Food Vending: Adaptation Under Difficult Circumstances
The respondents discussed in this article depended on food vending as their main source of income. To succeed in this activity requires shrewd marketing and hard work. For the majority food vending was basically a hanging on and coping strategy, offering very limited surplus for investment. Food vending allowed them merely to stay in town while maintaining a foot in their home villages. The paper presents both a descriptive and an analytical account of food vending activities by female heads of households in Masvingo. The officially imposed constraints on food vending demonstrate the existence of competing and conflicting rationalities between male decision-makers and poor women. The inter -connections between food vendors and the formal markets are noted. Journal of Social Development in Africa Vol 15 No 2 2000, pp. 69-92
Conceptualizing Livelihood Strategies in African Cities
The usefulness of the informal sector and the survival strategies approaches for understanding African urban economies has been undermined by the transformations in urban livelihood strategies brought about by the continent's economic crises and neoliberal economic reform policies. Contemporary livelihood strategies in many African cities involve participation in multiple economic activities, usually in both the formal and informal sectors. This paper proposes the “multiple modes of livelihood” (MML) approach as a framework for capturing this emerging livelihood strategy and presents evidence to show the magnitude of the strategy and the kind of activities undertaken. Development and planning implications of this strategy include the following: i) planning theories must reflect the changing livelihood in African cities; ii) the different geographies of such activities within and between urban areas, the proliferation of home-based enterprises in the middle- and professional-class neighborhoods, the emergence of nontraditional household arrangements, and the importance of urban agriculture suggest the need to indigenize urban planning in Africa; and iii) the proliferation of multiple livelihood strategies, especially among public sector employees, has significant implications for national development, especially as it relates to the performance of the public sector.
Coated-wire electrodes containing polymer immobilized ionophores blended with poly(vinyl chloride).
Polymers containing covalently attached 18-crown-6 or 2.2.2 cryptand units were incorporated into plasticized PVC membranes and the composite membranes were examined as potassium ion sensor elements. Ionophores were linked to carboxy-PVC and to poly(acrylic acid) via amide linkages to an alkyl spacer unit. Coated-wire electrodes (CWEs) from the immobilized ionophores gave acceptable responses, but conventional ion-selective membrane electrodes (ISEs) prepared by solvent casting were inactive. Dip-cast membranes did give active ISEs. Potassium electrode performance was independent of the loading of the ionophore within the acrylate support polymer, but depended upon the spacer length. Ion selectivity varied with the ionophore loading within the support polymer. Selectivity is a composite of the ionophore selectivity and ion-exchange interactions with the acrylate backbone, giving selectivities akin to carboxylate substituted crown ethers, notably enhanced monovalent/divalent ion discrimination relative to the ionophore in solution. Polymer immobilization extended the lifetime of active electrodes.