Frequency of pain crises in sickle cell anemia and its relationshipwith the sympatho-vagal balance, blood viscosity and inflammation Auteur(s) : Nebor, Danitza Bowers, Andre Hardy-Dessources, Marie-Dominique Knight-Madden, Jennifer Romana, Marc Reid, Harvey Barthélémy, Jean-Claude Cumming , Vanessa Auteurs secondaires : Inserm U763, Pointe-à-Pitre, Guadeloupe; Université des Antilles et de la Guyane ; Inserm U763, Pointe-à-Pitre, Guadeloupe; Université des Antilles et de la Guyane Department of Basic Medical Sciences (Physiology Section), Faculty of Medical Sciences ; Department of Basic Medical Sciences (Physiology Section), Faculty of Medical Sciences Sickle Cell Unit, Tropical Medicine Research Institute ; Sickle Cell Unit, Tropical Medicine Research Institute Système Nerveux Autonome - Epidémiologie, Physiologie, Ingénierie, Santé (SNA-EPIS) ; Université Jean Monnet [Saint-Étienne] (UJM) - Centre Hospitalier Universitaire de Saint-Etienne Adaptations au Climat Tropical, Exercice et Santé (ACTES) ; Université des Antilles et de la Guyane (UAG) Éditeur(s) : HAL CCSD Ferrata Storti Foundation Résumé : International audience BackgroundRecent evidence suggests that autonomic nervous system activity could be involved in thepathophysiology of sickle cell disease, but it is unclear whether differences in autonomic nervoussystem activity are detectable during steady state in patients with mild and severe disease.The aim of the present study was to compare the autonomic nervous system activity, bloodrheology, and inflammation in patients with sickle cell anemia according to the frequency ofacute pain crisis.Design and MethodsTwenty-four healthy volunteers, 20 patients with sickle cell anemia with milder disease, and15 patients with sickle cell anemia with more severe disease were recruited. Milder disease wasdefined as having no pain crisis within the previous year. More severe disease was defined ashaving had within the previous year three or more pain crises which were documented by aphysician and required treatment with narcotics. The autonomic nervous system activity wasdetermined by spectral analysis of nocturnal heart rate variability. Blood viscosity determinationand measurements of several inflammatory markers (interleukin-6, soluble vascular celladhesion molecule-1, soluble CD40 ligand and sL-selectin) were made on blood samples collectedin steady-state conditions.ResultsResults showed that: 1) patients who had suffered more frequent pain crises had lowerparasympathetic activity and greater sympatho-vagal imbalance than both controls andpatients with milder disease. However, when adjusted for age, no significant difference wasdetected between the two sickle cell anemia patient groups; 2) patients who had suffered morefrequent pain crises had higher blood viscosity than patients with milder disease, and this wasnot dependent on age.ConclusionsResults from the present study indicate that both the autonomic nervous system activity andblood viscosity are impaired in patients with sickle cell anemia exhibiting high frequency ofpain crisis in comparison with those who did not experience a crisis within the previous year. ISSN: 0390-6078 hal-01163973 https://hal.univ-antilles.fr/hal-01163973 DOI : 10.3324/haematol.2011.047365 | Partager |
Instabilities and deformation in the sedimentary cover on the upper slope of the southern Aquitaine continental margin, north of the Capbreton canyon (Bay of Biscay) Auteur(s) : Gonthier, E Cirac, P Faugeres, J Gaudin, Mathieu Cremer, M Bourillet, Jean-francois Éditeur(s) : Institut de Ciències del Mar de Barcelona, CSIC Résumé : Acoustic and core data have recently been collected on the shelf break and the upper part of the slope of the south Aquitaine continental margin. They reveal the major role played by mass-flow gravity processes in deposit erosion and redistribution, modelling of the sea-bed, and transfer of sediment toward the deep-sea. The study region is bounded in the south by the Capbreton canyon. The northern area, which shows a smooth morphology, is characterised by small-scale deformations due to sediment creep or low-amplitude slide processes. The deformations are associated with mini listric-like faults that bound packets of sediments in which the deposit geometry is typical of constructional sediment waves. These sediment waves result from the interaction