The author(s) of this article has(ve) requested that it be retracted from publication
Volume 8, Issue 2, September 2014, Pages 159–171
Tassew Alemayehu1 and ASSEFA SERGAWIE2
1 Department of Biology, Adigrat University, Adigrat, Tigray, P.Box. 50, Ethiopia
2 College of natural and computational sciences, department of chemistry, Adis Abeba Inistitute Technology University, Adis Abeba, Ethiopia