85 research outputs found
A Policy Brief on Adopting the Somali Camel for Enhanced Profitability and Pastoral Resilience in Northern Kenya
Persistent drought and high temperatures in Isiolo and Marsabit counties of northern Kenya repeatedly devastate livestock herds particularly cattle making the pastoralists less resilient, more vulnerable to climate change and poor. To address this challenge, an IGAD funded project promoted adoption of Somali camel breed, trained farmers on improved management and also estimated potential profitability of rearing the camel. Through the project, trainers were trained and facilitated to train 240 peri-urban Somali camel producers in Isiolo and Marsabit on breeding, health, routine husbandry and marketing. Impact study documenting positive stories of change was conducted at the end. Producers who hitherto made zero money from their camels were making KES. 42,000 a month from sale of 20 litres of milk daily from only 5 milking camels; producers had adopted a new grazing management strategy that ensured daily access of the camel milk market and conservation of grazing areas around settlements; motor bikes had been adopted as means delivering milk to collection centers thus creating jobs for the youth; the beneficiary producers were spending more money on production inputs. In terms of policy, the county governments of Isiolo and Marsabit need to appreciate the huge business potential in Somali camel rearing and the magnitude of positive change that can be brought about by capacity training of producers on improved camel management technologies and agree to allocate more funds in support of livestock production extension services
Spatial heterogeneity of habitat suitability for Rift Valley fever occurrence in Tanzania: an ecological niche modelling approach
Despite the long history of Rift Valley fever (RVF) in Tanzania, extent of its suitable habitat in the country remains unclear. In this study we investigated potential effects of temperature, precipitation, elevation, soil type, livestock density, rainfall pattern, proximity to wild animals, protected areas and forest on the habitat suitability for RVF occurrence in Tanzania. Presence-only records of 193 RVF outbreak locations from 1930 to 2007 together with potential predictor variables were used to model and map the suitable habitats for RVF occurrence using ecological niche modelling. Ground-truthing of the model outputs was conducted by comparing the levels of RVF virus specific antibodies in cattle, sheep and goats sampled from locations in Tanzania that presented different predicted habitat suitability values. Habitat suitability values for RVF occurrence were higher in the northern and central-eastern regions of Tanzania than the rest of the regions in the country. Soil type and precipitation of the wettest quarter contributed equally to habitat suitability (32.4% each), followed by livestock density (25.9%) and rainfall pattern (9.3%). Ground-truthing of model outputs revealed that the odds of an animal being seropositive for RVFV when sampled from areas predicted to be most suitable for RVF occurrence were twice the odds of an animal sampled from areas least suitable for RVF occurrence (95% CI: 1.43, 2.76, p < 0.001). The regions in the northern and central-eastern Tanzania were more suitable for RVF occurrence than the rest of the regions in the country. The modelled suitable habitat is characterised by impermeable soils, moderate precipitation in the wettest quarter, high livestock density and a bimodal rainfall pattern. The findings of this study should provide guidance for the design of appropriate RVF surveillance, prevention and control strategies which target areas with these characteristics
Is small beautiful? Understanding the contribution of small businesses in township tourism to economic development
The increased importance attached by policy-makers to the anticipated developmental effects of tourism in developing countries has been insufficiently examined by academic researchers, particularly in the context of the contribution of small firms in urban areas. This deficiency is addressed by providing a review of existing research followed by an analysis of interviews with 90 tourism business located within and outside the townships of Langa and Imizamo Yethu, Cape Town, South Africa. The findings reveal tensions between the different actors involved in township tourism. While the involvement of small, locally owned, businesses is beneficial, it is limited by conflicts of interest, lack of trust, limited social networks and little attachment to the township locality. The discussion highlights the complexity of tourism's role in economic development, which has significant implications for local policy-makers
