17 research outputs found
Genotype analysis of Escherichia coli strains isolated from children and chickens living in close contact
Escherichia coli isolates from rectal swabs from 62 chickens and stools from 42 children living in close contact with chickens on the same farms in Kiambu district, Kenya, were compared for their genetic relatedness. Antibiotic susceptibility profiles broadly categorized isolates from the children and from the chickens into two separate clusters: the majority (144; 85.5%) of the E. coil isolates from children were multidrug resistant, while the majority (216; 87.1%) of the E. coli isolates from chickens were either fully susceptible or resistant only to tetracycline. Sixty- and 100- to 110- MDA plasmids were found to encode the transferable resistance to co- trimoxazole and tetracycline. HindIII restriction endonuclease digestion of the 60- and 100- to 110-MDA plasmids produced four distinct patterns for isolates from children and three distinct patterns for isolates from chickens. XbaI digestion of genomic DNA followed by pulsed-field gel electrophoresis (PFGE) analysis produced 14 distinct clusters. There were six distinct PFGE clusters among the isolates from children, while among the isolates from chickens there were seven distinct clusters. Only one PFGE cluster contained isolates from both children and chickens, with the isolates displaying an approximately 60% coefficient of similarity. This study showed that although several different genotypes of E. coli were isolated from children and chickens from the same farms, the E. coli strains from these two sources were distinct
Characterisation of dairy systems supplying the Nairobi milk market: a pilot survey in Kiambu District for the identification of target groups of producers
The Compact Linear Collider (CLIC) - 2018 Summary Report
The Compact Linear Collider (CLIC) is a TeV-scale high-luminosity linear collider under development at CERN. Following the CLIC conceptual design published in 2012, this report provides an overview of the CLIC project, its current status, and future developments. It presents the CLIC physics potential and reports on design, technology, and implementation aspects of the accelerator and the detector. CLIC is foreseen to be built and operated in stages, at centre-of-mass energies of 380 GeV, 1.5 TeV and 3 TeV, respectively. CLIC uses a two-beam acceleration scheme, in which 12 GHz accelerating structures are powered via a high-current drive beam. For the first stage, an alternative with X-band klystron powering is also considered. CLIC accelerator optimisation, technical developments and system tests have resulted in an increased energy efficiency (power around 170 MW) for the 380 GeV stage, together with a reduced cost estimate at the level of 6 billion CHF. The detector concept has been refined using improved software tools. Significant progress has been made on detector technology developments for the tracking and calorimetry systems. A wide range of CLIC physics studies has been conducted, both through full detector simulations and parametric studies, together providing a broad overview of the CLIC physics potential. Each of the three energy stages adds cornerstones of the full CLIC physics programme, such as Higgs width and couplings, top-quark properties, Higgs self-coupling, direct searches, and many precision electroweak measurements. The interpretation of the combined results gives crucial and accurate insight into new physics, largely complementary to LHC and HL-LHC. The construction of the first CLIC energy stage could start by 2026. First beams would be available by 2035, marking the beginning of a broad CLIC physics programme spanning 25-30 years
And so the youth fire raged on youth and practices of democracy and empowerment in Brazil and Kenya
Heeding the 2013 CODESRIA / CLASCO call to attend to the localized entanglements of democracy and neoliberalism, this research is oriented by the bid to see what other political spaces have been established by young people in Kenya and Brazil, and what this says about how they fit in to normative political fora with their hegemonic discourses of democracy and neoliberalism; ideologies which often seek to impose on youth particular kinds of political practices and subjectivities. Overwhelmingly, it is also an attempt to share strategies and political imaginations that have emerged from poor urban youth in both countries; approaches, I argue, that also gesture towards the futures for these youth, their urban settings, and of the democratic and neoliberal political processes that have been entrenched in their national spaces
Feed utilisation options for smallholder dairy farmers
A Participatory Rural Appraisal (PRA) was conducted with smallholder dairy farmers in the central highlands of Kenya, where smallholder mixed farming systems predominate. Shortage of fodder is the principal problem as a result of decreasing farm size and, therefore, cattle are rarely fed ad libitum. Given this constraint, the aim of the PRA was to determine whether farmers employ practices which affect feed utilisation through manipulation of intake and feeding behaviour. Do different farmers with access to the same quantity and type of feed choose to utilise those feeds in different ways? When identifying researchable issues which could allow Development of improved feeding strategies, it is important to consider novel practices which may benefit other farmers with similar resources