of depositional and gravity deformation processes. In the southern area, closer to the canyon, wave-like structures are still present but mostly of smaller size. They only result from gravity deformation processes without any evidence of constructional processes. In the vicinity of the Capbreton canyon, the shelf break and upper slope have a much more uneven morphology with sedimentary reliefs, escarpments and depressions directed toward the canyon thalweg. The depressions look like slide scars, and could be the result of regressive slides initiated at the top of the canyon flank. The age of the sliding event responsible for the formation of the depression observed today could be middle to upper Quaternary. Since their formation, these depressions act as conduits that channel the transfer of shelf sediment into the canyon, as demonstrated by the occurrence of a meandering channel on the sea-floor of one depression. Scientia Marina (0214-8358) (Institut de Ciències del Mar de Barcelona, CSIC), 2006-06 , Vol. 70 , N. 1 , P. 89-100 Droits : 2006 Institut de Ciències del Mar de Barcelona http://archimer.ifremer.fr/doc/2006/publication-3960.pdf http://archimer.ifremer.fr/doc/00000/3960/ | Partager |
Windsor Downs golf course on North Cat Cay, Bahamas ; The Bryant Slides Collection ; The Bryant Slides Collection, Bahamas 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. Cat Cay refers to two islands in the Bahamas, North Cat Cay and South Cat Cay which is uninhabited. North Cat Cay was purchased in 1931 by Louis Wasey as a private island and is presently (2013) owned by members of the Cat Cay Yacht Club. After converting the island to a private club, Wasey built a nine-hole golf course now known as Windsor Downs. The course occupies the center of the island and is named for the Duke of Windsor, who was the Governor of the Bahamas during World War II. The golf course, pictured, features sand traps, a lake, grassy fields, and is planted with many palm trees. Slide labeled Cat Cay, Mar '46. Bahamas -- North America -- North Cat Cay, Bimini 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 3:7 http://ufdc.ufl.edu/AA00028369/00001 | Partager |
New cytotoxic cyclic peptide from the latex of Croton urucurana Baillon (Euphorbiaceae) and in vitro investigation of its mechanisms of action ; Un nouveau cyclopeptide cytotoxique extrait du latex de Croton urucurana Baillon (Euphorbiaceae) : étude in vitro de son activité cytotoxique ; Novo ciclopeptídeo citotóxico do látex de croton urucurana baillon (Euphorbiaceae) e investigação de seu mecanismo de ação in vitro Auteur(s) : Cândido Bacani, Priscila de Matos Auteurs secondaires : 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 ) Université Rennes 1 Georges Baffet Walmir Silva Garcez Éditeur(s) : HAL CCSD Résumé : Croton urucurana Baillon (Euphorbiaceae), plant species popularly known in Brazil as “sangra-d’água”, is commonly found in Mato Grosso do Sul State (midwestern Brazil), where its latex is popularly used to treat several types of cancer. Despite the ethnopharmacological significance of the species, no phytochemical or cytotoxic studies of its latex have been published. In this context, the aim of the present study was to assess the cytotoxic activity of crude extracts, fractions and isolated compound from the latex of C. urucurana and to investigate the effects of crourorb A1 on the viability, apoptosis, cell cycle and cell migration of human hepatocarcinoma cell lines (Huh-7). Also, we have evaluated the viability of Huh-7 cells treated with crourorb A1 in 3D collagen gels. The cytotoxicity was detected using the sulforhodamine B (SRB) assay against six human cancer cells lines and one nontumor NIH/3T3 cell line (murine fibroblast). Studies on the mechanism of cell death of crourorb A1 were conducted in different test systems in vitro. The bioactive ethyl acetate phase obtained from the latex of C. urucurana afforded a novel cyclic peptide, [1−9-NαC]-crourorb A1, that proved active against NCIADR/ RES (ovary, multidrug-resistance phenotype) cells with the same potency as doxorubicin (positive control) and inactive up to the highest concentration tested against nontumor NIH/3T3 cells (GI50 = > 250 μg/mL). Crourorb A1 treatment decreases the cell viability of Huh-7 at dose and time dependent manner associated with induction of apoptosis by