应用核不育技术根治桑给巴尔采采蝇

:1 994年开始应用昆虫不育技术根治坦桑尼亚桑给巴尔的温古贾岛采采蝇(GlossinaausteniNewstead)项目。该项目在坦桑大陆东北部建立了采采蝇人工大量繁殖、辐射不育设施 ,在温古贾岛上空用轻型飞机航空释放雄性不育采采蝇。在全岛设立多达 70 0个粘虫板 ,监测野生和不育采采蝇种群 ,同时在 38个监测区用MHCT等技术监测采采蝇传播的家畜锥虫病。释放了约 80 0万只雄性不育采采蝇。南半岛不育 /野生的雄蝇比由 1 995年中期前的小于 2 0 / 1上升到大于 1 0 0 / 1 ,导致雌蝇诱导不育率快速上升。野生采采蝇密度于 1 996年初开始急速下降 ,最后 1只野生雄性和雌性采采蝇分别于 1 996年第 32、36周捕获。锥虫病发病率也降至 1 %以下 ,而且仅限于Trypanosomavivax。在最后 1只野生采采蝇捕获约 6代的时间后 ,于 1 997年 1 1月底停止航空释放雄性不育采采蝇 ,经独立专家组评估后 ,正式宣告桑给巴尔采采蝇已被根治     

A Large-scale Trial to Evaluate the Efficacy of a 1% Pour-on Formulation of Cyfluthrin (Cylence,Bayer) in Controlling Bovine Trypanosomosis in Eastern Zambia

A trial to evaluate the efficacy of a 1% cyfluthrin pour-on formulation (Cylence, Bayer) in reducing the incidence of bovine trypanosomosis was conducted in an area of ca. 2000 km2 of the Eastern Province of Zambia. The trial area was cultivated and carried a cattle population of approximately 11 animals/km2. Cattle were the main host of tsetse. Following the free of charge treatment of the adult cattle at intervals of 7 weeks and at a dosage of 15 ml/100 kg body weight, there was an increase in the average packed cell volume in the herd although the decline in the incidence of trypanosomal infections was more prolonged. The monthly incidence of trypanosomal infections started to decline substantially 8 months after the treatments were initiated. No trypanosomal infections were detected from 10 months after the start of the trial.     

Animal Health and Disease Control in the Usangu Wetland of Southwestern Tanzania

The Usangu Wetland in the Southern Highlands of Tanzania has always been a major livestock production area. This paper describes the physical and social enviroment of these Plains before presenting a short history of the veterinary services in the area. The main part of the paper examines, through historical records and interviews with livestock owners and administrative officials, the history of the major diseases affecting livestock.     

Land-use and land-cover dynamics in response to changes in climatic,biological and socio-political forces: the case of southwestern Ethiopia

Few studies of land-use/land-cover change provide an integrated assessment of the driving forces and consequences of that change, particularly in Africa. Our objectives were to determine how driving forces at different scales change over time, how these forces affect the dynamics and patterns of land use/land cover, and how land-use/land-cover change affects ecological properties at the landscape scale. To accomplish these objectives, we first developed a way to identify the causes and consequences of change at a landscape scale by integrating tools from ecology and the social sciences and then applied these methods to a case study in Ghibe Valley, southwestern Ethiopia. Maps of land-use/land-cover change were created from aerial photography and Landsat TM imagery for the period, 1957–1993. A method called `ecological time lines' was developed to elicit landscape-scale explanations for changes from long-term residents. Cropland expanded at twice the speed recently (1987–1993) than two decades ago (1957–1973), but also contracted rapidly between 1973–1987. Rapid land-use/land cover change was caused by the combined effects of drought and migration, changes in settlement and land tenure policy, and changes in the severity of the livestock disease, trypanosomosis, which is transmitted by the tsetse fly. The scale of the causes and consequences of land-use/land-cover change varied from local to sub-national (regional) to international and the links between causes and consequences crossed scales. At the landscape scale, each cause affected the location and pattern of land use/land cover differently. The contraction of cropland increased grass biomass and cover, woody plant cover, the frequency and extent of savanna burning, and the abundance of wildlife. With recent control of the tsetse fly, these ecological changes are being reversed. These complex patterns are discussed in the context of scaling issues and current conceptual models of land-use/land-cover change.     

Lipopolysaccharide binding protein in the acute phase response of experimental murine Trypanosoma brucei brucei infection

Cellular responses to lipopolysaccharide (LPS) are enhanced by LPS-binding protein (LBP). The present study investigated the acute phase response of LBP during Trypanosoma brucei brucei infection in mice. Mean plasma concentrations of LBP increased two-fold by the seventh day following infection, but decreased to intermediate levels by the 14th day. There were no significant differences in LBP concentrations of infected/antibiotic-treated and infected/untreated mice. At 35 days post-infection, the infected mice were treated with the anti-trypanosomal diminazine aceturate (Berenil^®). LBP levels of the mice then decreased to pre-infection levels within one-week. This demonstrated that LBP is an acute phase protein during murine trypanosomosis. Furthermore, opportunistic secondary bacterial infection during trypanosomosis did not seem to play an important role in the changes in plasma LBP levels. We speculate that the marked concomitant increases in plasma LBP and endotoxin-like activity following murine trypanosome infection might play an important role in the pathogenesis of trypanosomosis.