287 research outputs found
Study of the Root System of Local and Improved Sorghum Cultivars Grown in Mali
Roots play a fundamental role in plant growth by supplying water and mineral to the stem and
leaves. These underground organs are much less known than the aerial organs mainly due to the
difficult access to the root systems in soil. In spite of this, only a few studies were conducted on
roots. Given the importance of roots for plant growth, a better understanding of their functioning
may help solve some issues such as water stress that can affect the performance of the crops. A
total of 100 sorghum cultivars collected in the Sahelian zone of Mali an area receiving an annual
rainfall of 200 to 600 mm, were used in a root characterization study. The plant materials were
composed of 4 races and 5 intermediates sorghum races. Seeds of the entries were planted
directly in PVC tubes of 1m containing soil and arranged in completely randomized design with
three replications; in one planting date. Each tube was planted in a dugout ground to 50 cm deep.
The tubes were distant of 0.50 m within each row and 0.75 m between rows. The trial was watered
from the tap every two days until harvest. The results showed high variability among the varieties
studied for root length and root density, with a root length reaching over 1.00m. The study did not
identify any pattern in the root systems of the four races and their five intermediates races.
However, there was a positive correlation between root length and density indicating an increase in
root length correspond to an increased root density. The diversity found in the root system could be
a basis for improving root architecture in breeding populations and the evaluation of the behaviour
of the sorghum varieties with different root systems in water stress conditions
Development and Utilisation of Improved WhiteSeeded, Tan-Plant Grain Sorghum Cultivars in Mali
The pedigree breeding method was successfully adopted to develop high yielding, white-seeded, grain sorghum cultivars with other attributes including âtanâ plants, sensitivity to photoperiod and excellent adaptation to the Sudanian and Sahelian agro-ecological conditions in Mali. The new cultivars possess an excellent grain quality which added value for processing. The breeding process included crossing of local guinea race cultivars and improved or introduced Caudatum race varieties, selected from F2, F3, F4, F5 and F6 generations, conducting yield and grain quality trials of advanced lines on station and on-farm with farmer participatory selection. Processing quality of the grain was evaluated through measuring the decortication yield of each cultivar using the TADD (Tangential Abrasive Dehuller Device); measuring shelf life of processed flour in bags made of polyethylene for 3 months; manufacturing of new products by partially substituting wheat flour with flour of new sorghum varieties in pastry and biscuits. The study revealed a series of improved lines with "tan" plants, white grain, Guinea race type characterised by a loose panicle, long glumes and a hard grain. The best example of new cultivars NâTenimissa, was described as the first white, âtanâ plant, straw-coloured glume, photoperiod sensitive and high yielding sorghum cultivar with a white endosperm, and a thin pericarp developed in Mali. The cultivar has almost the same decortication yield with already adopted varieties by farmers. Its flour yield is similar to that of local guinea cultivars, and its flour is nearly as white as wheat flour. The analysis of various organoleptic parameters indicated that partially substituting wheat with 20% sorghum flour made the preferred biscuit by consumers prompting the commercial manufacturing of a biscuit called Deliken by the General Alimentation du Mali (GAM). A commercial sorghum supply chain was initiated by linking smallholders producing the new cultivar to a grain trader for selling the grain to the industry. This shows a path for the future in the diversification of uses of a local staple crop, sorghum. It is based on a strong Public-Private Partnership to link smallholders to the commercial supply chain, providing an incentive for farmers to grow new and highly productive cultivars for the development of value-added products
