Phylogeography, Risk Factors and Genetic History of Hepatitis C Virus in Gabon, Central Africa

BACKGROUND: The epidemiological and molecular characteristics of hepatitis C virus (HCV) infection in the general population have been poorly investigated in Africa. The aim of this study was to determine the prevalence, genotype distribution and epidemic history of HCV in the Gabonese general population. METHODS/PRINCIPAL FINDINGS: A total of 4042 sera collected from adults in 220 villages in all nine administrative areas of the country were screened for antibodies to HCV. HCV NS5B region sequencing was performed for molecular characterization and population genetic analyses. Of 4042 tested sera, 455 (11.2%) were positive. The seroprevalence of HCV varied significantly by administrative area, with the highest rate in Ogooue-Lolo province (20.4%) and the lowest in Ogooue-Maritine province (3.7%). History of parenteral injections, past hospital admission and age over 55 years were independent risk factors for HCV infection (p<0.0001). Phylogenetic analyses showed that 91.9% of the strains were genotype 4 (HCV-4), 5.7% genotype 1 and 2.2% genotype 2. HCV-4 strains were highly heterogeneous, with more than eight subtypes; subtype 4e predominated (57.3%). Coalescence analyses indicated that subtype 4e was the oldest, with an estimated most recent common ancestor of 1702 [95% CI, 1418-1884]. The epidemic profile indicated that it spread exponentially during the first part of the 20th century, probably by iatrogenic transmission. CONCLUSIONS/SIGNIFICANCE: These results confirm the endemicity of HCV subtype 4e in Gabon and show that its spread is due to a cohort effect, with previous, possibly iatrogenic events. More extensive epidemiological studies are needed to better characterize the route of transmission and the dissemination of HCV in Gabon

Régiologie et régionymie du Saint-Laurent en aval du lac Ontario

Le texte comprend trois parties. La première rappelle les caractéristiques thématiques fondamentales du réseau hydrographique d'abord au plan du relief, du climat et des eaux. L'auteur s'attarde davantage à l'étude des différents aspects du langage laurentien (qui a deux sens), laurentin et laurentide.La deuxième partie est consacrée à la régiologie (étude des régions) et à la régionymie (étude du nom des régions) du secteur reliant le lac Ontario à l'île d'Anticosti. L'on fait d'abord un rappel des régionalisations proposées notamment celles de Marie-Victorïn, Hamelin, Brochu, Dionne, Rousseau, Laverdière, Gauthier et autres. La majorité des auteurs s'entendent pour fixer aux mêmes endroits les discontinuités majeures du cours, mais ils ont hésité entre un estuaire long et un estuaire court. En considérant tout un groupe de facteurs, LEH divise cette section du Saint-Laurent en six secteurs dont quatre estuariens.La troisième partie, régionale elle aussi, est consacrée au golfe du Saint-Laurent qui devient subdivisé en trois zones profondes et quatre plate-formes. Les caractéristiques générales de cette mer épicontinentale sont discutées y compris celles des glaces flottantes.L'ensemble du Saint-Laurent constitue un triple réseau, international, pluriprovincial et intraquébécois. De l'Ontario à l'Atlantique, la nappe laurentine comprend treize régions principales. Le Saint-Laurent est un fleuve aimé.The paper deals with the Saint Lawrence River and the Gulf of Saint Lawrence whose specific name was given by J. Cartier in August 1535. By derivation, « laurentian » (originally, a geologic term) and « Laurentides » (first, a shield region in Québec) have been coined. Since 1935, several authors (Marie-Victorin) have tried to regionalize the water body, almost the Estuary section whose external limits are still a matter of discussions. If among many facets, an estuary is that part of a river in which the fluvial current meets the sea's tide, the St. Lawrence Estuary must start East of Québec city (lake Saint-Pierre). On the other hand, the majority of maps do not include Anticosti Island in the Gulf of St. Lawrence itself and many climatic isopleths cross the island. So, the Estuary may be short or long, that means a difference of 300 miles in length. Any-way, suitable wording has been suggested to name the 13 laurentian sections : 2 sectors above Lake Saint-Pierre ; 4 for the estuary ; 7 in the Gulf. In writings, we use « Moyen estuaire » (Middle Estuary) since 1955; the expression, as some others, was picked up. Along the shores and in the islands, the « choronymy » shows a multicultural strata complex with a dominance of sound franconyms.The author discuss also aspects of the Saint Lawrence Lowlands that are pertinent to his hydrographic subject ; these themes concern geologic evolution, climatic and bio-geographic characters, floating ice or « glaciel » situation, human and economic elements. On the methodological stand point, this paper may belong to what is called global geography

