351 research outputs found

    Modelling Formal and Informal Domestic Water Consumption in Accra

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    Urban utilities in developing countries are often unwilling to extend coverage or improve services for fear that not enough water is available. This study used modelling to project the city-level water demand implications of slum water improvements in Accra (Ghana). The research collated existing data around water use patterns and also used purpose-designed surveys to explore usage and demand in slum communities in more depth

    Community Case Management of Fever Due to Malaria and Pneumonia in Children Under Five in Zambia: A Cluster Randomized Controlled Trial

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    In a cluster randomized trial, Kojo Yeboah-Antwi and colleagues find that integrated management of malaria and pneumonia in children under five by community health workers is both feasible and effective. BACKGROUND. Pneumonia and malaria, two of the leading causes of morbidity and mortality among children under five in Zambia, often have overlapping clinical manifestations. Zambia is piloting the use of artemether-lumefantrine (AL) by community health workers (CHWs) to treat uncomplicated malaria. Valid concerns about potential overuse of AL could be addressed by the use of malaria rapid diagnostics employed at the community level. Currently, CHWs in Zambia evaluate and treat children with suspected malaria in rural areas, but they refer children with suspected pneumonia to the nearest health facility. This study was designed to assess the effectiveness and feasibility of using CHWs to manage nonsevere pneumonia and uncomplicated malaria with the aid of rapid diagnostic tests (RDTs). METHODS AND FINDINGS. Community health posts staffed by CHWs were matched and randomly allocated to intervention and control arms. Children between the ages of 6 months and 5 years were managed according to the study protocol, as follows. Intervention CHWs performed RDTs, treated test-positive children with AL, and treated those with nonsevere pneumonia (increased respiratory rate) with amoxicillin. Control CHWs did not perform RDTs, treated all febrile children with AL, and referred those with signs of pneumonia to the health facility, as per Ministry of Health policy. The primary outcomes were the use of AL in children with fever and early and appropriate treatment with antibiotics for nonsevere pneumonia. A total of 3,125 children with fever and/or difficult/fast breathing were managed over a 12-month period. In the intervention arm, 27.5% (265/963) of children with fever received AL compared to 99.1% (2066/2084) of control children (risk ratio 0.23, 95% confidence interval 0.14–0.38). For children classified with nonsevere pneumonia, 68.2% (247/362) in the intervention arm and 13.3% (22/203) in the control arm received early and appropriate treatment (risk ratio 5.32, 95% confidence interval 2.19–8.94). There were two deaths in the intervention and one in the control arm. CONCLUSIONS. The potential for CHWs to use RDTs, AL, and amoxicillin to manage both malaria and pneumonia at the community level is promising and might reduce overuse of AL, as well as provide early and appropriate treatment to children with nonsevere pneumonia.United States Agency for International Development (GHSA-00-00020-00) with Boston University; President's Malaria Initiativ

    Local sales restrictions significantly reduce the availability of menthol tobacco: findings from four Minnesota cities

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    BACKGROUND In 2017 and 2018, Minneapolis, St. Paul, Duluth and Falcon Heights, Minnesota were among the first US cities to restrict the sale of menthol tobacco to adult-only stores. The study examined changes in the availability and marketing of these products following policy implementation. METHODS Retail store audits were conducted approximately 2 months pre-policy and post-policy implementation. Tobacco retail stores (n=299) were sampled from tobacco licensing lists in Minneapolis, St. Paul, Duluth and Falcon Heights, as well as six comparison cities without menthol policies. The presence of menthol tobacco was assessed, along with the number of interior and exterior tobacco ads and promotions at each store. RESULTS The majority of policy intervention stores (grocery, convenience stores and pharmacies) were compliant (Minneapolis, 84.4%; Duluth, 97.5%; and St. Paul and Falcon Heights, 100.0%) and did not sell menthol tobacco. In contrast, menthol tobacco was available in all comparison city stores, and most (96.0%) exempted tobacco shops and liquor stores post-policy implementation. Two Minneapolis convenience stores added interior tobacco shops, allowing them to continue selling menthol tobacco. Significant decreases in menthol tobacco marketing post-policy were observed in the stores' interior in Minneapolis, St. Paul and Duluth (p<0.001) and on the stores' exterior in Duluth (p=0.023). CONCLUSIONS Findings demonstrate high rates of compliance, indicating that sales restrictions can significantly reduce the availability of menthol tobacco. However, challenges to policy adherence underscore the need for continued monitoring and enforcement action

    Onfarm evaluation of maize varieties in the transitional and savannah zones of Ghana: determinants of farmer preferences

