Received: 19 July 2018
Accepted: 3 January 2019
First Online: 14 January 2019
Ethics approval and consent to participate
: This research did not use human subjects and therefore was exempt from Virginia Polytechnic Institute and State UniversityInstitutional Review Board review.
: This review only utilizes available published data within the literature and no new information was gathered from research participants.
: The authors declare that they have no financial or other competing interests related to the content of this manuscript.
: Springer Nature remains neutral with regard to jurisdictional claims in published maps and institutional affiliations.