Monitoring and Forecasting of Coastal Erosion in the Context of Climate Change in Saint Louis (Senegal)

Owing to its unique physical and socio-economic characteristics, the Saint Louis region stands out as one of the most susceptible areas in Senegal to the adverse impacts of coastal erosion. The dynamics of erosion in this region are significantly influenced by the Langue de Barbarie (LB), a sand spit formed at the mouth of the Senegal River. Initially, in 2003, a 4 m wide artificial breach was strategically introduced to mitigate flooding; however, sediment dynamics expanded it to 6 km by 2020, thereby affecting the entire region. This study delves into the coastline change of the LB, specifically divided into three zones (LB-1, LB-2, and LB-3), spanning the period from 1994 to 2042. Leveraging Geographic Information System (GIS) and remote sensing techniques, our investigation reveals that, prior to the breach’s creation, the average dynamic coastline rates in zones LB-1, LB-2, and LB-3 were estimated at 4.4, 5.9, and 4.4 m/year, respectively. Subsequent to the breach, these rates shifted to −1.2, 8.4, and −2.7 m/year, with the most significant erosion observed alongshore of LB-3 at −6.6 m/year during the period 2002–2012. Projecting into 2032, LB-1 and LB-3 are anticipated to experience erosion rates of −11.5 and −26.8 m/year, respectively, while the LB-2 records an estimated accretion rate of 8.41 m/year. Eroded areas are expected to total 571,458 m2, while accumulated areas are expected to total 67,191 m2. By 2042, zones LB-1, LB-2, and LB-3 are expected to experience erosion rates of −23 and −53.6 m/year, resulting in the erosion of 1,021,963 m2 and the accumulation of 94,930 m2 with a dynamic rate of 168.2 m/year in zone LB-3. These results have significant implications for solving the urgent issue of coastal erosion in LB. © 2024 by the authors

Leiomyosarcome retro-rectal : place de la voie d’abord périnéale

Introduction : les tumeurs rétro rectales se développent dans l’espace limité en avant par le rectum, en arrière par la pièce sacro coccygienne, en bas par les releveurs et les muscles anococcygiens, latéralement par les uretères et les vaisseaux iliaques .leur incidence est estimée à 1/40 000, leur nature histologique est très variable et 30 à 50 % d’entre elles sont malignes ou le deviennent au cours de l’évolution.Observation : nous rapportons le cas d’un leiomyosarcome  rétro- rectal  chez un patient de 40 ans qui se plaignait depuis 2 ans de douleurs pelviennes paroxystiques avec pesanteur et pollakiurie .le toucher rectal perçoit une masse latero-rectale gauche. La Tomodensitométrie été en faveur d’une collection abcédée, en montrant une formation hypodense, et c’est l’imagerie par résonance magnétique nucléaire qui a posé le diagnostic de processus tumoral latero-rectal gauche, arrivant au contact du plancher pelvien et autorisant la voie d’abord périnéale de cette tumeur dont l’exérèse était complète sans effraction capsulaire. L’examen anatomopathologique de la pièce de résection a conclu après immunohistochimie à un leiomyosarcome de bas grade de malignité .une radiothérapie complémentaire centrée sur le site opératoire a été indiquée pour prévenir une éventuelle récidive locorégionale. Conclusion : Le leiomyosarcome retrorectal est une tumeur rare qui pose des problèmes d’abord chirurgical. Le pronostic reste relativement réservé et il faut guetter une éventuelle récidive. Le traitement néo-adjuvent n’est pas encore codifi

Acute traumatic abdominal wall hernia

Although blunt abdominal trauma is frequent, traumatic abdominal wall hernias (TAWH) are rare. We describe a large TAWH with associated intra-abdominal lesions that were caused by high-energy trauma. The diagnosis was missed by clinical examination but was subsequently revealed by a computed tomography (CT) scan. Repair consisted of an open anatomical reconstruction of the abdominal wall layers with reinforcement by an intraperitoneal composite mesh. The patient recovered well and the results of a post-operative CT scan are presented

Hepatitis B Virus Genotype Study in West Africa Reveals an Expanding Clade of Subgenotype A4