caspase 3/7 activation and increasing expression of pro-apoptotic proteins: Bak, Bid, Bax, Puma, Bim, and Bad and clived-caspase3 protein. The JNK/MAP pathway is involved in this induced cell death. Crourorb A1 effect is also associated with G2/M phase cell cycle arrest. In parallel, we observed that crourorb A1 treatment resulted in an increase of cyclin-dependent kinase (CDK1), cyclin B1 and cyclin D1 expressions. A significant reduction of Huh-7 cells migration by crourorb A1 can be assessed and we also show that cells grown on 3D collagen gels exhibited increased resistance to crourorb A1 when compared to 2D cell culture. Croton urucurana Baillon (Euphorbiaceae), est une plante très connue et utilisée en médecine traditionnelle au Brésil, la «sangra-d’água» retrouvée dans l'État du Mato Grosso do Sul (région Centre-Ouest du Brésil). Son latex est abondamment utilisé en médecine traditionnelle dans le traitement de plusieurs types de cancer. En dépit de son importance ethnopharmacologique, on ne trouve aucune étude sur sa composition chimique ou sur sa potentielle activité anti-cancéreuse. L’objectif de ce travail a été d'évaluer l'activité cytotoxique des extraits totaux, fractions d’extraits et de molécules purifiées, isolées du latex de C. urucurana. Nous avons étudié plus particulièrement les effets du crourorb A1 sur la viabilité, l'apoptose, le cycle cellulaire et la migration de cellules issues de carcinome hépatocellulaire humaine (Huh-7). Nous avons également évalué l’effet du crourorb A1sur la viabilité des cellules Huh-7 cultivées dans les gels de collagène en 3D. L' activité cytotoxique ont été réalisées par le test à la sulforhodamine B sur six lignées cellulaire cancéreuses et sur une lignée cellulaire non cancéreuse de fibroblastes murins, les cellules NIH/3T3. L'étude phytochimique de la fraction ‘acétate d'éthyle’ du latex de C. urucurana bioguidé a permis d’obtenir un nouveau cyclopeptide que nous avons nommé [1-9-NαC]-crourorb A1. Le crourorb présente une cytotoxicité puissante sur la lignée cellulaire cancéreuse NCI-ADR/RES (ovaire, le phénotype de multirésistance) à un niveau équivalent à celle de la doxorubicine (témoin positif). Ce composé est de plus pratiquement inactif (GI50 = >250 μg/mL) sur la lignée non cancéreuse NIH/3T3. L'évaluation de la cytotoxicité in vitro du crourorb A1 (test wst1) sur les cellules Huh-7 a démontré que la viabilité des cellules est inhibée de manière dose et temps-dépendant. Nous avons mesuré une forte activation des caspases 3 et 7 et une nette augmentation de l’expression des protéines pro-apoptotiques (Bak, Bid, Bax, Puma, Bim et Bad) ainsi que de la caspase 3 clivée par le crourorb A1. Nous avons également déterminé que la voie de signalisation JNK-MAPkinase semble nécessaire à l’induction de la mort cellulaire des cellules Huh-7 traitées au crourorb A1. Le crourob A1 induit un arrêt du cycle cellulaire en phase G2/M. En parallèle, les expressions de la cycline-dépendante kinase CDK1, des cyclines B1 et D1 sont augmentées après traitement au crourorb A1. De plus, le crourorb A1 a un effet inhibiteur significatif de la migration des cellules Huh-7, en présence ou absence de mitomycine C. Nous avons également confirmé, l’effet inhibiteur du crourob A1 sur la viabilité des cellules Huh7 cultivées en 3D dans les gels de collagène 1 et démontré que les cellules cultivées en 3D semblent plus résistantes au crourorb A1 par rapport aux cultures en monocouche 2D. Croton urucurana Baillon (Euphorbiaceae) é uma espécie arbórea conhecida popularmente no Brasil como “sangra d´água”, comumente encontrada no estado de Mato Grosso do Sul, onde seu látex tem sido utilizado na medicina popular no tratamento de vários tipos de câncer. Apesar de sua importância etnofarmacológica, não há relatos de estudos relacionados à sua composição química ou atividades anticâncer na literatura. Nesse contexto, o objetivo do presente estudo foi avaliar a atividade citotóxica de extratos, fases, frações e da substância isolada do látex de C. ururucurana e investigar os mecanismos celulares e moleculares in vitro responsáveis pela citotoxicidade da substância isolada considerando seu potencial apoptótico e influência sobre a progressão do ciclo celular em uma linhagem de hepatocarcinoma celular humano (Huh-7), bem como, os efeitos desta substância sobre a migração e viabilidade