144 research outputs found
Valuation of the industrial heritage of the city of Rufisque, backup and transmission: what impact on local development?: the case of the former Bata
(INTRODUÇÂO) Le choix d'un sujet du mémoire n'est jamais anodin.Entreprendre cette proposition de recherche sur la valorisation du patrimoine industriel de la ville de Rufisque, sauvegarde et transmission : quel impact sur le développement local et portant sur le cas spécifique de l’ex manufacture Bata constitue un défit et une fierté. D’abord en tant que natif de cette ville tricentenaire qui porte toujours les vestiges de la préhistoire, et dont les habitants étaient considérés comme des citoyens Français (à l’opposé des indigènes)1, ensuite parce que le patrimoine industriel n’est pas très bien connu au Sénégal et enfin l’intérêt historique et son importance socioculturel et économique sur le développement local. Quand les sciences sociales parlent de patrimoine industriel, elles évoquent point un «fonds de commerce», mais un héritage, une mémoire, les traces d'un passé industriel révolu. Une ouverture croissante des entreprises en état d'activité à la réflexion sur elles-mêmes conduit du reste certaines d'entre elles, depuis peu, à créer le lien nécessaire entre ces deux concepts, économique et culturel, en réévaluant l'histoire de l'entreprise comme un des articles de son bilan, et en lui prêtant désormais l'attention que mérite une ressource «morale» où puiser à la fois pour résoudre des problèmes de gestion et pour conforter l'image interne et externe de l’entreprise2. Le patrimoine historique de l'industrie, concrètement, ce sont lestraces, plus ou moins bien préservées, de son fonctionnement et de son insertion dans le paysage ou dans la société.Les archives d'entreprises, les murs des usines, les débris des infrastructures ou de l'outillage, les collections de produits (ne serait-ce que sur catalogue), l'impact sur l'environnement, la mémoire des dernières générations de patrons ou de salariés: autant d'éléments matériels ou de souvenirs (immatériel) dont il est de mieux en mieux admis aujourd'hui qu'on ne saurait se passer pour écrire l'histoire de l'industrie, une histoire inscrite non seulement dans les statistiques, les enquêtes, les comptabilités, mais aussi dans l'espace en trois dimensions, dans la vision d'une population, dans des vies quotidienne
Thibault Ehrengardt, Reggae et politique dans les années 70
L’ouvrage Reggae et politique dans les années 70 de Thibault Ehrengardt vient se positionner d’emblée contre une dérive facile et courante, celle de ne voir le reggae qu’à travers le prisme enchanteur du Rasta militant mais apolitique, image d’Épinal battue en brèche par cette étude qui met en avant le fait politique - pour ne pas dire politicien. La coïncidence entre l’avènement de l’âge d’or du reggae et la capacité du personnel politique jamaïcain à en tirer profit forme la toile de fond d..
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
An evaluation of groundwater vulnerability assessment methods in a rapidly urbanizing city: evidence from Dakar, Senegal
In rapidly growing cities in the tropics, unregulated urban development presents a major risk to groundwater quality. Here, we assess the vulnerability of an unconfined aquifer of Quaternary sands in the Thiaroye area of Dakar (Senegal) to contamination using four GIS-based indices (DRASTIC, DRASTIC_N, SINTACS, SI). Our correlation of assessed vulnerability to observed impact is semi-quantitative, relating observed groundwater quality, based on nitrate concentrations and tryptophan-like fluorescence to vulnerability degrees (i.e. coincidence rates). We show that considerably more of the Thiaroye area has a “very high vulnerability” according to SI (36%) relative to DRASTIC (5%) and SINTACS (9%); “high vulnerability” is estimated using DRASTIC_N (100%), DRASTIC (66%) and SINTACS (69%). Single-parameter sensitivity tests show that groundwater depth, soil, topography, land use and redox parameters strongly influence assessments of groundwater vulnerability. Correlation with observed nitrate concentrations reveals aquifer vulnerability is better represented by SI (coincidence rates of 56%) relative to DRASTIC_N (43%), SINTACS (38%) and DRASTIC (34%). The underestimation of groundwater vulnerability in Dakar using DRASTIC, DRASTIC_N and SINTACS is attributed to their reliance on an assumed capacity of the unsaturated zone to attenuate surface or near-surface contaminant loading, which in the low-income (Thiaroye) area of Dakar is thin and affords limited protection. The inclusion of a land-use parameter in SI improves the characterization of groundwater vulnerability in this low-income, rapidly urbanizing area of Dakar
Infectiousness of the human population to Anopheles arabiensis by direct skin feeding in an area hypoendemic for malaria in Senegal.
