Étude comparative des peuplements ichtyologiques de l’Aire Marine Protégée de Joal-Fadiouth et des pêcheries des zones du pourtour non protégées à l’exploitation halieutique

L'effondrement des stocks de poisson est dû à la surexploitation des peuplements ichtyologiques consécutifs aux mauvaises pratiques de pêche au Sénégal. Cette situation a amené les écologistes marins et les gestionnaires de l'environnement à réévaluer les méthodes traditionnelles de gestion des ressources halieutiques. Pour connaitre la dynamique des peuplements ichtyologiques, nous avons mené une étude comparative des peuplements ichtyologiques de l’Aire Marine Protégée de Jaol-Fadiouth et des pêcheries des zones non protégées à l’exploitation halieutique durant la saison froide 2015. Ainsi, l’exploitation des données de pêches expérimentales réalisées au niveau de 16 stations dans les deux zones a permis de faire l’étude. L’analyse des paramètres environnementaux relevés sur chaque station montre que la zone de l’aire marine protégée est similaire à celle des zones non protégées à l’exploitation halieutique. Par conséquent, les éventuelles différences de peuplement ne s'expliquent pas par la variabilité des paramètres physicochimiques. L’analyse de paramètres physico-chimiques, des indicateurs de biodiversité à savoir : la richesse spécifique, les indices de diversité de Shannon-Weaver et d’équitabilité Pielou ont permis de déterminer les caractéristiques environnementales, la composition et la nature des peuplements, d'évaluer l'impact des mesures de gestion des différentes zones.   The collapse of fish stocks is due to the overexploitation of fish populations as a result of poor fishing practices in Senegal. This situation has led marine ecologists and environmental managers to re-evaluate traditional methods of managing fishery resources. In order to know the dynamics of the ichthyological populations, we conducted a comparative study of the ichthyological populations of the Jaol-Fadiouth Marine Protected Area and the fisheries of the areas not protected from fishing during the 2015 cold season. Thus, the exploitation of data from experimental fisheries carried out at 16 stations in the two areas allowed the study to be carried out. The analysis of the environmental parameters recorded at each station shows that the area of the marine protected area is similar to that of the areas not protected from fisheries exploitation. Therefore, any differences in population size cannot be explained by the variability of physico-chemical parameters. The analysis of physico-chemical parameters, biodiversity indicators such as species richness, the Shannon-Weaver diversity index and the Pielou equitability index allowed us to determine the environmental characteristics, the composition and the nature of the populations, and to evaluate the impact of the management measures of the different areas

Gene expression profiling in blood from cerebral malaria patients and mild malaria patients living in Senegal

International audienceBACKGROUND:Plasmodium falciparum malaria remains a major health problem in Africa. The mechanisms of pathogenesis are not fully understood. Transcriptomic studies may provide new insights into molecular pathways involved in the severe form of the disease.METHODS:Blood transcriptional levels were assessed in patients with cerebral malaria, non-cerebral malaria, or mild malaria by using microarray technology to look for gene expression profiles associated with clinical status. Multi-way ANOVA was used to extract differentially expressed genes. Network and pathways analyses were used to detect enrichment for biological pathways.RESULTS:We identified a set of 443 genes that were differentially expressed in the three patient groups after applying a false discovery rate of 10%. Since the cerebral patients displayed a particular transcriptional pattern, we focused our analysis on the differences between cerebral malaria patients and mild malaria patients. We further found 842 differentially expressed genes after applying a false discovery rate of 10%. Unsupervised hierarchical clustering of cerebral malaria-informative genes led to clustering of the cerebral malaria patients. The support vector machine method allowed us to correctly classify five out of six cerebral malaria patients and six of six mild malaria patients. Furthermore, the products of the differentially expressed genes were mapped onto a human protein-protein network. This led to the identification of the proteins with the highest number of interactions, including GSK3B, RELA, and APP. The enrichment analysis of the gene functional annotation indicates that genes involved in immune signalling pathways play a role in the occurrence of cerebral malaria. These include BCR-, TCR-, TLR-, cytokine-, FcεRI-, and FCGR- signalling pathways and natural killer cell cytotoxicity pathways, which are involved in the activation of immune cells. In addition, our results revealed an enrichment of genes involved in Alzheimer's disease.CONCLUSIONS:In the present study, we examine a set of genes whose expression differed in cerebral malaria patients and mild malaria patients. Moreover, our results provide new insights into the potential effect of the dysregulation of gene expression in immune pathways. Host genetic variation may partly explain such alteration of gene expression. Further studies are required to investigate this in African populations

Practice of diagnostic hysteroscopy after myomectomy in the prevention of intrauterine adhesions: experience of Ouakam military hospital (Dakar, Senegal)