de células Huh-7 cultivadas em geis de colágeno em 3D. O ensaio de citotoxicidade in vitro foi realizado com o corante sulforrodamina B (SRB) em seis linhagens de células neoplásicas humanas e uma linhagem de células não neoplásicas NIH/3T3 (fibloblasto murinho). Os estudos de mecanismos de ação com crourorb A1 foram conduzidos em diferentes sistemas-teste in vitro. O estudo fitoquímico biomonitorado da fase bioativa acetato de etila do látex de C. urucurana resultou no isolamento de um novo ciclopeptídeo denominado [19-NαC]-crourorb A1, que apresentou potente atividade citotóxica frente à linhagem de células neoplásicas NCI-ADR/RES (ovário com fenótipo de resistência a múltiplos fármacos), com a mesma potência que a doxorrubicina (controle positivo), e foi inativa até a maior concentração testada (GI50 = >250 μg/mL) frente à linhagem de células não neoplásicas 3T3. A exposição de células Huh-7 ao crourorb A1 resultou em uma diminuição da viabilidade celular de maneira dose e tempo-dependentes. Nós observamos um aumento da atividade de caspases 3 e 7 e um aumento da expressão de proteínas próapoptóticas (Bak, Bid, Bax, Puma, Bim e Bad) e caspase 3 clivada após tratamento com crourorb A1. Além disso, observamos que a via de sinalização celular MAP/JNK foi necessária para induzir a morte celular em células Huh-7 tratadas com crourorb A1. Os efeitos de crourorb A1 foram também associados com o acúmulo de células na fase G2/M do ciclo celular. Em paralelo, as expressões da cinase dependente da ciclina (CDK1), ciclina B1 e ciclina D1 foram aumentadas após tratamento com crourorb A1. Foi demonstrado também o envolvimento de crourorb A1 na redução da migração de células Huh-7 cultivadas na presença e ausência de mitomicina C. A avaliação da viabilidade de células Huh-7 cultivadas em geis de colágeno em 3D apontou uma maior resistência destas células ao crourorb A1 quando comparadas com a cultura de células em 2D. https://tel.archives-ouvertes.fr/tel-01478286 NNT : 2016REN1B010 tel-01478286 https://tel.archives-ouvertes.fr/tel-01478286 https://tel.archives-ouvertes.fr/tel-01478286/document https://tel.archives-ouvertes.fr/tel-01478286/file/DE-MATOS-CANDIDO-BACANI-Priscila.pdf | Partager |
Men gather at the wharf market, Nassau Harbor, New Providence, Bahamas ; The Bryant Slides Collection ; The Bryant Slides Collection, Bahamas Nassau Hope Town 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. Men talking in the open air market on the wharf of the Nassau Harbor. Bicycles and produce, which includes cabbages and sugar cane, are present. In the background are sailboats with cargo. Bahamas -- North America --Nassau, New Providence Island 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 15:3 http://ufdc.ufl.edu/AA00029401/00001 | Partager |
Mesoscale variability from a high-resolution model and from altimeter data in the North Atlantic Ocean Auteur(s) : Brachet, Sidonie Le Traon, Pierre-yves Le Provost, Christine Éditeur(s) : Amer Geophysical Union Résumé : The objective of the paper is to analyze the degree of realism of the Parallel Ocean Program ( POP) model of the Los Alamos Laboratory using the combined TOPEX/Poseidon and ERS-1/2 (TPERS) sea level anomaly (SLA) data sets and to present a detailed study of mesoscale characteristics in the North Atlantic. This description spans 8 years of data from 1993 to 2000. At first, we focus on the analysis of the mean eddy kinetic energy ( EKE) and show that the major characteristics of mesoscale variability are realistically simulated despite an overestimation of the EKE model in the Gulf Stream region. We then describe the SLA space and timescales and propagation velocities at a resolution never achieved before. There is a high level of agreement between the model and altimeter values regarding spatial scales and propagation velocities. POP timescales are, however, significantly longer in the subtropical regions. The westward zonal propagation velocity of both the model and the observations are higher than the speed computed from standard Rossby wave theory. The effect of mean current advection on POP and TPERS propagation velocities is also clearly seen in the Labrador Current and in the Gulf Stream and its recirculations. Finally, a study of the seasonal and interannual variability of the high-frequency (HF) EKE is carried out. The model reproduces