1,721,012 research outputs found
Epidémiologie moléculaire et génétique des populations de Plasmodium falciparum dans l'archipel des Comores. Implications pour la lutte antipaludique.
No full textPlasmodium falciparum malaria is the main health problem in Comoro archipelago. The present work proposes a synthesis of its available epidemiological data, and an application of the recent molecular epidemiology and population genetics tools to the comoran malaria situation. This appears contrasted on the archipelago. Malaria morbidity is important on Grande Comore, Moheli and Anjouan islands, and their P. falciparum populations are quite homogeneous. Conversely, morbidity is limited in Mayotte, where cases are half imported from nearby islands, and half autochthonous and concentrated in Bandraboua, a residual and genetically isolated transmission focus where malaria is epidemic. Chemoresistance levels are globally high on the archipelago, but also contrasted because of different drug selective pressures. These data suggest : (1) the need to organize a separated surveillance of drug resistance in each of the four islands, (2) the theoretic possibility of a malaria elimination from the 4 islands at the same time but not from a sole one, and (3) the need to strengthen efforts for preventing malaria epidemics in Bandraboua. Arrival of artemisininbased treatments in Comoros, the large distribution of treated bednets and the recent mass treatment on Moheli, should rapidly reshape this epidemiologic situation. They should also raise the relevance of a distant chemoresistance surveillance from Marseille, where genetical representativeness of imported parasites has been limited.Le paludisme à P. falciparum constitue le problème de santé publique principal sur l'archipel des Comores. Le présent travail propose une synthèse des informations relatives à son épidémiologie, associée à une application des méthodes récentes d'épidémiologie moléculaire et de génétique des populations plasmodiales à la situation comorienne. Celle-ci apparaît contrastée. Ainsi, Grande Comore, Mohéli et Anjouan sont des îles marquées par une morbidité palustre importante, et leur population plasmodiale est globalement homogène. La morbidité est en revanche beaucoup plus faible à Mayotte, où les cas sont pour moitié d'origine importée depuis les îles voisines, et pour moitié autochtones et concentrés dans le foyer résiduel et génétiquement isolé de Bandraboua selon une distribution microépidémique. Les niveaux de chimiorésistance, globalement élevés, sont également contrastés, du fait de pressions médicamenteuses différentes. En complément des stratégies actuelles de lutte antipaludique, ces informations conduisent donc à recommander : (1) la nécessité d'une surveillance de la chimiorésistance séparée pour chaque île, (2) le principe d'une élimination du paludisme sur les 4 îles à la fois et non pas sur une seule, et (3) un renforcement de la prévention des épidémies sur la commune de Bandraboua. Mais l'arrivée des ACT, la large distribution des moustiquaires imprégnées et le récent traitement de masse sur Mohéli devraient modifier à court terme cette situation épidémiologique. Ils devraient également relancer la pertinence d'une surveillance de la chimiorésistance excentrée à Marseille, où la représentativité génétique des parasites importés est pour l'instant limitée
Dynamic study of cholera epidemics in Africa and in Haiti and application to the implementation of elimination strategies
No full textLe choléra est une diarrhée hydrique sévère volontiers épidémique causée par des Vibrio cholerae O1 toxinogènes. Ses déterminants environnementaux ont donné naissance à un paradigme influent sur les stratégies de lutte, qui sont se sont avérées peu efficientes en Afrique comme en Haïti. Elles pourraient être améliorées par une meilleure compréhension de la dynamique des épidémies. La synthèse bibliographique des influences de l'environnement sur les épidémies de choléra en Afrique y montre les limites du paradigme environnemental. L'étude multidisciplinaire des origines de l'épidémie de choléra en Guinée en 2012 suggère fortement qu'elle fut importée par voie humaine depuis la Sierra Leone voisine. Une description spatio-temporelle du choléra au Mozambique démontre l'hétérogénéité de sa transmission et amène à questionner le concept d'endémicité du choléra. Depuis son importation en Haïti en octobre 2010, l'épidémie de choléra présente également une répartition spatiale et temporelle très hétérogène. Son importante rétractation en saison sèche et son absence d'enracinement significatif dans l'environnement laissent espérer la possibilité d'une élimination rapide à condition d'apporter une réponse ciblée à tous les foyers épidémiques du pays. Une stratégie d'élimination basée sur nos recommandations y est actuellement menée par le Ministère de la Santé, l'UNICEF et leurs partenaires. Après des résultats spectaculaires en 2013 et au premier semestre 2014, la situation s'est à nouveau dégradée pendant la saison des pluies. Une élimination du choléra dans saison sèche à venir demeure cependant réaliste si nous parvenons à convaincre et remobiliser les acteurs de terrain.Cholera is an epidemic acute watery diarrhea caused by toxigenic bacteria Vibrio cholerae O1. Its environment determinants have been at the source of a popular paradigm. Many recent control strategies have shown little efficiency in Africa or in Haiti, but they could be improved by a better comprehension of the epidemics dynamic. The bibliographic synthesis of environment influences on cholera in Africa highlights the limits of the environmental paradigm on this continent. A multidisciplinary study of the origin of cholera epidemic in Guinea in 2012 strongly suggests it was humanly imported from nearby Sierra Leone. A space-time description of cholera in Mozambique demonstrates heterogeneous transmission patterns and challenges the concept of cholera endemicity. Since its importation in Haiti in October 2010, cholera transmission also exhibits a marked spatio-temporal heterogeneity. Cholera important retraction during the dry season and its absence of significant establishment in the Haitian environment suggest it may be possible to rapidly eliminate cholera in the country, provided that every outbreak focus receives a targeted response. An elimination strategy based on our recommendations is currently implemented by Haitian Ministry of Health, UNICEF and their partners. After spectacular results in 2013 and during the first half of 2014, the situation has slowly deteriorated during the rainy season. However, cholera elimination during the coming dry season remains realistic provided that we succeed in persuading and remobilizing the partners present on the field
[The surprising disappearance of cholera in Haiti].
No full textInternational audienceNo abstract provided
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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