30 research outputs found
Effets du travail du sol sur le comportement chimique et biologique du sol et les conséquences sur le rendement d’un blé tendre (Triticum aestivum L.) dans la région « non chernozem » de la fédération de Russie.
Objectif : L’objectif de cette étude est de comparer les effets de six techniques culturales de mise en place du blé tendre sur certaines propriétés chimiques et biologiques du sol et les conséquences sur le rendement grain et ses composantes dans la région «non chernozem» en 7ème années de rotation.Méthodologie et résultats : Le dispositif expérimental utilisé est un Split plot à quatre répétitions comprenant chacune un témoin (labour conventionnel sur 20 cm) et cinq traitements labours. Il s’agit : du labour traditionnel sur 30 cm, du travail minimum sur 8 cm, l’alternance du labour conventionnel avec travail minimum, du labour conventionnel exécuté après un labour profond à la charrue à socs et enfin du labour conventionnel pratiqué après un labour profond l’aide au chisel anglais type Paraplay sur 30 cm. Les résultats ont montré : pour le labour traditionnel continu (LT-27-30) et périodique (LC-20 après LT-27-30) des teneurs élevées en nitrate respectif de 28,5 et 27,7 mg/kg sur la couche 0-30 cm. Pour les techniques minimales de travail (LM-8) et (LM-8/LC-20), ces quantités ont été supérieures dans les 10 premiers centimètres du sol respectif de 16,7 et 26,1 mg/kg et subissent une chute importante dans les horizons sous-jacents. Les quantités de phosphore et de potassium ont évolué sur la couche 0-20 cm de 21 à 27 mg/100 g et de 14 à 15 mg/100 g respectivement. Le labour minimum sur cette couche a enregistré des concentrations beaucoup plus faible, soit 9,5 mg/100 g pour le phosphore et 10 mg/100 g pour potassium.Conclusion et application des résultats : Une étude économique est nécessaire pour se prononcer sur la technique à pratiquer. Cependant dans les conditions de nos essais, nous préconisons une alternance de la méthode traditionnelle avec labour profond avec le labour superficiel de 8 cm. Le nombre d’années accordé à chaque type de labour dans la rotation doit être sensiblement égal pour l’obtention de meilleurs résultats.Mots clés : Labour, blé tendre, paramètres chimiques, activité biologique, composantes, rendemen
Sorghum grain as human food in Africa: relevance of content of starch and amylase activities
Sorghum is a staple food grain in many semi-arid and tropic areas of the world, notably in Sub-Saharan Africa because of its good adaptation to hard environments and its good yield of production. Among important biochemical components for sorghum processing are levels of starch (amylose and amylopectin) and starch depolymerizing enzymes. Current research focus on identifying varieties meeting specific agricultural and food requirements from the great biodiversity of sorghums to insure food security. Results show that some sorghums are rich sources of micronutrients (minerals and vitamins) and macronutrients (carbohydrates, proteins and fat). Sorghum has a resistant starch, which makes it interesting for obese and diabetic people. In addition, sorghum may be an alternative food for people who are allergic to gluten. Malts of some sorghum varieties display a-amylase and ß-amylase activities comparable to those of barley, making them useful for various agro-industrial foods. The feature of sorghum as a food in developing as well as in developed countries is discussed. A particular emphasis is made on the impact of starch and starch degrading enzymes in the use of sorghum for some African foods, e.g. “tô”, thin porridges for infants, granulated foods “couscous”, local beer “dolo”, as well agro-industrial foods such as lager beer and bread.Keywords: sorghum, a-amylase, b-amylase, starch, infant porridge, beer, couscous, dolo, tô, brea
Village Baseline Study: Site Analysis Report for Kollo – Fakara, Niger (NI0111)
The village baseline study of Tigo Zéno village in the CCAFS benchmark site Fakara in Niger took place from 23 to 25 of June 2011. Focus group discussions were conducted separately for men and women. Tigo Zéno’s natural resources are degraded, with sparse tree population. Water is scarce and temporary, the farmlands have eroded, and soil is infertile with low productivity. People are particularly concerned about the presence and expansion of gullies (“koris”) that have created uncultivable areas, major declines in soil fertility, destruction of crops during serious overflow of ponds and heavy rainfall, and significant reduction in the size of farmlands, especially those belonging to women, who have smaller farmlands than men
