Evolution de la Mangrove de la Reserve de Biosphere du Delta du Saloum, Senegal

The mangrove is at the base of many ecological and socioeconomic functions in the Saloum Delta. However, in recent years, this ecosystem is subject to degradation whose causes are natural and human. It is thus necessary to study the dynamics of this ecosystem in order to understand the factors that contribute to its degradation. The remote sensing is a frequently used tool for monitoring environments. It is often used to study the spatiotemporal evolution of wetlands in the Sahelian zone. The adopted approach integrates Corona aerial photography, 1984 and 1999 Landsat satellite imagery, Sentinel 2 satellite imagery and fieldwork. The results show a regressive dynamics of the mangrove swamp which translates as follows: 55831.03 ha in 1965, 53533.70 ha in 1984, 54,135.86 ha in 1999, 53691.69 ha in 2017 and a decline rate of 3.83% between 1965 and 2017. La mangrove est à la base de multiples fonctions écologiques et socioéconomiques dans le delta du Saloum. Cependant, depuis quelques années, cet écosystème est soumis à une dégradation dont les causes sont d’ordre naturel et anthropique. Il s’avère ainsi important d’étudier la dynamique de cet écosystème pour comprendre les facteurs qui concourent à sa dégradation. La télédétection constitue un outil fréquemment utilisé pour le suivi des milieux. Il est souvent utilisé pour étudier l’évolution spatiotemporelle des milieux humides en zone sahélienne. Dans le cas de cette étude, la méthodologie utilisée intègre le traitement des photographies aériennes Corona de 1965, des images satellitaires Landsat de 1984 et 1999, Sentinel 2 de 2017 et destravaux de terrain pour l’élaboration des cartes d’occupation du sol. Les résultats montrent une dynamique à tendance régressive de la mangrove qui se traduit de la sorte : 55831,03 ha en 1965, 53533,70 ha en 1984, 54135,86 ha en 1999, 53691,69 ha en 2017 et un taux de recul de 3,83% entre 1965 et 2017

Dynamique Spatio-temporelle de la Mangrove du bas Delta du Fleuve Sénégal de 1980 à 2021: Approche par Télédétection et Système d’Information Géographique

Le bas delta du fleuve Sénégal est une zone d’intérêt écologique au regard de la pluralité d’aires protégées qui sont localisées. Ce milieu, qui se caractérise par la diversité de ses ressources naturelles, développe une très grande vulnérabilité imputable à des causes aussi bien naturelles qu’anthropiques. Depuis quelques décennies, cette fragilité du milieu se répercute sur la mangrove qui assume difficilement ses fonctions socioéconomiques et écologiques. Dès lors, il convient d’analyser la dynamique spatiotemporelle de cet écosystème afin de comprendre les facteurs qui interviennent dans sa dégradation. Dans cette étude, l’objectif a été atteint au moyen de la télédétection à travers le traitement d’images satellitaires Landsat 1980 et 2000, Sentinel 2021 combiné à des travaux de terrains. Cela a permis la réalisation de cartes d’occupation du sol et de cartes de changements. Les résultats démontrent une tendance globale à la hausse de la mangrove avec des espaces couverts qui sont passés de 1 105,82 ha en 1980 à 1 482,32 ha en 2021 malgré une perte de superficies de 166,92 ha sur cette période.             The lower delta of the Senegal River is a zone of ecological interest with regard to the plurality of protected areas that are located. This environment, which is characterized by the diversity of natural resources, develops a very great vulnerability due to natural and anthropic causes. For several decades, this fragility of the environment has had repercussions on the mangrove, which is having difficulty fulfilling its socio-economic and ecological functions. Therefore, it is necessary to analyze the spatiotemporal dynamics of this ecosystem in order to understand the factors involved in its degradation. In this study, this objective was achieved by means of remote sensing through the processing of Landsat 1980 and 2000, Sentinel 2021 satellite images combined with field work. This allowed the realization of land use maps and change maps. The results show an overall increasing trend of the mangrove with areas covered that have increased from 1 105.82ha in 1980 to 1 482.32ha in 2021 despite a loss of area of 166.92 ha over this period

Dynamique Spatio-temporelle de la Mangrove du bas Delta du Fleuve Sénégal de 1980 à 2021: Approche par Télédétection et Système d’Information Géographique

