Fair use statement
I think the use of copies of figures from copyrighted scientific articles on this site is fair use based on the four criteria by which this is usually judged.
Nature of the use: This site has a non-commercial purpose. The use of each figure is transformative. The data shown in each figure is used to analyze ideas not contemplated by the authors.
Nature of the copyrighted material: The figures are factual representations of the observations of the authors, and the presentation itself is standard rather than innovative.
Amount of use: In almost all cases only a single figure is used from any one article.
Effect on commercial value of material used: My access of the material was through the publisher's website or from legitimate open-access sources such as PubMed or Google Scholar, or from a source distributed under the terms of a Creative Commons Attribution-Non Commercial License. Use here would not be a substitute for someone interested in obtaining access to the entire original article, but rather might stimulate their obtaining legitimate access. All articles referenced are cited and listed in Literature Cited page.
Nevertheless, if a copyright owner if good faith represents that their rights have been infringed, I intend not to contest removal of the offending material according to the provisions of the Digital Millenium Copyright Act of 1998.