Éditeur(s) : Université de Bucarest - Université de Bretagne occidentale
Résumé : This study is focusing on the architecture and recent sedimentary evolution of the Danube channel, the youngest channel-levee system in the Danube deep-sea fan. The study was conducted as part of the BlaSON French-Romanian Project, and combined high-resolution seismic-reflection profiles and chirp profiles with multibeam bathymetry and piston cores. This data set was acquired in 1998 during a joint survey IFREMER-GeoEcoMar of the north-western Black Sea. Previous seismic and acoustic data were also used. The Danube deep-sea fan is a large passive-margin mud-rich fan. Like the other systems of this type (Amazon fan, Mississippi fan or Indus fan) the Danube fan consists of stacked channel-levee systems intercalated with mass-transport deposits. Seismic and sedimentary facies in the Danube fan are similar to those identified in most of the mud-rich systems. Nevertheless, the Danube fan is distinguished by a specific feature: its development in a freshwater environment. This is due to the peculiar water-level history of the Black Sea controlled by the link to the Mediterranean through the Strait of Bosphorus and the Sea of Marmara. This connexion was successively interrupted (during sea level lowstands) and re-established (when the sea level was rising above the Bosphorus). Temporary absence of marine water influx during lowstands together with large freshwater inputs from the Danube and other major rivers changed the Black Sea into a freshwater lake during times of fan activity. This peculiarity possibly favourised the development of hyperpycnal flow at the Danube mouth and the initiation of turbidity currents in the deep-sea fan. The Danube channel is directly connected to the large shelf-indenting Danube canyon (also known as Viteaz canyon). The Danube canyon is deeply incised into the shelf margin for 26 km landward of the shelfbreak. During lowstands this canyon acted as the most important path for sediment supply to the deep sea in this part of the continental margin. It consists of a main trough with steep flanks, and a meandering thalweg cut into the flat canyon floor, attesting for the development of the canyon by erosion in the entrenched axial thalweg. Sections with specific morphology, orientation and gradient identified along the canyon, are interpreted as phases of landward expansion of the canyon. Internal structure of the canyon shows several erosional surfaces, which indicate that the present morphology of the canyon is the result of its polyphasic evolution. Instability in the zone of the canyon is related to the important sediment supply at the Danube mouth, to the presence of the gas in the surficial sediment, and possibly under a structural control. The upper part of the Danube channel (between the Danube canyon and ~1400 m depth) consists in a single leveed-channel that has undergone significant overbank deposition, as attested by the well-developed levees. The levees are strongly asymmetrical, being higher and wider on the right-hand side looking downstream. This type of asymmetry is rather common in deep-sea fans, and is generally attributed to the Coriolis effect (Menard, 1955). The channel is slightly sinuous, partially filled and incised by an entrenched thalweg, connected to the axial thalweg of the Danube canyon. Detailed seismic investigation inside the channel trough documented several depositional phases within the channel fill, separated by erosional surfaces. These surfaces are associated with distinct terraces identified on the multibeam bathymetry, that can be followed downward along the main trough axis. The valley fill deposits (where not removed by the subsequent erosional event) show an axial HAR (High Amplitude Reflections) seismic facies with lateral lower amplitude continuous reflections consisting in a levee facies, as proved by sampling. This indicates that filling up was associated with flow within the channel, and not with interruption of fan activity. On the middle slope below 1400 m, this single channel bifurcates through repeated avulsions. As a result, several highly meandering channels developed. The onlap relationships between these channels indicate that only one channel was active at a time. Each phase of avulsion resulted in a depositional unit consisting in a basal unchannelized lobe defined as High Amplitude Reflection Packets (HARP, Flood et al., 1991) that underlies a channel-levee system. The deposition of HARPs was associated with the readjustment of the longitudinal profile of the channel after the breaching of a levee, which resulted in remobilization of upslope channel deposits and eroded levees. When this adjustment was complete, erosion ceased and levees began to develop above the HARPs (Pirmez et al., 1997). All the identified phases of avulsion followed the same pattern: (1) breaching of the lower and narrower left levee; (2) building of a unit of High Amplitude Reflector Packets (HARP) basinward of the bifurcation point by the unchannelized flow, while the former channel was abandoned; and (3) initiation of a new meandering leveed channel. The northward migration of the resulting units through repeated bifurcations is influenced by the asymmetry between levees (hence by the Coriolis effect), and confined between the high levees of the initial phase of the Danube channel (to the south) and the steep relief of the Dniepr fan (to the north). Structure of the fan valley fill indicate that the erosional surfaces inside the upper channel could be formed in response of successive avulsions, by the adjustment of the longitudinal profile of the channel following the breaching of a levee wall. Sediments removed by erosion formed the HARP lobes basinward of the avulsion point. When this adjustment was complete, a channel-levee system developed downward of the bifurcation, overlying the HARPs, but also upward of this point, as a confined channel-levee system inside the erosional trough of the fan valley. Fluvial incisions identified on the continental shelf, together with the coastline location during the last active period of the Danube channel, indicated that the paleo-Danube was directed towards the head of the Danube canyon. Paleo-Danube mouth was fairly close (ca. 10 km) to the Danube canyon, supplying sediment to the Danube channel. Furthermore, hyperpycnal flow probably prevailed in the freshwater environment that characterized the Black Sea during times of fan activity. These conditions would have enabled the development of a quasi-continuous river-canyon-deep-sea fan system, ensuring the effective transfer of the sediment between the coastal zone and the deep sea.
Ce travail est consacré à l'étude de l'architecture et de l'évolution sédimentaire récente de l'éventail profond du Danube, en particulier de son dernier système chenal-levée: le chenal du Danube. L'étude a été réalisée dans le cadre du projet de coopération franco-roumaine BlaSON, à partir des données sismiques, bathymétriques-acoustiques et sédimentologiques acquises en 1998 lors d'une campagne en mer Noire réalisée par IFREMER et GeoEcoMar. Des données sismiques et acoustiques antérieures ont été également utilisées. L'éventail profond du Danube s'enserre dans la catégorie des grands éventails vaseux. Comme les autres systèmes de ce genre (tel que les éventails de l'Amazone, du Mississippi ou de l'Indus) il est constitué d'une succession de systèmes chenaux-levées intercalés avec des dépôts de transport en masse. Le fonctionnement de l'éventail était conditionné par la baisse du niveau marin lors des périodes glaciaires. Ses faciès sismiques et sédimentaires s'apparentent aux faciès qui caractérisent la plupart des éventails de ce type. L'éventail du Danube constitue néanmoins un cas particulier parmi les autres systèmes étudiés, du fait de son fonctionnement dans un bassin lacustre. Ceci est dû à la situation spécifique de la mer Noire dont la connexion avec la Méditerranée, par le détroit de Bosphore et la mer de Marmara, a été successivement interrompue (au cours de périodes de bas niveau) et reprise (quand le niveau marin remontait en dépassant le seuil du Bosphore). L'absence de l'apport d'eau salée pendant les périodes glaciaires, associée avec l'augmentation de l'apport fluvial, ont déterminé l'installation d'un milieu d'eau douce dans la mer Noire à chaque fois que la baisse du niveau permettait la reprise du fonctionnement de l'éventail profond. Cette situation particulière aurait favorisé la formation des courants hyperpycnaux à l'embouchure d'un fleuve du débit du Danube qui déversait ses eaux turbides dans un bassin lacustre, et aurait donc influencé l'apparition de courants de turbidité dans l'éventail profond. Le chenal du Danube s'est développé sur la pente continentale en prolongation du canyon du Danube (ou Viteaz) auquel il est directement connecté. Le canyon est incisé de manière significative (26 km) dans la plate-forme continentale. Au cours de bas-niveaux marins il constituait la principale voie de transfert des sédiments terrigènes vers le bassin profond dans cette partie de la marge. Le canyon est constitué par une entaille avec des flancs abrupts et un talweg axial incisé, qui montre l'importance du processus d'érosion du fond pour le développement du canyon. Les segments qui ont été identifiés le long du canyon, avec des morphologies, des orientations et des pentes spécifiques, sont interprétés comme des phases d'avancement du canyon vers la côte. Plusieurs incisions sont visibles dans la structure interne du canyon et témoignent que la morphologie actuelle du canyon est le résultat de son évolution polyphasée. L'instabilité de la zone du canyon est en relation avec les apports sédimentaires importants à l'embouchure du Danube, avec la présence du gaz dans les sédiments superficiels, et possiblement sous un contrôle structural. Sur la pente supérieure (entre le canyon du Danube et environ 1400 m de profondeur) le chenal du Danube présente des levées bien développées et fortement asymétriques, avec la levée droite plus haute et plus large que la levée gauche. Ce type d'asymétrie, fréquemment décrit dans les éventails profonds est généralement attribué à l'effet Coriolis (Menard, 1955). Le chenal est légèrement sinueux, partiellement comblé et incisé par un talweg axial qui représente la continuation sur la pente du talweg incisé dans le canyon du Danube. L'analyse sismique détaillée du remplissage de la vallée montre plusieurs phases de dépôt, séparées par des discontinuités érosives. Ces surfaces d'érosion correspondent à des terrasses emboîtées, relativement parallèles le long de la vallée, visibles dans la bathymétrie. Les dépôts qui constituent le remplissage du chenal présentent un faciès sismique de type HAR (High Amplitude Reflections) dans l'axe du chenal, partiellement (ou parfois totalement) enlevé par les phases d'érosion subséquentes, qui continue latéralement avec des réflexions litées correspondant à un faciès sédimentaire de levée. Le remplissage de la vallée a été donc associé avec des écoulements dans le chenal, et non pas avec l'interruption de son fonctionnement. Sur la pente inférieure, le chenal unique bifurque plusieurs fois par avulsion et forme de nouveaux systèmes chenaux-levées méandriformes. Ces systèmes se succèdent verticalement en onlap, ce qui montre qu'un seul chenal a été actif à la fois. Chaque phase d'avulsion a eu comme résultat la mise en place d'une unité constituée par un lobe défini comme "High Amplitude Reflection Packets" (HARP, Flood et al., 1991) à la base, et un système chenal-levée au sommet. Le dépôt d'un lobe HARP est associé avec de l'érosion dans le chenal en amont du point d'avulsion pour l'ajustement de son profil après la rupture de la levée. Quand le chenal a retrouvé son profil d'équilibre, l'érosion a cessé et des levées ont commencé à se développer au-dessus des HARPs (Pirmez et al., 1997). Toutes les phases d'avulsion se sont développées d'après le même modèle: (1) la rupture de la levée gauche, plus étroite; (2) le dépôt d'un lobe HARP par les écoulements non-chenalisés en aval du point d'avulsion, et l'abandon de l'ancien chenal; (3) l'initiation d'un nouveau système chenal-levée. La migration systématique du chenal vers le nord est influencée par l'assymétrie des levées (donc par la force de Coriolis), et confinée entre les grandes levées de la phase initiale du chenal du Danube, au sud, et le relief abrupt de l'éventail du Dniepr au nord. La structure sédimentaire du chenal du Danube indique que les surfaces érosives à l'intérieur du remplissage du chenal se seraient formées en réponse aux avulsions, du fait de l'ajustement du profil du chenal après la rupture d'une levée. Les sédiments du chenal érodés au cours de ce processus ont formé les lobes HARP. Quand le chenal a retrouvé son profil d'équilibre, un système chenal-levée s'est développé en aval du point d'avulsion au dessus du lobe HARP, mais aussi en amont de ce point, où il se trouve confiné dans la vallée érosive. Les incisions fluviatiles identifiés sur la plate-forme continentale et la position de la ligne de côte pendant la dernière période d'activité du chenal du Danube montrent que le paléo-Danube se dirigeait directement vers la tête du canyon du Danube. Son embouchure était située à proximité du canyon, qui alimentait le chenal du Danube. Cependant, les courants hyperpycnaux devaient prévaloir dans le milieu de salinité réduite qui caractérisait la mer Noire lors des périodes actives de l'éventail. Ces conditions auraient favorisé la mise en place d'un système quasi-continu fleuve-canyon-éventail profond, qui contrôlait le transfert des sédiments entre la côte et le bassin profond.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/2002/these-1206.pdf
http://archimer.ifremer.fr/doc/00000/1206/