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    Maize is one of the most important food crops in Ghana even though its production has not reached self sufficiency levels. Drought and striga infestation are among the most important production constraints of maize in Ghana. Promising high yielding, drought and striga tolerant maize varieties are being evaluated by CSIR and IITA in participatory on-farm trials and demonstrations. These varieties however need to meet farmers’ varietal preferences in order for them to adopt. This study therefore sought to assess farmers’ preference for the different drought tolerant maize varieties, and determine factors that influence their choices. Kendall’s coefficient of concordance was used to test the level of agreement between farmers on their preferences. The ordered logistic regression was used to estimate the determinants of farmer’s preference using cross-sectional observations from 120 maize farmers in the Transitional and Savannah zones of Ghana. Results indicate that maize varieties that are early maturing (2.38) and drought tolerant (2.45) were most preferred by farmers. Area under maize cultivation, fertilizer usage and family size are the factors that were found to influence farmers’ preference for improved maize varieties. These factors should therefore be considered in varietal promotion

    Assessment of early-maturing maize hybrids and testing sites using GGE biplot analysis

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    Article Purchased; Published: 7 Sept. 2017Identification of outstanding maize (Zea mays L.) hybrids for target environments is complicated by genotype × environment interactions. Thirty-two early-maturity maize hybrids were evaluated at eight locations in Nigeria and six locations in Ghana for 2 yr to (i) identify high-yielding, stable hybrids across locations and/or hybrids specifically adapted to different locations, and (ii) identify ideal test sites for selection of superior hybrids in the two countries. Genotype, country, year, location (country), and their interactive effects were significant (P < 0·01) for grain yield, days to anthesis and silking, anthesis-silking interval, plant and ear aspects, and ears per plant. Mean grain yield of the hybrids ranged from 3177 kg ha−1 for EWH-5 to 4596 kg ha−1 for EWH-29. The genotype main effects plus genotype × environment interaction (GGE) biplot analysis revealed that EWH-29, EWH-8, and EWH-30 did not differ significantly in grain yield and were the most stable hybrids in both countries, whereas EWH-26 and EWH-32 were the most stable hybrids only in Ghana. The GGE biplot analysis identified Samaru, Kafin Soli, and Minjibir in Nigeria and Nyankpala, Damongo, and Fumesua in Ghana as the most discriminating locations. Minjibir (Nigeria) and Nyankpala (Ghana), being most discriminating and representative locations, were considered the ideal testing sites for the respective countries. The type of cultivars evaluated determined the most suitable locations for multilocation testing within Ghana and Nigeria. Whereas hybrids EWH-29, EWH-8, and EWH-30 should be suitable for production in Nigeria, EWH-26 and EWH-32 should be promoted for production in Ghana

    The impact of low erythrocyte density in human blood on the fitness and energetic reserves of the African malaria vector Anopheles gambiae

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    Background Anaemia is a common health problem in the developing world. This condition is characterized by a reduction in erythrocyte density, primarily from malnutrition and/or infectious diseases such as malaria. As red blood cells are the primary source of protein for haematophagous mosquitoes, any reduction could impede the ability of mosquito vectors to transmit malaria by influencing their fitness or that of the parasites they transmit. The aim of this study was to determine the impact of differences in the density of red blood cells in human blood on malaria vector (Anopheles gambiae sensu stricto) fitness. The hypotheses tested are that mosquito vector energetic reserves and fitness are negatively influenced by reductions in the red cell density of host human blood meals commensurate with those expected from severe anaemia. Methods Mosquitoes (An. gambiae s.s.) were offered blood meals of different packed cell volume(PCV) of human blood consistent with those arising from severe anaemia (15%) and normalPCV (50%). Associations between mosquito energetic reserves (lipid, glucose and glycogen)and fitness measures (reproduction and survival) and blood meal PCV were investigated. Results The amount of protein that malaria vectors acquired from blood feeding (indexed by haematin excretion) was significantly reduced at low blood PCV. However, mosquitoes feeding on blood of low PCV had the same oviposition rates as those feeding on blood of normal PCV, and showed an increase in egg production of around 15%. The long-term survival of An. gambiae s.s was reduced after feeding on low PCV blood, but PCV had no significant impact on the proportion of mosquitoes surviving through the minimal period required to develop and transmit malaria parasites (estimated as 14 days post-blood feeding). The impact of blood PCV on the energetic reserves of mosquitoes was relatively minor. Conclusions These results suggest that feeding on human hosts whose PCV has been depleted due to severe anaemia does not significantly reduce the fitness or transmission potential of malaria vectors, and indicates that mosquitoes may be able exploit resources for reproduction more efficiently from blood of low rather than normal PCV

