximately 42.15 Gb 91 after filtering, removing approximately 6% of the data."

Level of interest An article of importance in its field Quality of written English Acceptable Statistical review Yes, and I have assessed the statistics in my report. Declaration of competing interests I declare that I have no competing interests.

Authors' response to reviewers: (http://www.gigasciencejournal.com/imedia/1431416853179284_comment.pdf)