Drs Richards, Scheckel, and Poole provided substantial contributions to conception and design, acquisition of data, or analysis and interpretation of data; Drs Richards, Scheckel, and Newman, and Ms Anderson drafted the article or revised it critically for important intellectual content; Drs Richards, Scheckel, Newman, and Poole, and Miss Anderson gave final approval of the version of the article to be published; and all authors agree to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.