Éditeur(s) : HAL CCSD International Medical Press
Résumé : International audience
BACKGROUND: Psychiatric disorders are relatively common among HIV-infected patients. However, there are few studies about their potential risk factors. This analysis aimed to measure the incidence of severe psychiatric events (PE) among patients receiving combination antiretroviral therapy (cART) of the French APROCO-COPILOTE (ANRS CO8) cohort, and to identify the medical and socio-behavioural correlates of their first episode of depression, suicide or suicide attempt (D/S/SA). METHODS: APROCO-COPILOTE is a cohort of patients started on a protease inhibitor regimen between 1997 and 1999, with prospective medical standardized records and self-administered questionnaires collecting socio-demographic and socio-behavioural data. This analysis included all 11-year follow-up visits for 1,095 patients having completed baseline self-administered questionnaires. A proportional hazard Cox model was used to identify the correlates of a first D/S/SA event. RESULTS: The overall prevalence of severe PE remained low: 50 patients experienced 67 events (incidence rate [95% CI] =1.04 [0.82, 1.32] per 100 person-years). Depression (n=16), suicides (n=5) and suicide attempts (n=14) were the most frequently diagnosed PE (0.54 [0.39, 0.76] per 100 person-years) among 25 patients. Multivariate results showed that unemployment, unstable housing, detectable viral load and smoking more than 20 cigarettes/day were independently associated with D/S/SA. CONCLUSIONS: Although the incidence of severe PE remained relatively low among the patients of APROCO-COPILOTE cohort, this study's results underline a clinically important problem in HIV-infected patients receiving cART. Furthermore, our findings not only emphasize the importance of comprehensive care, especially for socially vulnerable patients, but may also help future studies designed to assess the effectiveness of interventions in reducing the risk of PE during cART.
ISSN: 1359-6535

hal-00875183
https://hal.archives-ouvertes.fr/hal-00875183
DOI : 10.3851/IMP2102
PUBMED : 22544079

