South Africa has a wide range of soils and climates. Extensive studies, especially over the past 25 years, have been conducted into practices and systems which could conserve the soil, water, energy and other resources required for sustainable crop production under various of these soil and climate combinations. Some of the results obtained and ongoing or envisaged work is outlined. It is hypot...

The management of running waters is of great importance for the life of our society and one of the challenges to be met by future generations. The sustainable use of water resources for their exploitation in different aspects is essential. Also, the maintenance of good water quality, both sanitary and environmental, is essential, since it depends largely on the conservation of biodiversity (Fer...

This article addresses the tradeoff between the losses caused by a new virus and the size of the team for developing an antivirus against the virus. First, an individual-level virus spreading model is proposed to capture the spreading process of the virus before the appearance of its natural enemy. On this basis, the tradeoff problem is modeled as a discrete optimization problem. Next, the infl...

46 Finance & Development / September 1998 OVERTY is both more widespread and more persistent in the Philippines than in neighboring ASEAN (Association of South East Asian Nations) countries. While the poverty rate has decreased in the Philippines over the past 25 years, the decline has been slower than in other ASEAN countries. Some of the blame for the Philippines’ slow progress in reducing th...

This paper models how a nation’s military manpower system affects the decision to go to war. Manpower systems differ primarily in how they distribute costs: the volunteer system shares the war’s manpower costs broadly, while the draft forces a subset of the population to bear a disproportionate share of the load. This difference affects an officeand policy-motivated politician’s decision to go ...

The Riacho Fundo qualitative model, a product of the Brazilian case study run by the Univeristy of Brasilia in Naturnet project, was evaluated by stakeholders. The Riacho Fundo basin is located near Brasilia, the new capital, and changes in land use are held responsible for major changes in the area, including deforestation, erosion, loss of biodiversity and water resources, and decrease in eco...

ORK-LOAD CONTROL FACTORS in clinical laboratories are not available in the literature. Business engineering and manpower-study methods are not readily applicable to laboratory work in which varied human elements exist. The remarkable variety of methods, choice of technics, personal viewpoints, lack of contacts, and few chances for direct comparison with the work of others in the field also make...

The study of Fanta et al. (2001) investigated the variability of annual river flow of the southern African region. The assessment results may be useful for practitioners to improve water resources planning and management in this region in the future. However, the methodology used by the authors is questionable and the objective of the present paper is to point out some drawbacks in that methodo...