591 research outputs found

    Examining the early distribution of the artemisinin-resistant Plasmodium falciparum kelch13 R561H mutation in areas of higher transmission in Rwanda

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    BACKGROUND: Artemisinin resistance mutations in Plasmodium falciparum kelch13 (Pfk13) have begun to emerge in Africa, with Pfk13-R561H being the first reported in Rwanda in 2014, but limited sampling left questions about its early distribution and origin. METHODS: We genotyped P. falciparum positive dried blood spot (DBS) samples from a nationally representative 2014-2015 Rwanda Demographic Health Surveys (DHS) HIV study. DBS were subsampled from DHS sampling clusters with >15% P. falciparum prevalence, as determined by rapid testing or microscopy done during the DHS study (n clusters = 67, n samples = 1873). RESULTS: We detected 476 parasitemias among 1873 residual blood spots from a 2014-2015 Rwanda Demographic Health Survey. We sequenced 351 samples: 341/351 were wild-type (97.03% weighted), and 4 samples (1.34% weighted) harbored R561H that were significantly spatially clustered. Other nonsynonymous mutations found were V555A (3), C532W (1), and G533A (1). CONCLUSIONS: Our study better defines the early distribution of R561H in Rwanda. Previous studies only observed the mutation in Masaka as of 2014, but our study indicates its presence in higher-transmission regions in the southeast of the country at that time

    Reproductive Performances of a cameroonian dual-purpose local chicken strain fed pelleted diets containing graded levels of cassava and sweet potato meal as an energy substitute for maize.

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    The continuous rising price of maize due to an increasing competition between humans and livestock requires palliative measures to sustain animal production. cassava-sweet potato meal combination can be used as a substitute for maize in feeding chicken. This study aimed at improving poultry productivity through the enhancement of the reproductive performances of Cameroon Kabir chickens fed pelleted diets of graded levels inclusion of cassava-sweet potato meal as an energy substitute for maize.315 Kabir chickens (270 hens and 45 rosters) of 23 weeks of age, were randomly allocated to five treatments T1, T2, T3, T4 and T5 with graded levels of cassava-sweet potato meal as energy substitute for maize, and eggs were collected for the evaluation of laying performances and characteristics. Fertility and hatchability were also evaluated across four successive batches of incubations. The eggs? weight was significantly (P<0.05) different between treatments at weeks 2, 4, 5 and 12, highly significant (P<0.01) at week 9, and very highly significant (P<0.001) at week 6, 7, 8 and 10. The highest number of eggs laid, egg weight and mass were recorded in chicken receiving 25% (T2) replacement of maize with cassava and sweet potato meal, followed by T4 (75%), T5 (100%), T3 (50%) while T1, receiving control diet without cassava and sweet potato meal performed less for all the parameters. Generally, the trend of the feed conversion ratio was decreasing with increasing the inclusion level of cassava and sweet potato meal. The egg index showed significant differences in weeks 6 and 12, while week 2 showed high significant difference between the treatments. T2 (25%) recorded the highest fertility, while animals receiving control ration without maize substitution recorded the highest hatchability. In general, incorporation of 25% of fifty-fifty percent weight to weight of cassava and sweet potato meal can be recommended for reproduction in chicken without affecting neither the hatchability nor the physical characteristics of the eggs, though hatchability will require better attention

    Metabolizable energy and metabolizability coefficients of moringa and bocaiuva for slow-growing broilers at different ages.

