La nouvelle donne politique de l'île de la Réunion (2010-2014/2015) Auteur(s) : Combeau, Yvan Année de publication : Loading the player... Éditeur(s) : CRPLC : Centre de Recherche sur les Pouvoirs Locaux dans la Caraïbe Extrait de : "Etat et sociétés en Outre-mer" : colloque, les 27 et 28 novembre 2014. Université des Antilles et de la Guyane Description : Yvan Combeau, Professeur en Histoire à l'Université de la Réunion, propose une analyse sur l'histoire politique immédiate de La Réunion permettant de mettre en perspective l'évolution des positions de la société et du personnel politique. Le propos a pour objet de caractériser les actuels positionnements de La Réunion sur les projets de décentralisation, la définition d'une région-stratège, les dimensions politiques de l'Indianocéanie, etc. Dans un premier temps, la communication s'attache à caractériser le présent d'une société politique réunionnaise, avec les nouveaux rapports de forces politiques (évolutions électorales depuis quatre années, stratégies de coalitions...) et une présentation d'un paysage politique atomisé. Elle souligne la reconstruction et la fragmentation du tableau politique. Sur ce nouvel échiquier en mouvement, le second temps porte sur les oscillations et recompositions des discours politiques quand ils abordent les enjeux institutionnels et sociaux qui traversent la société réunionnaise. A un an des élections régionales de 2015, La Réunion politique s'observe encore comme une "instable photographie". Droits : CC-BY-NC-ND - Attribution - Pas d'utilisation commerciale - Pas de modification Permalien : http://www.manioc.org/fichiers/V16010 V16010 | Partager |
L'insertion régionale des RUP de la Caraïbe dans leur environnement : de la coopération régionale à la diplomatie territoriale Auteur(s) : Galy, Karine Année de publication : Loading the player... Éditeur(s) : LC2S : Laboratoire Caribéen de Sciences Sociales Extrait de : "The European unions outermost regions and their sovereign neighbours economic development, integration and migration" : conférence, le 16 mars 2017. Description : Karin Galy présente une réflexion sur l'insertion régionale des territoires ultramarins ou RUP « Région Ultra Périphérique ». Elle explique que cela fait partie des enjeux fondamentaux de leur développement durable. Elle observe l'enjeu de leur insertion dans leur environnement Amérique-Caraïbe qui est associé à un développement économique, social, culturel, environnemental mutuellement profitable en relation avec le plan de l'Union européenne qui a pour objectif de renforcer l'intégration des RUP au sein de leur zone respective. Droits : CC-BY-NC-ND - Attribution - Pas d'utilisation commerciale - Pas de modification Permalien : http://www.manioc.org/fichiers/V17032 V17032 | Partager |
A relic of the old city wall ; The Bryant Slides Collection ; The Bryant Slides Collection, Cuba Auteur(s) : Unknown ( Photographer ) Résumé : The slides were taken on collecting trips sponsored by the William L. Bryant Foundation, where books, music and art indigenous to the regions were gathered. The are organized by geographical location. Located on Havana's Port Avenue is the ruin if the old city wall and the Fort of Havana. Cuba -- Caribbean region -- Havana Droits : All rights to images are held by the respective holding institution. This image is posted publicly for non-profit educational uses, excluding printed publication. For permission to reproduce images and/or for copyright information contact Special Collections & University Archives, University of Central Florida Libraries, Orlando, FL 32816 phone (407) 823-2576, email: speccoll@mail.ucf.edu CFM1972_01a Sheet 26: 15 http://ufdc.ufl.edu/CA01200414/00001 | Partager |
Cuban soldiers in Havana ; The Bryant Slides Collection ; The Bryant Slides Collection, Cuba Auteur(s) : Unknown ( Photographer ) Résumé : The slides were taken on collecting trips sponsored by the William L. Bryant Foundation, where books, music and art indigenous to the regions were gathered. The are organized by geographical location. A photograph of a group of Cuban soldier standing in formation in Havana's Port Avenue. Pictured on the left, there are several old American cars, and on the right is a relic of the old city wall. The are several people looking on from the sidewalk as well as from the balconies of the surrounding buildings. Cuba -- Caribbean region -- Havana Droits : All rights to images are held by the respective holding institution. This image is posted publicly for non-profit educational uses, excluding printed publication. For permission to reproduce images and/or for copyright information contact Special Collections & University Archives, University of Central Florida Libraries, Orlando, FL 32816 phone (407) 823-2576, email: speccoll@mail.ucf.edu CFM1972_01a Sheet 84: 14 http://ufdc.ufl.edu/CA01200460/00001 | Partager |
"Ougan", voodoo priest and his wife ; Bryant Slides Collection ; Bryant Slides Collection, Haiti Auteur(s) : Unknown ( Photographer ) Résumé : The slides were taken on collecting trips sponsored by the William L. Bryant Foundation, where books, music and art indigenous to the regions were gathered. They are organized by geographical location. Holding a bottle and a machete, Voodoo priest praying with his wife on her knees while other servants observe Haiti -- Caribbean region Haiti Haiti Haiti Droits : All rights to images are held by the respective holding institution. This image is posted publicly for non-profit educational uses, excluding printed publication. For permission to reproduce images and/or for copyright information contact Special Collections & University Archives, University of Central Florida Libraries, Orlando, FL 32816 phone (407) 823-2576, email: speccoll@mail.ucf.edu CFM1972_01a Sheet 49: 15 http://ufdc.ufl.edu/CA01200309/00001 | Partager |
Photograph taken on a road to Trinidad ; The Bryant Slides Collection ; The Bryant Slides Collection, Cuba Auteur(s) : Unknown Iznaga, Pedro, 1817-1879 ( Builder ) Iznaga, Alejo, 1792-1845 ( Builder ) Résumé : The slides were taken on collecting trips sponsored by the William L. Bryant Foundation, where books, music and art indigenous to the regions were gathered. The are organized by geographical location. The house pictured is a Cuban thatched huts know as a Bohio. Visible in the background is the Manacas Iznaga Tower. The tower was built by sugar baron family between 1835-1845 Cuba -- Caribbean region -- Trinidad Droits : All rights to images are held by the respective holding institution. This image is posted publicly for non-profit educational uses, excluding printed publication. For permission to reproduce images and/or for copyright information contact Special Collections & University Archives, University of Central Florida Libraries, Orlando, FL 32816 phone (407) 823-2576, email: speccoll@mail.ucf.edu CFM1972_01a Sheet 24: 20 http://ufdc.ufl.edu/CA01200379/00001 | Partager |