Hepatitis B virus (HBV) classification comprises up to 10 genotypes with specific geographical distribution worldwide, further subdivided into 40 subgenotypes, which have different impacts on liver disease outcome. Though extensively studied, the classification of subgenotype A sequences remains ambiguous. This study aimed to characterize HBV isolates from West African patients and propose a more advanced classification of subgenotype A. Fourteen HBV full-length genome sequences isolated from patients from The Gambia and Senegal were obtained and phylogenetically analyzed. Phylogenetic analysis of HBV genotype A sequences isolated from Senegalese and Gambian patients exhibited separate clusters from the other known and confirmed subgenotypes A (A1, A2, A6). Most of the sequences (10/14) clustered with an isolate from Cuba, reported as subgenotype A4 (supported by maximal bootstrap value). Four isolates from The Gambia and Senegal clustered separately from all other subgenotypes and samples sequenced in the study. Three of which from The Gambia, designated as an expanding clade of subgenotype A4, exhibited a mean inter-subgenotypic nucleotide divergence over the entire genome sequence higher than 4% in comparison with the other subgenotypes and the other isolates sequenced in the study, except with subgenotype A4 isolates (3.9%), and this was supported by a maximal bootstrap value. The last one from Senegal seemed to be an expanding subgenotype close to the new clade of A4. Amino acid analysis unveiled a novel motif specific to these isolates. This study revealed an expanding evolution of HBV subgenotype A and novel amino acid motifs. It also highlighted the need for a consensus regarding the analysis and classification of HBV sequence

Electrodeposition of CuGaSe2 and CuGaS2 thin films for photovoltaic applications

The final publication is available at Springer via http://dx.doi.org/10.1007/s10008-016-3237-0.Abstract CuGaSe2 and CuGaS2 polycrystalline thin film absorbers were prepared by one-step electrodeposition from an aqueous electrolyte containing CuCl2, GaCl3 and H2SeO3. The pH of the solution was adjusted to 2.3 by adding HCl and KOH. Annealing improved crystallinity of CuGaSe2 and further annealing in sulphur atmosphere was required to obtain CuGaS2 layers. The morphology, topography, chemical composition and crystal structure of the deposited thin films were analysed by scanning electron microscopy, atomic force microscopy, energy dispersive spectroscopy and X-ray diffraction, respectively. X-Ray diffraction showed that the asdeposited CuGaSe2 film exhibited poor crystallinity, but which improved dramatically when the layers were annealed in forming gas atmosphere for 40 min. Subsequent sulphurization of CuGaSe2 films was performed at 400 °C for 10 min in presence of molecular sulphur and under forming gas atmosphere. The effect of sulphurization was the conversion of CuGaSe2 into CuGaS2. The formation of CuGaS2 thin films was evidenced by the shift observed in the X-ray diffraction pattern and by the blue shift of the optical bandgap. The bandgap of CuGaSe2 was found to be 1.66 eV, while for CuGaS2 it raised up to 2.2 eV. A broad intermediate absorption band associated to Cr and centred at 1.63 eV was observed in Cr-doped CuGaS2 films.This work was supported by Ministerio de Economia y Competitividad (ENE2013-46624-C4-4-R) and Generalitat Valenciana (Prometeus 2014/044). One of the authors (S. Ullah) acknowledges the European Union (IDEAS-Call-3, Innovation and Design for Euro-Asian scholars) for its financial support.Ullah, S.; Mollar García, MA.; Marí, B. (2016). Electrodeposition of CuGaSe2 and CuGaS2 thin films for photovoltaic applications. Journal of Solid State Electrochemistry. 20(8):2251-2257. https://doi.org/10.1007/s10008-016-3237-0S22512257208Calixto ME, Sebastian PJ, Bhattacharya RN, Noufi (1999) Sol Energ Mat Sol C 59:75–84Mandati S, Sarada BV, Dey SR, Joshi SV (2015) J Power Sources 273:149–157Jacobsson TJ, Fjällström V, Edoff M, Edvinsson T (2015) Sol Energ Mat Sol C 134:185–193Carrete A, Placidi M, Shavel A, Pérez Rodríguez A, Cabot A (2015) Phys Stat Sol (a) 212:67–71Saji VS, Ik-Ho C, Lee CW (2011) Sol Energy 86:2666–2678Park MG, Ahn SJ, Yun JH, Gwak J, Cho A, Ahn SK, Shin K, Nam D, Cheong H, Yoon K (2012) J Alloy Compd 513:68–74Saji VS, Lee SM, Lee CW (2011) J Korean Electrochem Soc 14:61–70Donglin X, Jangzhuang L, Man X, Xiujian Z (2008) J Non-Cryst Solids 354:1447–1450Araujo J, Ortíz R, López-Rivera A, Ortega JM, Montilla M, Alarcón D (2007) J Solid State Electroch 11(Issue 3):407–412Palacios P, Sanchez K, Conesa JC, Fernandez JJ, Wahnon P (2007) Phys Stat Sol A 203:1395–1401Palacios P, Sanchez K, Conesa JC, Wahnon P (2006) Thin Solid Films 515:6280–6284Lee H, Lee J-H, Hwang Y-H, Kim Y (2014) Curr Appl Phys 14:18–22Kim D, Kwon Y, Lee D, Yoon S, Lee S, Yoo B (2015) J Electrochem Soc 162:D36–D41Hou WW, Bob B, Li S, Yang Y (2009) Thin Solid Films 517:6853–6856Lee J, Lee W, Shrestha NK, Lee DY, Lim I, Kang SH, Nah YC, Lee SH, Yi W, Han SH (2014) Mater Chem Phys 144:49–54Yang JY, Lee D, Huh K, Jung SJ, Lee JW, Lee HC, Baek DH, Kim BJ, Kim D, Nam J, Kim GY, Jo W (2015) RSC Adv 5:40719–407257Sall T, Nafidi A, Marí B, Mollar M, Hartiti B, Fahoume M (2014) J Semicond 35:0630021–0630025Lee JH, Song WC, Yi JS, Joonyang K, Han WD, Hawang J (2003) Thin Solid Films 431-432:349–353Prabukanthan P, Dhanasekaran R (2007) Cryst Growth Des 7:618–623Guillemoles JF, Cowache P, Lusson A, Fezzaa K, Boisivon F, Vedel J, Lincot D (1996) J Appl Phys 79:7293–7302Aguilera I, Palacios P, Wahon P (2010) Sol Energ Mat Sol C 94:1903–1906Palacios P, Aguilera I, Wahnón P, Conesa JC (2008) J Phys Chem C 112:9525–952