Lexicography in Gabon : a survey

This paper traces the historical development of lexicography in Gabon. Gabon, like most African countries, is multilingual. The recent inventories of languages spoken in Gabon are those established by Jacquot (1978) and Kwenzi-Mikala (1998). According to Kwenzi-Mikala (1997), there are 62 speech forms divided into 10 language groups or language-units in Gabon. These speech forms co-exist with French, the official language. In fact, in article 2 of paragraph 8 of the revised Constitution of 1994 the following can be read: "The Gabonese Republic adopts French as the official language. Furthermore, she endeavours to protect and promote the national languages." This constitutional arrangement naturally makes French the language used in education, administration and the media. The survey of lexicography in Gabon that is presented here includes the linguistic situation in and the language policy of Gabon, the lexicographic survey itself, as well as the lexicographic needs of the different speech forms (including languages and dialects). Initially, the pioneers of Gabonese lexicography were missionaries or colonial administrators. Very little was done in this field by the Gabonese themselves. Although credit is to be given to these early works, there are a number of shortcomings regarding the linguistic as well as the metalexicographic contents of dictionaries and lexicons produced during this period. In fact, the main weak point of those studies was the lack of tones in the written transcription of oral productions and orthographic problems. Furthermore, in those contributions, the theory of lexicography is largely unknown and lexico-graphic works are hardly ever based on authentic data corpora of the languages being described.Le présent article retrace l'histoire de la discipline lexicographique au Gabon. Comme la plupart des pays africains, le Gabon est un état multilingue. Les classifications établient par Jacquot (1978) et Kwenzi-Mikala (1998) sont souvent citées comme les travaux d'inventaire les plus récents sur les parlers gabonais. Selon Kwenzi-Mikala (1997), le Gabon compte 62 parlers reparties en 10 unités-langues. Les dits parlers cohabitent avec le français qui faut-il le rappeler jouit d'un statut particulier. En effet, à l'article 2 du paragraphe 8 de la Loi fondamentale révisée de 1994, on peut lire ceci: «La République gabonaise adopte le français comme langue officielle. En outre, elle s'engage à protéger et à promovoir les langues nationales». Cette disposition constitutionnelle fait naturellement du français le véhicule et la matière de l'instruction, la langue de l'administration et celle des médias. L'état des lieux de la lexicographie au Gabon présenté ici prend en compte la situation et la politique linguistique au Gabon, l'état des connaissances lexicographiques à proprement parler ainsi que les besions lexicographiques des différents parlers au regard de ce qui existe déjà. Les premiers travaux à caractère lexicographique ont été réalisés essentiellement par les missionnaires et les administrateurs coloniaux. Très peu de gabonais étaient engagés dans la confection des dictionnaires et lexiques à cette époque pionnière. Enfin, il convient de souligner que le principal talon d'Achille de ces travaux de la première heure est à la fois linguistique et métalexicographi-que. En effet, la majorité de ces travaux ne prennent pas en compte le système tonal des parlers décrits et s'inscrivent rarement dans un cadre théorique défini. Enfin, ils souffrent de nombreuses insuffisances orthographiques et sont rarement basés sur des corpus linguistiques

A new species of Monanthotaxis from Gabon with a unique inflorescence type for Annonaceae

Monanthotaxis Baillon (1890: 878) currently consists of 56 species (Rainer & Chatrou 2006) confined to tropical Africa and Madagascar and is the second most species-rich genus of Annonaceae in Africa after Uvaria Linnaeus (1753: 536). Both genera belong to the tribe Uvarieae Hooker & Thomson (1855: 91, 92). Circumscription of this tribe has recently been modified to comply with the principle of monophyly, and it now almost exclusively consists of climbing species, all from the Old World tropics (Chatrou et al. 2012). Generic circumscription within Uvarieae has been in disarray for considerable time. Delimitation of Uvaria and related genera has recently been modified based on phylogenetic relationships (Zhou et al. 2010, Zhou et al. 2009). Monanthotaxis was monophyletic in Wang et al. (2012), based on a limited sampling of seven species. Subsequent study with increased sampling (Hoekstra, unpub.) has revealed that the African species of Friesodielsia van Steenis (1948: 458) and Exellia Boutique (1951b: 117) are nested in Monanthotaxis. Whatever the solution and taxonomic consequences, the name Monanthotaxis with the type Monanthotaxis congoensis Baillon (1890: 879) will be retained as it is the oldest valid generic name. Along with phylogenetic analysis, we are conducting a taxonomic revision. The last revision of Monanthotaxis and allied genera was published over a century ago by Engler & Diels (1901). Since then, only contributions to local floras have been published (e.g. Boutique 1951a, Le Thomas 1969, Robson 1960, Verdcourt 1971a). While studying the material of Monanthotaxis, we encountered a remarkable new species, which differs from all other species of Annonaceae in its large and lax panicle-like inflorescence. Panicle-like inflorescences are rare in Annonaceae, and those that have been recorded are either congested, as in e.g. Unonopsis and Guatteria (Erkens et al. 2008, Maas et al. 2007), or with only a few flowers, as in Monanthotaxis le-testui Pellegrin (1950: 75). This new species is probably closely related to M. congoensis since they share several characters. Verdcourt (1971b) divided the genus in three subgenera and five sections. In his classification, this new species would join M. congoensis in the typical section Monanthotaxis, which is easily distinguished by having flowers with the four to six petals in a single whorl and less than 17 stamens. Because it is so similar to M. congoensis, our new species will almost certainly be classified within Monanthotaxis, and we decided to publish it before a new generic classification has been completed