Inhibition of resistance-refractory P. falciparum kinase PKG delivers prophylactic, blood stage, and transmission-blocking antiplasmodial activity
The search for antimalarial chemotypes with modes of action unrelated to existing drugs has intensified with the recent failure of first-line therapies across Southeast Asia. Here, we show that the trisubstituted imidazole MMV030084 potently inhibits hepatocyte invasion by Plasmodium sporozoites, merozoite egress from asexual blood stage schizonts, and male gamete exflagellation. Metabolomic, phosphoproteomic, and chemoproteomic studies, validated with conditional knockdown parasites, molecular docking, and recombinant kinase assays, identified cGMP-dependent protein kinase (PKG) as the primary target of MMV030084. PKG is known to play essential roles in Plasmodium invasion of and egress from host cells, matching MMV030084's activity profile. Resistance selections and gene editing identified tyrosine kinase-like protein 3 as a low-level resistance mediator for PKG inhibitors, while PKG itself never mutated under pressure. These studies highlight PKG as a resistance-refractory antimalarial target throughout the Plasmodium life cycle and promote MMV030084 as a promising Plasmodium PKG-targeting chemotype
A G358S mutation in the Plasmodium falciparum Na<sup>+</sup> pump PfATP4 confers clinically-relevant resistance to cipargamin
Diverse compounds target the Plasmodium falciparum Na(+) pump PfATP4, with cipargamin and (+)-SJ733 the most clinically-advanced. In a recent clinical trial for cipargamin, recrudescent parasites emerged, with most having a G358S mutation in PfATP4. Here, we show that PfATP4(G358S) parasites can withstand micromolar concentrations of cipargamin and (+)-SJ733, while remaining susceptible to antimalarials that do not target PfATP4. The G358S mutation in PfATP4, and the equivalent mutation in Toxoplasma gondii ATP4, decrease the sensitivity of ATP4 to inhibition by cipargamin and (+)-SJ733, thereby protecting parasites from disruption of Na(+) regulation. The G358S mutation reduces the affinity of PfATP4 for Na(+) and is associated with an increase in the parasite’s resting cytosolic [Na(+)]. However, no defect in parasite growth or transmissibility is observed. Our findings suggest that PfATP4 inhibitors in clinical development should be tested against PfATP4(G358S) parasites, and that their combination with unrelated antimalarials may mitigate against resistance development
Chemogenomics identifies acetyl-coenzyme A synthetase as a target for malaria treatment and prevention
We identify the Plasmodium falciparum acetyl-coenzyme A synthetase (PfAcAS) as a druggable target, using genetic and chemical validation. In vitro evolution of resistance with two antiplasmodial drug-like compounds (MMV019721 and MMV084978) selects for mutations in PfAcAS. Metabolic profiling of compound-treated parasites reveals changes in acetyl-CoA levels for both compounds. Genome editing confirms that mutations in PfAcAS are sufficient to confer resistance. Knockdown studies demonstrate that PfAcAS is essential for asexual growth, and partial knockdown induces hypersensitivity to both compounds. In vitro biochemical assays using recombinantly expressed PfAcAS validates that MMV019721 and MMV084978 directly inhibit the enzyme by preventing CoA and acetate binding, respectively. Immunolocalization studies reveal that PfAcAS is primarily localized to the nucleus. Functional studies demonstrate inhibition of histone acetylation in compound-treated wild-type, but not in resistant parasites. Our findings identify and validate PfAcAS as an essential, druggable target involved in the epigenetic regulation of gene expression
Randomized controlled field trial to assess the immunogenicity and safety of rift valley fever clone 13 vaccine in livestock