Éditeur(s) : HAL CCSD Elsevier Masson
Résumé : International audience
Cancer is the main complication of transplantation surgery. The literature concerning renal transplant recipients among the Afro-Caribbean population is scant. The aim of this study was to determine the incidence of cancer in these patients, with the secondary objective being to identify predisposing factors for cancer. This was an epidemiological and retrospective study that included all Guadeloupians of phototype V-VI undergoing renal transplantation from 01/01/2004 to 31/12/2011. Skin cancer screening was performed before transplantation and during an annual dermatological consultation following transplantation. Screening for non-cutaneous cancers was guided by clinical symptoms or by the results of the screening examinations recommended in the current guidelines. At the study time-point (31/12/2011), all patients were examined by a dermatologist. One hundred and two patients were included : 42 women and 60 men (mean age: 52.1±11.6 years at transplantation). Eight cancers were diagnosed. The cumulative incidence of cancer was 7.8% at 3 years. Three factors were associated with more rapid onset of cancer: personal history or familial history of cancer, and genital lesion induced by HPV. Our results suggest a low incidence of cancer in Afro-Caribbean renal transplant patients. Personal or family history of cancer and HPV-induced genital lesions would appear to accelerate the onset of cancer in this population.
ISSN: 0151-9638

hal-01260468
https://hal.archives-ouvertes.fr/hal-01260468
https://hal.archives-ouvertes.fr/hal-01260468/document
https://hal.archives-ouvertes.fr/hal-01260468/file/2015%2C%20Ameline.pdf
https://hal.archives-ouvertes.fr/hal-01260468/file/14%20148%20Fig%201%20ap.pdf

Éditeur(s) : Elsevier Sci Ltd
Résumé : A detailed morphological analysis of the outer shelf and continental slope of the Western Gulf of Lion is presented, based on swath bathymetry data together with sub-bottom profiles and high resolution seismic reflection profiles. These data reveal two main erosive features, of very different dimensions: the axial incision and the canyon's major valley. The height of axial incisions' flanks with respect to the canyon deepest point (the thalweg) ranges from 40 to 150 m. It creates a small axial erosive path within the canyon's major valley, which is typically bounded by flanks of more than 700 m in height. We interpret the axial incision observed in the sea floor as the imprint of turbidity currents that eroded the floor of canyons during phases of connection to rivers (hyperpycnal turbidity current). Such currents are most likely to have formed during the Last Glacial Maximum (LGM) as both proximity of the shoreline (due to the lowstand of sea level) and high detrital sediment supply (due to glacial abrasion upstream) increased the flow of sediments delivered to the canyon heads. Fossil axial incisions, observed in seismic lines, are related to equivalent conditions. The axial incision, however, has a key influence on canyon evolution as it triggers mass wasting of different sizes that affect the canyon's major valley (head and flanks). We interpret the geometry of the canyon's major valley as the result of recurrent activity of axial incisions. These periods of activity occurred during low sea levels at glacial maxima and show a cyclicity of 100,000 years for the last 400,000 years.
Marine And Petroleum Geology (0264-8172) (Elsevier Sci Ltd), 2005-06 , Vol. 22 , N. 6-7 , P. 805-826

Droits : 2005 Elsevier Ltd All rights reserved
http://archimer.ifremer.fr/doc/2005/publication-353.pdf
DOI:10.1016/j.marpetgeo.2005.03.011
http://archimer.ifremer.fr/doc/00000/353/

Éditeur(s) : HAL CCSD
Résumé : National audience
Objective of the study An estimation of burden of serious fungal diseases in France is essential data to inform public health priorities on the importance of resources and research needed on these infections. In France, precise data are available for invasive fungal diseases but estimates for several other diseases such as chronic and immunoallergic diseases are by contrast less known. Materials and methods A systematic literature search was conducted using the Web of Science Platform. Published epidemiology papers reporting fungal infection rates from France were identified. Where no data existed, we used specific populations at risk and fungal infection frequencies in those populations to estimate national incidence or prevalence, depending on the condition. Results The model predicts high prevalences of severe asthma with fungal sensitization episodes (189 cases/100,000 adults per year), of allergic bronchopulmonary aspergillosis (145/100,000) and of chronic pulmonary aspergillosis (5.24/100,000). Besides, estimated incidence for invasive aspergillosis is 1.8/100,000 annually based on classical high risk factors. Estimates for invasive mucormycosis, pneumocystosis and cryptococcosis are 0.12/100,000, 1/100,000 and 0.2/100,000, respectively. Regarding invasive candidiasis, more than 10,000 cases per year are estimated, and a much higher number of recurrent vaginal candidiasis is probable but must be confirmed. Finally, this survey was an opportunity to report a first picture of the frequency of tinea capitis in France. Conclusion Using local and literature data of the incidence or prevalence of fungal infections, approximately 1,000,000 (1.47%) people in France are estimated to suffer from serious fungal infections each year. © 2016 Elsevier Masson SAS
Journal de Mycologie Medicale

hal-01467554
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01467554
DOI : 10.1016/j.mycmed.2016.11.001
PUBMED : 27887809

Éditeur(s) : HAL CCSD BioMed Central
Résumé : ICARE Study Group
International audience
BackgroundPopulation attributable risks (PARs) are useful tool to estimate the burden of risk factors in cancer incidence. Few studies estimated the PARs of oral cavity cancer to tobacco smoking alone, alcohol drinking alone and their joint consumption but none performed analysis stratified by subsite, gender or age. Among the suspected risk factors of oral cavity cancer, only PAR to a family history of head and neck cancer was reported in two studies. The purpose of this study was to estimate in France the PARs of oral cavity cancer to several recognized and suspected risk factors, overall and by subsite, gender and age.MethodsWe analysed data from 689 oral cavity cancer cases and 3481 controls included in a population-based case–control study, the ICARE study. Unconditional logistic regression models were used to estimate odds ratios (ORs), PARs and 95 % confidence intervals (95 % CI).ResultsThe PARs were 0.3 % (95 % CI −3.9 %; +3.9 %) for alcohol alone, 12.7 % (6.9 %–18.0 %) for tobacco alone and 69.9 % (64.4 %–74.7 %) for their joint consumption. PAR to combined alcohol and tobacco consumption was 74 % (66.5 %–79.9 %) in men and 45.4 % (32.7 %–55.6 %) in women. Among suspected risk factors, body mass index 2 years before the interview <25 kg.m−2, never tea drinking and family history of head and neck cancer explained 35.3 % (25.7 %–43.6 %), 30.3 % (14.4 %–43.3 %) and 5.8 % (0.6 %–10.8 %) of cancer burden, respectively. About 93 % (88.3 %–95.6 %) of oral cavity cancers were explained by all risk factors, 94.3 % (88.4 %–97.2 %) in men and only 74.1 % (47.0 %–87.3 %) in women.ConclusionOur study emphasizes the role of combined tobacco and alcohol consumption in the oral cavity cancer burden in France and gives an indication of the proportion of cases attributable to other risk factors. Most of oral cavity cancers are attributable to concurrent smoking and drinking and would be potentially preventable through smoking or drinking cessation. If the majority of cases are explained by recognized or suspected risk factors in men, a substantial number of cancers in women are probably due to still unexplored factors that remain to be clarified by future studies.
ISSN: 1471-2407