Direct skin feeding experiments are sensitive assays to determine human infectiousness to mosquitoes but are rarely used in malaria epidemiological surveys. We determined the infectiousness of inhabitants of a malaria hypoendemic area in Senegal. Gametocyte prevalence by microscopy was 13.5% (26 of 192). Of all individuals who were gametocyte positive, 44.4% (11 of 25) infected ≥ 1 Anopheles arabiensis mosquito and 10.8% (54 of 500) of mosquitoes became infected. Of all individuals who were gametocyte negative by microscopy, 4.3% (7 of 162) infected ≥ 1 mosquito and 0.4% (12 of 3240) of mosquitoes became infected. The 18.2% (12 of 66) of all mosquito infections was a result of submicroscopic gametocyte carriage and two individuals without asexual parasites or gametocytes by microscopy were infectious to mosquitoes. When infectivity and local demography was taken into account, children 5-14 years of age contributed 50.8% of the human infectious reservoir for malaria. Adults and submicroscopic gametocyte carriers may contribute considerably to onward malaria transmission in our setting
Insecticide Resistance Profiling of Anopheles coluzzii and Anopheles gambiae Populations in the Southern Senegal: Role of Target Sites and Metabolic Resistance Mechanisms
The emergence and spread of insecticide resistance among the main malaria vectors is threatening the effectiveness of vector control interventions in Senegal. The main drivers of this resistance in the Anopheles gambiae complex (e.g., An. gambiae and Anopheles coluzzii) remains poorly characterized in Senegal. Here we characterized the main target site and metabolic resistances mechanisms among the An. gambiae and An. coluzzii populations from their sympatric and allopatric or predominance area in Senegal. Larvae and pupae of An. gambiae s.l. were collected, reared to adulthood, and then used for insecticides susceptibility and synergist assays using the WHO (World Health Organisation) test kits for adult mosquitoes. The TaqMan method was used for the molecular characterization of the main target site insecticide resistance mechanisms (Vgsc-1014F, Vgsc-1014S, N1575Y and G119S). A RT-qPCR (Reverse Transcriptase-quantitative Polymerase Chaine Reaction) was performed to estimate the level of genes expression belonging to the CYP450 (Cytochrome P450) family. Plasmodium infection rate was investigated using TaqMan method. High levels of resistance to pyrethroids and DDT and full susceptibility to organophosphates and carbamates where observed in all three sites, excepted a probable resistance to bendiocarb in Kedougou. The L1014F, L1014S, and N1575Y mutations were found in both species. Pre-exposure to the PBO (Piperonyl butoxide) synergist induced a partial recovery of susceptibility to permethrin and full recovery to deltamethrin. Subsequent analysis of the level of genes expression, revealed that the CYP6Z1 and CYP6Z2 genes were over-expressed in wild-resistant mosquitoes compared to the reference susceptible strain (Kisumu), suggesting that both the metabolic resistance and target site mutation involving kdr mutations are likely implicated in this pyrethroid resistance. The presence of both target-site and metabolic resistance mechanisms in highly pyrethroid-resistant populations of An. gambiae s.l. from Senegal threatens the effectiveness and the sustainability of the pyrethroid-based tools and interventions currently deployed in the country. The Kdr-west mutation is widely widespread in An. coluzzii sympatric population. PBO or Duo nets and IRS (Indoor Residual Spraying) with organophosphates could be used as an alternative measure to sustain malaria control in the study area
Entomological impact of indoor residual spraying with pirimiphos-methyl: a pilot study in an area of low malaria transmission in Senegal.
BACKGROUND: Scaling-up of effective anti-malarial control strategies in Central-West region of Senegal has resulted in the sharp decline in malaria prevalence in this area. However, despite these strategies, residual malaria transmission has been observed in some villages (hot spots). The objective of this study was to assess the impact of indoor residual spraying (IRS) with pirimiphos-methyl on malaria transmission in hot spot areas. METHODS: The malaria vector population dynamics were monitored in each of the six selected villages (4 of which used IRS, 2 were unsprayed control areas) using overnight human landing catches (HLC) and pyrethrum spray catches (PSC). The host source of blood meals from freshly fed females collected using PSC was identified using the direct ELISA method. Females caught through HLC were tested by ELISA for the detection of Plasmodium falciparum circumsporozoite protein and Anopheles gambiae complex was identified using PCR. RESULTS: Preliminary data shown that the densities of Anopheles populations were significantly lower in the sprayed areas (179/702) compared to the control. Overall, malaria transmission risk was 14 times lower in the intervention zone (0.94) compared to the control zone (12.7). In the control areas, three Anopheles species belonging to the Gambiae complex (Anopheles arabiensis, Anopheles coluzzii and Anopheles melas) maintained the transmission, while only An. coluzzii was infective in the sprayed areas. CONCLUSION: The preliminary data from this pilot study showed that IRS with the CS formulation of pirimiphos-methyl is likely very effective in reducing malaria transmission risk. However, additional studies including further longitudinal entomological surveys as well as ecological and ethological and genetical characterization of vectors species and their populations are needed to better characterize the entomological impact of indoor residual spraying with pirimiphos-methyl in the residual transmission areas of Senegal
Antimicrobial resistance in outpatient Escherichia coli urinary isolates in Dakar, Senegal.