Manacas Iznaga Tower ; The Bryant Slides Collection ; The Bryant Slides Collection, Cuba Auteur(s) : Unknown Iznaga, Pedro, 1817-1879 ( Builder ) Iznaga, Alejo, 1792-1845 ( Builder ) Résumé : The slides were taken on collecting trips sponsored by the William L. Bryant Foundation, where books, music and art indigenous to the regions were gathered. The are organized by geographical location. The Manacas Iznaga Tower is located in Valle de los Ingenios in Trinidad, Cuba, which was a major center for sugar mills. The tower stands approximately 45 feet tall and was used by the sugarcane plantation owner in order to keep watch over his slaves in the fields. It was built in 1816 and stands seven stories high. The ringing of the bell signified various messages, but mostly the beginning and end of the work day for the slaves in the sugar fields. A local legend states that the tower was built by Pedro and Alejo Iznaga to house Alejo's wife, who had been unfaithful to him. The photograph also shows the remains of the Iznaga plantation, as well as several Royal Palm trees and a Poinciana tree in the background. Cuba -- Caribbean region -- Mantanzas Droits : All rights to images are held by the respective holding institution. This image is posted publicly for non-profit educational uses, excluding printed publication. For permission to reproduce images and/or for copyright information contact Special Collections & University Archives, University of Central Florida Libraries, Orlando, FL 32816 phone (407) 823-2576, email: speccoll@mail.ucf.edu CFM1972_01a Sheet 85: 17 http://ufdc.ufl.edu/CA01200483/00001 | Partager |
The Castillo de San Pedro del Morro in Santiago ; The Bryant Slides Collection ; The Bryant Slides Collection, Cuba Auteur(s) : Unknown ( Photographer ) Antonelli, Giovanni Battista, 16th/17th cent. ( Architect ) Résumé : The slides were taken on collecting trips sponsored by the William L. Bryant Foundation, where books, music and art indigenous to the regions were gathered. The are organized by geographical location. A view of river from the upper level of the castle. Castillo de San Pedro del Morro was designed in 1637 by Giovanni Battista Antonelli (also known as Juan Battista Antonelli), a member of a Milanese family of military engineers, on behalf of the governor of the city, Pedro de la Roca de Borja, as a defense against raiding pirates. Cuba -- Caribbean region -- Santiago de Cub Droits : All rights to images are held by the respective holding institution. This image is posted publicly for non-profit educational uses, excluding printed publication. For permission to reproduce images and/or for copyright information contact Special Collections & University Archives, University of Central Florida Libraries, Orlando, FL 32816 phone (407) 823-2576, email: speccoll@mail.ucf.edu CFM1972_01a Sheet 26: 8 http://ufdc.ufl.edu/CA01200407/00001 | Partager Voir aussi Castillo de San Pedro del Morro (Santiago, Cuba) Forts & fortifications Cuba -- Description and travel Castles -- Cuba -- Santiago de Cuba Harbors -- Cuba -- Santiago de Cuba Observation towers -- Cuba Watchtowers -- Cuba Staircases -- Cuba -- Santiago Historic sites -- Cuba -- Santiago de Cuba |
Voodooists on their knees ; Bryant Slides Collection ; Bryant Slides Collection, Haiti Auteur(s) : Unknown ( Photographer ) Résumé : The slides were taken on collecting trips sponsored by the William L. Bryant Foundation, where books, music and art indigenous to the regions were gathered. They are organized by geographical location. Voodoo priestesses on their knees, holding a big stick. Other attendees of the ceremony sitting and observing. Haiti -- Caribbean region Haiti Haiti Haiti Droits : All rights to images are held by the respective holding institution. This image is posted publicly for non-profit educational uses, excluding printed publication. For permission to reproduce images and/or for copyright information contact Special Collections & University Archives, University of Central Florida Libraries, Orlando, FL 32816 phone (407) 823-2576, email: speccoll@mail.ucf.edu CFM1972_01a Sheet 51: 1 http://ufdc.ufl.edu/CA01200319/00001 | Partager |
Cross-shelf structure of coastal upwelling : a two - dimensional extension of Ekman's theory and a mechanism for inner shelf upwelling shut down Auteur(s) : Estrade, Philippe Marchesiello, P Colin De Verdiere, A Roy, C Éditeur(s) : Yale University Résumé : Sea-surface temperature images of the coastal upwelling regions off Northwest Africa show that the core of upwelling is sometimes located far from the coast. This has been documented in three regions that share a common feature, namely a wide and shallow continental shelf. This upwelling feature plays a key role in the ecology of the Canary Current System. It creates an innerfront which provides retention for biological material, e.g. fish eggs and larvae, in the highly productive nearshore environment. An analytical model has been developed based on a two dimensional extension of Ekman's solution. The linear and steady response of a homogeneous ocean forced by an upwelling-favorable wind provides a mechanism for the upwelling separation from the coast. The merging of the surface and bottom Ekman layers induces a very weak cross-shore circulation and a "kinematic barrier" for the Ekman transport divergence. In the case of an alongshore wind, the barrier is located near the isobath h ≈ 0.4D, where D is the thickness of Ekman layers. This yields an upwelling cell which is essentially concentrated in the region 0.5D < h < 1.25D, with upwelling occurring preferentially near the isobath h ≈ 0.6D. It turns out that the cross-shore width of upwelling scales with D/S, the ratio of Ekman depth to bottom topographic slope. The application of this solution to real bathymetric profiles rationalizes, not only the offshore upwelling observations in Northwest Africa, but also the influence of topography on the cross-shelf structure of a wind-driven coastal upwelling. The model also quantifies the effect of the cross-shore wind component showing how it drives the nearshore pressure gradient adjustment and how it affects the upwelling. A linear numerical experiment reproduces the theoretical steady solution, thereby allowing investigation of the transient regime. Relaxation of the hypothesis in the numerical model validates the linear assumption of the theory and then allows investigation of the sensitivity to friction parameterizations and the influence of stratification. The latter leads to an "oscillation" of the upwelling cell with seaward migration driven by outcropping and homogeneization of the water column, and, coastal incursion driven by a "boundary layers splitting" process caused by shoreward advection of the isopycnal dome and stratification of the inner shelf. Journal of Marine Research (Yale University), 2008-09 , Vol. 66 , N. 5 , P. 589-616 Droits : 2008 Yale University http://archimer.ifremer.fr/doc/2008/publication-6334.pdf DOI:10.1357/002224008787536790 http://archimer.ifremer.fr/doc/00000/6334/ | Partager |
Conditions et contraintes de l'usage de jeux sérieux en classe. Enquête sur le déploiement d'une plateforme dans 30 collèges français Auteur(s) : Ladage, Caroline Ravestein, Jean Auteurs secondaires : Roux, Christian Année de publication : Loading the player... Éditeur(s) : EUTIC : le réseau international et interdisciplinaire pour les Enjeux et Usages des Technologies de l'Information et de la Communication Extrait de : "Les écosystèmes numériques et la démocratisation informationnelle" : colloque, les 3 et 4 novembre 2015. Université des Antilles Description : A travers l'analyse de données issus de questionnaires renseignés par les enseignants et élèves usagers, par des observations dans les classes et l'analyse de forums dédiés, cette communication, contribuée par Caroline Ladage, Jean Ravestein et Christian Roux de l'Université Aix-Marseille, tente de cerner les conditions et contraintes, en particulier didactiques, de l'usage d'une plateforme de jeux sérieux déployée dans la région française PACA1 dans une trentaine de collèges : le projet SCOLA2, piloté par un consortium d'universités et d'entreprises de l'industrie du design numérique. Le « démonstrateur » de la plateforme propose (outre des fonctionnalités en termes de classe virtuelle, forums et centre de documentation) des jeux sérieux en mathématiques pour les classes de collège. L'enquête, menée par une équipe de cinq personnes a débuté dès la conception du projet et accompagne la mise en place de l'artefact sous forme de régulations auprès des différents acteurs depuis 2012. Siècle(s) traité(s) : 21 Droits : CC-BY-NC-ND - Attribution - Pas d'utilisation commerciale - Pas de modification Permalien : http://www.manioc.org/fichiers/V15385 V15385 | Partager |
