emphasis on milk yield (my) as well as milk yield persistency (myp) and calving interval (ci) is necessary to achieve more sustainable productionin dairy cattle. therefore the main objective of this study was to find an optimum regression model to estimate economic values for my, myp and ci.using a deterministic bio-economic model, seventyfiveproduction states differing mainly in my, mypand ciw...

the objective of this study was to estimate genetic parameters coupled with genetic and phonotypic trends for age at first calving (afc), open days(od) and milk yield(my) of first lactation in iranian holstein cows. records of reproduction and production for genetic evaluation from 1984 to 2005 for afc, od and my were 71736, 20126 and 20126, respectively. single and two-variable animal models w...

Dedication This dissertation is dedicated to my loving wife. Her continued support and unconditional love have provided me enough energy and time to continue and finish my research. This work is also dedicated to my parents, who have been beyond patient and have always been there when I needed them. Their love for their children is beyond any that I have ever witnessed. 4 Acknowledgments I woul...

In this text, associated with my opening lecture at the first INDRUM Conference, I will reflect on the achievements and challenges of mathematics education research at university level, in the light of my experience both as a researcher and a university teacher. First, I will come back to the historical evolution of this field of research through the retrospective analysis of some selected epis...

Andrén and colleagues (2008) recently published a paper reminding us of good scientific practice, taught and learnt during our early years of research, but frequently forgotten. This article has a similar objective. It is highly likely that the majority of microbial ecologists have taken a basic course in statistics. Unfortunately, the basic principles of statistical analysis and its significan...

Leader opening and closing behaviors are assumed to foster high levels of employee exploration and exploitation behaviors, hence motivating employee innovative performance. Applying the ambidexterity theory of leadership for innovation, results revealed that leader opening and closing behaviors positively predicted employee exploration and exploitation behaviors, respectively, above and beyond ...