Systematic designs for experiments with mixtures

In this paper systematic designs for experiments with mixtures are developed. The plan of analysis of the experiment is discussed for a quadratic model of SCHEFF É (1958) for q-component mixture with orthogonal polynomials of third degree describing the time trends.     

Geographic views of human development

Human development can be divided into three stages: human ancestors (Lower Palaeolithic), early human races (Middle Palaeolithic) and modern humans (Upper Palaeolithic). Regional differentiation has been detected in the Lower Palaeolithic and is strongly developed in the Middle Palaeolithic but continues into the Upper Palaeolithic less marked. Clearly mixture at all levels accounts for this. Early humans absorbed the pre-existing regionalizations even as they further differentiated. Modern humans resulted from Upper Palaeolithic people spreading across the world and again absorbing the previous differentiations.