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    This study aimed to determine nutrient metabolizability coefficients and apparent metabolizable energy (AME) and nitrogen-corrected AME (AMEn) values of moringa leaf meal and bocaiuva pulp for slow-growing broilers. Three hundred and fifty 1-day-old chicks of the Red Naked Neck line were allocated to five treatments in a completely randomized design with seven replicates of 10 birds. Treatments consisted of a control diet and four test diets. The proportion of ingredients evaluated in the test diets was 20% moringa leaf meal and bocaiuva pulp and 40% corn and soybean meal. The total excreta collection method was applied with 1% ferric oxide included in the diets as a marker of start and end of collection, in the starter, grower and finisher phases. The metabolizability coefficients of dry matter, crude protein and ether extract and the AME and AMEn values of moringa leaf meal, bocaiuva pulp, corn and soybean meal were determined. Data were subjected to analysis of variance and means were compared by Tukey?s test at the 5% probability level. The protein from moringa leaf meal and the fat from bocaiuva pulp are highly metabolizable by birds at different ages. The AME and AMEn values of moringa leaf meal ranged from 2557 to 2868 Kcal/kg and 2205 to 2479 Kcal/kg, respectively. In bocaiuva pulp, AME and AMen ranged between 2680 and 3119 Kcal/kg and 2483 and 2490 Kcal/kg, respectively. Therefore, the alternative ingredients can be used in the formulation of diets for slow-growing broilers to partially replace corn and soybean meal

    Estratégia de Controle Cooperativo em Unidades de Geração Distribuídas Integrada a Sistemas de Armazenamento de Energia Elétrica / Cooperative Control Strategy in Distributed Generation Units Distributed Generation Units Integrated with Power Storage Systems

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    O aumento do nível de penetração de fontes re[1]nováveis conectadas a rede elétrica através de conversores de potência, pode provocar instabilidades em microrredes CA devido à natureza não-despachável em potência desses sistemas. A integração de sistemas de armazenamento de energia elétrica ao inversor do gerador distribuído pode suavizar a injeção de potência no ponto de acoplamento comum (PAC), contribuindo para a estabilidade de tensão e de frequência do sistema de potência. Neste trabalho, propõe-se uma estratégia de controle cooperativo para regular a tensão do barramento CC integrada a uma estrutura de armazenamento de um sistema de geração distribuída para minimizar eventuais flutuações de tensão e de frequência no PAC. Comparações com métodos tradicionais de controle são realizados para avaliar a efetividade do método proposto. A validação da estratégia de controle é realizada por meio de resultados experimentais

    Ovelha pantaneira, um grupamento genético naturalizado do Estado do Mato Grosso do Sul, Brasil.

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    O grupamento genético ovino pantaneiro tem origem no Pantanal, bioma singular que exerce seleção natural intensa nos animais domésticos naturalizados. Devido às condições ambientais reinantes na planície alagada, os ovinos pantaneiros sul-mato-grossenses desenvolveram características adaptativas e produtivas que justificam a sua conservação. Os estudos até o momento concentraram-se nos aspectos morfométricos, para definição de padrões raciais, e no desempenho produtivo (carne, lã, leite, peles, reprodução e sanidade), que resultaram em bons resultados comparados a raças ovinas exóticas. Os estudos de características genéticas, para orientar os programas de seleção e melhoramento, estão em andamento, com o objetivo de complementar os estudos científicos que subsidiam o registro da raça Ovelha Pantaneira

    Preparation and Evaluation of Rice Bran-Modified Urea Formaldehyde as Environmental Friendly Wood Adhesive

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    In this study, defatted rice bran (RB) is used to prepare an environmentally friendly adhesive through chemical modifications. The RB is mixed with distilled water with ratios of 1:5 and 1:4 to prepare Type A and Type B adhesives, respectively having pH of 6, 8 and 10. Type A adhesive is prepared by treating RB with 1% potassium permanganate and 4% poly(vinyl alcohol), whereas Type B is formulated by adding 17.3% formaldehyde and 5.7% urea to RB. Viscosity, gel time, solid content, shear strength, Fourier transform infrared (FTIR) spectroscopy is carried out, and glass transition temperature (T-g), and activation energy (E-a) are determined to evaluate the performance of the adhesives. E-a data reveal that adhesives prepared at mild alkaline (pH 8) form long-chain polymers. Gel time is higher in the fabricated adhesives than that of the commercial urea formaldehyde (UF). FTIR data suggest that functional groups of the raw RB are chemically modified, which enhances the bondability of the adhesives. Shear strength data indicates that bonding strength increases with increasing pH. Similar results are also observed for physical and mechanical properties of fabricated particleboards with the adhesives. The results demonstrate that RB-based adhesives can be used as a potential alternative to currently used UF-based resin
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