An eddy-permitting model of the Atlantic circulation: Evaluating open boundary conditions Auteur(s) : Treguier, Anne-marie Barnier, B De Miranda, A Molines, J Grima, N Imbard, M Madec, G Messager, Christophe Éditeur(s) : American Geophysical Union Résumé : As part of the French CLIPPER project, an eddy permitting model of the Atlantic circulation has been run for 22 years. The domain has open boundaries at Drake passage and at 30 degreesE, from Africa to Antarctica. The simulated mean circulation, as well as the eddy activity, is satisfactory for a 1/3 degrees model resolution, and the meridional heat transport at 30 degreesS is within the range estimated from observations. We use the "mixed" open boundary algorithm of Barnier et al. [1998], which has both a radiation condition and a relaxation to climatology. The climatological boundary forcing strongly constrains the solution in the whole domain. The model heat balance adjusts through the surface (heat flux retroaction term) more than the open boundaries. The radiation phase velocities calculated within the algorithm are analyzed. This shows, quite surprisingly, that both the eastern and western boundaries have a similar behavior, regardless of the preferred directions for advection (mainly eastward) and wave propagation (mainly westward). Our results confirm that open boundary algorithms behave differently according to the dynamics of the region considered. The passive boundary condition that Penduff et al. [2000] applied successfully in the north eastern Atlantic does not work in the present South Atlantic model. We emphasize the need for a careful prescription of the climatology at the open boundary, for which a new approach based on synoptic sections is implemented. Journal of Geophysical Union - Research C - Oceans (0148-0227) (American Geophysical Union), 2001-10 , Vol. 106 , N. C10 , P. 22115-22129 Droits : 2001 American Geophysical Union http://archimer.ifremer.fr/doc/2001/publication-454.pdf DOI:10.1029/2000JC000376 http://archimer.ifremer.fr/doc/00000/454/ | Partager |
Geographic distance, water circulation and environmental conditions shape the biodiversity of Mediterranean rocky coasts Auteur(s) : Rattray, Alex Andrello, Marco Asnaghi, Valentina Bevilacqua, Stanislao Bulleri, Fabio Cebrian, Emma Chiantore, Mariachiara Claudet, Joachim Auteurs secondaires : Centre for Integrative Ecology, School of LES Department of Biology [Pisa] ; University of Pisa [Pisa] Centre d’Ecologie Fonctionnelle et Evolutive (CEFE) ; Institut de Recherche pour le Développement (IRD [France-Sud]) - Centre National de la Recherche Scientifique (CNRS) - Université de Montpellier (UM) - Institut national de la recherche agronomique [Montpellier] (INRA Montpellier) - École pratique des hautes études (EPHE) - Centre international d'études supérieures en sciences agronomiques (Montpellier SupAgro) - Université Paul-Valéry - Montpellier 3 (UM3) - Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro) Ecole Pratique des Hautes Etudes, Laboratoire de Biologie, Biogéographie et Ecologie des Vertébrés ; Université des Sciences Department of Earth, Environmental and Life Sciences (DISTAV) ; Universita degli studi di Genova Department of Biological Environmental Science and Technology Centre d'Estudis Avançats de Blanes (CEAB) ; Consejo Superior de Investigaciones Científicas [Spain] (CSIC) Centre de recherches insulaires et observatoire de l'environnement (CRIOBE) ; Université de Perpignan Via Domitia (UPVD) - École pratique des hautes études (EPHE) - Centre National de la Recherche Scientifique (CNRS) Éditeur(s) : HAL CCSD Inter-Research Résumé : International audience Ecological connectivity is important for effective marine planning and biodiversity conservation. Our aim was to identify factors important in influencing variation in benthic community structure on shallow rocky reefs in 2 regions of the Mediterranean Sea with contrasting oceanographic regimes. We assessed beta (β) diversity at 146 sites in the littoral and shallow sub-littoral from the Adriatic/Ionian Seas (eastern region) and Ligurian/Tyrrhenian Seas (western region) using a null modelling approach to account for variation in species richness. The distance decay relationship between species turnover within each region and geographic distance by sea was determined using generalised linear models. Mantel tests were used to examine correlations between β diversity and connectivity by ocean currents, estimated from Lagrangian dispersal simulations. Variation in β diversity between sites was partitioned according to environmental and spatial components using a distance-based redundancy approach. Species turnover along a gradient of geographic distance was greater by a factor of 3 to 5 in the western region than the eastern region, suggesting lower con-nectivity between sites. β diversity was correlated with connectivity by ocean currents at both depths in the eastern region but not in the western region. The influence of spatial and environmental predictors of β diversity varied considerably between regions, but was similar between depths. Our results highlight the interaction of oceanographic, spatial and environmental processes influencing benthic marine β diversity. Persistent currents in the eastern region may be responsible for lower observed β diversity compared to the western region, where patterns of water circulation are more variable. Marine Ecology Progress Series Droits : http://creativecommons.org/licenses/by/ hal-01357935 https://hal-univ-perp.archives-ouvertes.fr/hal-01357935 https://hal-univ-perp.archives-ouvertes.fr/hal-01357935/document https://hal-univ-perp.archives-ouvertes.fr/hal-01357935/file/m553p001.pdf DOI : 10.3354/meps11783 | Partager |
Mulching effects of fresh Sargassum Seaweed on soil properties and plant growth ; Effets des Sargasses Seaweed sur les propriétés du sol et la croissance des plantes. Auteur(s) : Lopez, Francis Année de publication : Loading the player... Éditeur(s) : Université des Antilles. Service commun de la documentation University of West Indies, Barbados Extrait de : 52e congrès annuel de la Société caribéenne des plantes alimentaires / 52nd annual meeting of the Caribbean food crops society (CFCS), du 10 au 16 juillet 2016. INRA, CFCS Description : Mulch application of Sargassum seaweed (Sargassum spp.) to soil can help to reduce beach contamination in the Caribbean Region while providing beneficial horticultural effects. This study investigated the effects of fresh Sargassum mulch on soil properties and plant growth in a test crop of tomato (Solanum lycopersicum L. â? ? HA 3019â? TM). Fresh Sargassum material (washed and unwashed) was applied as mulches (0, 5 and 8cm thick) to small field plots one week after transplanting of 3-week-old seedlings. The mulch material was raked away from the plots after three weeks exposure. Observations on soil moisture, electrical conductivity, pH and biological activity, and plant growth were made at 1 to 2-week intervals over a 6-week period with additional soil measurements after 10 weeks. Soil biological activity (respiration) was increased by the Sargassum mulch with values being similar for the 5cm and 8cm mulch layers. Soil moisture content, pH and electrical conductivity (EC) were increased as the mulch layer increased and EC values were only marginally reduced by Sargassum washing. An increase in plant growth compared to the control treatment was noted only in the washed Sargassum treatments. Potential benefits of Sargassum seaweed mulches on soil properties and plant growth can be nullified due to soil salinization effects. Siècle(s) traité(s) : 21 Droits : CC-BY-NC-ND - Attribution - Pas d'utilisation commerciale - Pas de modification Permalien : http://www.manioc.org/fichiers/V16269 V16269 | Partager |
