Funding for this research was provided by:
Agricultural Research Service (2011-68001-30167)
Received: 2 April 2018
Accepted: 25 April 2019
First Online: 16 May 2019
Ethics approval and consent to participate
: This study was approved by the University of California (UC), Davis Institutional Review Board. Legal guardians of eligible children provided written informed consent.
: Not applicable.
: The authors declare that they have no competing interests.
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