Spread of yellow fever virus outbreak in Angola and the Democratic Republic of the Congo 2015-16: a modelling study.

BACKGROUND: Since late 2015, an epidemic of yellow fever has caused more than 7334 suspected cases in Angola and the Democratic Republic of the Congo, including 393 deaths. We sought to understand the spatial spread of this outbreak to optimise the use of the limited available vaccine stock. METHODS: We jointly analysed datasets describing the epidemic of yellow fever, vector suitability, human demography, and mobility in central Africa to understand and predict the spread of yellow fever virus. We used a standard logistic model to infer the district-specific yellow fever virus infection risk during the course of the epidemic in the region. FINDINGS: The early spread of yellow fever virus was characterised by fast exponential growth (doubling time of 5-7 days) and fast spatial expansion (49 districts reported cases after only 3 months) from Luanda, the capital of Angola. Early invasion was positively correlated with high population density (Pearson's r 0·52, 95% CI 0·34-0·66). The further away locations were from Luanda, the later the date of invasion (Pearson's r 0·60, 95% CI 0·52-0·66). In a Cox model, we noted that districts with higher population densities also had higher risks of sustained transmission (the hazard ratio for cases ceasing was 0·74, 95% CI 0·13-0·92 per log-unit increase in the population size of a district). A model that captured human mobility and vector suitability successfully discriminated districts with high risk of invasion from others with a lower risk (area under the curve 0·94, 95% CI 0·92-0·97). If at the start of the epidemic, sufficient vaccines had been available to target 50 out of 313 districts in the area, our model would have correctly identified 27 (84%) of the 32 districts that were eventually affected. INTERPRETATION: Our findings show the contributions of ecological and demographic factors to the ongoing spread of the yellow fever outbreak and provide estimates of the areas that could be prioritised for vaccination, although other constraints such as vaccine supply and delivery need to be accounted for before such insights can be translated into policy. FUNDING: Wellcome Trust

Quantitative analysis of particles, genomes and infectious particles in supernatants of haemorrhagic fever virus cell cultures

Information on the replication of viral haemorrhagic fever viruses is not readily available and has never been analysed in a comparative approach. Here, we compared the cell culture growth characteristics of haemorrhagic fever viruses (HFV), of the Arenaviridae, Filoviridae, Bunyaviridae, and Flavivridae virus families by performing quantitative analysis of cell culture supernatants by (i) electron microscopy for the quantification of virus particles, (ii) quantitative real time PCR for the quantification of genomes, and (iii) determination of focus forming units by coating fluorescent antibodies to infected cell monolayers for the quantification of virus infectivity

Biosafety standards for working with Crimean-Congo hemorrhagic fever virus

In countries from which Crimean-Congo haemorrhagic fever (CCHF) is absent, the causative virus CCHF virus (CCHFV) is classified as a hazard group 4 agent and handled in containment level 4. In contrast, most endemic countries out of necessity have had to perform diagnostic tests under biosafety level (BSL) 2 or 3 conditions. In particular, Turkey and several of the Balkan countries have safely processed more than 100000 samples over many years in BSL-2 laboratories. It is therefore advocated that biosafety requirements for CCHF diagnostic procedures should be revised, to allow the required tests to be performed under enhanced BSL-2 conditions with appropriate biosafety laboratory equipment and personal protective equipment used according to standardized protocols in the affected countries. Downgrading of CCHFV research work from Cl- 4,BSL-4 to Cl-3 ,BSL-3 should also be considered.Funding was received through CCH Fever Network (Collaborative Project) supported by the European Commission under the Health Cooperation Work Program of the 7th Framework Program (Grant agreement no. 260427) (http://www.cch-fever.eu/).http://vir.sgmjournals.orghb2017Veterinary Tropical Disease