Evaluation of apoptotic- and autophagic-related protein expressions before and after IVM of fresh, slow-frozen and vitrified pre-pubertal mouse testicular tissue Auteur(s) : Dumont, L. Chalmel, F. Oblette, A. Berby, B. Rives, A. Duchesne, V. Rondanino, C. Rives, N. Auteurs secondaires : Gamétogenèse et Qualité des Gamètes (GQG) ; Université de Rouen Normandie (URN) ; Normandie Université (NU) - Normandie Université (NU) - Université Lille 2 - Faculté de Médecine Institute for Research and Innovation in Biomedicine (IRIB) ; Université de Rouen Normandie (URN) ; Normandie Université (NU) - Normandie Université (NU) - Institut National de la Santé et de la Recherche Médicale (INSERM) Institut de recherche, santé, environnement et travail [Rennes] (Irset) ; Université d'Angers (UA) - Université des Antilles et de la Guyane (UAG) - Université de Rennes 1 (UR1) - École des Hautes Études en Santé Publique [EHESP] (EHESP) - Institut National de la Santé et de la Recherche Médicale (INSERM) - Structure Fédérative de Recherche en Biologie et Santé de Rennes ( Biosit : Biologie - Santé - Innovation Technologique ) Éditeur(s) : HAL CCSD Résumé : International audience STUDY QUESTION: Do freezing and in vitro culture procedures enhance the expression of proteins involved in apoptotic or autophagic pathways in murine pre-pubertal testicular tissue? SUMMARY ANSWER: IVM strongly modified apoptosis- and autophagy-related relative protein levels in mice testicular tissue whereas the impact of cryopreservation procedures was minimal at the end of the culture. WHAT IS KNOWN ALREADY: In vitro spermatogenesis remains a challenging technical issue as it imposes to find a very close balance between survival and death of germ cell natural precursors (i.e. gonocytes and spermatogonia), which will eventually undergo a complete spermatogenesis close to in vivo conditions. The establishment of efficient culture conditions coupled with suitable cryopreservation procedures (e.g. controlled slow freezing [CSF] and solid surface vitrification [SSV]) of pre-pubertal testicular tissue is a crucial step in the fields of fertility preservation and restoration to improve the spermatic yield obtained in vitro. STUDY DESIGN, SIZE, DURATION: Here, we study cryopreservation procedures (i.e. CSF or SSV) and the impact of culture media compositions. A first set of 66 mouse pre-pubertal testes were directly cultured during 30, 36, 38 and 60 days (D) from 2.5 to 6.5-day-old CD-1 mice to evaluate the impact of time-aspect of culture and to endorse the reverse phase protein microarrays (RPPM) technique as an adapted experimental tool for the field of in vitro spermatogenesis. Ninety others fresh, slow-frozen and vitrified pre-pubertal testes were cultured during 30 days for the principal study to evaluate the impact of cryopreservation procedures before and after culture. Thirty-four testes dissected from 2.5, 6.5, 36.5, 40.5, 42.5 and 62.5 days postpartum (dpp) mice, corresponding to the time frames of spermatogenesis orchestrated in vitro, were used as in vivo controls. PARTICIPANTS/MATERIALS, SETTING, METHODS: After in vitro culture, testicular tissue samples originated from 2.5 or 6.5-day-old CD-1 male mice were analyzed using RPPM. This targeted proteomic technique allowed us to assess the expression level of 29 apoptosis- and autophagy-related factors by normalizing blank-corrected signal values. In addition, morphological analyses (e.g. HES, PAS, TRA98 and CREM) and DNA fragmentation in intra-tubular cells (i.e. terminal deoxynucleotidyl transferase dUTP nick end labeling; TUNEL) were assessed for the distinct experimental conditions tested as well as for in vivo control mouse testes. MAIN RESULTS AND THE ROLE OF CHANCE: A validation of the RPPM procedure in the field of in vitro spermatogenesis was completed with assay and array robustness before a principal study concerning the evaluation of the impact of in vitro culture and cryopreservation procedures. The proportion of elongated spermatids and the total cell number per seminiferous tubule tended to be very different between the in vivo and in vitro conditions (P < 0.05), suggesting the presence of a beneficial regulation on the first spermatogenesis wave by intrinsic apoptosis (Caspase₉) and autophagy (Atg5) factors (P < 0.0003 and r2 = 0.74). Concerning the impact of culture media compositions, a basic medium (BM) composed of αMEM plus 10% KnockOut™ serum replacement and gentamicin supplemented with retinol (Rol) and vitamin E (Vit. E) was selected as the best culture medium for fresh 6.5 dpp tissue cultured during 30D with 27.7 ± 8.10% of seminiferous tubules containing elongated spermatids. Concerning the impact of cryopreservation procedures, SSV did not have any impact on the morphological parameters evaluated after culture in comparison to fresh tissue (FT) controls. The proportion of tubules with elongated spermatids on testicular explants cultured with BMRol+Vit. E was not different between SSV (6.6 ± 1.6%) and CSF (5.3 ± 1.9%); however, round spermatids were observed more frequently for SSV (19 ± 6.2%) than CSF (3.3 ± 1.9%, P = 0.0317). Even if the proportion of TUNEL-positive cells for BMRol+Vit. E was higher at D30 after SSV (4.12 ± 0.26%) than CSF (1.86 ± 0.12%, P = 0.0022) and FT (2.69 ± 0.33%, P = 0.0108), the DNA damages observed at the end of the culture (i.e. D30) were similar to respective 6.5 dpp controls. In addition, the relative protein level expression ratio of an apoptotic factor, the phosphorylated FADD on Fas, was reduced by 64-fold in vitrified testes cultured with BMRol+Vit. E. Furthermore, we found in this study that the StemPro®-34 SFM culture medium supplemented with growth factors (e.g. EGF, bFGF, GDNF and LIF) prevented the differentiation of spermatogonial stem cells in favor of a significant proliferation with a better architectural pattern than in vivo 6.5 dpp controls with an increase of seminiferous tubules area for FT (P = 0.0357) and CSF (P = 0.0317). LIMITATIONS REASONS FOR CAUTION: Despite our promising results, the evaluation of apoptotic- and autophagic-related proteins was studied for a limited amount of proteins and on global testicular tissue. WIDER IMPLICATIONS OF THE FINDINGS: The data presented herein will help to improve apoptotic and autophagic understanding during the first spermatogenic wave. Moreover, our findings illustrate for the first time that, using finely-tuned experimental conditions, a testicular in vitro culture combined with proteomic technologies may significantly facilitate the study of cryopreservation procedures and in vitro culture evaluations. This study may also contribute to improve work on testicular tissues from pre-pubertal and adolescent cancer survivors. STUDY FUNDING/COMPETING INTEREST(S): This study was supported by a Ph.D. grant from the Rouen Normandie Université and a financial support from 'la Ligue nationale contre le cancer' (both awarded to L.D.), funding from Institute for Research and Innovation in Biomedicine (IRIB), Agence de la Biomédecine, and co-supported by European Union and Région Normandie. Europe gets involved in Normandie with European Regional Development Fund (ERDF). The authors declare that there is no conflict of interest. Molecular Human Reproduction hal-01647081 https://hal-univ-rennes1.archives-ouvertes.fr/hal-01647081 DOI : 10.1093/molehr/gax054 PUBMED : 29040674 | Partager |
