271 research outputs found

    Role of livestock on mixed smallholder farms in the Ethiopian Highlands : a case study from the Baso and Worena Wereda near Debre Berhan

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    The productivity of livestock in sub-Saharan Africa in terms of milk and meat is the lowest of any world region. The outcome of livestock development projects has been disappointing. Low returns to investment in such projects have often arisen from poor project design, in turn the result of inadequate understanding of the relevant livestock production systems. Livestock in sub-Saharan Africa is concentrated on smallholder farms, where crop and livestock husbandry are practiced in association. The role of livestock in such "mixed" farming systems and the interactions between the crop and livestock components have often been poorly understood.The highlands have the highest density of both the human and livestock populations of any major ecological zone in sub- Saharan Africa. Almost all the livestock of this zone can be found on mixed smallholder farms. Ethiopia accounts for 50% of the African highland landmass, and has the largest livestock herd on the African continent. This study reviews the role of livestock on mixed smallholder farms in the Ethiopian highlands.The study takes a farming systems approach to research. It was undertaken within the framework of the Highlands Programme of the International Livestock Centre for Africa (ILCA). Field data were collected from 1979 to 1985 through farm management and household economic surveys of a total of 170 traditional smallholder farms located in four different Peasants Associations of the Baso and Worena district. The area is representative of the higher altitude zone of the Ethiopian highlands, and is located in a cereal-livestock zone. The farming system is based on smallholder rainfed subsistence agriculture, annual crops planted by broadcasted seed, rudimentary implements and an ox-drawn wooden plough, the 'maresha'. The results of this study show that livestock are of crucial importance to this farming system, and that there is a high level of crop-livestock integration. Livestock provide a dominant part of the farm's cash income and gross margin. The main outputs of cattle were intermediate products used as inputs into the crop production enterprise, such as draught power for land cultivation and crop threshing, and manure for fertilizer. The availability of animal draught power was a significant factor in determining the level of farm grain production. Livestock generated a substantial amount of employment, and was of prime importance in providing security and a source of investment to the farm household. Animals, particularly small ruminants, were sold according to cash flaw needs, and purchased as a store of wealth. Donkeys provide almost all the transport of inputs and outputs of agricultural products. The data show that livestock productivity is low for final products, but high in terms of intermediate products. The main production and institutional constraints to increased farm output are identified and discussed. The principal constraint to the development of livestock production for increased offtake of meat and milk is the importance given by farmers to the intermediate functions of livestock.Research on relevant technology to increase the productivity of livestock in the Ethiopian highlands is reviewed. At ILCA's experiment station in Debre Berhan, research was undertaken on possible interventions for the farming system of the Baso and Worena district. Two technologies related to smallholder livestock production appeared particularly promising: the use of crossbred dairy cows (Boran x Friesian) for milk production, and the use of a newly developed single-ox plough. The encouraging results of on-station research and an ex-ante evaluation using a linear programming model led to the initiation of farmer-managed on-farm trials of both technologies in the same peasants associations in which the diagnostic studies had been undertaken previously. The productivity of test farms was compared with that of other farms that served as a control. Crossbred dairy cows had significantly higher milk yields than cows of local breeds, incomes of dairy test farmers were significantly higher than those of control farmers, and no major problems were encountered in technology adoption. The major constraints to dairy development in the area were found to be a shortage of feed during the dry season, lack of milk marketing facilities particularly during the main fasting period, occasional disease problems of crossbred cattle, and the lack of appropriate breeding services. If adequate extension services can be provided, smallholder dairy production on the basis of crossbred cows could be an efficient vehicle for agricultural development in the area. Verification trials were also conducted on the utilisation and rate of adoption of the single-ox plough for land cultivation. Both utilisation and adoption were low. An important weakness of the technology appeared to be the poor structural stability of the single-ox unit compared with the traditional 'maresha'. plough drawn by a pair of oxen. The research findings suggest that single-ox ploughing may be useful for seed covering operations, but could not replace the use of paired oxen for land cultivation.The study concludes with an appraisal of the methodological approach taken in the research process, and a discussion of the transferability of the research results that were obtained. The implications of the study for future research work m agriculture and livestock in the Ethiopian highlands are also discussed.</TT

    The use of single oxen for crop cultivation in Ethiopia

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    Reports experiences with on-farm trials to assess the use of single oxen for work on mixed smallholder farms in the central highlands of Ethiopia, with particular reference to draft power and agricultural production, design and testing of the single ox technique, and results obtained during the 1983 crop year and future prospects with respect to feed requirements and advantages of using the single ox

    Does mass drug administration for the integrated treatment of neglected tropical diseases really work? Assessing evidence for the control of schistosomiasis and soil-transmitted helminths in Uganda

