Contents

RESEARCH ARTICLES 

Mathematics

On the equation xy = z (y - x2) over a unique factorization domain 

1-15

Yismaw Alemu

Abstract

Statistics

The efficiency of OLS estimator in the linear-regression model with spatially correlated errors 

17-33

Butte Gotu

Abstract

Agricultural Science

Growth performance of crossbred dairy cattle at Asella Livestock Farm, Arsi Ethiopia 

35-49

Abdinasir Ibrahim and Eskil Brännäng

Abstract

Geology

Surface kinetic temperature mapping using satellite spectral data in 

Central Main Ethiopian Rift and adjacent highlands 

51-68

Tenalem Ayenew

Abstract

Epithermal gold occurrences in the lakes district of the Main Ethiopian Rift and Tendaho area of the Afar Rift: discovery of a metallogenic province 

69-91

Solomon Tadesse

Abstract

SHORT COMMUNICATIONS

The impact of uncontrolled waste disposal on surface water quality in Addis Ababa, Ethiopia 

93-104

Tamiru Alemayehu

Abstract

Test of endothelial monolayer integrity in the presence or absence of endotoxin and anti-tnf-a monoclonal antibodies 

105-112

Andualem Mossie, Stefan Eriksson, Hassen Taha Sherief and Legesse Zerihun

Abstract

The synergistic effects of Metarhizium anisopliae (Metschikoff) with the acyl urea insecticides teflubenzuron and diflubenzuron for Schistocerca gregaria (Orthoptera: Acrididae) 

113-125

Emiru Seyoum

Abstract

FEATURE ARTICLES

Lake Afdera: a threatened saline lake in Ethiopia 

127-131

Abebe Getahun

Abstract

Twin carbon arc torch 

133-138

David A. Skelskey

Abstract