Publications

Economic values for production traits (milk yield, MY, g; 12-month live weight, yLW, kg; consumable meat percentage, CM, {%}) and functional traits (mature doe live weight, DoLW, kg; mature buck live weight, LWb, kg; kidding frequency, KF; pre-weaning survival rate, PrSR, {%}; post-weaning survival rate, PoSR,{%}; doe survival rate, DoSR, {%}; and residual feed intake, RFI, kg) were estimated using profit functions for the Small East African goat. The scenario evaluated was a fixed flock size, and the resultant economic values (Kes per doe per year) were 34.46 (MY), 62.35 (yLW), 40.69 (CM), 0.15 (DoLW), 2.84 (LWb), 8.69 (KF), 17.38 (PrSR), 16.60 (PoSR), 16.69 (DoSR) and -3.00 (RFI). Similarly, the economic values decreased by -14.7 {%} (MY), -2.7 {%} (yLW), -23.9 {%} (CM), -6.6 {%} (DoLW), -98 {%} (LWb), -8.6 {%} (KF), -8.2 {%} (PrSR), -8.9 {%} (PoSR), -8.1 {%} (DoSR) and 0 {%} (RFI) when they were risk rated. The economic values for production and functional traits, except RFI, were positive, which implies that genetic improvement of these traits would have a positive effect on the profitability in the pastoral production systems. The application of an Arrow-Pratt coefficient of absolute risk aversion ($łambda$) at the level of 0.02 resulted in a decrease on the estimated economic values, implying that livestock keepers who were risk averse were willing to accept lower expected returns. The results indicate that there would be improvement in traits of economic importance, and, therefore, easy-to-manage genetic improvement programmes should be established.

Solid-state nanostructured gas sensors based on oxide materials play an important role in environmental monitoring, chemical process control, and personal safety. Yet, the underlying operating mechanism is still not well comprehended, while a deeper understanding would possibly lead to the engineering of sensing elements with enhanced sensitivities. Here we present ab initio density functional theory calculations that provide a comprehensive description of the ethanol sensing mechanism for ZnO nanowires: our results reveal that the competitive adsorption at the nanostructure surfaces between the analyte and the oxygen molecules present in the atmosphere induces a switching in surface conductance between semiconducting and conducting behavior that is related to the ethanol concentration and can be detected electronically, thus disclosing the sensing mechanism.