This research was conducted within the framework of the MU-IUC
program which is a 10 year (2004–2013) collaborative research program
between the Flemish Universities (Belgium) and Mekelle University
(Ethiopia) with the financial support of VLIR (Vlaamse
Interuniversitaire Raad—Flemish Interuniversity Council). The authors
would like to thank Mekelle University for providing logistic support
and the two anonymous reviewers for their valuable comments.