160 research outputs found
Geochemistry and Petrology of Metasediments Associated with Gold Mineralization in Imonga Area, Eastern DR Congo
The Imonga sector is located in the Eastern of DR Congo, precisely within the Maniema province located in the Central African Karagwe Ankole belt, which forms together with the Kibara belt a Mesoproterozoic geological structure. This study gives fresh information on the origin of the metasediments in this zone, their geochemical and petrographic characteristics, and the genetic model of the gold mineralization that they contain. Field observations, as well as petrographic and geochemical studies reveal that the metasediments consist of sericitoschists and quartzites. Petrographic work revealed varying proportions of sericite and quartz with subordinate iron-oxide minerals. Geochemically, most of the analyzed metasediments displayed higher SiO2 contents and enriched in Fe2O3. They belong to the groups of shales and sand (sometimes rich in iron), litharenite and grauwakes derived from quartzose sedimentary and mafic igneous provenance. Their protholites are intermediate altered (70 < CIA < 90) andesitic, granite and granodioritic rocks emplaced in a geotectonic active continental margin. Gold mineralization in the Imonga sector occur in veins. Gold mineralization is controlled by veins which occur as micro veins with small thickness. The mineralization consists of specific grains and nanoparticles pyrite associated with gold, hematite and goethite. The hydrothermal alteration accompanying this mineralization consists of silica, goethite and sericite-carbonate. Keywords: Metasediment, sericitoschist, quartzite, sericite, goethite, vein, Gold, Imonga, Eastern DR Congo DOI: 10.7176/JEES/13-2-04 Publication date:March 31st 202
Human African trypanosomiasis amongst urban residents in Kinshasa: a case-control study.
BACKGROUND: Increasing numbers of human African trypanosomiasis (HAT) cases have been reported in urban residents of Kinshasa, Democratic Republic Congo since 1996. We set up a case-control study to identify risk factors for the disease. METHODS: All residents of the urban part of Kinshasa with parasitologically confirmed HAT and presenting for treatment to the city's specialized HAT clinics between 1 August, 2002 and 28 February, 2003 were included as cases. We defined the urban part as the area with contiguous habitation and a population density >5000 inhabitants per square kilometre. A digital map of the area was drawn based on a satellite image. For each case, two serologically negative controls were selected, matched on age, sex and neighbourhood. Logistic regression models were fitted to control for confounding. RESULTS: The following risk factors were independently associated with HAT: travel, commerce and cultivating fields in Bandundu, and commerce and cultivating fields in the rural part of Kinshasa. No association with activities in the city itself was found. DISCUSSION: In 2002, the emergence of HAT in urban residents of Kinshasa appears mainly linked to disease transmission in Bandundu and rural Kinshasa. We recommend to intensify control of these foci, to target HAT screening in urban residents to people with contact with these foci, to increase awareness of HAT amongst health workers in the urban health structures and to strengthen disease surveillance
Serological Survey of Foot-and-Mouth Disease Virus in Buffaloes ( Syncerus caffer
A study was conducted to determine the serotypes of foot-and-mouth disease viruses (FMDV) circulating in African buffaloes (Syncerus caffer) from selected areas in Zambia. Sera and probang samples were collected between 2011 and 2012 and analysed for presence of antibodies against FMDV while probang samples were used to isolate the FMDV by observing cytopathic effect (CPE). Samples with CPE were further analysed using antigen ELISA. High FMD seroprevalence was observed and antibodies to all the three Southern African Territories (SAT) serotypes were detected in four study areas represented as follows: SAT2 was 72.7 percent; SAT1 was 62.6 percent; and SAT3 was 26.2 percent. Mixed infections accounted for 68.6 percent of those that were tested positive. For probang samples, CPE were observed in three of the samples, while the antigen ELISA results showed positivity and for SAT1 (n=1) and SAT2 (n=2). It is concluded that FMDV is highly prevalent in Zambian buffaloes which could play an important role in the epidemiology of the disease. Therefore livestock reared at interface with the game parks should be included in all routine FMDV vaccination programmes
ASSESSMENT OF COMMON BEAN CULTIVAR DIVERSITY IN SELECTED COMMUNITIES OFCENTRAL UGANDA
Common bean ( Phaseolus vulgaris ) L. diversity has been nurtured by
Uganda\u2019s farming communities and in return it has sustained their
livelihoods for over 40 decades. Despite the farmers\u2019 invaluable
effort in perpetuating this diversity, there is limited overall
understanding of its status and dynamics on-farm. This study assessed
the amount and status of the cultivar diversity in selected rural and
peri-urban communities of central Uganda. Data were purposefully
collected from 120 households through household surveys, focus group
discussions and direct field observations. Diversity measures, status
of the cultivars and morphological distinctiveness were estimated by
Simpson\u2019s index of diversity (1-D), four cell analysis and
cluster analysis, respectively. A total of 24 cultivars were observed
in the whole study, and both communities had equal cultivar
richness.There were no significant differences in the number of
cultivars maintained by the farmers in the rural and those in the
