1 Department of Epidemiology, Jiann-Ping Hsu College of Public Health, Georgia Southern University, Statesboro, GA 30458, USA. Electronic address: cfung@georgiasouthern.edu.
2 College of Engineering, University of Georgia, Athens, GA, USA.
3 Department of Psychology, Emory University, Atlanta, GA, USA.
4 Journalism and Media Studies Centre, University of Hong Kong, Hong Kong Special Administrative Region, China.