Les aspects parasitologiques de l'épidémiologie du paludisme dans le Sahara malien
Dans le cadre de l'Ă©valuation Ă©pidĂ©miologique de la Transsaharienne, une enquĂȘte transversale paludomĂ©trique a Ă©tĂ© rĂ©alisĂ©e d'AoĂ»t 1988 Ă Septembre 1988 le long du tronçon malien. Neuf localitĂ©s ont Ă©tĂ© visitĂ©es : Douentza, Gossi, Bourem, Almoustarat, Anefis, Aguel-Hoc, Tarlit, Tessalit, Kidal, Bouressa. 2185 unitĂ©s ont Ă©tĂ© prĂ©levĂ©es pour les Ă©tudes cliniques, parasitologiques et immunologiques. L'indice plasmodique global est de 5,3 % avec une grande variation du Sud (44,6 %) au Nord (0 %). L'indice gamĂ©tocytique et l'indice splĂ©nique sont trĂšs faibles. #P. falciparum est l'espĂšce dominante. #P. malariae a Ă©tĂ© dĂ©crit une fois en association avec #P. falciparum. #P. ovale n'a jamais Ă©tĂ© observĂ©. Par contre un cas de #P. vivax a Ă©tĂ© dĂ©crit chez une jeune fille leucoderme de 8 ans Ă Kidal. #A. gambiae s.s. (forme Mopti) et #A. arabiensis sont les principaux vecteurs au Nord du Mali. Une hypothĂšse de circulation de #P. vivax dans le Sahara malien est Ă©mise. (RĂ©sumĂ© d'auteur
Rice yields enhanced through integrated management of cover crops and phosphate rock in phosphorus-deficient ultisols in West Africa
The relatively low solubility and availability of phosphorus (P) from indigenous phosphate rock could be enhanced by legumes in the acid soils of humid forest agroecosystems. Crotalaria micans L. was grown in a screenhouse without P or with P from triple superphosphate (TSP) and Malian Tilemsi Rock P. The P response of 20 cover crops was field-evaluated using TSP and Rock P. In both experiments, the fertilized cover crops were followed by upland rice without mineral N or P application. Mean rice grain yield and agronomic residual P-use efficiency were similar for both P sources. In the field, 1-year fallow treatment of Canavalia ensiformis (velvet bean) supplied with Mali Rock P gave the highest rice grain yield of 3.1 Mg ha-1, more than 180% that of 2-year continuous unfertilized rice (cv. 'WAB 56-50'). Among continuous rice plots, 'NERICA 2' (interspecific rice) supplied with Rock P produced the highest yield (2.0 Mg ha-1), suggesting that 'NERICA 2' might have greater potential to solubilize rock P. Results indicate that when combined with an appropriate legume, indigenous rock-P can release sufficient P to meet the P requirement of the legume and a following upland rice crop in rotation
Options de ModĂšles dâAffaires pour Assurer la DurabilitĂ© de lâUtilisation des Services dâInformation Climatique au SĂ©nĂ©gal
USAID/CINSERE (Services dâinformation climatiques pour amĂ©liorer la rĂ©silience et la
productivité au Sénégal) est un projet de résilience qui vise à renforcer les capacités nationales
pour la production, lâaccĂšs et la diffusion efficiente dâinformations mĂ©tĂ©orologiques et climatiques
(IC) et de dĂ©velopper des stratĂ©gies pour une mise Ă lâĂ©chelle durable de lâutilisation des services
dâinformation mĂ©tĂ©orologiques et climatiques (SIC) sur toute lâĂ©tendue du territoire national. Le
projet est financĂ© par lâUSAID et mis en oeuvre par le Programme de Recherche du CGIAR sur le
Changement Climatique, lâAgriculture et la SĂ©curitĂ© Alimentaire hĂ©bergĂ© par ICRISAT
(CCAFS/ICRISAT) en collaboration avec lâANACIM. La zone dâintervention du projet est celle
des projets Feed the Future (FtF) au Sénégal, notamment Naatal Mbay (clÎturé en 2019),
Yaajeende (remplacé par Kawolor en 2018), ERA (remplacé par Youth in Agriculture en 2018) et
COMFISH (remplacé par Dekkal Geej en 2019).
DĂ©marrĂ© en Mai 2016 pour une durĂ©e de trois ans (Jusquâen mai 2019), le projet a bĂ©nĂ©ficiĂ© dâune
extension dâun an. Ainsi, cette premiĂšre phase de lâUSAID/CINSERE prend fin en avril 2020.