Diversité et Distribution du Peuplement Ichtyofaune dans l'Estuaire de Betsiboka, Nord-Ouest de Madagascar

L'estuaire de Betsiboka, situé sur la côte nord-ouest de Madagascar, est le plus grand écosystème estuarien du pays. L'article explore la diversité des poissons dans cet estuaire, mettant en lumière la distribution ichtyologique au sein de cet écosystème. La méthodologie adoptée comprend deux approches d'échantillonnage des poissons, à savoir le suivi des prises de la petite pêche et la pêche expérimentale. Les données ont été traitées à l'aide du logiciel R, et les indices écologiques tels que l'Indice de Shannon-Weaver, l'Indice d'Équitabilité de Piélou, l'Indice de Similarité de Jaccard, ainsi que la classification hiérarchique, ont été évalués à l'aide du package "Vegan". Les résultats montrent une richesse spécifique élevée, avec 63 espèces distinctes. Les analyses des indices écologiques montrent des variations spatiales de la diversité spécifique et des similitudes entre les villages. La classification hiérarchique confirme la formation de deux groupes distincts. Cette étude contribue significativement à l'enrichissement des connaissances sur la diversité et la répartition des poissons dans l'estuaire de Betsiboka, offrant ainsi une base solide pour la gestion durable de la pêche et de cet écosystème vital. &nbsp; The Betsiboka Estuary, located on the northwest coast of Madagascar, is the largest estuarine ecosystem in the country. This article explores the diversity of fish in this estuary, focusing on species distribution within this ecosystem. The methodology employed includes two fish sampling approaches: small-scale fishing catch monitoring and experimental fishing. Data were processed using the R software, and ecological Index such as the Shannon Index, Pielou's Evenness Index, Jaccard Similarity Index, along with hierarchical clustering, were assessed using the "Vegan" package. The results emphasize a diversity of species, with 63 distinct species identified. Analyses of ecological indices showcase spatial variations in specific diversity and similarities between villages. Hierarchical clustering affirms the formation of two distinct groups. This research significantly contributes to advancing understanding regarding the diversity and distribution of fish in the Betsiboka Estuary, establishing a solid groundwork for the sustainable management of fisheries and this crucial ecosystem

Distribution and activity of virioplankton in the Toliara Large Reef (Madagascar)

Until then, the study of aquatic viruses concerned almost exclusively temperate and polar environments while the tropics were rarely explored. In this study, we examined the spatial and temporal variability of viral and bacterial communities in two different tide periods (spring/ neap tide), on 22 stations covering the Toliara Large Reef (TLR) located in Madagascar. The coupling of these two communities was also analyzed in several contrasted stations of the reef by physiological and ecological descriptors means. The epifluorescence microscopy technique allowed to achieve the bacterial and viral count support of this work. The results obtained show that the bacterial and viral concentrations for the whole TLR were significantly higher during spring than neap tide, probably because of the hydrodynamics very marked in this area. In addition, the Mitomycin C used permitted to establish that the cells fraction in phase of lysogenic infection was very low (&lt; 3%) despite the oligotrophic status of TLR waters. This suggests that the lysogeny was the viral reproduction dominant strategy, which was diverted spontaneously and in a continuous way towards the lytic pathway, under the solar conditions’ influence. Finally, we show that the viruses form a dynamic and ubiquitous component of reef ecosystems, whose activity appears once again, closely related to the physico-chemical and biological environment nature.Keywords: Virus, lysogeny, lysis, tropical latitud