          Le bas delta du fleuve Sénégal est une zone d’intérêt écologique au regard de la pluralité d’aires protégées qui y sont localisées. Ce milieu, qui se caractérise par la diversité de ses ressources naturelles, développe une très grande vulnérabilité imputable à des causes aussi bien naturelles qu’anthropiques. Depuis quelques décennies, cette fragilité du milieu se répercute sur la mangrove qui assume difficilement ses fonctions écologiques et socioéconomiques. Dès lors, il convient d’analyser la dynamique spatiotemporelle de cet écosystème afin de comprendre les facteurs qui interviennent dans sa dégradation. Dans cette étude, l’objectif a été atteint au moyen de la télédétection à travers le traitement d’images satellitaires Landsat 1980 et 2000, Sentinel 2021 combiné à des travaux de terrains. Cela a permis la réalisation de cartes d’occupation du sol et de cartes de changements. Les résultats démontrent une tendance globale à la hausse de la mangrove avec des espaces couverts qui sont passés de 1 105,82 ha en 1980 à 1 482,32 ha en 2021 malgré une perte de superficies de 166,92 ha sur cette période.   The lower delta of the Senegal River is a zone of ecological interest with regard to the plurality of protected areas that are located. This environment, which is characterized by the diversity of natural resources, develops a very great vulnerability due to natural and anthropic causes. For several decades, this fragility of the environment has had repercussions on the mangrove, which is having difficulty fulfilling its socio-economic and ecological functions. Therefore, it is necessary to analyze the spatiotemporal dynamics of this ecosystem in order to understand the factors involved in its degradation. In this study, this objective was achieved by means of remote sensing through the processing of Landsat 1980 and 2000, Sentinel 2021 satellite images combined with field work. This allowed the realization of land use maps and change maps. The results show an overall increasing trend of the mangrove with areas covered that have increased from 1 105.82ha in 1980 to 1 482.32ha in 2021 despite a loss of area of 166.92 ha over this period

Dynamique Spatio-temporelle de la Mangrove du bas Delta du Fleuve Sénégal de 1980 à 2021: Approche par Télédétection et Système d’Information Géographique

Le bas delta du fleuve Sénégal est une zone d’intérêt écologique au regard de la pluralité d’aires protégées qui sont localisées. Ce milieu, qui se caractérise par la diversité de ses ressources naturelles, développe une très grande vulnérabilité imputable à des causes aussi bien naturelles qu’anthropiques. Depuis quelques décennies, cette fragilité du milieu se répercute sur la mangrove qui assume difficilement ses fonctions socioéconomiques et écologiques. Dès lors, il convient d’analyser la dynamique spatiotemporelle de cet écosystème afin de comprendre les facteurs qui interviennent dans sa dégradation. Dans cette étude, l’objectif a été atteint au moyen de la télédétection à travers le traitement d’images satellitaires Landsat 1980 et 2000, Sentinel 2021 combiné à des travaux de terrains. Cela a permis la réalisation de cartes d’occupation du sol et de cartes de changements. Les résultats démontrent une tendance globale à la hausse de la mangrove avec des espaces couverts qui sont passés de 1 105,82 ha en 1980 à 1 482,32 ha en 2021 malgré une perte de superficies de 166,92 ha sur cette période.             The lower delta of the Senegal River is a zone of ecological interest with regard to the plurality of protected areas that are located. This environment, which is characterized by the diversity of natural resources, develops a very great vulnerability due to natural and anthropic causes. For several decades, this fragility of the environment has had repercussions on the mangrove, which is having difficulty fulfilling its socio-economic and ecological functions. Therefore, it is necessary to analyze the spatiotemporal dynamics of this ecosystem in order to understand the factors involved in its degradation. In this study, this objective was achieved by means of remote sensing through the processing of Landsat 1980 and 2000, Sentinel 2021 satellite images combined with field work. This allowed the realization of land use maps and change maps. The results show an overall increasing trend of the mangrove with areas covered that have increased from 1 105.82ha in 1980 to 1 482.32ha in 2021 despite a loss of area of 166.92 ha over this period

Variational and Shape Prior-based Level Set Model for Image Segmentation

International audienceA new image segmentation model based on level sets approach is presented herein. We deal with radiographic medical images where boundaries are not salient, and objects of interest have the same gray level as other structures in the image. Thus, an a priori information about the shape we look for is integrated in the level set evolution for good segmentation results. The proposed model also accounts a penalization term that forces the level set to be close to a signed distance function (SDF), which then avoids the re-initialization procedure. In addition, a variant and complete Mumford-Shah model is used in our functional; the added Hausdorff measure helps to better handle zones where boundaries are occluded or not salient. Finally, a weighted area term is added to the functional to make the level set drive rapidly to object's boundaries. The segmentation model is formulated in a variational framework, which, thanks to calculus of variations, yields to partial differential equations (PDEs) to guide the level set evolution. Results obtained on both synthetic and digital radiographs reconstruction (DRR) show that the proposed model improves on existing prior and non-prior shape based image segmentation

(Not) Keeping the stem straight: a proteomic analysis of maritime pine seedlings undergoing phototropism and gravitropism