Droits : http://creativecommons.org/licenses/by/
hal-01258466
http://hal.upmc.fr/hal-01258466
http://hal.upmc.fr/hal-01258466/document
http://hal.upmc.fr/hal-01258466/file/BMCC.pdf
DOI : 10.1186/s12885-015-1841-5

Éditeur(s) : HAL CCSD
Résumé : National audience
The last study describing the epidemiology of malaria in French Guiana was published 20 years ago. Yet French Guiana in the Americas along with Mayotte in the Indian Ocean is the only French territory with persisting endemic malaria. The purpose of this study is to provide an update based on official malaria surveillance data as well as on information from hospital records and various field surveys that have been carried out in recent years. Due to recurrent problems in collecting thorough, continuous, and consistent data, exact determination of incidence by plasmodium species has always been difficult in French Guiana. These problems include not only the remote location of endemic areas and intense unpredictable migration patterns but also poor data collection methods that do not always ensure consistency and homogeneity. Another factor hindering thorough collection of conventional epidemiological data is the requirement for rapid effective treatment in remote regions. The overall incidence of malaria in French Guiana appears to have remained stable since the beginning of the decade with an average of 3,920 case reports per year for an incidence rate of 20 per thousand, noting that three fourths of the 206,000 inhabitants of French Guiana live outside of endemic areas. Overall involvement of P. falciparum and P. vivax appears to be equal with P. malariae accounting for only 2.6% of cases. Trends in recent years indicate an increase in the number of cases involving P. vivax especially in the eastern zones, i.e. in the Oyapock focus where annual incidences in children have reached up to 500 per thousand and in the whole region located between Saint Georges and Cayenne. Conversely a decrease in endemic levels has been observed in western areas, especially for P. falciparum in the upper and middle focuses of the Maroni. Most zones now causing problems are located near migration points, particularly in relation with clandestine gold panning activities. In the coastal strip where the three main cities with most of the population are located, most reported cases are imported but local cases may occur. In general local transmission in these areas has been promptly controlled but trends indicate that incidence of these events may be rising. Anopheles darlingi is still recognized as the main vector but its role in transmission is less obvious in eastern areas where increasing evidence suggests that other species may contribute to maintaining endemic levels. These findings indicate that the extensive resources deployed in this French territory (public financing, health care network, public awareness campaigns, and training of health care personnel in diagnosis and treatment of malaria) have helped reduce the number of severe cases in an unfavorable epidemiological setting.
Médecine tropicale : revue du Corps de santé colonial

pasteur-00583514
https://hal-riip.archives-ouvertes.fr/pasteur-00583514
PUBMED : 19499726

Éditeur(s) : Scientific Technical Research Council Turkey-tubitak
Résumé : In 2002, the Bosphorus outlet was mapped using an EM 300 multibeam echo-sounder together with a Chirp sonar system. This survey, carried out on board the Ifremer RV 'Le Suroit' in the frame of the BlaSON project, completes the data previously acquired directly at the mouth of the Bosphorus by Di Iorio et al. (1999) in the frame of a NATO SACLANT Undersea Research project using jointly the NATO RV Alliance, and the Turkish Navy Survey ship 'Cubuklu'. This acoustic imaging has identified a canyon system at the slope and a shallow marine fan, which contains shelf incisions extending the Istanbul Strait incision. Multibeam bathymetry, ultra-high resolution seismic profiling and coring correlations on this subaqueous fan area allowed reconstruction of morphology and patterns of sediment distribution indicative of high energy sediment transport processes. The discovery of a shallow water/shelf type fan directly off shore from the Bosphorus and connected to its outlet is consistent with the theories of sudden discharges of large volumes of water. Age dating obtained at the bottom of this subaqueous shelf fan yielded an age of 6700 yr C-14 BP (uncorrected age) for the first marine mollusc encountered at the base. This is in accordance with a last and abrupt reconnection of the Marmara Sea to the Black Sea. A detailed morphological map of the shelf and slope along with seismic profile interpretation and core correlation is presented here. A synthesis is proposed to explain the formation of this subaqueous fan and its relationship with the last connection between Black and Marmara seas aft er the Last Glacial Maximum. This interpretation can be summarized as follows: stage A corresponds to the first erosion surface seen on the shelf related to the Last Glacial Maximum low stand; stage B is the ravine surface onlapping to ca. -30, -40 m; stage C is a second erosional surface related to a sea level fall and eroding most of underlying Unit 1B; and stage D corresponds to the onset of the fan deposit during a period of high water run-off from the Black Sea entering from the Bosphorus. Avulsion branches show that this fan has been active for a long time.
Turkish Journal Of Earth Sciences (1300-0985) (Scientific Technical Research Council Turkey-tubitak), 2011 , Vol. 20 , N. 3 , P. 287-305

Droits : 2011 TÜBİTAK
http://archimer.ifremer.fr/doc/00036/14676/13677.pdf
http://archimer.ifremer.fr/doc/00036/14676/

