Evaluation de lignées intra et inter spécifiques de riz en conditions irriguées au Sénégal

Parmi les deux espèces de riz cultivées, l’espèce africaine Oryza glaberrima Steudt. est une source de gènes utiles pour des caractères importants, qui n’existent pas chez l’espèce asiatique Oryza sativa L., limitant ainsi ses performances en Afrique. Cela a inspiré le processus d’hybridation interspécifique entre ces espèces pour développer un nouveau type de riz mieux adapté aux conditions de production du paysan africain. Dans l’optique d’élargissement de la diversité génétique du riz cultivé en conditions irriguées, l’évaluation des performances de 31 lignées intra- et interspécifiques, a été effectuée, dans un dispositif à blocs de Fisher à 2 répétitions, sur deux sites et deux saisons, dans la vallée du fleuve Sénégal. L’analyse de variance combinée sur site et saison a montré un effet très significatif du génotype sur l’ensemble des caractères étudiés. Un effet significatif de la saison sur le cycle et de l’interaction Génotype x Site (G x E) sur la hauteur a aussi été observé. Cependant, aucun effet G x E sur le rendement et le nombre de panicules par m2 n’a été observé. Les rendements moyens varient entre 6,61 et 8,78 t.ha-1. Les lignées prometteuses identifiées devraient contribuer à l’amélioration des performances du riz cultivé dans la région.© 2016 International Formulae Group. All rights reserved.Mots clés: Sénégal, lignées, diversité génétique, rendement, riziculture irriguéeEnglish Title: Evaluation of intra- and interspecific rice lines under irrigated conditions in SenegalEnglish AbstractAmong the two cultivated rice species, the African species Oryza glaberrima Steudt. is a source of useful genes for important traits, which do not exist in the Asian species Oryza sativa L., limiting thus its performance, in Africa. This has inspired the interspecific hybridization process between the two species to develop a new type of rice best suited to the production conditions of the African peasant. With the aim of broadening the genetic diversity cultivated rice in irrigated conditions, the performance evaluation of 31 lines, intra- and inter, was conducted in a randomized complete block design with 2 replications, on two sites and two seasons in the Senegal River valley. The analysis of variance combined over site and season shows a highly significant difference of Genotype (G) for all studied traits. A significant effect of season on cycle, and interaction genotype x location (G x E) on plant height, was also observed. However, no (G x E) effect on yield and number of panicles per quadrate meter were observed. The average of yield varies between 6.61 and 8.78  t.ha-1. Identified promising lines should contribute to the sustainable improvement of the performance of rice cultivated in the area.Keywords: Senegal, lines, genetic diversity, grain yield, irrigated ric

The synthesis and the reactivity of arene ruthenium oxalato complexes

This article outlines the reactions of the well known [RuCl(η6-p-cymene)]2(μ-η4-C2O4) and [RuCl(η6-p-cymene)(η2-dppm)][PF6] ruthenium complexes with C2O4(Me4N)2 in the mol ratios 1:1 and 2:1. While the 2:1 ratio reaction led to the sole and expected binuclear product {[Ru(η6-p-cymene)(η2-dppm)]2(μ-η2-C2O4)}[PF6]2, the reaction also afforded the unexpected mononuclear complex [RuCl(η2-C2O4)(η6-p-cymene)][Me4N]. This can also be obtained in improved yield by reacting [RuCl2(p-cymene)]2 with C2O4[Me4N]2 in a 1:1 mol ratio. Surprisingly, when [RuCl(η6-p-cymene)]2(μ-η4-C2O4) was reacted with an equimolar amount of the ligand dppm, the expected complex {[Ru(η6-p-cymene)]2(μ-η4-C2O4)(μ-dppm)}[PF6]2 was accompanied by [RuCl(η6-p-cymene)(η2-dppm)][PF6] in an inseparable solid mixture. KEY WORDS: Ruthenium, Arene, p-cymene, Mesitylene, Oxalate, bis-(Dipenylphosphino)methane  Bull. Chem. Soc. Ethiop. 2008, 22(2), 207-217

L'expertise pour prédire la production cotonnière en Afrique de l'Ouest : est-elle une solution face aux aléas climatiques émergents ?

Description du sujet. Face aux effets attendus des aléas climatiques sur l'économie des pays d'Afrique de l'Ouest, anticiper la production agricole est devenu une priorité pour les acteurs du développement. L'article porte sur l'estimation précoce de la production cotonnière avant la récolte au Sénégal, par voie d'expertise de la SODEFITEX. Objectifs. L'étude a pour objectifs d'expliciter les connaissances mobilisées par les experts pour prédire le rendement, eu égard à l'incertitude sur les conditions climatiques à venir, et d'évaluer la performance des prévisions, selon le niveau territorial considéré. Méthode. Pour atteindre ces deux objectifs, l'article s'appuie sur l'analyse statistique de la production cotonnière au Sénégal de 2004 à 2015, combinée à une enquête réalisée auprès de 32 experts de la SODEFITEX. Résultats. L'analyse des résultats d'enquête met en évidence une prévision principalement établie sur la base de l'état des cultures, des pratiques culturales au premier rang desquelles la date de semis et, pour certains experts, de l'historique de la production et son environnement organisationnel et social. La comparaison des prévisions avec la production effective montre que les experts surestiment systématiquement les niveaux de production inférieurs à 1 000 kg.ha-1, en conditions climatiques défavorables. Conclusions. Dans un contexte de faible documentation scientifique sur l'estimation précoce de la production par voie d'expertise, les résultats de l'étude éclairent sur les connaissances mobilisées et la performance des prévisions délivrées, ouvrant ainsi la voie à une critique rationnelle de l'expertise. La diversité de points de vue mise en évidence par l'analyse multicritère, entre niveaux hiérarchiques et entre agents de même niveau, souligne le besoin de confrontation des connaissances pour faire émerger les variables explicatives nécessaires à la prévision et tendre vers une objectivité accrue de l'expertise face aux aléas climatiques récurrents