    Beyond UVJ: Color Selection of Galaxies in the JWST Era

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    We present a new rest-frame color-color selection method using "synthetic usgsu_s-g_s and gsisg_s-i_s'', (ugi)s(ugi)_s colors to identify star-forming and quiescent galaxies. Our method is similar to the widely-used UVU-V versus VJV-J (UVJUVJ) diagram. However, UVJUVJ suffers known systematics. Spectroscopic campaigns have shown that UVJUVJ-selected quiescent samples at z3z \gtrsim 3 include 1030%\sim 10-30\% contamination from galaxies with dust-obscured star formation and strong emission lines. Moreover, at z>3z>3, UVJUVJ colors are extrapolated because the rest-frame J-band shifts beyond the coverage of the deepest bandpasses at <5 μm< 5~\mu m (typically SpitzerSpitzer/IRAC 4.5 μm\mu m or future JWSTJWST/NIRCam observations). We demonstrate that (ugi)s(ugi)_s offers improvements to UVJUVJ at z>3z>3, and can be applied to galaxies in the JWSTJWST era. We apply (ugi)s(ugi)_s selection to galaxies at 0.5<z<60.5<z<6 from the (observed) 3D-HST and UltraVISTA catalogs, and to the (simulated) JAGUAR catalogs. We show that extrapolation can affect (VJ)0(V-J)_0 color by up to 1 magnitude, but changes (usis)0(u_s-i_s)_0 color by \leq 0.2 mag, even at z6z\simeq 6. While (ugi)s(ugi)_s-selected quiescent samples are comparable to UVJUVJ in completeness (both achieve \sim85-90% at z=33.5z=3-3.5), (ugi)s(ugi)_s reduces contamination in quiescent samples by nearly a factor of two, from \simeq35% to \simeq17% at z=3z=3, and from \simeq 60% to \simeq 33% at z=6z=6. This leads to improvements in the true-to-false-positive ratio (TP/FP), where we find TP/FP \gtrsim 2.2 for (ugi)s(ugi)_s at z3.56z \simeq 3.5 - 6, compared to TP/FP << 1 for UVJUVJ-selected samples. This indicates that contaminants will outnumber true quiescent galaxies in UVJUVJ at these redshifts, while (ugi)s(ugi)_s will provide higher-fidelity samples.Comment: Submitted to Ap

    Needs assessment to strengthen capacity in water and sanitation research in Africa:experiences of the African SNOWS consortium

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    Despite its contribution to global disease burden, diarrhoeal disease is still a relatively neglected area for research funding, especially in low-income country settings. The SNOWS consortium (Scientists Networked for Outcomes from Water and Sanitation) is funded by the Wellcome Trust under an initiative to build the necessary research skills in Africa. This paper focuses on the research training needs of the consortium as identified during the first three years of the project

    Perceived stressors of climate vulnerability across scales in the Savannah zone of Ghana: a participatory approach

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    Smallholder farmers in sub-Saharan Africa are confronted with climatic and non-climatic stressors. Research attention has focused on climatic stressors, such as rainfall variability, with few empirical studies exploring non-climatic stressors and how these interact with climatic stressors at multiple scales to affect food security and livelihoods. This focus on climatic factors restricts understanding of the combinations of stressors that exacerbate the vulnerability of farming households and hampers the development of holistic climate change adaptation policies. This study addresses this particular research gap by adopting a multi-scale approach to understand how climatic and non-climatic stressors vary, and interact, across three spatial scales (household, community and district levels) to influence livelihood vulnerability of smallholder farming households in the Savannah zone of northern Ghana. This study across three case study villages utilises a series of participatory tools including semi-structured interviews, key informant interviews and focus group discussions. The incidence, importance, severity and overall risk indices for stressors are calculated at the household, community, and district levels. Results show that climatic and non-climatic stressors were perceived differently; yet, there were a number of common stressors including lack of money, high cost of farm inputs, erratic rainfall, cattle destruction of crops, limited access to markets and lack of agricultural equipment that crossed all scales. Results indicate that the gender of respondents influenced the perception and severity assessment of stressors on rural livelihoods at the community level. Findings suggest a mismatch between local and district level priorities that have implications for policy and development of agricultural and related livelihoods in rural communities. Ghana’s climate change adaptation policies need to take a more holistic approach that integrates both climatic and non-climatic factors to ensure policy coherence between national climate adaptation plans and District development plans
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