Éditeur(s) : HAL CCSD
Résumé : The present study addresses the question of increasing need in water supply. One line of research consists in investigating karst aquifers that represent significant water supplies for the areas around the Mediterranean. This work aims at developing a methodology of predictive evaluation of karst distribution and karst thickness within the carbonate massifs. It is based on the study of the Tethysian carbonate platform from the area of Montpellier, South of France. This area underwent a polyphased, complex, tectonic evolution, involving successive karst forming events. The approach is based on the relationships between eustacy and geodynamics, on one hand, and base-level variation recorded within palaeokarsts, on the other hand. Sedimentary fill of palaeokarsts allows to identify distinct karstification phases and sometimes to date them. It is a marker of base-level variations, which we attempt to quantify, that is responsible for karst formation and karst filling and sealing. For three palaeokarsts of regional extent, we analyze : karst sedimentary-fill, the distribution along upstream-downstream profile, the vertical extension of palaeokarsts, indicative of the base-level lowering. - The " Bauxite palaeokarst " results from the two-stage evolution of the " Isthme Durancien " : i) Bauxitic weathering of the Neocomian cover over the southern Massif Central , related to an inversion during Barremian ; ii) ≥1600 m uplift and exhumation during Aptian-Albian, inducing erosion of alterites, upstream, and deposition of detrital bauxites, downstream. - The " Early Paleocene palaeokarsts with marine sedimentary-fill " indicate base level variations of more than 350m in the upstream area. It is suggested here that such base-level variations, exceeding eustacy and recorded in tabular undeformed series, result from desiccation-flooding events in an endoreic silled basin. - The " Miocene palaeokarst with Cevennes-sourced sediment-fill " records a Serravalian-Tortonian base-level drop, depicted by canyon incision in the hinterland of the Gulf of Lion Margin. Uplift values of ≥ 400m upstream, about 250m in an intermediate area and 10's of m downstream, are measured. The present 3D geometry and distribution of carbonate massifs (exposed and covered) are modeled in the study area, from the Cevennes to the Mediterranean. The 3D geological model integrates seismic reflection, borehole and gravimetric data. Tectonic restoration of a N-S section, extracted from the 3D model, allows to reconstruct paleo-base-levels with respect with the carbonate massifs, at different stages of deformation and successive phases of karstification. The 3D paleo-flows through carbonates across the study area, are thus constrained, especially during the Messinian desiccation stage. Application of the results to hydrogeology leads to the following : - Uplift of upstream hinterland (Cretaceous, Miocene) produces large amplitude karsts, but they do not make significant reservoirs. - Karstification responsible for the development of important and deep karst reservoirs is related to desiccation of endoreic basins (early Paleocene and Messinian). - Theses two events have produced two main deep karst reservoirs, with a gravimetric signature : (1) Upstream of Montpellier Thrust, between Pic St Loup, Les Matelles Fault and Hérault Basin, a deep karsts developed over 900m thickness in the Malm limestone, during Paleocene. (2) Downstream (south) of Montpellier Thrust, the coastal karsts extend offshore over more than 10km, they are sealed by a thick Miocene to Quaternary cover, and they result from the Messinian event.
Cette étude s'inscrit dans un contexte de demande croissante en ressources en eau, conduisant à mieux contraindre et estimer la distribution des aquifères karstifiés qui représentent une ressource importante, notamment sur le pourtour méditerranéen. Le but de ce travail est d'élaborer une méthode prédictive de la distribution de la karstification et de l'épaisseur de massifs carbonatés karstifiés, notamment pour les karsts profonds. La méthodologie est développée à partir de l'étude des karsts de la plateforme carbonatée téthysienne du Languedoc montpelliérain; région qui a subi une histoire tectonique complexe et polyphasée, entrainant des phases de karstification successives. Elle est basée sur la compréhension des relations entre eustatisme, géodynamique et niveau de base, enregistrées par les paléokarsts de la région. Le remplissage sédimentaire des paléokarsts permet d'identifier les épisodes de karstification et de les dater ; c'est un marqueur des variations -que l'on cherche à quantifier- du niveau de base local responsable de la formation et du comblement des karsts. On analyse 3 paléokarsts d'extension régionale dont on peut étudier : le remplissage karstique, la distribution le long de profils amont-aval et l'extension verticale indicatrice de l'amplitude de l'abaissement du niveau de base dont il est issu. On en déduit les causes géodynamiques à l'origine de leur formation: - Le " paléokarst des bauxites " à remplissage caractéristique, résulte de l'évolution en 2 phases de " l'Isthme Durancien " : altération bauxitique de la couverture néocomienne sur le sud du Massif Central, liée à une inversion au Barrémien, suivi d'une surrection ≥ 1600m à l'Aptien-Albien, causant l'érosion des altérites en amont et le dépôt des bauxites détritiques en aval. - Le " paléokarst à remplissage marin paléocène inférieur " indique des variations du niveau de base local ≥350m dans la zone amont sud-cévenole. On propose que ces variations de niveau de base d'amplitude très supérieures aux variations eustatiques et dans une zone faiblement déformée, résultent d'assèchements et d'ennoiements d'un bassin endoréique à seuil. - Le " paléokarst à remplissage détritique d'origine cévenole ", enregistre la chute du niveau de base au Serravalien-Tortonien, qui se traduit par l'incision de canyons dans l'arrière-pays de la marge du Golfe du Lion. On détermine une surrection de plus de 400 mètres à l'amont, près de 250m dans les blocs faillés intermédiaires et quelques dizaines de mètres dans la zone avale. En parallèle, on établit la géométrie et la distribution actuelles des massifs carbonatés dans la zone d'étude (y compris sous couverture), en construisant un modèle géologique 3D, des Cévennes à la Méditerranée. On intègre les données de sismique réflexion, de forages et les données gravimétriques. La restauration tectonique séquentielle d'une coupe Nord-Sud extraite du modèle géologique permet d'appréhender la position des paléo-niveaux de base par rapport aux massifs carbonatés, pour chaque époque de karstification. On déduit l'organisation 3D des paléo-écoulements à travers la géométrie complexe des massifs carbonatés languedociens, notamment pendant l'évènement messinien. En terme d'évaluation de la ressource en eau, on déduit que: - Les surrections de l'arrière-pays (Crétacé " moyen ", Miocène) produisent des karsts de grande amplitude, mais ne constituent pas de réservoirs significatifs. - La karstification à l'origine de réservoirs exploitables importants et profonds est créée par l'assèchement de bassins endoréiques, qui ont affecté la région au Paléocène inférieur et au Messinien . - Ces deux évènements sont à l'origine de deux principaux réservoirs karstiques profonds qui ont une signature gravimétrique : (1) En amont du chevauchement de Montpellier, entre le Pic Saint Loup, la faille des Matelles et le bassin de l'Hérault, le karst profond se développe sur une épaisseur atteignant 900m, et est attribuée à l'événement du Paléocène. (2) Au Sud du chevauchement de Montpellier les karsts côtiers s'étendent jusqu'à plus de 10 km au large, scellés par une épaisse couverture Miocène et Plio-Quaternaire, et résultent de l'événement Messinien.
https://tel.archives-ouvertes.fr/tel-00936257

tel-00936257
https://tel.archives-ouvertes.fr/tel-00936257
https://tel.archives-ouvertes.fr/tel-00936257/document
https://tel.archives-ouvertes.fr/tel-00936257/file/thA_se_husson_couleurs.pdf

Éditeur(s) : EDP Sciences
Résumé : The reproductive dynamics of swordfish (Xiphias gladius) was investigated from catches of the Reunion Island-based longline swordfish fishery between 19-25 degrees S and 48-54 degrees E. Thus, 1727 swordfish (size range 75-289 cm, lower jaw-to-fork length, LJFL) were sampled on board commercial fishing vessels during the period of May 1998 to January 2001. Reproductive activity was assessed using macroscopic gonad characteristics, trends of gonadal indexes for both sexes, oocyte size-frequency distributions and microscopic investigation of oocyte development stages. Size at first maturity (L-50) for female and male swordfish was estimated in Indian Ocean for the first time. L50 was estimated at 170 cm and 120 cm (LJFL) for females and males, respectively. Spawning occurred from October to April in the vicinity of Reunion Island where sex ratio of caught populations fluctuated seasonally. The seasonal changes in sex ratio and the incidence of larger individuals at the beginning of the spawning season provide some preliminary indications of synchronized movements of swordfish between spawning grounds and neighboring regions. Our results add significantly to knowledge about the reproductive biology of swordfish in the southwestern Indian Ocean. An overview of the available information on reproductive biology and dynamics of swordfish in Indian Ocean and eastern Pacific indicated that spawning activity is localized in discrete areas, and showed that there is incomplete information on spawning grounds in this extended area.
La dynamique de la reproduction est étudiée chez des espadons (Xiphias gladius) capturés dans l'océan Indien, entre 19–25 °Sud et 48–54 °Est, par les palangriers de l'île de La Réunion. Ainsi, 1727 espadons de tailles comprises entre 75 et 289 cm (de l'extrémité de la mâchoire inférieure à la fourche caudale) ont été échantillonnés à bord de navires professionnels, de mai 1998 à janvier 2001. La reproduction est évaluée en analysant : les caractéristiques macroscopiques des gonades, l'évolution des indices gonadiques des deux sexes, les distributions de fréquence de taille des ovocytes et le développement des ovocytes au niveau microscopique. La taille à première maturité sexuelle (L50) des espadons de l'océan Indien est estimée pour la première fois ; elle atteint 170 cm pour les femelles et 120 cm pour les mâles. La saison de ponte s'étend d'octobre à avril aux abords de l'île tandis que le sexe-ratio fluctue de façon saisonnière. Les variations saisonnières du sexe-ratio et l'apparition de grands individus au début de la saison de ponte suggèrent des déplacements d'espadons entre cette zone de ponte et les régions voisines. Nos résultats apportent des informations fondamentales sur la biologie de la reproduction de l'espadon dans le sud-ouest de l'océan Indien. L'analyse de la bibliographie concernant biologie et la dynamique de la reproduction de l'espadon dans l'océan Indien et dans le Pacifique Est indique que l'activité de ponte est très localisée et que la connaissance des aires de pontes est encore incomplète dans cette région étendue.
Aquatic Living Resources (0990-7440) (EDP Sciences), 2009 , Vol. 22 , N. 1 , P. 45-58