Primary Breast Burkitt’s Lymphoma in an HIV-Infected Woman
A 30-year-old HIV positive woman presented with a multifocal mass tumour associated with axillary and lateral-cervical lymphadenopathy in the right breast. Laboratory examination of the biopsy confirmed a case of mammary Burkitt’s lymphoma with a nodular infiltration of the breast. Antiretroviral treatment and chemotherapy were effective to control the tumour. Although Burkitt’s lymphoma rarely involves the breasts, it should be considered during routine breast examination of African woman
Failure to Recognize Nontuberculous Mycobacteria Leads to Misdiagnosis of Chronic Pulmonary Tuberculosis
BACKGROUND: Nontuberculous mycobacterial (NTM) infections cause morbidity worldwide. They are difficult to diagnose in resource-limited regions, and most patients receive empiric treatment for tuberculosis (TB). Our objective here is to evaluate the potential impact of NTM diseases among patients treated presumptively for tuberculosis in Mali. METHODS: We re-evaluated sputum specimens among patients newly diagnosed with TB (naĂŻve) and those previously treated for TB disease (chronic cases). Sputum microscopy, culture and Mycobacterium tuberculosis drug susceptibility testing were performed. Identification of strains was performed using molecular probes or sequencing of secA1 and/or 16S rRNA genes. RESULTS: Of 142 patients enrolled, 61 (43%) were clinically classified as chronic cases and 17 (12%) were infected with NTM. Eleven of the 142 (8%) patients had NTM disease alone (8 M. avium, 2 M. simiae and 1 M. palustre). All these 11 were from the chronic TB group, comprising 11/61 (18%) of that group and all were identified as candidates for second line treatment. The remaining 6/17 (35.30%) NTM infected patients had coinfection with M. tuberculosis and all 6 were from the TB treatment naĂŻve group. These 6 were candidates for the standard first line treatment regimen of TB. M. avium was identified in 11 of the 142 (8%) patients, only 3/11 (27.27%) of whom were HIV positive. CONCLUSIONS: NTM infections should be considered a cause of morbidity in TB endemic environments especially when managing chronic TB cases to limit morbidity and provide appropriate treatment
Molecular identification of Mycobacterium bovis from cattle and human host in Mali: expanded genetic diversity
Tropical Data: Approach and Methodology as Applied to Trachoma Prevalence Surveys
PURPOSE: Population-based prevalence surveys are essential for decision-making on interventions to achieve trachoma elimination as a public health problem. This paper outlines the methodologies of Tropical Data, which supports work to undertake those surveys. METHODS: Tropical Data is a consortium of partners that supports health ministries worldwide to conduct globally standardised prevalence surveys that conform to World Health Organization recommendations. Founding principles are health ministry ownership, partnership and collaboration, and quality assurance and quality control at every step of the survey process. Support covers survey planning, survey design, training, electronic data collection and fieldwork, and data management, analysis and dissemination. Methods are adapted to meet local context and needs. Customisations, operational research and integration of other diseases into routine trachoma surveys have also been supported. RESULTS: Between 29th February 2016 and 24th April 2023, 3373 trachoma surveys across 50 countries have been supported, resulting in 10,818,502 people being examined for trachoma. CONCLUSION: This health ministry-led, standardised approach, with support from the start to the end of the survey process, has helped all trachoma elimination stakeholders to know where interventions are needed, where interventions can be stopped, and when elimination as a public health problem has been achieved. Flexibility to meet specific country contexts, adaptation to changes in global guidance and adjustments in response to user feedback have facilitated innovation in evidence-based methodologies, and supported health ministries to strive for global disease control targets
The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance
INTRODUCTION
Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic.
RATIONALE
We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs).
RESULTS
Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants.