Leg 209 summary : processes in a 20-km-thick conductiver boundary layer beneath the Mid-Atlantic Ridge, 14°-16°N Auteur(s) : Kelemen, Peter, Kikawa, Eiichi Miller, D. Jay Ildefonse, Benoit Godard, Marguerite Auteurs secondaires : Department of Earth and Environmental Sciences [Columbia] (EESC) ; Columbia University [New York] Lamont-Doherty Earth Observatory (LDEO) ; Columbia University [New York] Deep‐Sea Research Department ; Japan Agency for Marine-Earth Science and Technology (JAMSTEC) Integrated Ocean Drilling Program ; Texas A&M University [College Station] Géosciences Montpellier ; Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS) Éditeur(s) : HAL CCSD Ocean Drilling Programm Résumé : This paper provides a summary of postcruise scientific results from Ocean Drilling Program (ODP) Leg 209 available to date, building upon shipboard observations and syntheses summarized in the Leg 209 Initial Results volume. During Leg 209, 19 holes were drilled at 8 sites along the Mid-Atlantic Ridge from 14°43´ to 15°44´N, mainly in residual mantle peridotite intruded by gabbroic rocks, in order to understand the tectonic and structural processes responsible for formation of oceanic lithosphere with abundant residual peridotite exposed on the seafloor coupled with a relatively low proportion of volcanic rocks. Based on proportions of recovered lithologies, the entire area may be underlain by mantle peridotite with ~20%–40% gabbroic intrusions and impregnations. Impregnated peridotites with olivine + two pyroxenes + plagioclase + spinel that apparently formed in equilibrium probably record crystallization from primitive mid-ocean-ridge basalt at pressures of 0.5–0.6 GPa. Metamorphic equilibria record isobaric cooling to ~1100°C at this pressure. Thus, the conductively cooled thermal boundary layer beneath the Mid-Atlantic Ridge in this region is >15 km thick. Combined crystallization and reaction with residual peridotite formed a series of impregnated peridotites recording increasing Na content at nearly constant Mg#; this process could explain some of the variation in fractionation-corrected Na (e.g., Na = 8.0) observed in mid-ocean-ridge basalts. Clinopyroxene textures and compositions record such impregnation processes, and they are particularly well documented for Site 1274. Other Leg 209 gabbroic rocks formed from extensive crystallization of highly evolved melts, indicating that a substantial proportion of melt entering the thermal boundary layer crystallizes entirely beneath the seafloor, with no volcanic equivalent. Alteration of peridotites occurred over a range of temperatures and is the result of three distinct processes: rock-dominated serpentinization with formation of brucite in olivine-rich lithologies, fluid-dominated serpentinization with formation of magnetite and no brucite, and fluid-dominated talc alteration with addition of SiO2 as well as H2O and oxygen. The latter two processes also exhibit detectable trace element metasomatism that is distinct in its character from the igneous impregnation described in the previous paragraph. Microstructures show that most residual peridotites were not ductilely deformed at temperatures less than ~1200°C. Structural and paleomagnetic data require tectonic rotations of relatively undeformed blocks; some rotations probably exceeded 60° around nearly horizontal axes parallel to the rift axis. Rotations occurred along several generations of high-temperature mylonitic shear zones extending deeper than 15 km depth and numerous faults at lower temperature. Early formed shear zones and faults were passively rotated around later features; such a process could have produced low-angle fault surfaces without slip on low-angle faults. This region provides end-member examples of processes that are common at many or most slow-spreading ridges. Osmium isotope ratios indicate an ancient history of depletion for residual peridotites from the 14°–16°N region along the Mid-Atlantic Ridge. Though depleted Os isotope ratios in peridotite have been reported elsewhere along the global ridge system, the values from this region are among the most depleted. In general, Os isotope ratios from mid-ocean-ridge basalts are systematically more radiogenic than Os isotope ratios from ridge peridotite samples, suggesting a polygenetic heterogeneous source for mid-ocean-ridge basalts. Geochemical studies of zircons from Leg 209 gabbroic rocks and impregnated peridotites, together with other ridge and arc-related zircons, indicate that ridge zircons have systematically lower fractionation-corrected U and Th concentrations compared to arc zircons. This observation provides a tool for interpreting the tectonic provenance of ancient detrital zircons and indicates an arclike provenance for Hadean detrital zircons. Geobiological studies and aerobiological studies were also undertaken during Leg 209. The geobiological work found no measurable microbial enhancement of olivine dissolution rate, possibly because the samples from Leg 209 were sterile. The aerobiological study determined that dust from North Africa, collected from the derrick of the JOIDES Resolution during Leg 209, contains a variety of abundant microorganisms. Proceedings ODP, scientific results, 209 hal-00407966 https://hal.archives-ouvertes.fr/hal-00407966 DOI : 10.2973/odp.proc.sr.209.001.2007 | Partager |
La dynamique des pêches côtières du pays bigouden Auteur(s) : Charuau, Anatole Résumé : In the beginning, the coastal fleet of the Bigouden region fished by trawling and was completely focused on exploiting lobster and hake. It is a traditional business that expanded between the last war and the 70s, reaching its peak between 1975 and 1980.
The best image to give an idea of this fleet is that of a "bucket waterwheel" endlessly discharging its catch in the four ports of the Guilvinec district. Where there is a seafaring business in Guilvinec, Loctudy and Saint-Guénolé, there is a complementarity that is expressed in two ways:
- coastal fishing constitutes a very noticeable and regular supplement to production, since sales happen daily and only bad winter weather causes a relative decrease in the supplement. - coastal fishing gives a flattering image of the port based on the display of high-quality leading market products: daily live lobster, hake and angler.
In this study, we have above all tried to evaluate the situation of the Bigouden coastal system as an entity, while including in the same analysis the species, fleets and the exploitation of the resource. For the main species, a balance sheet is proposed. It covers the lobster, hake and angler separately. Lobster, because of its small amount of movement, can be considered as being an isolated stock, while fish belong to much more wide-ranging groups.
The lobster has gained from various increases in meshing that have been imposed since 1971, even if these have not always been strictly applied. One of the results of this management by means of meshing is a "depreciation" of the variations of daily yields around an average value of 100kg.