Durant presque quatre années de mise en oeuvre, des résultats assez probants ont été atteints tant
dans la production des SIC, la communication et lâutilisation de ces SIC, que dans le renforcement
des capacités des bénéficiaires à utiliser de façon efficiente ces SIC. Dans le souci de préserver les
acquis du projet et dâassurer une mise Ă lâĂ©chelle soutenue du systĂšme de dĂ©veloppement et de
fourniture des IC en vue dâune utilisation durable des IC au SĂ©nĂ©gal, lâUSAID a recommandĂ©
lâidentification, le test, la validation et la mise en oeuvre de modĂšles Ă©conomiques viables
impliquant des partenaires aussi bien du public que du privé (PPP). Le projet USAID/CINSERE
sâest donc inspirĂ© des expĂ©riences et leçons apprises au SĂ©nĂ©gal, au Ghana, au Mali, en Inde et en
Amérique Latine (Colombie) en matiÚre de modÚles économiques dans la fourniture des SIC pour
bùtir des modÚles adaptés au contexte du Sénégal. Ce document présente les modÚles identifiés
ainsi que les défis et perspectives
Population genetic structure of Schistosoma haematobium and Schistosoma haematobium x Schistosoma bovis hybrids among school-aged children in CĂŽte d'Ivoire
While population genetics of Schistosoma haematobium have been investigated in West Africa, only scant data are available from Cote d'Ivoire. The purpose of this study was to analyze both genetic variability and genetic structure among S. haematobium populations and to quantify the frequency of S. haematobium x S. bovis hybrids in school-aged children in different parts of Cote d'Ivoire. Urine samples were subjected to a filtration method and examined microscopically for Schistosoma eggs in four sites in the western and southern parts of Cote d'Ivoire. A total of 2692 miracidia were collected individually and stored on Whatman((R)) FTA cards. Of these, 2561 miracidia were successfully genotyped for species and hybrid identification using rapid diagnostic multiplex mitochondrial cox1 PCR and PCR Restriction Fragment Length Polymorphism (PCR-RFLP) analysis of the nuclear ITS2 region. From 2164 miracidia, 1966 (90.9%) were successfully genotyped using at least 10 nuclear microsatellite loci to investigate genetic diversity and population structure. Significant differences were found between sites in all genetic diversity indices and genotypic differentiation was observed between the site in the West and the three sites in the East. Analysis at the infrapopulation level revealed clustering of parasite genotypes within individual children, particularly in Duekoue (West) and Sikensi (East). Of the six possible cox1-ITS2 genetic profiles obtained from miracidia, S. bovis cox1 x S. haematobium ITS2 (42.0%) was the most commonly observed in the populations. We identified only 15 miracidia (0.7%) with an S. bovis cox1 x S. bovis ITS2 genotype. Our study provides new insights into the population genetics of S. haematobium and S. haematobium x S. bovis hybrids in humans in Cote d'Ivoire and we advocate for researching hybrid schistosomes in animals such as rodents and cattle in Cote d'Ivoire
Differential infectivity of gametocytes after artemisinin-based combination therapy of uncomplicated falciparum malaria
Background:Â Most malaria-endemic countries use artemisinin-based combination therapy (ACT) as their first-line treatment. ACTs are known to be highly effective on asexual stages of the malaria parasite. Malaria transmission and the spread of resistant parasites depend on the infectivity of gametocytes. The effect of the current ACT regimens on gametocyte infectivity is unclear.
Objectives: This study aimed to determine the infectivity of gametocytes to Anopheles gambiae following ACT treatment in the field.
Methods:Â During a randomised controlled trial in Bougoula-Hameau, Mali, conducted from July 2005 to July 2007, volunteers with uncomplicated malaria were randomised to receive artemether-lumefantrine, artesunate-amodiaquine, or artesunate-sulfadoxine/pyrimethamine. Volunteers were followed for 28 days, and gametocyte carriage was assessed. Direct skin feeding assays were performed on gametocyte carriers before and after ACT administration.
Results: Following artemether-lumefantrine treatment, gametocyte carriage decreased steadily from Day 0 to Day 21 post-treatment initiation. In contrast, for the artesunate-amodiaquine and artesunate-sulfadoxine/pyrimethamine arms, gametocyte carriage increased on Day 3 and remained constant until Day 7 before decreasing afterward. Mosquito feeding assays showed that artemether-lumefantrine and artesunate-amodiaquine significantly increased gametocyte infectivity to Anopheles gambiae sensu lato (s.l.) (p < 10â4), whereas artesunate-sulfadoxine/pyrimethamine decreased gametocyte infectivity in this setting (p = 0.03).