Droits : 2009 EDP Sciences
http://archimer.ifremer.fr/doc/2009/publication-6353.pdf
DOI:10.1051/alr/2009007
http://archimer.ifremer.fr/doc/00000/6353/

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
Background: Heterogeneous patterns of malaria transmission are thought to be driven by factors including host genetics, distance to mosquito breeding sites, housing construction, and socio-behavioural characteristics. Evaluation of local transmission epidemiology to characterize malaria risk is essential for planning malaria control and elimination programmes. The use of geographical information systems (GIS) techniques has been a major asset to this approach. To assess time and space distribution of malaria disease in Bandiagara, Mali, within a transmission season, data were used from an ongoing malaria incidence study that enrolled 300 participants aged under six years old ". Methods: Children's households were georeferenced using a handheld global position system. Clinical malaria was defined as a positive blood slide for Plasmodium falciparum asexual stages associated with at least one of the following signs: headache, body aches, fever, chills and weakness. Daily rainfall was measured at the local weather station. Landscape features of Bandiagara were obtained from satellite images and field survey. QGIS™ software was used to map malaria cases, affected and non-affected children, and the number of malaria episodes per child in each block of Bandiagara. Clusters of high or low risk were identified under SaTScan W software according to a Bernoulli model. Results: From June 2009 to May 2010, 296 clinical malaria cases were recorded. Though clearly temporally related to the rains, Plasmodium falciparum occurrence persisted late in the dry season. Two " hot spots " of malaria transmission also found, notably along the Yamé River, characterized by higher than expected numbers of malaria cases, and high numbers of clinical episodes per child. Conversely, the northeastern sector of the town had fewer cases despite its proximity to a large body of standing water which was mosquito habitat. Conclusion: These results confirm the existence of a marked spatial heterogeneity of malaria transmission in Bandiagara, providing support for implementation of targeted interventions. Background Malaria is one of the leading causes of morbidity and mortality in the world, with an estimated 3.3 billion people at risk of malaria [1]. The incidence of malaria worldwide is estimated to be 216 million cases per year, with 81% of these cases occurring in sub-Saharan Africa. Malaria kills approximately 655,000 people per year; 91% of deaths occur in sub-Saharan Africa [1], mostly in children under five years of age. In Mali, West Africa, malaria represents 36.5% of consultation motives in health center, it is a leading cause of morbidity and mortality children of less than five years of age and the first reason of anaemia in pregnant women [2]. Malaria transmission is seasonal. Malaria parasite transmission and clinical disease are characterized by important microgeographic variation, often between adjacent villages, households or families [3-8]. This local heterogeneity is driven by a variety of factors including human genetics [9,10], distance to potential breeding sites [11,12], housing construction
ISSN: 1475-2875

hal-01307672
https://hal-amu.archives-ouvertes.fr/hal-01307672
https://hal-amu.archives-ouvertes.fr/hal-01307672/document
https://hal-amu.archives-ouvertes.fr/hal-01307672/file/1475-2875-12-82.pdf
DOI : 10.1186/1476-072X-2-5

Éditeur(s) : HAL CCSD Oxford University Press (OUP)
Résumé : International audience
Background: The objective of the study was to determine the incidence of transaminase elevation during dengue, and its predictive factors. Methods: In 2013, a longitudinal study was performed using data from all cases of dengue seen in Cayenne Hospital. Cox proportional modeling was used. Signs of major transaminase elevation were defined as an increase in aspartate amino transferase (AST) or alanine amino transferase (ALT) concentration over 10 times the normal value (10N). Results: There were 1574 patients and 13 249 person-days of follow-up. The incidence rate for signs of trans-aminase elevation (10N) was 0.55 per 100 person-days. Six patients had major transaminase elevation with AST.1000 units (0.43 per 1000 patient-days), and 73 patients (4.6%) developed transaminase elevation with AST .10N. The variables independently associated with major transaminase elevation were hyponatremia, low platelets, dehydration, hematocrit increase, food intolerance, positive nonstructural protein 1 (NS1), age over 15 years and the notion of paracetamol intake. Conclusions: Although very frequent, the incidence of major transaminase elevation was lower than reported elsewhere perhaps because of good access to care, or of the particular serotype causing this epidemic. The patients with transaminase elevation tended to be older, more severe and taking paracetamol.
ISSN: 0035-9203

inserm-01475594
http://www.hal.inserm.fr/inserm-01475594
http://www.hal.inserm.fr/inserm-01475594/document
http://www.hal.inserm.fr/inserm-01475594/file/2016%2C%20Djossou%20-%20Incidence%20and%20predictive%20factors%20of%20transaminase.pdf
DOI : 10.1093/trstmh/trv117

Éditeur(s) : HAL CCSD BioMed Central
Résumé : International audience
Background: Despite intensive research over several decades, the etiology of multiple sclerosis (MS) remains poorly understood, although environmental factors are supposedly implicated. Our goal was to identify spatial clusters of MS incident cases at the small-area level to provide clues to local environmental risk factors that might cause or trigger the disease. Methods: A population-based and multi-stage study was performed in the French Brittany region to accurately ascertain the clinical onset of disease during the 2000-2004 period. The municipality of residence at the time of clinical onset was geocoded. To test for the presence of MS incidence clusters and to identify their approximate locations, we used a spatial scan statistic. We adjusted for socioeconomic deprivation, known to be strongly associated with increased MS incident rates, and scanned simultaneously for areas with either high or low rates. Sensitivity analyses (focusing on relapsing-remitting forms and/or places of residence available within the year following clinical onset) were performed. Results: A total of 848 incident cases of MS were registered in Brittany, corresponding to a crude annual incidence rate of 5.8 per 100,000 inhabitants. The spatial scan statistic did not find a significant cluster of MS incidence in either the primary analysis (p value >= 0.56) or in the sensitivity analyses (p value >= 0.16). Conclusion: The findings of this study indicate that MS incidence is not markedly affected across space, suggesting that in the years preceding the first clinical expression of the disease, no environmental trigger is operative at the small-area population level in the French Brittany region.
ISSN: 1476-072X

hal-01616063
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01616063
DOI : 10.1186/s12942-017-0108-6
PUBMED : 28934989

