Amazonia is home to a number of Amerindian groups who make a living by some combination of swidden horticulture, hunting, fishing and foraging. These populations have been disappearing at a rapid rate since the turn of the century as areas of forest and cerrado have been developed (Ribeiro, 1967), but there are still a number of Amerindian groups that are self-sufficient, or almost self sufficient, in food production, and have diets that appear to be traditional. The purpose of this paper is to review what is known of the diet and nutritional status of these groups.
Ideally we would like to be able to define Amerindian diets in terms of ecological variables, the characteristics of food resources, patterns of food selection and use, and the implications that these have for dietary adequacy, nutritional status and health. We would also like to understand how these change with contact and assimilation into Western society. However, much of what is known about diet in Amazonia is anecdotal. This kind of information is useful in providing a preliminary description of the diet, but provides little on which to judge the adequacy of the diet or potential nutritional problems. There is somewhat better information available on nutritional status, especially anthropometric indicators of nutritional status, but the interpretation of these indices is not straight forward because they are sensitive to a variety of environmental variables, as well as diet.
A variety of methods have been developed for assessing body composition, including isotopic determination of total body water, whole body 40 K counting, radiography, electrical conductance and impedance, etc. Two of the most common methods of assessing body composition, however, are hydrostatic weighing and determination of skinfold thicknesses. Although we won’t be doing hydrostatic weighing as part of the lab activities, the method is important for you to understand.
The hydrostatic or underwater weighing method is based upon the assumption that the body is composed of two components or compartments. The components are fat-free or lean mass (FFM), which is assumed to have a density of 1.10 kg/L, and a fat component, which is assumed to have a density of 0.90 kg/L. The density of the whole body, therefore, will depend upon the relative size of these two components. If the body density is known, it is possible to convert this to a % body fat using the following equation, which was derived by Siri: % fat= (495/body density)-450.
The objective of the firm consists of maximising its market value, so economists like to think. In practice, however, some firms do not pursue this objective, because the agency problems generated by the separation of ownership and control emerge. The problems of asymmetric information and moral hazard, and the lacks of monitoring mechanisms could lead to managers’ opportunist behaviours. In this context, the managers pursue their own interests which are not aligning with the shareholders’ objectives, and therefore, they expropriate rents to the shareholders, decreasing the firm results, and harming the other stakeholders of the firm.