Background: Surgical treatment of myomas may be the cause of some complications, including intrauterine adhesions. The objective of the study was to evaluate the incidence of intrauterine adhesions in patients who underwent myomectomy by laparotomy or hysteroscopic resection.Methods: We carried out a prospective single center study from August 1st 2016 to May 31st 2017 in the gynaecological and obstetrical department of Ouakam the Military Hospital (Senegal). We included patients who underwent myomectomy by laparotomy with opening of the uterine cavity or myomectomy by hysteroscopy. A diagnostic hysteroscopy was performed to search post-operative intrauterine adhesions. For each patient, we studied the socio-demographic aspects, the surgical approach, the delay of diagnostic hysteroscopy, the appearance of uterine cavity and the tolerance of hysteroscopy.Results: 54 patients underwent the diagnostic hysteroscopy. The mean age was 36 years old. The main indication of myomectomy was menorrhagia. 37 patients underwent myomectomy by laparotomy and 17 by hysteroscopy. Each case was followed by a post-operative diagnostic hysteroscopy with a mean delay time of 58 days. We found post-operative intrauterine adhesions in 7 patients (5 in the laparotomy group and 2 in hysteroscopy group).Conclusions: Early diagnostic hysteroscopy after myomectomy should be done in our context to reduce post-operative intrauterine adhesions and preserve the patient’s fertility

Biogeochemical Dynamics of Molybdenum in a Crater Lake: Seasonal Impact and Long-Term Removal

International audienceDespite a large variety of processes that can control Mo and its potential to become an environmental tracer of euxinic environment, this element is not often studied in lakes. The aim of this paper is to identify main seasonal biogeochemical processes that involve Mo in a well constrained freshwater system (Lake Pavin water-column) in order to evaluate their respective importance. In Lake Pavin, 4 main processes have been identified: 1) the transitional process represented by Mo assimilation of by phytoplankton in the epilimnion (nitrogen biological fixation and nitrate assimilation); 2) transient process represented by dissolved Mo adsorption onto Fe and Mn metal oxides at oxic/anoxic interface (depth 50 - 60 m); 3) Mo precipitation where apparent sulfide production rate is maximum, and from 80 m depths; 4) release of dissolved Mo due to Mo benthic flux or input from a deep source

Migration of intrauterine device into the pelvic cavity: exploration strategy and management in African environment

IUD migration is a rare complication. We report our experience in the treatment of five cases of uterine perforation and migration of IUDs. The average age of patients was 34.6 years, an average parity was 4. All patients felt an unusual pain during insertion of the IUD Tcu 380A. The location of the IUD was done through ultrasound and hysterography. Removal by laparoscopy was performed in all cases. The immediate impacts of the surgery were simple. Hysterography has its place in the location of the migrated IUD. Prevention is a good IUD insertion technique

NCR3 polymorphism, haematological parameters, and severe malaria in Senegalese patients

Background Host factors, including host genetic variation, have been shown to influence the outcome of Plasmodium falciparum infection. Genome-wide linkage studies have mapped mild malaria resistance genes on chromosome 6p21, whereas NCR3-412 polymorphism (rs2736191) lying within this region was found to be associated with mild malaria. Methods Blood samples were taken from 188 Plasmodium falciparum malaria patients (76 mild malaria patients, 85 cerebral malaria patients, and 27 severe non-cerebral malaria patients). NCR3-412 (rs2736191) was analysed by sequencing, and haematological parameters were measured. Finally, their association with clinical phenotypes was assessed. Results We evidenced an association of thrombocytopenia with both cerebral malaria and severe non-cerebral malaria, and of an association of high leukocyte count with cerebral malaria. Additionally, we found no association of NCR3-412 with either cerebral malaria, severe non-cerebral malaria, or severe malaria after grouping cerebral malaria and severe non-cerebral malaria patients. Conclusions Our results suggest that NCR3 genetic variation has no effect, or only a small effect on the occurrence of severe malaria, although it has been strongly associated with mild malaria. We discuss the biological meaning of these results. Besides, we confirmed the association of thrombocytopenia and high leukocyte count with severe malaria phenotypes

Foetal instrumental extractions (IE) at the maternity at Nabil Choucair Health Center (Senegal) from 2005 to 2016: epidemio-clinical and prognostic aspects

Background: The main objective was to take stock of practices on instrumental extractions at the maternity of Nabil Choucair Health Center.Methods: This was a prospective, descriptive study from 1 January 2005 to 31 April 2016. The collection was carried out through the data sheet completed on the basis of an analysis of files, the delivery register and the anaesthesia register of the operating room. The data was entered using the Sphinx software version 5 and the data analysis performed by Epi info version 3.5.Results: 240 instrumental extraction cases were compiled, and their frequency was 0.4%. The mean age of patients was 24.8 years. Obstetric vacuum was the most commonly used instrument (66.4%) and an episiotomy was performed in 73.6%. Maternal complications were dominated by simple perineal tears (6.2%).Conclusions: Instrumental extractions should be rehabilitated in our maternity facilities to combat the outbreak of the caesarean section. Instrumental extractions indications and techniques should be controlled to avoid complication

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

Multiply-periodic hypersurfaces with constant nonlocal mean curvature

We study hypersurfaces with fractional mean curvature in N-dimensional Euclidean space. These hypersurfaces are critical points of the fractional perimeter under a volume constraint. We use local inversion arguments to prove existence of smooth branches of multiply-periodic hypersurfaces bifurcating from suitable parallel hyperplanes