About the Authors
Umeå Centre for Global Health Research, Epidemiology and Global Health, Department of Public Health and Clinical Medicine, Umeå University, Umeå, Sweden
Laboratory of Mathematical Parallel Systems, Department of Mathematics & Statistics, York University, Toronto, Ontario, Canada
Environmental Health Institute, National Environment Agency, Singapore, Singapore
The authors have declared that no competing interests exist.
Conceived and designed the experiments: YLH. Analyzed the data: YLH HZ NN JR. Wrote the paper: YLH HZ NN LCN JR.