BACKGROUND:Although livestock vaccination is effective in preventing Rift Valley fever (RVF) epidemics, there are concerns about safety and effectiveness of the only commercially available RVF Smithburn vaccine. We conducted a randomized controlled field trial to evaluate the immunogenicity and safety of the new RVF Clone 13 vaccine, recently registered in South Africa. METHODS:In a blinded randomized controlled field trial, 404 animals (85 cattle, 168 sheep, and 151 goats) in three farms in Kenya were divided into three groups. Group A included males and non-pregnant females that were randomized and assigned to two groups; one vaccinated with RVF Clone 13 and the other given placebo. Groups B included animals in 1st half of pregnancy, and group C animals in 2nd half of pregnancy, which were also randomized and either vaccinated and given placebo. Animals were monitored for one year and virus antibodies titers assessed on days 14, 28, 56, 183 and 365. RESULTS:In vaccinated goats (N = 72), 72% developed anti-RVF virus IgM antibodies and 97% neutralizing IgG antibodies. In vaccinated sheep (N = 77), 84% developed IgM and 91% neutralizing IgG antibodies. Vaccinated cattle (N = 42) did not develop IgM antibodies but 67% developed neutralizing IgG antibodies. At day 14 post-vaccination, the odds of being seropositive for IgG in the vaccine group was 3.6 (95% CI, 1.5 - 9.2) in cattle, 90.0 (95% CI, 25.1 - 579.2) in goats, and 40.0 (95% CI, 16.5 - 110.5) in sheep. Abortion was observed in one vaccinated goat but histopathologic analysis did not indicate RVF virus infection. There was no evidence of teratogenicity in vaccinated or placebo animals. CONCLUSIONS:The results suggest RVF Clone 13 vaccine is safe to use and has high (>90%) immunogenicity in sheep and goats but moderate (> 65%) immunogenicity in cattle
The sero-epidemiology of Rift Valley fever in people in the Lake Victoria Basin of western Kenya
Rift Valley fever virus (RVFV) is a zoonotic arbovirus affecting livestock and people. This study was conducted in western Kenya where RVFV outbreaks have not previously been reported. The aims were to document the seroprevalence and risk factors for RVFV antibodies in a community-based sample from western Kenya and compare this with slaughterhouse workers in the same region who are considered a high-risk group for RVFV exposure. The study was conducted in western Kenya between July 2010 and November 2012. Individuals were recruited from randomly selected homesteads and a census of slaughterhouses. Structured questionnaire tools were used to collect information on demographic data, health, and risk factors for zoonotic disease exposure. Indirect ELISA on serum samples determined seropositivity to RVFV. Risk factor analysis for RVFV seropositivity was conducted using multi-level logistic regression. A total of 1861 individuals were sampled in 384 homesteads. The seroprevalence of RVFV in the community was 0.8% (95% CI 0.5–1.3). The variables significantly associated with RVFV seropositivity in the community were increasing age (OR 1.2; 95% CI 1.1–1.4, p<0.001), and slaughtering cattle at the homestead (OR 3.3; 95% CI 1.0–10.5, p = 0.047). A total of 553 slaughterhouse workers were sampled in 84 ruminant slaughterhouses. The seroprevalence of RVFV in slaughterhouse workers was 2.5% (95% CI 1.5–4.2). Being the slaughterman, the person who cuts the animal’s throat (OR 3.5; 95% CI 1.0–12.1, p = 0.047), was significantly associated with RVFV seropositivity. This study investigated and compared the epidemiology of RVFV between community members and slaughterhouse workers in western Kenya. The data demonstrate that slaughtering animals is a risk factor for RVFV seropositivity and that slaughterhouse workers are a high-risk group for RVFV seropositivity in this environment. These risk factors have been previously reported in other studies providing further evidence for RVFV circulation in western Kenya
The African Union and the African Peace and Security Architecture: Past, Present and Future
Ten years after the formal launch of the African Union (AU), which emerged from the Organisation of African Unity (OAU), it is appropriate to refl ect on whether it will achieve its intended objectives of peace and security. In 2002, the AU adopted the Protocol on the Peace and Security, an institutional framework – also referred to as the African Peace and Security Architecture (APSA) – designed to oversee the successful implementation of the continent’s peace and security strategy. This article will briefl y outline Africa’s peace and security challenges and how they informed the creation of APSA, examining the emergence and genesis of the AU and the institutionalisation of APSA, and undertaking a critical prognosis of its present status of implementation and an assessment of its prospects
The moral dimension of international dispute settlement Communicative ethics and sub-national conflict resolution mechanisms
SIGLEAvailable from British Library Document Supply Centre-DSC:DXN024468 / BLDSC - British Library Document Supply CentreGBUnited Kingdo
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