230 research outputs found

    Closed-Form Solution of Radial Transport of Tracers in Porous Media Influenced by Linear Drift

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    The authors thank Olakunle Popoola and Ofomana Emmanuel for useful discussions of this topic.Peer reviewedPublisher PD

    The AgResults Nigeria Aflasafe TM Challenge Project: 2019 Annual Report

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    This report documents the key activities that were carried under the AgResults Aflasafe Pilot Project during the 2018/ 2019 maize-growing season on the verification process to trigger premium payments for successfully harvested and aggregated Aflasafe™-treated maize

    Investigation of drift phenomena at the pore-scale during flow and transport in porous media

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    Acknowledgments: We express our appreciation to the Petroleum Technology Development Fund, Nigeria (PTDF), for funding this research project.Peer reviewedPublisher PD

    Universal and Non-Universal First-Passage Properties of Planar Multipole Flows

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    The dynamics of passive Brownian tracer particles in steady two-dimensional potential flows between sources and sinks is investigated. The first-passage probability, p(t)p(t), exhibits power-law decay with a velocity-dependent exponent in radial flow and an order-dependent exponent in multipolar flows. For the latter, there also occur diffusive ``echo'' shoulders and exponential decays associated with stagnation points in the flow. For spatially extended dipole sinks, the spatial distribution of the collected tracer is independent of the overall magnitude of the flow field.Comment: 7 pages, LaTe

    Efficacy and safety of the six-dose regimen of artemether-lumefantrine in pediatrics with uncomplicated Plasmodium falciparum malaria: A pooled analysis of individual patient data

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    Patient data from eight clinical trials were pooled and analyzed to study the efficacy and safety of the six-dose versus four-dose regimen of artemether-lumefantrine (coartemether; Coartem) in children weighing 5-25 kg. A total of 544 patients with uncomplicated P. falciparum malaria (six-dose: 343; four-dose: 201), matched for demographic and baseline characteristics and individual coartemether doses were included in the analysis. Analysis of day 28 cure rate based on the intention-to-treat and evaluable populations yielded corrected cure rates for the six-dose regimen of 93% and 96% compared with 61% and 76%, respectively, for the four-dose regimen (P \u3c 0.0001 for both comparisons). Similarly high cure rates were achieved with the six-dose regimen in non-immune infants weighing as little as 5 kg. The six- and four-dose regimens were equally well tolerated. The main finding of this analysis is that the six-dose regimen of coartemether is safe and more efficacious than the four-dose regimen in children. Copyright © 2006 by The American Society of Tropical Medicine and Hygiene

    MOISTURE – SOLID TRANSFER DURING OSMOTIC DEHYDRATION OF BANANA (MUSA SAPIETUM) VARIETIES

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    Moisture-Solids transfer during the osmotic dehydration of three banana (Musa Sapietum) varieties was investigated. Cavendish, Omini-red and Cooking banana were transversely sliced into 10, 15 and 200m thicknesses. Sample of each thickness were immersed in 250, 600 and 680B sucrose solutions. A fruit: solution ratio of 1:20 (w/w) was maintained. The fruit-solution mixtures were kept at 270, 340 and 400C for 12 hours. Samples were evaluated gravimetrically at 2 hours interval. Moisture and total solids contents were determined and expressed as g water/g dry matter (DM) and g solids/g initial mass respectively. Moisture contents on dry basis of the banana slices were found to decrease with increased immersion time, solution concentration and temperature. However, moisture contents decreased with decreased slice thickness. Total solids content increased with increased immersion time, solution concentration and temperature, but decreased with decreased slice thickness. Omini red cultivar had the lowest moisture content and the highest total solids content at the end of 12 hours of osmotic treatment. Complex polynomial equation showing the relationship with moisture and total solids contents with immersion time showed high correlation (R2 = 0.9919 – 1.000)

    Knowledge and utilization of intermittent preventive treatment for malaria among pregnant women attending antenatal clinics in primary health care centers in rural southwest, Nigeria: a cross-sectional study

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    <p>Abstract</p> <p>Background</p> <p>Intermittent preventive treatment for prevention of malaria in pregnancy (IPTp) is a key component of malaria control strategy in Nigeria and sulfadoxine-pyrimethamine (SP) is the drug of choice. Despite the evidence of the effectiveness of IPTp strategy using SP in reducing the adverse effects of malaria during pregnancy the uptake and coverage in Nigeria is low. This study set out to assess the use of IPTp among pregnant women attending primary health centres in the rural area and determine factors that influence the uptake.</p> <p>Methods</p> <p>A cross-sectional study was carried out between July and August 2007 among 209 pregnant women selected by systematic random sampling from antenatal care attendees at primary health care in a rural Local Government Area of Ekiti State, Nigeria. Information on knowledge of IPT, delivery, adherence and acceptability was obtained using an interviewer administered questionnaire. Descriptive statistics such as means, range, proportions were used. Chi-square test was used to examine association between categorical variables. All analyses were performed at 5% level of significance.</p> <p>Results</p> <p>One hundred and nine of 209 (52.2%) respondents have heard about IPTp but only 26 (23.9%) were able to define it. Fifty seven (27.3%) reported to have received at least one dose of IPTp during the index pregnancy and all were among those who have heard of IPTp (52.3%). Twenty one of the 57 (36.8%) took the SP in the clinic. Only three of the twenty-one (14.3%) were supervised by a health worker. Twenty two of the 36 women (61.1%) who did not take their drugs in the clinic would have liked to do so if allowed to bring their own drinking cups. Almost half (43.9%) of those who had used IPTp during the index pregnancy expressed concern about possible adverse effect of SP on their pregnancies. Periodic shortages of SP in the clinics were also reported.</p> <p>Conclusion</p> <p>In this study, IPTp use among pregnant women was very low and there was poor adherence to the Directly Observed Therapy (DOT) scheme. Concerted effort should be made to increase awareness of IPTp among the public especially women of child bearing age. Health workers should also be trained and monitored to ensure adherence.</p