peri-urban communities. Both communities had substantial cultivar
evenness (0.81 and 0.82 in rural and peri-urban, respectively),
although only 19% of cultivars were grown on relatively larger areas
and by many households. Impressively, at least 30% of the households in
each community nurtured different sets of cultivars. We thus recommend
the need to put in place incentive mechanisms that can encourage a
section of the community to continue conserving P. vulgaris diversity
on-farm to ensure its continued evolution and adaptation to changing
biotic and abiotic factors.La diversit\ue9 du haricot commun ( Phaseolus vulgaris ) L. a
\ue9t\ue9 d\ue9velopp\ue9 par des communaut\ue9s de fermiers
en Ouganda et, en retour, la culture a durablement contribu\ue9 au
bien \ueatre familial pendant plus de quarante ans. Malgr\ue9 des
efforts consid\ue9rables des fermiers dans la perp\ue9tuation de
cette diversit\ue9, la compr\ue9hension de sa situation et
dynamique en champ reste limit\ue9e. Cette \ue9tude a
\ue9valu\ue9 le nombre et la situation de la diversit\ue9 des
cultivars dans des communaut\ue9s s\ue9lectionn\ue9es en milieux
rural et p\ue9ri-urbain de l\u2019Ouganda central. Les donn\ue9es
d\u2019\ue9taient collect\ue9es de fa\ue7on raisonn\ue9e dans
120 m\ue9nages \ue0 travers une enqu\ueate de m\ue9nage, les
groupes de discussions et des observations directes sur terrain. Des
mesures de diversit\ue9, la situation des cultivars et la
diff\ue9renciation morphologique \ue9taient estim\ue9es par
l\u2019index de diversit\ue9 de Simpson (1-D), quatre analyses de
cellules et l\u2019analyse de groupes, respectivement. Un total de 24
cultivars \ue9tait observ\ue9 dans toute l\u2019\ue9tude, et
toutes les deux communaut\ue9s avaient une richesse \ue9gale de
cultivars. Aucune diff\ue9rence significative n\u2019\ue9tait
trouv\ue9e dans le nombre de cultivars maintenu par les fermiers
ruraux et p\ue9ri-urbains. Les deux communaut\ue9s avaient un
nombre substantiellement invariant de cultivars (0.81 et 0.82 en milieu
rural et p\ue9ri-urbain, respectivement), malgr\ue9 que 19%
seulement des cultivars \ue9taient cultiv\ue9s relativement sur des
vastes \ue9tendues et par plusieurs m\ue9nages. De fa\ue7on
impressionnante, au moins 30% des m\ue9nages dans chaque
communaut\ue9 avaient d\ue9velopp\ue9 diff\ue9rents types de
cultivars. Ceci d\ue9montre le besoin de mettre en place des
m\ue9canismes d\u2019encouragement des communaut\ue9s afin de
continuer la conservation en milieux paysan de la diversit\ue9 du P.
vulgaris pour assurer son \ue9volution continue et l\u2019adaptation
au changement des facteurs biotiques et abiotiques
Advancing the right to health in East and Southern Africa regional workshop report
The main conversation of the workshop in Entebbe (Uganda) explored regional health systems through the OPERA framework, an assessment process which triangulates Outcomes, Policy Efforts and Resources to make an overall Assessment. This report covers discussions and panel discussions between expert participants. To enhance monitoring, compliance and fulfilment of economic and social rights the Centre for Economic and Social Rights (U.S.) developed a holistic approach and step by step framework known as the OPERA framework. It applies a multi-disciplinary approach that offers practical guidance, tools and techniques, as a critical tool in monitoring state compliance on the right to health
Has continued exposure to banana Xanthomonas Wilt worsened farmers’ welfare over time? Evidence from banana-producing households in Uganda
The livelihoods of millions of banana-farming households have been affected by Banana Xanthomonas Wilt (BXW) in Uganda for nearly two decades. The disease has no known cure, all banana cultivars grown are susceptible to it and it is endemic in all banana-producing regions in the country. This study analysed the long-term impact of the disease on the livelihoods of banana-producing households. Using a balanced panel dataset of 1,056 households, which were visited in 2015 and revisited in 2018, provides the opportunity to empirically measure the long-term consequences of the disease on farmers’ economic wellbeing in the four major banana growing regions in Uganda. We find striking results pertinent to disease incidence, success in disease management, household income and poverty when deploying BXW control practices. Although the disease has remained present in farmers’ fields, there is a significant reduction in household poverty levels. Results show that some farmers expanded the
production of beans and coffee without encroaching on their banana plantations. Increase in bean production was largely through intercropping. Investment in coffee was constrained by land ownership, hence only a viable venture for the wealthy farmers who own bigger pieces of land. Land-poor farmers continued to rely on bananas for their livelihoods. Consistent participation in disease management training significantly influenced adoption of the cultural control practices. Consequently, farming households that systematically adopted these practices were able to maintain low levels of disease incidence, improve productivity by 438 kg/ha/year and increased their daily and annual household income by US648), respectively. The findings suggest that banana is an important crop to smallholder farmers and expansion into other cash crops requires bigger
resource outlays, and that despite continued exposure to BXW, farmers’ income increased over time. Farmers should continuously and systematically use the recommended control practices to avoid BXW resurgence and, consequently, a reduction in their income
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