Funding for this research was provided by:
National Science Foundation (1509342, 1537015)
Air Force Office of Scientific Research (15RT0189)
Article History
Received: 30 January 2017
Accepted: 25 September 2017
First Online: 11 October 2017
Ethics approval and consent to participate
: Not applicable.
: The authors declare that they have no competing interests.
: Not applicable.