Éditeur(s) : Springer
Résumé : The Golo Margin in eastern Corsica is dissected by four canyons and two gullies which fed turbidite systems. Study of the dispersal of surficial sediments and flow dynamic in the Golo system is based on Kullenberg and interface cores interpreted in relation to a previously published seismic dataset. Cores were described in detail and interpreted within a sedimentary and stratigraphic framework. During the last 42,000 years, gravity processes which occurred in the large systems with a canyon source were mainly slide-induced, differentiated turbulent surges and hyperpycnal flows. Processes occurring in the small system with a gully source are mainly hyperconcentrated and concentrated flows. Deposits from the Corsican Margin can intercalate with products of processes triggered on the Pianosa Ridge located in the eastern part of the basin. During relative sea-level lowstands or during periods of rapid or high-amplitude sea-level fall, only large canyons (South and North Golo) are supplied by carbonate-rich hyperconcentrated and concentrated flows which are channelled in incised valleys on the shelf. During periods of slow or low-amplitude sea-level fall and during sea-level rise, sediments are trapped on a shelf delta and intensely winnowed by shelf hydrodynamic processes. Sand-rich hyperconcentrated and concentrated flows occur. All the systems fed by a canyon are active simultaneously. Gullies form and are active only during periods of sea-level rise. During relative highstands of sea level (Holocene), all the system is draped by hemipelagic sediments. Relative sea-level changes and canyon location relative to river mouths have a strong influence on the nature of sediment input, and the initiation and type of gravity flows which, in turn, control morphology and geometry.
Geo-Marine Letters (0276-0460) (Springer), 2006-12 , Vol. 26 , N. 6 , P. 373-395

Droits : 2006 Springer
http://archimer.ifremer.fr/doc/2006/publication-3594.pdf
DOI:10.1007/s00367-006-0045-z
http://archimer.ifremer.fr/doc/00000/3594/

Éditeur(s) : HAL CCSD MDPI
Résumé : International audience
Malaria remains one of the most common vector-borne diseases in the world and the definition of novel control strategies can benefit from the modeling of transmission processes. However, data-driven models are often difficult to build, as data are very often incomplete, heterogeneous in nature and in quality, and/or biased. In this context, a knowledge-based approach is proposed to build a robust and general landscape-based hazard index for malaria transmission that is tailored to the Amazonian region. A partial knowledge-based model of the risk of malaria transmission in the Amazonian region, based on landscape features and extracted from a systematic literature review, was used. Spatialization of the model was obtained by generating land use and land cover maps of the cross-border area between French Guiana and Brazil, followed by computing and combining landscape metrics to build a set of normalized landscape-based hazard indices. An empirical selection of the best index was performed by comparing the indices in terms of adequacy with the knowledge-based model, intelligibility and correlation with P. falciparum incidence rates. The selected index is easy to interpret and successfully represents the current knowledge about the role played by landscape patterns in malaria transmission within the study area. It was significantly associated with P. falciparum incidence rates, using the Pearson and Spearman correlation coefficients (up to 0.79 and 0.75, respectively; p-value < 0.001), and the linear regression coefficient of determination (reaching 0.63; p-values < 0.001). This study establishes a spatial knowledge-driven, landscape-based hazard malaria index using remote sensing that can be easily produced on a regular basis and might be useful for malaria prediction, surveillance, and control. Keywords: remote sensing; land use and land cover; landscape metric; knowledge-based hazard modeling; malaria; cross-border area between French Guiana and Brazil
ISSN: 2072-4292

hal-01355255
https://hal.archives-ouvertes.fr/hal-01355255
https://hal.archives-ouvertes.fr/hal-01355255/document
https://hal.archives-ouvertes.fr/hal-01355255/file/010066865.pdf
IRD : fdi:010066865

Éditeur(s) : Université de Guyane
Extrait de : "Bals masqués de Guyane et d'ailleurs. Identités et imaginaires carnavalesques en question" : colloque international, les 26 et 27 janvier 2017. Université de Guyane
Description : Mouvement de la créolité dans l'oeuvre de Patrick Chamoiseau. Le masque Marianne Lapofig, figure dans le carnaval martiniquais : son costume est fait, d'un amas de peau de bananes séchées, surmonté d'un masque qui cherche à reproduire la tête d'un ours. Le masque a été créé, suite à un incident qui a mis à la fin du 19è siècle au début du 20è siècle, la ville de Saint-Pierre en émoi. Un ours qui se serait échappé d'un cirque, qui se produisant dans la cité, emmenant la troupe à lui substituer une dénommée Marianne, qui fut affublée de feuilles de bananes séchées, en lieu et place de l'animal qui n'était plus là. Cette mésaventure, a inspiré à certains carnavaliers, la confection d'un costume de feuilles, ainsi que l'invention de son exhibition, durant le carnaval, cet ours végétal est accompagné de deux comparses, l'un, représentant le dompteur qui le tien en laisse, tandis que l'autre, le fait danser au rythme de ses musiques. Dans l'oeuvre de Chamoiseau, la danse de Marianne était classique, familière dans le carnaval jusque dans les années 50. Son masque s'est imposé dans son imaginaire, on voit apparaitre la silhouette de Marianne de façon discrète mais avec insistance dans ses ?uvres. Le masque Marianne est souvent associé à un autre masque rouge dit "maque du diable" et les deux constitue une sorte de binôme métonymique du carnaval. Chamoiseau reprend la tradition du carnaval, sans y laisser contraindre acceptant de la transformer, de la recréer, de la faire évoluer, montrant une richesse à refaçonner.
Siècle(s) traité(s) : 20
Droits : CC-BY-NC-ND - Attribution - Pas d'utilisation commerciale - Pas de modification
Permalien : http://www.manioc.org/fichiers/V17168
V17168

Éditeur(s) : HAL CCSD Wiley
Résumé : SUBSURF
International audience
Similarity of form between subaerial and submarine landscapes affected by erosion could suggest similarities in the process of erosion, such as by runoff and sedimentary flows, respectively. On the other hand, if aspects of form vary, its characteristics may be used to identify the environmental origin of erosion. Towards these goals, this contribution addresses the morphology of submarine volcanoes (seamounts) with widely differing histories of erosion. One set from the Pacific Ocean never exposed above sea level includes Cretaceous-age seamounts near Hawai'i (including Apu'upu'u Seamount), two seamounts of < 3 Ma in age near a mid-ocean ridge and the 11-4 Ma Jasper Seamount. These seamounts are all isolated from continents and hence from any erosion associated with mass wasting of unstable terrigenous deposits. In such isolated submarine environments, surfaces erode slowly from in situ weathering, mass wasting and scouring by sedimentary flows initiated by slope failure in pelagic or bedrock materials. The Pacific seamounts are compared with Valencia Seamount in the western Mediterranean, exposed subaerially for 100-400 k.y. during the Messinian Salinity Crisis before 5 Ma. Multibeam and deeply towed sidescan sonar data of Valencia Seamount reveal features typical of subaerial erosion of volcanic islands, such as canyons and relatively uneroded sectors (planezes) between them. Using a simple topographical reconstruction, the apparent erosion depth typically reaches 100 m within canyons and up to 180 m in places. Whereas the younger Pacific seamounts do not show these erosional features, the much older Cretaceous seamounts do have channels, which in one example suggests up to 200 m of incision. Both Valencia and Apu'upu'u seamounts have channel longitudinal profiles that are steep and typically linear to concave upwards. The erosion depth of Apu'upu'u Seamount is significant, despite the seamount's persistent submarine environment, because of its greater age, steeper flanks and greater contributing areas to channels compared with Valencia Seamount. These results illustrate that the channel morphology resulting from submarine erosion can become similar to that produced by subaerial erosion given sufficient time.
ISSN: 0950-091X

hal-00411425
https://hal.archives-ouvertes.fr/hal-00411425
DOI : 10.1111/j.1365-2117.2008.00355.x