Conclusion: Different ACT regimens could lead to gametocyte populations with different capacity to infect the Anopheles vector. Frequent assessment of the effect of antimalarials on gametocytogenesis and gametocyte infectivity may be required for the full assessment of treatment efficacy, the potential for spread of drug resistance and malaria transmission in the field
A comparative, randomized clinical trial of artemisinin/naphtoquine twice daily one day versus artemether/lumefantrine six doses regimen in children and adults with uncomplicated falciparum malaria in CĂŽte d'Ivoire
<p>Abstract</p> <p>Background</p> <p>Drug resistance in <it>Plasmodium falciparum </it>poses a major threat to malaria control. Combination anti-malarial therapy, including artemisinins, has been advocated to improve efficacy and limit the spread of resistance. The fixed combination of oral artemether-lumefantrine (AL) is highly effective and well-tolerated. Artemisinin/naphtoquine (AN) is a fixed-dose ACT that has recently become available in Africa.</p> <p>The objectives of the study were to compare the efficacy and safety of AN and AL for the treatment of uncomplicated <it>falciparum </it>malaria in a high transmission-intensity site in Ivory Coast.</p> <p>Methods</p> <p>We enrolled 122 participants aged 6 months or more with uncomplicated <it>falciparum </it>malaria. Participants were randomized to receive either artemisinin/naphtoquine or artemether/lumefantrine with variable dose according to their weight. Primary endpoints were the risks of treatment failure within 28 days, either unadjusted or adjusted by genotyping to distinguish recrudescence from new infection.</p> <p>Results</p> <p>Among 125 participants enrolled, 123 (98.4%) completed follow-up. Clinical evaluation of the 123 participants showed that cumulative PCR-uncorrected cure rate on day 28 was 100% for artemisinin/naphtoquine and 98.4% for artemether/lumefantrine. Both artemisinin-based combinations effected rapid fever and parasite clearance.</p> <p>Interpretation</p> <p>These data suggest that Arco<sup>Âź </sup>could prove to be suitable for use as combination antimalarial therapy. Meanwhile, pharmacokinetic studies and further efficacy assessment should be conducted before its widespread use can be supported.</p
Investigation of Factors Affecting Medication Adherence Among People Living with HIV/AIDS under Non - Governmental Organizations in Senegal
Abstract A ims:This prospective cross-sectional study was carried out to determine factors such as clinical and demographic variab les that may affect medication adherence among people living with HIV/AIDS (PLWHA) receiving treatment at the Institute of health and hygiene of Dakar, but are affiliated to Non-Govern mental Organizations which are HIV/AIDS support group based in Dakar..All consenting subjects from these two support groups were enrolled into study but 305 PLWHA volunteered to participate throughout the three months period of the study. Methods: The study was conducted with the aid of structured interview assisted questionnaires to obtain informat ion on demographic characteristics such as age, sex, occupation, marital status, educational backgrounds, and source of support. Information on availability and side effects of antiretroviral drugs were also obtained. Results:This study indicated that majority of people liv ing with HIV/AIDS interviewed were females (80.3%) while (19.7%) were males. Male respondents show better adherence (91.7%) to ARV med ications than female counterparts (83.7%). Subjects in age the age groups 24-35 years wh ich is the most sexually active groups are mo re vulnerab le (59.1%) when co mpared to other age groups. A large nu mber, (67.2%) were married and there was a significant difference between marital status of PHWHA (P<0.05) and level of adherence to antiretroviral med ications. Descriptive and Chi-square statistical tests were used respectively to evaluate the distribution of respondent's opinion and investigate the level of association between the variables being consideredand respondent'sadherence to antiretroviral med ications. Conclusion: We conclude that there is need to carry out further study in order to fully exp lore the extent to which marital status and other factors can affect medication adherence of people living with HIV/AIDS
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