35 research outputs found

    Aménagements hydro-agricoles et santé (vallée du fleuve Sénégal)

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    La transmission du paludisme dans le delta du fleuve Sénégal a été étudiée dans trois villages, deux villages de riziculture irriguée dont un d'aménagement récent et un village de culture pluviale traditionnelle. La riziculture irriguée a entraîné une pullulation de moustiques et principalement d'#Anopheles pharoensis. La densité de ses populations est très importante et liée aux cycles des cultures dans la zone rizicole, son indice d'anthropophilie est élevé mais la longévité des femelles est très faible. #An. gambiae s.l. vecteur majeur du paludisme au Sénégal est, dans le delta, remplacé par #An. pharoensis$, vecteur secondaire dont l'aptitude à assurer une bonne transmission n'est pas prouvée. La riziculture irriguée n'a pas entraîné une augmentation de la transmission du paludisme. (Résumé d'auteur

    The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

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    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

    Afri-Can Forum 2

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    Instrumentation de la supervision de l'apprentissage par la réutilisation d'indicateurs (modèles et architecture)

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    L'instrumentation de la supervision passe par la compréhension de son utilité et de sa faisabilité. Les indicateurs fournissent au tuteur des informations lui permettant de réguler les activités d'apprentissage au niveau Cognitif, Pédagogique, Social et Technique. Cette thèse se propose de répondre aux questions portant sur l'identification des types d'indicateurs utiles à chaque rôle de régulation du tuteur et sur la proposition d'une méthodologie permettant de réutiliser un ensemble d'indicateurs, de ces types, dans un environnement de supervision. Le modèle CAS de supervision propose une taxonomie permettant au tuteur d'avoir une perception de l'activité d'apprentissage. Une enquête auprès de tuteurs en ligne a montré que les indicateurs Cognitifs permettent de jouer des rôles pédagogique et cognitif, les indicateurs Sociaux le rôle social. L'utilité des indicateurs d'Activité (Parcours et Technique) n'en est pas clairement ressortie. L'enquête révèle également un besoin de personnalisation de la supervision. A la problématique d'instrumentation de la réutilisation, nous répondons en proposant un formalisme de Patron d'Indicateur Réutilisable qui permet de capitaliser les savoir-faire en terme de définition d'indicateur, ainsi qu'une Architecture Multi-Agent Ouverte permettant de les réutiliser dans de nouveaux contextes de supervision. Ces savoir-faire, modélisés en termes de fonction, peuvent dans l'architecture proposée se déployer et se combiner pour informer le tuteur sur l'activité d'apprentissage. Les opérations d'Agrégation et de Composition sont définies sur les fonctions indicateur . L'environnement EM-AGIIR, implémentant l'architecture proposée est ouvert, évolutif et permet au tuteur de personnaliser son activité de supervision. Un ensemble d'indicateurs sur les traces du projet MATES du réseau européen Kaleidoscope y ont été réutilisés.The instrumentation of the supervision needs the understanding of its utility and its feasibility. Indicators supply to the tutor of the information allowing him to regulate learning activities at the Cognitive, Pedagogical, Social and Technical level. This thesis try to answer the questions concerning the identification of the types of indicators useful for every role of regulation of the tutor, and at the suggestion of a methodology allowing to reuse a set of indicators, of these types, in an supervision environment. The model CAS of supervision proposes a taxonomy allowing the tutor to have a perception of the learning activity. A survey with on-line tutors showed that the Cognitive indicators allow playing pedagogical and cognitive roles, the Social indicators, the social role. The utility of the Activity indicators (Navigation and Technique) did not clearly stand out from it. For the problem of re-use instrumentation, we answer by proposing a Pattern of Reusable Indicator formalism which allows capitalizing the know-how in term of indicator definition, as well as an Opened Multi-agent Architecture allowing to reuse them in new supervision contexts. These know-how, modelled in terms of function, can in the architecture suggested display and combine themselves to inform the tutor about the learning activity. The Aggregation and Composition operations are defined on the "indicator" functions. The EM-AGIIR environment, implementing the proposed architecture, reused a set of indicators on the tracks of the MATES project of a the european network Kaleidoscope.GRENOBLE1-BU Sciences (384212103) / SudocSudocFranceF

    Design patterns for recording and analysing usage of learning systems: State of art of tracking and analysing usage

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    http://www.noe-kaleidoscope.org/Research report - Report number D32.3.1This document presents a state of art according to three aspects: use analysis in a wide point of view, tracking and analysing usages and what's on Design Pattern. The objective of this state of art is to synthetise actual works about tracking and analysing usages in order to isolate possibilities of patterns, that's the aim of DPULSE Jeirp. The work on the state of art has been organised as a collaborative task of the DPLUS members. A lot of papers and projects on this topic have been studied. This document is the synthesis of this work, compiled and enriched by the Metah team
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