For the hake, the dominant trait is an increase in yields in the last few years in accordance with an improvement of the situation in the Gulf of Gascony due to a generalised decrease of effort and a modification of the exploitation profile since the appearance of boulters and straight nets. Whereas the situation for lobster fisheries, as regards the hake's marketable size, did not improve, since the demand for small hake still exists, we have nonetheless been witnessing for about ten years a slow diversification of the fleets' business activities, which is much more in line with sequential hake fisheries' logical outline of exploitation. When lobster yields decrease, one part of the fleet focuses on the fish at the edges of the lobster fisheries.
For the angler, we see rather similar phenomena and a significant increase in unloading of the two species by lobster fishermen due also to a widening of their fishing areas. On the lobster mudflats themselves, there is no notable change in exploitation in the historical records. All studies of coastal fishing always come up against the problem of acquiring statistical data and the Bigouden region is no exception to the rule.
To improve this situation, in 1987 and 1988 two items were chosen:
- a better awareness of the activity and of the areas frequented, by survey during unloading in Guilvinec and in Loctudy.
- a detailed description of the haul by species, by sampling, in Loctudy, on two-thirds of coastal sales, between December 1987 and November 1988.
For this reason, analysis of fleets by type is still cursory and covers only one year. The appearance of new trends towards fish can only be described qualitatively, since there is no historical record. The classification of boats was done by analysing data furnished by the auctions. This first assessment is not necessarily reliable, above all because of the auctions' inaccurate description of the hauls, a deficiency that we have tried to overcome by surveying in Loctudy.
In conclusion, we are witnessing in the Bigouden region, as in other entities, a rebalancing between traditional business activities and modern trends. Lobster fishing, almost exclusive before the 1980s, is tending to decrease for two main reasons:
- a generalised decrease in activity in the lobster fisheries due to non-renewal of coastal fish fleets,
- The transfer of part of the lobster fishermen's activities to fish, since the lobster and its accompanying catch no longer seemed able to insure the economic viability of new ships.
Other maritime districts resolved their lobster problem in a different way. The Lorient fishermen improved their yields by using more capable trawlers, the fishermen of Sable by exploiting the hake fish run to the fullest and limiting their lobster fishing to the best season. The Bigouden region is slowly turning to the second solution, as it renews its fleet.
A ses origines, la flottille côtière du pays bigouden péchant au chalut, est tout entière orientée vers l'exploitation de la langoustine et du merlu. Il s'agit d'une activité traditionnelle qui s' amplifie entre la dernière guerre et les années 70 pour atteindre son apogée entre 1975 et 1980. La meilleure image que l'on puisse donner de cette flottille est celle d'une "noria" débarquant inlassablement sa capture dans les quatre ports du quartier du Guilvinec. Là où existe une activité hauturière à Guilvinec, Loctudy et Saint-Guénolé, il y a une complémentarité qui s'exprime de deux manières : - la pêche côtière constitue un appoint très appréciable et régulier de production, puisque la vente est quotidienne et que seules les intempéries hivernales entraînent une baisse relative des apports. - la pêche côtière donne du port une image flatteuse basée sur la présentation de produits d'appel de grande qualité : langoustine vivante, merlu et baudroies quotidiens. Dans cette étude, nous avons surtout tenté de faire le point sur le système côtier bigouden en tant qu'entité, en englobant dans la même analyse des espèces, les flottilles et l'exploitation de la ressource. Pour les espèces principales, un bilan est proposé. Il couvre séparément la langoustine, le merlu et les baudroies. La langoustine, en raison de ses faibles déplacements, peut être considérée comme constituant un stock isolé, alors que les poissons appartiennent à des ensembles beaucoup plus vastes. La langoustine a beaucoup gagné des diverses augmentations de maillage qui ont été imposées depuis 1971, même si elles n'ont pas toujours été appliquées avec rigueur. Un des résultats de cette gestion par les maillages est un "amortissement" des variations des rendements journaliers autour d'une valeur moyenne de 100 kg. Pour le merlu, le trait dominant est une augmentation des rendements dans les dernières années en accord avec une amélioration de la situation dans le Golfe de Gascogne due à une baisse généralisée de l'effort et à une modification du profil d'exploitation depuis l'apparition des palangriers et des filets droits. Si la situation sur les pêcheries de langoustine, au regard de la taille marchande du merlu, ne s'est pas améliorée puisque la demande de petits merluchons existe toujours, on assiste par contre depuis une dizaine d'années à une diversification lente des activités des flottilles entrant beaucoup mieux dans le schéma logique d'exploitation des pêcheries séquentielles de merlu. Quand les rendements en langoustine baissent, une partie de la flottille s'oriente vers les poisson sur les marges des pêcheries de langoustine. Pour les baudroies on observe des phénomènes assez analogues et une augmentation importante des débarquements des deux espèces par les langoustiniers due également à un élargissement de leurs zones de pêche. Sur les vasières à langoustine elles-mêmes, il n'y a pas de modification notable de l'exploitation dans la série historique. Toute étude des pêches côtières se heurte toujours au problème d'acquisition des données statistiques et le pays bigouden n'échappe pas à la règle. Pour améliorer cette situation, en 1987 et 1988, deux points ont été retenus : - une meilleure connaissance de l'effort et des zones fréquentées, par enquête au moment des débarquements à Guilvinec et à Loctudy, - une description détaillée des apports par espèce, par échantillonnage, à Loctudy, sur les 2/3 des ventes côtières, entre décembre 1987 et novembre 1988. Pour cette raison, l'analyse de flottilles en types est encore sommaire et n'a porté que sur une année. L'apparition des tendances nouvelles vers le poisson ne peut être décrite que qualitativement puisque la série historique n'existe pas. La classification des bateaux a été faite par l'analyse des données fournies par les criées. Ce premier diagnostic ne présente pas toutes les garanties en raison surtout d'une description peu fidèle des apports par les criées, déficience que l'on a essayé de pallier en enquêtant à Loctudy. En conclusion, on assiste dans le pays bigouden comme dans d'autres entités à un rééquilibrage entre les activités traditionnelles et des orientations modernes. La pêche de langoustine, quasi exclusive avant les années 1980, tend à décroître pour deux raisons principales : - une baisse généralisée de l'effort sur les pêcheries de langoustine due au nonrenouvellement des flottilles de pêche côtière, - le report d'une partie de l'effort des langoustiniers vers les pêcheries de poissons, la langoustine et sa capture accessoire ne semblant plus pouvoir assurer la rentabilité économique des navires neufs. D'autres quartiers maritimes ont résolu de façon différente leur problème langoustine. Les Lorientais ont amélioré leurs rendements en adoptant des chaluts plus performants, les Sablais en exploitant à fond la séquence des pêcheries de merlu et en limitant leur intervention sur la langoustine à la saison la plus favorable. Le pays bigouden s'engage lentement dans la seconde solution, au rythme du renouvellement de sa flottille. Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/1989/rapport-2202.pdf http://archimer.ifremer.fr/doc/00000/2202/ | Partager Voir aussi France Brittany Data Fishing zone Fleet Trawling Commercial species Costal fisheries Finistere Bretagne Télécharger |