CONCLUSION
Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century
Contribution of an innovation platform to change the management of collective irrigation: a case study from the Office du Niger (Mali)
In the Office du Niger large rice farming irrigation scheme in Mali, water management has been a permanent source of tension between the smallholder tenants and the administration. The transfer of tertiary canal maintenance to the tenant farmers was expected to improve water management but, in practice, that rather led to deterioration. An innovation platform, erected by the CoS-SIS (Convergence of Sciences – Strengthening Innovation Systems) Program, reached a consensual agreement to transfer the maintenance of tertiary canals to the tenant producers, and updated the Contrat Plan expropriation rules for failure to pay water fees as well as many other key dispositions ruling duties and responsibilities for all parties: farmers, Office du Niger agents and the State
Évaluation agro-morphologique de quelques variétés de poivron ou piment doux (Capsicum annuum L) au nord du Burkina Faso
Objectif: L’adaptation du piment doux ou Poivron (Capsicum annuum L.) aux conditions tropicales chaudes et humides pose des problèmes car dans ces zones la chaleur humide et la forte pression parasitaire affectent la culture et son rendement. L’objectif de cette étude est d’évalué les caractéristiques agromorphologiques de 5 variétés de poivron Papri Queen, Sahem, Spifire, PP0252-197 et Papri King dans les conditions climatiques et biotiques du nord du Burkina Faso.Méthodologie et résultats: Cinq variétés de poivron ont été évaluées dans un dispositif en blocs de Fisher à 4 répétitions au cours de la saison hivernale de 2014 - 2015 au nord de Burkina Faso. Onze (11) variables (09 quantitatives, 03 qualitatives) ont servi à l'évaluation agro-morphologique des cultivars. Les variétés ont observé un développement végétatif moins abondant et les hauteurs moyennes des plantes ont été 27,65 ; 33,14 ; 36,43 et 38,75 cm à 6, 8, 10 et 12 semaines après repiquage respectivement. Les densités ont été faibles à la récolte des poivrons. Elles ont évolué de 57,5 % chez PP 0252-197 et Spifire à 60,83% pour Papri King. Le nombre de jours 50% floraison est intervenu en moyenne entre le 58ème et le 84ème jour. Ce cycle a été plus court de 58 jours chez Papri Queen, plus long chez Spifire et PP0252-197 respectifs de 82 et 84 jours et de 75.jours chez Papri King et Sahem. Le poids moyen des fruits oscille entre 3,08 chez PP0252-197 et 6,93 grammes chez Sahem. S’agissant de la longueur moyenne du fruit, elle était plus importante chez Spifire (8,15 cm) et Sahem (9,95 cm) et plus faible chez Papri Queen (5,88 cm).Conclusion et application des résultats: Les variétés Papri Queen, Sahem et Papri King qui ont présenté les meilleurs développements végétatifs et les rendements les plus élevés (4,4 à 4,8 t/ha) pourraient être prometteurs pour la culture au Burkina Faso a condition de mieux adapter la période de culture. Toutes les variétés évaluées ont été sensibles à une virose transmise sans doute par les mouches blanches et les thrips du poivron et du piment (Scirtothrips dorsalis).Mots clés: Capsicum annuum L, adaptation, caractéristiques agro morphologiques, rendement, Burkina FasoEnglish Title: Agro-morphological evaluation of some varieties of paprika pepper (Capsicum annuum L) in northern Burkina FasoEnglish AbstractObjective: Sweet pepper or Paprika (Capsicum annuum L.) is an important market gardening plant grown on all continents. Its adaptation to hot and humid tropical conditions is problematic because in these areas moist heat and high parasite pressure affect the crop and its yield. The objective of this study is to evaluate the agro-morphological characteristics of 5 varieties of papri queen peppers, Sahem, Spifire, PP0252-197 and Papri King in the climatic and biotic conditions of northern Burkina Faso.Methodology and results: Five varieties of pepper were assessed in Full Random Block Device or Fisher Blocks with 4 repetitions during the winter season 2014 - 2015 in northern Burkina Faso. Eleven (11) variables (09 quantitative, 03 qualitative) were used for agro-morphological evaluation of cultivars. Varieties observed less abundant vegetative growth and medium sized plants were 27.65; 33.14; 36.43 and 38.75 cm at 6, 8, 10 and 12 weeks after transplanting respectively. Weak densities were recorded at harvest peppers. They evolved from 57.5% to PP 0252-197 and Spifire in 60.83% for Papri King. The number of days 50% flowering occurred on average between the 58th and the 84th day. This cycle has been shorter for Papri Queen (58 days). Varieties Spifire and PP0252-197 recorded a longer flowering cycle of 82 and 84 days respectively. Average fruit weight varies from 3.08 in PP0252-197 to 6.93 grams in Sahem. Varieties Spifire, Papri Queen, Papri King have observed average fruit weights of 4.0; 4.89 and 5.77.g respectively. Regarding the average fruit length, it was higher in Spifire (8.15 cm) and Sahem (9.95 cm) and weaker in Papri Queen (5.88 cm). However, Papri Queen and Papri King have found medium-sized fruits that are 1.9 cm larger.Conclusion and application of results: Varieties Papri Queen, Sahem and Papri King which had the best vegetative growth and the highest yields (4.4 to 4.8 t/ha), could be promising for cultivation in Burkina Faso. All varieties evaluated were susceptible to viruses probably transmitted by white flies and chili thrips (Scirtothrips dorsalis).).Keywords: Capsicum annuum L, adaptation, agro-morphological characteristics, yield, Burkina Fas