Effect of surface orientation on blistering of copper under high fluence keV hydrogen ion irradiation
Copper and hydrogen are among the most common elements that are widely used in industrial and fundamental research applications. Copper surfaces are often exposed to hydrogen in the form of charged ions. The hydrogen ions can accelerate towards the surface, resulting in an accumulation of hydrogen below the surface. Harmless in low concentrations, prolonged hydrogen exposure can lead to dramatic changes on copper surfaces. This effect is visible to the naked eye in the form of blisters densely covering the exposed surface. Blisters are structural modifications that can affect the physical properties of the surface including, for example, vacuum dielectric strength. Using scanning electron microscopy we found that the blistering of the irradiated polycrystalline copper surface does not grow uniformly with ion fluence. Initially, only some grains exhibit blisters, while others remain intact. Our experiments indicate that grains with the {100} orientation are the most prone to blistering, while the grains oriented in the {110} are the most resistant to it. Moreover, we noticed that blisters assume different shapes correlating with specific grain orientation. Good agreement of experiments with the atomistic simulations explains the difference in the shapes of the blisters by specific behavior of dislocations within the FCC crystal structure. Moreover, our simulations reveal the correlation of the delay in blister formation on surfaces with certain orientations compared to the others with the dependence of the hydrogen penetration depth and the depth and amount of vacancies in copper on the orientation of the irradiated surfacePeer reviewe
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Evaluating transdisciplinary science.
The past two decades have seen a growing interest and investment in transdisciplinary research teams and centers. The Transdisciplinary Tobacco Use Research Centers (TTURCs) exemplify large-scale scientific collaborations undertaken for the explicit purpose of promoting novel conceptual and methodological integrations bridging two or more fields. Until recently, few efforts have been made to evaluate the collaborative processes, and the scientific and public policy outcomes, of such centers. This manuscript offers a conceptual framework for understanding and evaluating transdisciplinary science and describes two ongoing evaluation studies covering the initial phase of the TTURC initiative. The methods and measures used by these studies are described, and early evaluative findings from the first 4 years of the initiative are presented. These data reveal progress toward intellectual integration within and between several of the TTURCs, and cumulative changes in the collaborative behaviors and values of participants over the course of the initiative. The data also suggest that different centers may follow alternative pathways toward transdisciplinary integration and highlight certain environmental, organizational, and institutional factors that influence each center's readiness for collaboration. Methodological challenges posed by the complexities of evaluating large-scale scientific collaborations (including those that specifically aspire toward transdisciplinary integrations spanning multiple fields) are discussed. Finally, new directions for future evaluative studies of transdisciplinary scientific collaboration, both within and beyond the field of tobacco science, are described
Evaluating transdisciplinary science.
The past two decades have seen a growing interest and investment in transdisciplinary research teams and centers. The Transdisciplinary Tobacco Use Research Centers (TTURCs) exemplify large-scale scientific collaborations undertaken for the explicit purpose of promoting novel conceptual and methodological integrations bridging two or more fields. Until recently, few efforts have been made to evaluate the collaborative processes, and the scientific and public policy outcomes, of such centers. This manuscript offers a conceptual framework for understanding and evaluating transdisciplinary science and describes two ongoing evaluation studies covering the initial phase of the TTURC initiative. The methods and measures used by these studies are described, and early evaluative findings from the first 4 years of the initiative are presented. These data reveal progress toward intellectual integration within and between several of the TTURCs, and cumulative changes in the collaborative behaviors and values of participants over the course of the initiative. The data also suggest that different centers may follow alternative pathways toward transdisciplinary integration and highlight certain environmental, organizational, and institutional factors that influence each center's readiness for collaboration. Methodological challenges posed by the complexities of evaluating large-scale scientific collaborations (including those that specifically aspire toward transdisciplinary integrations spanning multiple fields) are discussed. Finally, new directions for future evaluative studies of transdisciplinary scientific collaboration, both within and beyond the field of tobacco science, are described