35 research outputs found

    Isothermal, kinetics and thermodynamics studies of the biosorption of Pb (II) ion from aqueous solution using the scale of croaker fish (Genyonemus lineatus)

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    Biosorbent prepared from the scale of croaker fish (Genyonemus lineatus) has been used for the removal of Pb(II) ion from aqueous solution in a batch system. The effects of some important parameters such as pH, initial metal concentration, temperature and biosorbent dosage on biosorption capacity were investigated. Equilibrium time for the biosorption process is 20 and 30 min at lower and higher concentrations, respectively. The process at 28 °C is in agreement with a pseudo-second-order kinetics model. The equilibrium data obeyed the Langmuir adsorption isotherm with a maximum monolayer adsorption capacity of 14.58 mg g−1. The study showed that the sorption process depends on biomass dosage, temperature, pH and initial metal ion concentration. The calculated thermodynamics parameters (ΔGo, ΔHo and ΔSo) indicated that the biosorption of the metal ion onto fish scale is feasible, spontaneous and exothermic in nature

    Professional development in teaching and learning for early career academic geographers: Contexts, practices and tensions

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    This is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Geography in Higher Education on 16th May 2011, available online: doi: 10.1080/03098265.2011.563380This paper provides a review of the practices and tensions informing approaches to professional development for early career academic geographers who are teaching in higher education. We offer examples from Britain, Canada, Nigeria and the USA. The tensions include: institutional and departmental cultures; models that offer generic and discipline-specific approaches; the credibility of alternative settings for professional development in teaching and learning; the valuing of professional development and of teaching in academic systems of reward and recognition; and the challenges of balancing professional and personal life. We summarize concepts of good practice and suggest opportunities for future research

    Design and methods for a quasi-experimental pilot study to evaluate the impact of dual active ingredient insecticide-treated nets on malaria burden in five regions in sub-Saharan Africa

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    Background Vector control tools have contributed significantly to a reduction in malaria burden since 2000, primarily through insecticidal-treated bed nets (ITNs) and indoor residual spraying. In the face of increasing insecticide resistance in key malaria vector species, global progress in malaria control has stalled. Innovative tools, such as dual active ingredient (dual-AI) ITNs that are effective at killing insecticide-resistant mosquitoes have recently been introduced. However, large-scale uptake has been slow for several reasons, including higher costs and limited evidence on their incremental effectiveness and cost-effectiveness. The present report describes the design of several observational studies aimed to determine the effectiveness and cost-effectiveness of dual-AI ITNs, compared to standard pyrethroid-only ITNs, at reducing malaria transmission across a variety of transmission settings. Methods Observational pilot studies are ongoing in Burkina Faso, Mozambique, Nigeria, and Rwanda, leveraging dual-AI ITN rollouts nested within the 2019 and 2020 mass distribution campaigns in each country. Enhanced surveillance occurring in select study districts include annual cross-sectional surveys during peak transmission seasons, monthly entomological surveillance, passive case detection using routine health facility surveillance systems, and studies on human behaviour and ITN use patterns. Data will compare changes in malaria transmission and disease burden in districts receiving dual-AI ITNs to similar districts receiving standard pyrethroid-only ITNs over three years. The costs of net distribution will be calculated using the provider perspective including financial and economic costs, and a cost-effectiveness analysis will assess incremental cost-effectiveness ratios for InterceptorÂź G2, Royal GuardÂź, and piperonyl butoxide ITNs in comparison to standard pyrethroid-only ITNs, based on incidence rate ratios calculated from routine data. Conclusions Evidence of the effectiveness and cost-effectiveness of the dual-AI ITNs from these pilot studies will complement evidence from two contemporary cluster randomized control trials, one in Benin and one in Tanzania, to provide key information to malaria control programmes, policymakers, and donors to help guide decision-making and planning for local malaria control and elimination strategies. Understanding the breadth of contexts where these dual-AI ITNs are most effective and collecting robust information on factors influencing comparative effectiveness could improve uptake and availability and help maximize their impact
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