56 research outputs found

    Scientific basis for banana cultivar proportions on-farm in East Africa

    Get PDF
    Banana (Musa spp.) production and diversity in the East African region, has been on the decline for the last 20 years due to both a biotic and biotic problems. There has been an ecological and socio-economic imbalance in the East African Highland banana (Musa AAA-EA) growing systems due to this decline. However, farmers have been growing these bananas in cultivar mixtures, a practice which ensures the continuous sustainability of the system. Cultivar mixtures, however, seem to be in specific proportions based on the strength and weakness of eachcultivar and so affecting the clone sets to which cultivars belong, as well as providing predictions on the conservation status of each clone set. The primary objective of the study was to account for the farmers’perceptions behind cultivar proportions and to understand the scientific basis of these proportions in selected sites in East Africa. The study was carried out in Karagwe, Bushenyi and Masaka districts in East Africa, a region considered to be a secondary centre of diversity for bananas. Thirty farms were sampled in one selected parish/ward in the three sites for ecological data. The quadrat method was used to record abundances of identified cultivars in order to determine the cultivar proportions. Ethno-botanical data collected on traditional knowledgewas analysed for twenty-three identified traditional cultivar-selection criteria used in the participatory rural appraisal (PRA), as well as interviews from 15 key informants of each study area. A total of 105 cultivars were identified, 76% of which were the East African Highland bananas. Although fourteen cultivars were common to the three sites, Masaka had the highest proportion with Nfuuka cultivar leading the five clone sets. Cultivar diversity indices explained the proportions in terms of richness and evenness and Nfuuka was the richest clone set. Although all clone sets were represented at each site, they were not evenly distributed; a factor which is disadvantageous in the conservation status of the crop. While results indicated that the agro-ecological and traditional utilisation criteria formed the basis for cultivar proportions on farm for both Karagwe and Masaka, farmers were found to do so because of the high traditional values attached to the crop. However, knowing cultivar proportions in terms of richness and evenness can assist in predicting the stability or change in diversityof banana growing sites

    Influence of hydrological fluctuations on vegetation and Avifauna species composition, abundance and diversity in the Bahi Swamp wetlands Central Tanzania

    Get PDF
    This study was conducted in Bahi wetlands to assess the influence of  hydrological fluctuations on the vegetation and avifauna species  composition, abundance and diversity. A total of 80 rectangular vegetation plots measuring 2m x 5m were established along transect lines radiating from the core wetland, along eight cardinal directions each transect having a length of 1200m and accommodating 10 sampling points. Avifauna  species were inventoried in 3 points along each transect making a total of 24 sampling points for birds. One-way ANOVA was performed to  test for significant differences in the avifauna species diversity along the  hydrological gradient. A total of 40 avifauna species and 56 plant species belonging to 18 and 7 families respectively were recorded. There were  significant differences (p<0.05) in avifauna and plant species composition, abundance and diversity between distances from the centre of the wetland. Avifauna species abundance and diversity decreased with increasing   distance from centre of the wetland. Likewise, the abundance of plant species decreased with increasing distance from the centre of the wetland. The flora and avifauna species composition, abundance and diversity in theBahi wetlands are influenced by hydrological fluctuations, whereby the  composition, abundance and diversity are higher closer to the wetland than away from the edge of the wetland. The vegetation of wetland is  dominated by Leersia hexandra and other members of the Graminae  family. Bahi wetland is a refuge for migratory avifauna species. It was observed that both distant and African migrants visit the wetland for wintering. The most abundant species were Greater Flamingoes and Red Knobbed Coot. Awareness and education on the biodiversity values of the wetland is needed to influence conservation and sustainable utilization of  the wetland resources

    Characterization of MTAP gene expression in breast cancer patients and cell lines

    Get PDF
    MTAP is a ubiquitously expressed gene important for adenine and methionine salvage. The gene is located at 9p21, a chromosome region often deleted in breast carcinomas, similar to CDKN2A, a recognized tumor suppressor gene. Several research groups have shown that MTAP acts as a tumor suppressor, and some therapeutic approaches were proposed based on a tumors\ub4 MTAP status. We analyzed MTAP and CDKN2A gene (RT-qPCR) and protein (western-blotting) expression in seven breast cancer cell lines and evaluated their promoter methylation patterns to better characterize the contribution of these genes to breast cancer. Cytotoxicity assays with inhibitors of de novo adenine synthesis (5-FU, AZA and MTX) after MTAP gene knockdown showed an increased sensitivity, mainly to 5-FU. MTAP expression was also evaluated in two groups of samples from breast cancer patients, fresh tumors and paired normal breast tissue, and from formalin-fixed paraffin embedded (FFPE) core breast cancer samples diagnosed as Luminal-A tumors and triple negative breast tumors (TNBC). The difference of MTAP expression between fresh tumors and normal tissues was not statistically significant. However, MTAP expression was significantly higher in Luminal-A breast tumors than in TNBC, suggesting the lack of expression in more aggressive breast tumors and the possibility of using the new approaches based on MTAP status in TNB

    Evidence-based guidelines for supportive care of patients with Ebola virus disease.

    Get PDF
    The 2013-16 Ebola virus disease outbreak in west Africa was associated with unprecedented challenges in the provision of care to patients with Ebola virus disease, including absence of pre-existing isolation and treatment facilities, patients' reluctance to present for medical care, and limitations in the provision of supportive medical care. Case fatality rates in west Africa were initially greater than 70%, but decreased with improvements in supportive care. To inform optimal care in a future outbreak of Ebola virus disease, we employed the Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology to develop evidence-based guidelines for the delivery of supportive care to patients admitted to Ebola treatment units. Key recommendations include administration of oral and, as necessary, intravenous hydration; systematic monitoring of vital signs and volume status; availability of key biochemical testing; adequate staffing ratios; and availability of analgesics, including opioids, for pain relief

    New filovirus disease classification and nomenclature.

    Get PDF
    The recent large outbreak of Ebola virus disease (EVD) in Western Africa resulted in greatly increased accumulation of human genotypic, phenotypic and clinical data, and improved our understanding of the spectrum of clinical manifestations. As a result, the WHO disease classification of EVD underwent major revision
    • …
    corecore