<p>Abstract</p> <p>Background</p> <p>Plants are subjected to continuous stimuli from the environment and have evolved an ability to respond through various growth and development processes. Phototropism and gravitropism responses enable the plant to reorient with regard to light and gravity.</p> <p>Results</p> <p>We quantified the speed of maritime pine seedlings to reorient with regard to light and gravity over 22 days. Seedlings were inclined at 15, 30 and 45 degrees with vertical plants as controls. A lateral light source illuminated the plants and stem movement over time was recorded. Depending on the initial angle of stem lean, the apical response to the lateral light source differed. In control and 15° inclined plants, the apex turned directly towards the light source after only 2 h. In plants inclined at 30° and 45°, the apex first reoriented in the vertical plane after 2 h, then turned towards the light source after 24 h. Two-dimensional gel electrophoresis coupled with mass spectrometry was then used to describe the molecular response of stem bending involved in photo- and gravi-tropism after 22 hr and 8 days of treatment. A total of 486 spots were quantitatively analyzed using image analysis software. Significant changes were determined in the protein accumulation of 68 protein spots. Early response gravitropic associated proteins were identified, which are known to function in energy related and primary metabolism. A group of thirty eight proteins were found to be involved in primary metabolism and energy related metabolic pathways. Degradation of Rubisco was implicated in some protein shifts.</p> <p>Conclusions</p> <p>Our study demonstrates a rapid gravitropic response in apices of maritime pine seedlings inclined >30°. Little or no response was observed at the stem bases of the same plants. The primary gravitropic response is concomitant with a modification of the proteome, consisting of an over accumulation of energy and metabolism associated proteins, which may allow the stem to reorient rapidly after bending.</p

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

Qualite de vie apres un accident vasculaire cerebral au Senegal: a propos de 50 cas

Introduction: L’accident vasculaire cérébral (AVC) constitue une cause majeure de mortalité et de handicap chez les survivants. La qualité de vie dépend de la nature du handicap et de sa perception par le patient, son entourage et la communauté.Objectif: Notre objectif était d’évaluer le handicap après un AVC et d’apprécier son retentissement sur la qualité de vie des patients victimes.Patients et Méthodes: Nous avons mené une étude prospective, longitudinale de février 2008 à mai 2009, à la clinique neurologique de FANN. Les patients étaient vus à la phase initiale de l’AVC et 6 mois après et soumis à un questionnaire comportant plusieurs items relatifs à la nature de l’accident vasculaire cérébral, le vécu psychoaffectif et socioprofessionnel, l’index de Barthel a été utilisé chez tous les malades.Résultats: Nous avons colligé 50 patients âgés de 15 à 82 ans, avec une sex-ratio de 1,27. L’accident était ischémique dans 70%, hémorragique dans 30% des cas. 66% des patients avaient un index de Barthel entre (60-100), 6% étaient entre (0-20). Le score était meilleur chez les jeunes (15ans-34ans) qui avait tous un index entre (60-100). Par ailleurs 50% des patients de la tranche supérieure à 75ans étaient dans l’intervalle (60-100). Les AVCH avaient des Meilleurs résultats avec 73,3% à un index entre (60-100). seul 12% ont été réinsérés, sur le plan professionnel. 54,05%, n’ont pas noté de changement dans leur vie conjugale. Sur le plan familial, 56% ne notaient aucun changement. Une grande partie de notre série 44% acceptaient bien leurs  déficits,. 70% ne faisaient plus d’activités de temps libre.Conclusion: La qualité de vie est un concept multidimensionnel qui incorpore outre la santé physique les aspects mentaux et sociaux de la maladie.Mots clés: AVC, qualité de vie, SénégalEnglish Title: Quality of life after stroke in Senegal: about 50 casesEnglish AbstractIntroduction: Stroke is a major cause of mortality and disability in survivors. The quality of life depends on the nature of disability and its perception by the patient, his or her environment and community. The aim of this study was to assess disability after stroke and its impact on quality of life of patients (victims).Patients And Methods: We conducted a prospective, longitudinal study from February 2008 to May 2009, at the Neurological Clinic of Fann. Patients were seen at the initial phase of stroke and 6 months later and answered a questionnary containing 13 items like nature of stroke disability psychological emotional and socioprofessional filds. The index of barthel was used at all the patient’s.Results: We collected, were like this 50 patients aged 15-82 years with a sex ratio of 1.27. The accident was ischemic in 70% of cases, hemorrhagic in 30% of cases. 66% had a Barthel index between (60-100), 6% were between (0-20). The score was significantly better in young series (15-34), which all have a Barthel index between (60-100), more over 50% of patients in the portion above 75 years were in the range (60 - 100). Hemorragic stroke had the best results with 73.3% a Barthel index between (60-100). On a professional level, only 12% patients were rehabilitated. 54.05% didn’t notice any change in their marital life. On the home front, 56% noted any change. A large part of our series 44% accepted although their deficits. 70% didn’t have any more free time activities.Keywords: quality of life, stroke, Senega