Diversité et différentiation génétiques des populations de tortues vertes (Chelonia mydas) dans les sites de ponte et d'alimentation du sud-ouest de l'océan Indien : application aux stratégies de conservation de l'espèce Auteur(s) : Taquet, Coralie Éditeur(s) : Université de la Réunion Résumé : The green turtle (Chelonia mydas) is an emblematic species of marine life. However, nowadays it is subject to many threats (poaching, by-catch). Even if there is deep growing measures for its protection, the green turtle still is an endangered species and it is listed in Appendix I of Washington Convention (CITES). In order to elaborate efficient conservation and management plans, perfect knowledge of green turtle biology, but also of its population structure and their characteristics, are needed. In this thesis, we have assessed genetic structure of green turtle populations in the South-Western Indian Ocean by using genetic tools. In all, 1551 tissue samples have been collected from our study zone and from our control site French Polynesia (37 samples). All kinds if individuals were sampled (except males in reproductive phase) from 15 sampling sites including nesting, foraging, and immature development site. We used both control region of mitochondrial DNA and 6 microsatellite loci to better infer maternal and paternal lineages. We identified 29 haplotypes in the South-Western Indian Ocean. They are distributed in 3 independent and highly divergent clades, including one composed with haplotypes from Atlantic Ocean. For 7 of these haplotypes, it was the first time they were detected in the study zone. Fifteen haplotypes were previously undescribed, distributed in all the 3 clades. These new haplotypes seem to be specific to the South-Western Indian Ocean, which is then an original zone. Besides, we found a high allelic richness. These results show the South-western Indian Ocean is rich and very diversified. This region plays an important role in the global diversity of the species. The South-Western Indian Ocean is one of the two contact zones presently known between the two metapopulations of green turtles (Atlantic-Mediterranean and Indo-Pacific). This contact induces a genetic cline based on CM8 (Atlantic) and C3 (Indo-Pacific) haplotype frequencies. Analysis of the microsatellite differentiation between individuals provides evidence of genetic exchanges between the two metapopulations in the region. The South-Western Indian Ocean participates to green turtle global genetic mixing. Studying the influence of several intrinsic and extrinsic factors on population structuring provides useful information for management plan elaboration. We found no significant difference between genetic structures of foraging females and males, contrary to immature turtles which seem to be organised in 'regional pools'. This organisation could be due to both immature natal homing and influence of oceanic currents. High mitochondrial differentiation of nesting females and low global microsatellite differentiation of our samples indicate male-mediated gene flow among populations of the study zone. The genetic composition of a sampling site presents no significant variation along the year, even if we could notice some trends. Nevertheless, it can be significantly different from a year to an other one. This may result from alternation of distinct populations on the same site. We noticed different evolution in 10 or 20 years of the genetic composition depending on the sampling site. Geographic distance seems not to have significant influence on population structuring concerning microsatellite markers. Nesting females of Saziley Beach (Mayotte Island, Comoros Archipelago) present genetic divergence from females nesting in the two other sampled beaches of this island. The observed population structure shows no contradiction with the organisation of oceanic currents in the South-Western Indian Ocean. Comparing the results from the two genetic markers used, we identified 8 genetic differentiated clusters of turtles in the study zone and at least 6 distinct populations. These clusters constitute 8 potential management units (MUs) which could serve as basis in the elaboration of conservation and management plans. La tortue verte (Chelonia mydas) constitue l'un des espèces emblématiques de la vie marine, pourtant de nombreuses menaces pèsent de nos jours encore sur sa survie (braconnage, captures accidentelles). Ainsi, malgré l'essor de mesures de protection menées à travers pour sa sauvegarde, la tortue verte constitue une espèce 'en danger d'extinction' et figure dans l'Annexe I de la Convention de Washington (CITES). Afin d'élaborer des plans de gestion et de conservation qui soient efficaces, il est important d'avoir une parfaite connaissance de la biologie de la tortue verte, mais aussi de la structure de ses populations et de leurs caractéristiques. C'est dans ce cadre que s'inscrit la présente étude. L'objectif de cette étude était d'acquérir des connaissances sur la structure des populations de tortues vertes dans le sud-ouest de l'océan Indien grâce à l'utilisation de l'outil génétique. Au total, 1551 échantillons de tissu ont été collectés dans la zone d'étude et dans notre site témoin la Polynésie française (37 échantillons). Toutes les catégories d'individus ont été échantillonnées (excepté les mâles en phase de reproduction) et les 15 sites d'échantillonnage comprennent à la fois des sites de ponte, d'alimentation et de développement pour les immatures. Deux types de marqueurs ont été utilisés : la région contrôle de l'ADN mitochondrial et 6 loci microsatellites, afin d'appréhender au mieux l'apport des lignées maternelles et paternelles. Nous avons pu mettre en évidence la présence dans le sud-ouest de l'océan Indien de 29 haplotypes distincts, appartenant à trois clades fortement divergents dont l'un constitué d'haplotypes originaires de l'océan Atlantique. Parmi ces haplotypes, 7 ont été détectés pour la première fois dans la zone d'étude, et 15 autres n'ont jamais été précédemment décrits chez cette espèce. Ils sont présents dans chacun des 3 clades d'haplotypes. Ces nouveaux haplotypes semblent spécifiques à la région, et en font une zone originale. On observe par ailleurs une grande richesse allélique dans les effectifs analysés. Ces résultats montrent que le sud-ouest de l'océan Indien est une zone riche et très diversifiée. Cette région joue un rôle important dans la diversité génétique globale de l'espèce. Le sud-ouest de l'océan Indien constitue l'une des deux seules zones connues à l'heure actuelle de contact entre les deux métapopulations de tortues vertes (Atlantique-Méditerranée et Indo-Pacifique). Ce contact a entraîné la formation d'un cline génétique portant principalement sur les fréquences relatives des haplotypes CM8 (Atlantique) et C3 (Indo-Pacifique). Les résultats obtenus lors de l'analyse microsatellite de la différenciation entre les individus originaires des deux métapopulations montrent que le sud-ouest de l'océan Indien constitue une zone d'échanges génétiques entre les deux métapopulations, participant au brasage génétique de l'espèce. L'étude de facteurs, intrinsèques et extrinsèques, pouvant influencer la structuration des populations apportent de nombreuses informations qui pourraient s'avérer utiles lors de l'élaboration de plans de gestion. La structure des femelles et des mâles en alimentation ne diffère pas, contrairement à celle des immatures qui semble s'organiser en 'pools régionaux' qui seraient le fruit de l'interaction d'un comportement de philopatrie et d'une influence des courants océaniques. La forte différenciation mitochondriale des femelles en ponte et la très faible différenciation microsatellite observée à l'échelle de la région, indiquent