    Intermittent preventive treatment with sulphadoxine-pyrimethamine is effective in preventing maternal and placental malaria in Ibadan, south-western Nigeria

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    <p>Abstract</p> <p>Background</p> <p>Intermittent preventive treatment with sulphadoxine-pyrimethamine (IPT-SP) is currently the recommended regimen for prevention of malaria in pregnancy in endemic areas. This study sets out to evaluate the effectiveness of IPT-SP in the prevention of maternal and placental malaria in parturient mothers in Ibadan, Nigeria, where the risk of malaria is present all year round.</p> <p>Method</p> <p>During a larger study evaluating the epidemiology of congenital malaria, the effect of malaria prophylaxis was examined in 983 parturient mothers. Five hundred and ninety eight mothers (60.8%) received IPT-SP, 214 (21.8%) received pyrimethamine (PYR) and 171 (17.4%) did not take any chemoprophylactic agent (NC).</p> <p>Results</p> <p>The prevalence of maternal parasitaemia in the IPT-SP, PYR and NC groups was 10.4%, 15.9% and 17% respectively (p = 0.021). The prevalence of placental parasitaemia was 10.5% in the IPT-SP, 16.8% PYR and 17% NC groups, respectively (p = 0.015). The prevalence of maternal anaemia (haematocrit <30%) was 5.7% vs. 8.9% vs. 13.4% among the IPT-SP, PYR and NC groups respectively (p < 0.0001) while that of pre-term delivery (GA <37 weeks) was 10.5%, 19.2% and 25.3% among IPT-SP, PYR and NC groups respectively (p < 0.0001). Babies born to mothers in the IPT-SP, PYR and NC groups had mean birth weights of 3204 ± 487.16, 3075 ± 513.24 and 3074 ± 505.92 respectively (ρ < 0.0001). There was a trend towards a lower proportion of low birth weight babies in the IPT-SP group (p = 0.095).</p> <p>Conclusion</p> <p>IPT-SP is effective in preventing maternal and placental malaria as well as improving pregnancy outcomes among parturient women in Ibadan, Nigeria. The implementation of the recently adopted IPT-SP strategy should be pursued with vigour as it holds great promise for reducing the burden of malaria in pregnancy in Nigeria.</p

    Efficacy and safety of artemisinin-based antimalarial in the treatment of uncomplicated malaria in children in southern Tanzania

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    BACKGROUND\ud \ud Tanzania switched the antimalarial first line to sulphadoxine-pyrimethamine (SP) in 2001 from ineffective chloroquine (CQ). By 2003 higher levels of SP resistance were recorded, prompting an urgent need for replacing the first line drug with ACT, as currently recommended by the World Health Organization. Despite this recommendation country-specific evidence-based data to support efficacy and safety profile of ACT is still limited. A study on the efficacy and safety of artesunate plus amodiaquine (AS+AQ) and artemether plus lumefantrine (AL)(Coartem) was carried out in 2004 with the view of supporting the National Malaria Control Programme in the review of the policy in mainland Tanzania.\ud \ud METHODS\ud \ud An in vivo efficacy study was conducted at Ipinda and Mlimba health facilities between May and November 2004. The study recruited children aged 6-59 months presenting with symptoms of uncomplicated malaria, history of fever or an axillary temperature > or =37.5 degrees C; mono infection with Pasmodium falciparum (2,000-200,000 parasites/microl). Patients were randomized to received either SP or amodiaquine monotherapy or treated with standard doses of AS+AQ in Mlimba and Coartem in Kyela and followed-up for 28 days to assess treatment responses. This study reports results of the combination therapies.\ud \ud RESULTS\ud \ud A total of 157 children (76 in Mlimba and 99 in Kyela) who were enrolled in to the study and treated with either AL or AS+AQ were successfully followed-up. Both combinations were tolerated and effected rapid fever and parasite clearance. The crude ACPRs were 80 (87%) and 41 (63%) for AL and AS+AQ respectively. However, after PCR adjustments the corresponding figures raised to 100% (n = 86) and 93.8% (n = 45) in AL and AS+AQ groups, respectively. The mean haemoglobin improved moderately from day 0 to day 28 by 1 g/dl in AL and 0.4 g/dl in AS+AQ treatment group and was statistically significant (p < 0.001 both).\ud \ud CONCLUSION\ud \ud These findings provide substantial evidence that AL is highly efficacious in areas of high resistance of SP and supported the country's decision to switch from SP monotherapy to AL
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