International audienceBACKGROUND: Data regarding the evolution of antimicrobial resistance are needed to suggest appropriate empirical treatment of urinary tract infections (UTI) in developing countries. To assess the antimicrobial susceptibility of Escherichia coli, the predominant pathogen in community-acquired UTI, a prospective multicenter study was carried out in Dakar, Senegal. METHODOLOGY: From February 2004 to October 2006, 1010 non-duplicate E. coli strains were collected from four centres. Antimicrobial susceptibility testing was performed using disk diffusion method according to the recommendations of the CA-SFM (2004). RESULTS: Most of the isolates were resistant to amoxicillin (73.1%), amoxicillin-clavulanic acid (67.5%), cephalothin (55.8%), and trimethoprim/sulfamethoxazole (68.1%). Extended spectrum beta-lactamase was detected in 38 strains. The overall resistance rates to nalidixic acid, norfloxacin and ciprofloxacin were 23.9%, 16.4% and 15.5%, respectively. Most of the strains were susceptible to gentamicin, nitrofurantoin and fosfomycin (respective susceptibility rates, 93.8%, 89.9%, and 99.3%). During this period, a significant decrease in sensitivity was observed for cephalothin, fluoroquinolones and trimethoprim/sulfamethoxazole (p<0.001). CONCLUSIONS: These data suggest that trimethoprim/sulfamethoxazole may no longer be used as empirical treatment for community-acquired UTI in Dakar. In order to preserve the activity of fluoroquinolones for future years, alternatives such as fosfomycin or nitrofurantoin should be considered
The Gametocytocidal Efficacy of Different Single Doses of Primaquine with Dihydroartemisinin-piperaquine in Asymptomatic Parasite Carriers in The Gambia: A Randomized Controlled Trial
AbstractBackgroundAsymptomatic low-density gametocyte carriers represent the majority of malaria-infected individuals. However, the impact of recommended treatment with single low dose of primaquine and an artemisinin-based combination therapy to reduce transmission in this group is unknown.MethodsThis was a four-arm, open label, randomized controlled trial comparing the effect of dihydroartemisinin-piperaquine (DHAP) alone or combined with single dose of primaquine (PQ) at 0.20mg/kg, 0.40mg/kg, or 0.75mg/kg on Plasmodium falciparum gametocytaemia, infectiousness to mosquitoes and hemoglobin change in asymptomatic, malaria-infected, glucose-6-phosphate dehydrogenase (G6PD) normal individuals. Randomization was done using a computer-generated sequence of uneven block sizes with codes concealed in sequentially numbered opaque envelopes. The primary endpoint was the prevalence of P. falciparum gametocytemia at day 7 of follow-up determined by quantitative nucleic acid sequence based assay and analysis was by intention to treat. The trial has been concluded (registration number: NCT01838902; https://clinicaltrials.gov/ct2/show/NCT01838902).ResultsA total of 694 asymptomatic, malaria-infected individuals were enrolled. Gametocyte prevalence at day 7 was 37.0% (54/146; 95% CI 29.2–45.4), 19.0% (27/142; 95% CI 12.9–26.4), 17.2% (25/145; 95% CI 11.0–23.5) and 10.6% (15/141; 95% CI 6.1–16.9) in the DHAP alone, 0.20mg/kg, 0.40mg/kg, and 0.75mg/kg PQ arms, respectively. The main adverse events reported include headache (130/471, 27.6%), cough (73/471, 15.5%), history of fever (61/471, 13.0%) and abdominal pain (57/471, 12.1%). There were five serious adverse events however, none was related to the interventions.InterpretationA single course of PQ significantly reduces gametocyte carriage in malaria-infected asymptomatic, G6PD-normal individuals without increasing the risk of clinical anemia. The limited number of successful mosquito infections suggests that post-treatment transmission potential in this asymptomatic population is low
In-situ fluorescence spectroscopy indicates total bacterial abundance and dissolved organic carbon
We explore in-situ fluorescence spectroscopy as an instantaneous indicator of total bacterial abundance and faecal contamination in drinking water. Eighty-four samples were collected outside of the recharge season from groundwater-derived water sources in Dakar, Senegal. Samples were analysed for tryptophan-like (TLF) and humic-like (HLF) fluorescence in-situ, total bacterial cells by flow cytometry, and potential indicators of faecal contamination such as thermotolerant coliforms (TTCs), nitrate, and in a subset of 22 samples, dissolved organic carbon (DOC). Significant single-predictor linear regression models demonstrated that total bacterial cells were the most effective predictor of TLF, followed by on-site sanitation density; TTCs were not a significant predictor. An optimum multiple-predictor model of TLF incorporated total bacterial cells, nitrate, nitrite, on-site sanitation density, and sulphate (r2 0.68). HLF was similarly related to the same parameters as TLF, with total bacterial cells being the best correlated (ρs 0.64). In the subset of 22 sources, DOC clustered with TLF, HLF, and total bacterial cells, and a linear regression model demonstrated HLF was the best predictor of DOC (r2 0.84). The intergranular nature of the aquifer, timing of the study, and/or non-uniqueness of the signal to TTCs can explain the significant associations between TLF/HLF and indicators of faecal contamination such as on-site sanitation density and nutrients but not TTCs. The bacterial population that relates to TLF/HLF is likely to be a subsurface community that develops in-situ based on the availability of organic matter originating from faecal sources. In-situ fluorescence spectroscopy instantly indicates a drinking water source is impacted by faecal contamination but it remains unclear how that relates specifically to microbial risk in this setting
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