An improved maize marketing system for African countries: the case of Zimbabwe.

PIP: This article proposes a system for Zimbabwe which retains government control of national stocks and enables the parastatal marketing system to stabilize prices, at the same time ensuring a more rational delivery system in rural areas with prices reflecting storage and transport costs. The local population is encouraged to fulfill local needs, thus avoiding the expense of directing all marketing and processing through the urban areas. A more localized system will also have greater multiplier effects. Zimbabwe's maize marketing system is used to show how this system could be modified with benefits to rural consumers, producers and government. Data suggest there is little market exploitation: price differentials between markts reflect transport costs, returns on storage are reasonable, and voluntary procurement operations are usually able to stabilize prices. Zoning, movement restrictions and compulsory procurement have been shown to destabilize food markets; prices between markets are higher in periods of strict control than when marketing is relatively free. Controlled marketing answers a real political and economic need in Zimbabwe. Existing public food marketing agencies are not inherently inefficient. While stabilizing maize supply, there are important advantages in announcing preplanting prices, but any trade in maize only takes place after price setting. It is unlikely that there would be both imports and exports in any 1 year, except when previous contracts are being fulfilled. 2 policy options are available to cover anticipated periods of insufficient national maize production: the maintenance of a strategic reserve; and importation of maize to cover supply shortfalls. Single-channel marketing should be replaced by an internal free market operating between floor and ceiling prices by supply manipulation to prevent excessive producer and consumer welfare fluctuations. This system would be more efficient and have beneficial effects on development. It is more equitable for the rural poor, and result in greater stability of producer incomes, more reliable food supplies, higher producer prices and the release of public funds.^ieng

Evaluación de reactivos comerciales empleados en el diagnóstico de la enfermedad de Chagas en bancos de sangre de Chile: II aplicación rutinaria / Assesement of comercial kits used for Chagas' diseases diagnosis in blood banks: II routinary use

Aiming to study the applicability and reproducibility of four comercial kits used for the serological detection of Chagas disease (Chagatest-Inst Invest Paraguay, Ortho Chagas, Abbott Chagas (ELISA tests) and Estabilgen Hemo Chagas (indirect hemagglutination test), a comparative serological study was performed in 256 sera samples coming from a highly endemic area, 249 samples from a low endemic area, 180 reference sera and 2264 samples coming from three blood banks. Specificity of the kits was excellent and sensitivity ranged from 60 to 100 percent. The indirect hemagglutination test has the lower sensitivity. Some disagreements in the results were observed in the three blood banks, probably due to an unsatisfactory reactive management. We conclude that ELISA tests should be recommended for routine detection of Chagas disease and that for this purpose, a net of laboratories under the direction of a national reference center should exist. This center should assess new commercial products, train technicians and supervise the laboratories