Yamada, Masaaki
Yoo, Jongsoo
Jara-Almonte, Jonathan
Ji, Hantao
Kulsrud, Russell M.
Myers, Clayton E.
Article History
Received: 5 May 2014
Accepted: 23 July 2014
First Online: 10 September 2014
Competing interests
: The authors declare no competing financial interests.