Ectopia cordis about a case at Ourossogui regional hospital center

We report in this work, an extremely rare and major case of anterior body wall defects included ectopia cordis define by abnormal location of heart outside of the thorax. This case was diagnosed at the maternity of Ourossogui regional hospital center, in Senegal. Any scan was performed during the pregnancy. Newborn died 10 minutes after birth. Ectopia cordis is related to a possible ventral midline developmental abnormality. It’s associated to other midline abnormalities and is a part of pentalogy of Cantrell. An X-linked genetic abnormality

Long-Term Intrapatient Evolution During HIV-2 Infection

HIV-2 disease progression and transmission is attenuated compared to HIV-1, yet prospective studies examining HIV-2 intrapatient evolution have been limited. We examined viral sequence evolution in the C2V3C3 region of the viral env gene in 8 HIV-2 infected individuals from Dakar, Senegal, over the course of approximately 10 years. To compare results to HIV-1 infection, we reanalyzed data from our previous study that examined intrapatient evolution in HIV-1 infected individuals from the same population. HIV-2 sequences from early and late timepoints were phylogenetically intermixed for all subjects, and no distinct trends were observed in terms of increases or decreases in fragment size or number of N-linked glycosylation sites. In homologous env C2V3 sequence, rates of viral divergence and diversification were slower in individuals infected with HIV-2 than individuals with HIV-1. This data indicates that viral evolution occurs slowly in HIV-2 infection, which is consistent with the slow disease progression observed in HIV-2 infection, and supports the notion that viral evolution may be a relevant correlate for disease progression

Antibiotic susceptibility profile of Streptococcus pneumoniae isolated from acute respiratory infection in Dakar: a cross sectional study

Streptococcus pneumoniae is a pathogen causing pneumonia, meningitis, otitis and bacteraemia. Nowadays, S. pneumoniae is developing antibacterial resistance, particularly for those with reduced susceptibility to penicillin. The objective of this study was to assess the susceptibility profile of S. pneumoniae strains isolated from acute respiratory infections (ARIs) in children younger than 5 years of age in Dakar, Senegal. S. pneumoniae strains were isolated from broncho-alveolar lavages (BALs), nasopharyngeal swabs, and middle ear secretion from children in the Paediatric Department of Abass Ndao University Teaching Hospital and Paediatric Department of Roi Baudouin Hospital in Dakar, Senegal. The strains were cultivated on Columbia agar supplemented with 5% of horse blood and gentamicin (6 mg/L). Antibiotic susceptibility testing was performed using E-test method. A total of 34 strains of S. pneumoniae were isolated and identified in this study, among them 7 strains (20.58%) showed penicillin-resistance. Antibiotics such as amoxicillin/clavulanic acid (MIC90=0.036 μg/mL), cefuroxim (MIC90=0.38 μg/mL), cefixim (MIC90=1.5 μg/mL), as well as macrolides (azithromycin MIC90=1.5 μg/mL, clarithromycin MIC90=0.125 μg/mL) and fluoroquinolone (levofloxacin MIC90=1 μg/mL, ofloxacin MIC90=2 μg/mL) were mostly active. However, all S. pneumoniae strains were resistant to sulfamethoxazole/trimethoprim (MIC90: 32 μg/mL). Except of S. pneumoniae strains penicillin-resistance or reduced susceptibility, most strains were susceptible to β-lactams antibiotics commonly used in ARI treatment. Continuous surveillance of antimicrobial resistance patterns of pneumococcus strains is still crucial for effective control of ARIs in children

Application of Functional Data Analysis to Identify Patterns of Malaria Incidence, to Guide Targeted Control Strategies.

We introduce an approach based on functional data analysis to identify patterns of malaria incidence to guide effective targeting of malaria control in a seasonal transmission area. Using functional data method, a smooth function (functional data or curve) was fitted from the time series of observed malaria incidence for each of 575 villages in west-central Senegal from 2008 to 2012. These 575 smooth functions were classified using hierarchical clustering (Ward's method), and several different dissimilarity measures. Validity indices were used to determine the number of distinct temporal patterns of malaria incidence. Epidemiological indicators characterizing the resulting malaria incidence patterns were determined from the velocity and acceleration of their incidences over time. We identified three distinct patterns of malaria incidence: high-, intermediate-, and low-incidence patterns in respectively 2% (12/575), 17% (97/575), and 81% (466/575) of villages. Epidemiological indicators characterizing the fluctuations in malaria incidence showed that seasonal outbreaks started later, and ended earlier, in the low-incidence pattern. Functional data analysis can be used to identify patterns of malaria incidence, by considering their temporal dynamics. Epidemiological indicators derived from their velocities and accelerations, may guide to target control measures according to patterns