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    This paper was one of four papers commissioned to review the role of social sciences in NTD control by TDR, the Special Programme for Research and Training on Tropical Diseases, which is executed by WHO and co-sponsored by UNICEF, UNDP, the World Bank and WHO.This article has been made available through the Brunel Open Access Publishing Fund.Background: Less is known about mass drug administration [MDA] for neglected tropical diseases [NTDs] than is suggested by those so vigorously promoting expansion of the approach. This paper fills an important gap: it draws upon local level research to examine the roll out of treatment for two NTDs, schistosomiasis and soil-transmitted helminths, in Uganda. Methods: Ethnographic research was undertaken over a period of four years between 2005-2009 in north-west and south-east Uganda. In addition to participant observation, survey data recording self-reported take-up of drugs for schistosomiasis, soil-transmitted helminths and, where relevant, lymphatic filariasis and onchocerciasis was collected from a random sample of at least 10% of households at study locations. Data recording the take-up of drugs in Ministry of Health registers for NTDs were analysed in the light of these ethnographic and social survey data. Results: The comparative analysis of the take-up of drugs among adults revealed that although most long term residents have been offered treatment at least once since 2004, the actual take up of drugs for schistosomiasis and soil-transmitted helminths varies considerably from one district to another and often also within districts. The specific reasons why MDA succeeds in some locations and falters in others relates to local dynamics. Issues such as population movement across borders, changing food supply, relations between drug distributors and targeted groups, rumours and conspiracy theories about the 'real' purpose of treatment, subjective experiences of side effects from treatment, alternative understandings of affliction, responses to social control measures and historical experiences of public health control measures, can all make a huge difference. The paper highlights the need to adapt MDA to local circumstances. It also points to specific generalisable issues, notably with respect to health education, drug distribution and more effective use of existing public health legislation. Conclusion: While it has been an achievement to have offered free drugs to so many adults, current standard practices of monitoring, evaluation and delivery of MDA for NTDs are inconsistent and inadequate. Efforts to integrate programmes have exacerbated the difficulties. Improved assessment of what is really happening on the ground will be an essential step in achieving long-term overall reduction of the NTD burden for impoverished communities.This article is available through the Brunel Open Access Publishing Fund

    Orally active antischistosomal early leads identified from the open access malaria box.

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    BACKGROUND: Worldwide hundreds of millions of schistosomiasis patients rely on treatment with a single drug, praziquantel. Therapeutic limitations and the threat of praziquantel resistance underline the need to discover and develop next generation drugs. METHODOLOGY: We studied the antischistosomal properties of the Medicines for Malaria Venture (MMV) malaria box containing 200 diverse drug-like and 200 probe-like compounds with confirmed in vitro activity against Plasmodium falciparum. Compounds were tested against schistosomula and adult Schistosoma mansoni in vitro. Based on in vitro performance, available pharmacokinetic profiles and toxicity data, selected compounds were investigated in vivo. PRINCIPAL FINDINGS: Promising antischistosomal activity (IC50: 1.4-9.5 µM) was observed for 34 compounds against schistosomula. Three compounds presented IC50 values between 0.8 and 1.3 µM against adult S. mansoni. Two promising early leads were identified, namely a N,N'-diarylurea and a 2,3-dianilinoquinoxaline. Treatment of S. mansoni infected mice with a single oral 400 mg/kg dose of these drugs resulted in significant worm burden reductions of 52.5% and 40.8%, respectively. CONCLUSIONS/SIGNIFICANCE: The two candidates identified by investigating the MMV malaria box are characterized by good pharmacokinetic profiles, low cytotoxic potential and easy chemistry and therefore offer an excellent starting point for antischistosomal drug discovery and development

    Cellular and humoral immune responses and protection against schistosomes induced by a radiation-attenuated vaccine in chimpanzees

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    The radiation-attenuated Schistosoma mansoni vaccine is highly effective in rodents and primates but has never been tested in humans, primarily for safety reasons. To strengthen its status as a paradigm for a human recombinant antigen vaccine, we have undertaken a small-scale vaccination and challenge experiment in chimpanzees (Pan troglodytes). Immunological, clinical, and parasitological parameters were measured in three animals after multiple vaccinations, together with three controls, during the acute and chronic stages of challenge infection up to chemotherapeutic cure. Vaccination induced a strong in vitro proliferative response and early gamma interferon production, but type 2 cytokines were dominant by the time of challenge. The controls showed little response to challenge infection before the acute stage of the disease, initiated by egg deposition. In contrast, the responses of vaccinated animals were muted throughout the challenge period. Vaccination also induced parasite-specific immunoglobulin M (IgM) and IgG, which reached high levels at the time of challenge, while in control animals levels did not rise markedly before egg deposition. The protective effects of vaccination were manifested as an amelioration of acute disease and overall morbidity, revealed by differences in gamma-glutamyl transferase level, leukocytosis, eosinophilia, and hematocrit. Moreover, vaccinated chimpanzees had a 46% lower level of circulating cathodic antigen and a 38% reduction in fecal egg output, compared to controls, during the chronic phase of infection

    Parental transfer of the antimicrobial protein LBP/BPI protects Biomphalaria glabrata eggs against oomycete infections

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    Copyright: © 2013 Baron et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited. Funding: This work was funded by ANR (ANR-07-BLAN-0214 and ANR-12-EMMA-00O7-01), CNRS and INRA. PvW was financially supported by the BBSRC. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD

    Predicting the Impact of Long-Term Temperature Changes on the Epidemiology and Control of Schistosomiasis: A Mechanistic Model

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    , the causative agent of schistosomiasis in humans.The model showed that the impact of temperature on disease prevalence and abundance is not straightforward; the mean infection burden in humans increases up to 30°C, but then crashes at 35°C, primarily due to increased mortalities of the snail intermediate host. In addition, increased temperatures changed the dynamics of disease from stable, endemic infection to unstable, epidemic cycles at 35°C. However, the prevalence of infection was largely unchanged by increasing temperatures. Temperature increases also affected the response of the model to changes in each parameter, indicating certain control strategies may become less effective with local temperature changes. At lower temperatures, the most effective single control strategy is to target the adult parasites through chemotherapy. However, as temperatures increase, targeting the snail intermediate hosts, for example through molluscicide use, becomes more effective. will not respond to increased temperatures in a linear fashion, and the optimal control strategy is likely to change as temperatures change. It is only through a mechanistic approach, incorporating the combined effects of temperature on all stages of the life-cycle, that we can begin to predict the consequences of climate change on the incidence and severity of such diseases
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