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Evaluer les retombées économiques de manifestations sportives sur les territoires d’accueil est l’une des conditions permettant de décider de la pérennisation ou non de ces évènements. Cette évaluation revêt une grande importance pour les prestataires de services, les institutionnels et les diverses entreprises qui y sont engagés, car elle leur permet d’avoir une vision plus claire du marché, et le cas échéant d’ajuster et d’affiner leur politique évènementielle pour l’avenir. Aujourd’hui, apparaît de plus en plus un besoin croissant d’évaluation de la part de praticiens et d’acteurs publics impliqués dans les activités sportives. Ces derniers comme le grand public s’interrogent quelquefois sur l’utilité ou la pertinence économique et sociale de tels évènements.Aussi, l’objectif prioritaire de cette étude est de proposer dans le cas de la Guadeloupe, à partir d’un cadre conceptuel précis et d’une méthodologie partagée et éprouvée, une évaluation territoriale de l’impact économique et social de la Route du rhum, en retenant deux approches: l’une en niveau, déterminant successivement les valeurs du multiplicateur input-output à l’aide d’un tableau entrées-sorties (TES) de l’économie guadeloupéenne, et du multiplicateur de la base qui s’appuie sur les résultats d’une méta-analyse; l’autre , dynamique, spécifie par un modèle économétrique l’influence de la Route du rhum et d’autres variables sur la croissance économique de la Guadeloupe. L’enjeu consiste à se doter collectivement de points de repère afin que les différents acteurs de ce sport puissent situer les effets de leurs actions par rapport à d’autres pratiques, d’autres territoires, et à clarifier le niveau de contribution économique de cette activité sportive sur le territoire de Guadeloupe. Les résultats obtenus convergent et montrent qu’en dépit d’un succès indéniable au plan sportif et médiatique, la Route du rhum, évènement sportif de voile de haut niveau reliant tous les quatre ans St Malo à Pointe-a-Pitre, enregistre au plan économique des résultats modestes si l’on en juge à la fois par les médiocres retombées induites en matière de fréquentation touristique, par les faibles coefficients multiplicateurs de revenu affichés, par un ratio coût-bénéfice défavorable et par les incidences mineures que provoque cet évènement sur la croissance économique régionale.
Evaluation of economic effects from sport events is necessary to pursue or not these events. This evaluation is important for enterprises that provide goods and services also for the government, because it allows them to obtain an accurate vision of the future.Today, we have a growing need of evaluation from the people involved in sport activities. Sometimes, these people ask themselves on economic and social advantages of these events.The objective of this paper is to propose for Guadeloupe a rigourous methodology that assesses the economic and social impact of Route du rhum which is a transatlantic competition between St-Malo and Pointe-a-Pitre. We use two approaches: the first of which is level-based and determines the values of both economic base multipliers and input-output multipliers by composing an input-output table of the Guadeloupe economy. The second, dynamic approach specifies from an econometric model the impact of several variables, especially those of la Route du rhum. The goal is to provide findings to stakeholders of this sport for comparison. The results of the investigation merge and show globally weak economic performance of Route du rhum, particularly a poor cost-benefit ratio, weak economic multipliers and inter-industry linkages.
Guadeloupe

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.5296
http://journals.openedition.org/etudescaribeennes/5296

Éditeur(s) : Pêche thonière et dispositifs de concentration de poissons, Caribbean-Martinique, 15-19 Oct 1999
Résumé : French Polynesia started it's Fish Aggregating Device programme in June 1981 with the positioning of the first buoy offshore of the main island of Tahiti. Since then, 251 structures have been installed throughout the 5 archipelagoes of this French overseas territory. The shape and size of the devices have evolved 8 times over this period, however, a single model has not yet been adopted. Trials are currently underway using lighter structures similar to those found in the Indian Ocean. The anchoring lines have progressively been modified through better knowledge of material and product availability, as well as better understanding of environmental constraints. The programme is entirely financed by the territorial government and managed by the public sector. This ongoing technical assistance, aimed towards the local small-scale coastal fishery, is considered an important factor to maintaining this activity alive. Up until 1997, this economical support policy of outer island populations far from the metropolis central town, along with incidental fishing methods around FADs, have given mitigated results without nevertheless putting into cause this programme. The use of 'drifting handlines' retained at the surface by small indicator floats are one of the contributing factors to the degradation of the anchor lines. It is now commonly accepted that a new fishing strategy must be adopted so that professional coastal fishermen become more aware with regards to an expensive work tool due to local bathymetric conditions, so that fishing effort is increased through the development of better adapted fishing techniques, and finally so that community spirit rules over individualism.Original Abstract: Le programme d'ancrage de DCP en Polynesie francaise a vu le jour en juin 1981 avec l'implantation d'un premier dispositif au large des cotes de Tahiti. Depuis cette date, ce sont 251 structures qui ont ete installees dans les cinq archipels de ce pays d'outre-mer. La forme et la taille des bouees ont evolue huit fois sans etre definitivement arretees a un seul modele et des essais sur des structures legeres de type " Ocean Indien " sont en cours. Les lignes d'ancrage ont fait l'objet de modifications progressives en raison de meilleures connaissances des produits ainsi que des contraintes du milieu environnant. Ce programme est finance en totalite par le territoire de la Polynesie francaise et gere par le secteur public. Il s'adresse a la pecherie artisanale et cotiere qui considere depuis de nombreuses annees cette assistance technique comme un atout indispensable au maintien de son activite. La politique d'engagement de ce soutien economique jusqu'en 1997 aupres des populations d'iles et atolls tres eloignes de la capitale ainsi que l'incidence de la technique de peche la plus repandue autour des DCP ont abouti a des resultats mitiges sans pour autant remettre en cause ce programme. En effet, les lignes a main derivantes et retenues en surface par une petite bouee temoin sont un des principaux facteurs de degradation des lignes d'ancrage. Il est desormais reconnu par tous les intervenants qu'une nouvelle strategie doit etre deployee afin que les pecheurs cotiers professionnels soient mieux responsabilises face a un outil de travail onereux en raison de la bathymetrie environnante, pour que l'effort de peche soit accru par l'utilisation de techniques de peche mieux adaptees, et enfin que l'esprit communautaire prime sur l'individualisme.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00042/15292/12649.pdf
http://archimer.ifremer.fr/doc/00042/15292/

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Introduction Bien que les îles de la Caraïbe présentent des caractéristiques historiques, culturelles et économiques similaires, leur urbanisation et leur évolution démographique révèlent des discontinuités majeures. De façon générale, l’urbanisation est contrastée, ce qui conforte l’idée selon laquelle ces espaces insulaires sont des objets hétérogènes, en dépit de leurs critères historiques et culturels homogènes (Note de l’auteur). Les mutations socioéconomiques observées ont des incidence...
Caraïbes

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.342
http://journals.openedition.org/etudescaribeennes/342