l'existence de flux de gènes via les mâles. La composition génétique d'un site ne varie pas de manière significative au cours de l'année. Par contre, elle peut varier d'une année à l'autre, signifiant l'alternance dans certains sites de ponte de plusieurs populations distinctes. L'évolution de la composition génétique d'un groupe, au cours de 10 ou 20 ans, diffère selon le site considéré. La distance ne semble pas influencer de manière significative la structuration des populations au niveau microsatellite. Les femelles en ponte sur la plage de Saziley (Mayotte) diffèrent génétiquement de celles pondant sur les deux autres plages de l'île. La structure observée des populations est en accord avec l'organisation des courants océanique dans la région. La confrontation des résultats obtenus à partir des deux marqueurs génétiques utilisés, permet la détermination de 8 ensembles génétiquement différenciés dans la zone d'étude et l'identification d'au moins 6 populations distinctes. Ces ensembles constituent autant d'unités de gestion (MUs) potentielles qui pourront servir de base à l'élaboration de plans de gestion et de conservation. Droits : info:eu-repo/semantics/openAccess http://archimer.ifremer.fr/doc/2007/these-3532.pdf http://archimer.ifremer.fr/doc/00000/3532/ | Partager |
Active tectonics within the NW and SE extensions of the Pambak-Sevan-Syunik fault: Implications for the present geodynamics of Armenia Auteur(s) : RITZ, Jean-francois Avagyan, A. MKRTCHYAN, Mushgeh Nazari, H. Blard, P. -H. Karakhanian, A. Philip, Herve Balescu, S. Auteurs secondaires : Géosciences Montpellier ; Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS) Institute of Geological Sciences, National Academy of Sciences, Geological Survey of Iran Centre de Recherches Pétrographiques et Géochimiques (CRPG) ; Université de Lorraine (UL) - Centre National de la Recherche Scientifique (CNRS) Histoire Archéologie Littérature des Mondes Anciens (HALMA) - UMR 8164 (HALMA) ; Ministère de la Culture et de la Communication (MCC) - Université de Lille, Sciences Humaines et Sociales - Centre National de la Recherche Scientifique (CNRS) US Geological Survey [Denver] ; United States Geological Survey [Reston] (USGS) University of Québec, Montréal Dynamique de la Lithosphere ; Géosciences Montpellier ; Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS) - Université des Antilles et de la Guyane (UAG) - Institut national des sciences de l'Univers (INSU - CNRS) - Université de Montpellier (UM) - Centre National de la Recherche Scientifique (CNRS) Éditeur(s) : HAL CCSD Elsevier Résumé : International audience This study analyzes the active tectonics within the northwestern and southeastern extensions of the Pambak-Sevan-Syunik fault (PSSF), a major right-lateral strike-slip fault cutting through Armenia. Quantifying the deformations in terms of geometry, kinematics, slip rates and earthquake activity, using cosmogenic 3He, OSL/IRSL and radiocarbon dating techniques, reveal different behaviors between the two regions. Within the northwestern extension, in the region of Amasia, the PSSF bends to the west and splits into two main WNW–ESE trending reverse faults defining a compressional pop-up structure. We estimate an uplift rate and a shortening rate of 0.5 ± 0.1 mm/y and 1.4 ± 0.6 mm/y, respectively. This suggests that most of the ∼2 mm/y right lateral movement of the PSSF seems to be absorbed within the Amasia pop-structure. Within the southeastern extension, the PSSF shows signs of dying out within the Tsghuk Volcano region at the southernmost tip of the Syunik graben. There, the tectonic activity is characterized by a very slow NS trending normal faulting associated with a slight right-lateral movement. Slip rates analyses (i.e. vertical slip rate, EW stretching rate at 90° to the fault, and right-lateral slip rate of ∼0.2 mm/y, ∼0.1 mm/y and ∼0.05 mm/y, respectively) lead to the conclusion that the right lateral movement observed further north along the PSSF is mainly transferred within other active faults further west within the Karabagh (Hagari fault or other structures further northwestwards). Comparing our slip rates with those estimated from GPS data suggests that most of the deformation is localized and seismic, at least within the Tsghuk region. The geometrical and kinematic pattern observed within the two terminations of the PSSF suggests that the fault and its surrounding crustal blocks are presently rotating anticlockwise, as also observed within the GPS velocity field. This is consistent with the recent kinematic models proposed for the Caucasus-Kura-South Caspian region and brings a new insight into the present geodynamics of Armenia. ISSN: 1040-6182 hal-01307342 https://hal.archives-ouvertes.fr/hal-01307342 DOI : 10.1016/j.quaint.2015.05.021 | Partager |
Ressources patrimoniales et perspectives touristiques dans l’Est-Cameroun : potentialités et limites actuelles Auteur(s) : Moussa, Meirama Garba Éditeur(s) : Université des Antilles Études caribéennes Résumé : Le patrimoine et le tourisme sont des facteurs avérés de développement. De leur bonne exploitation peut contribuer à l’amélioration des conditions d’existence des populations locales. L’Est-Cameroun est le fief de ressources naturelles et culturelles d’une étonnante diversité pouvant impulser une forte activité touristique. Cependant, même si cette région reçoit chaque année des touristes nationaux et étrangers, elle ne peut pas se targuer de faire profiter sa population des effets directs, indirects et induits qu’engendrerait une activité touristique convenablement menée. Le présent article expose, dans une perspective historique (1980-2010), les raisons pour lesquelles, le tourisme et le développement de l’Est-Cameroun piétinent en dépit de ses nombreuses ressources patrimoniales.La collecte des données (écrites, orales, iconographiques, électroniques) sur le terrain de recherche associée à l’observation permet de constater que le tourisme fut très vite relégué au second plan. L’exploitation minière et forestière intensive, au lieu de faciliter l’émergence de la région, a plutôt hypothéquée son avenir. Le rôle des agences chargées de la gestion du tourisme à l’Est-Cameroun s’est limité à l’inventaire des sites touristiques, l’aménagement sporadique de quelques-uns et la mise en œuvre d’actions promotionnelles approximatives. La négligence du tourisme par les autorités camerounaises n’est pas une nouveauté ; elle a pour corollaire l’apparition de difficultés diverses (braconnage, manque de personnel, insécurité…). Heritage and tourism are recognized factors of development. Their good exploitation can contribute to the improvement of the conditions of existence of local populations. East-Cameroon is the fief of natural and cultural resources which can stimulate tourism. Although even if this region receives every year domestic and foreign tourists, its population cannot profit from direct, indirect and induced effects which would engender a suitably led tourist activity. The present article exposes, in a historical perspective (1980-2010), reasons why, tourism and development of East-Cameroon tramples in spite of its numerous heritage resources. The data collection (written, oral, iconographic, electronic…) on the research filed and personal observation allow to notice that tourism was very fast relegated in East-Cameroon. The intensive mining and forest exploitation have hypothecated the future of this area instead of developing it. Moreover, the role of tourism agencies in eastern Cameroon is limited itself to inventory of places of interest, sporadic development and approximate promotional actions. The negligence of tourism by the Cameroon authorities is not novelty; it has for corollary appearance of difficulties (as poaching, lack of personal, insecurity). Cameroun Droits : info:eu-repo/semantics/openAccess urn:doi:10.4000/etudescaribeennes.9453 http://journals.openedition.org/etudescaribeennes/9453 | Partager |