accurately most of the HF-EKE seasonal variations in the Caribbean Sea and at high latitudes despite a phase advance. A clear HF-EKE interannual variability is then evidenced. Our hypothesis is that a contraction of the subpolar and subtropical gyres due to the North Atlantic Oscillation (NAO) could explain a reduction of the eddy activity in the North Atlantic Current, in the Newfoundland basin, and in the Azores Current. In the Caribbean Sea, the interannual variability of the EKE for both POP and TPERS seems to be caused by an interannual variability of the wind stress. Journal Of Geophysical Research-oceans (0148-0227) (Amer Geophysical Union), 2004-12 , Vol. 109 , N. C1205 , P. 16 PP. Droits : 2004 AGU http://archimer.ifremer.fr/doc/00087/19841/17491.pdf DOI:10.1029/2004JC002360 http://archimer.ifremer.fr/doc/00087/19841/ | Partager |
Structural Metadata Creation and Quality Control Tool Auteur(s) : Sullivan, Mark V. Éditeur(s) : University of Florida Libraries / Digital Library of the Caribbean University of Florida Libraries / Digital Library of the Caribbean ( Gainesville, Florida ) Résumé : (Acquisition) Resource was uploaded and editing during training for dLOC partners in Gainesville, FL on 7/29/2013. Submitted by Mark Sullivan. Slides for dLOC partner training Droits : [cc0] The author dedicated the work to the Commons by waiving all of his or her rights to the work worldwide under copyright law and all related or neighboring legal rights he or she had in the work, to the extent allowable by law. http://ufdc.ufl.edu/AA00016215/00001 | Partager |
A group of men gathered in a church graveyard in Moore Town, Portland, Jamaica ; The Bryant Slides Collection ; The Bryant Slides Collection, Jamaica 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 group of men standing and resting on top of concrete graves in a church cemetery while a school boy holds a homemade cricket bat. The sign on the tree reads “Yes Holiday Markers! Johnnie as…Blue Boy…Present Prince Bunny …Nite… at…Ginger House, Soul Sound By… Blue-Pencil, Refreshments Galore… 50₵ Admission. Easter Mon. 3rd April.” Inhabitants of Moore Town, Portland, Jamaica are descendants of Maroons, escaped slaves who were able to maintain some aspects of their African cultures. Slide labeled Jam. Moore Town. Jamaica -- Caribbean region -- Moore Town, Portland 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 http://ufdc.ufl.edu/AA00031036/00001 | Partager |
Impact of lower plate structure on upper plate deformation at the NW Sumatran convergent margin from seafloor morphology Auteur(s) : Graindorge, D Klingelhoefer, Frauke Sibuet, Jean-claude Mcneill, L Henstock, T Dean, S Gutscher, M Dessa, J Éditeur(s) : Elsevier Résumé : We present results from multibeam bathymetric data acquired during 2005 and 2006, in the region of maximum slip of the 26 Dec. 2004 earthquake (Mw 9.2). These data provide high-resolution images of seafloor morphology of the entire NW Sumatra forearc from the Sunda trench to the submarine volcanic arc just north of Sumatra. A slope gradient analysis of the combined dataset accurately highlights those portions of the seafloor shaped by active tectonic, depositional and/or erosional processes. The greatest slope gradients are located in the frontal 30 km of the forearc, at the toe of the accretionary wedge. This suggests that long-term deformation rates are highest here and that probably only minor amounts of slip are accommodated by other thrust faults further landward. Obvious N-S oriented lineaments observed on the incoming oceanic plate are aligned sub-parallel to the fracture zones associated with the Wharton fossil spreading center. Active strike-slip motion is suggested by recent deformation with up to 20-30 m of vertical offset. The intersection of these N-S elongated bathymetric scarps with the accretionary wedge partly controls the geometry of thrust anticlines and the location of erosional features (e.g. slide scars, canyons) at the wedge toe. Our interpretation suggests that these N-S lineaments have a significant impact on the oceanic plate, the toe of the wedge and further landward in the wedge. Finally, the bathymetric data indicate that folding at the front of the accretionary wedge occurs primarily along landward-vergent (seaward-dipping) thrusts, all unusual style in accretionary wedges worldwide. The N-S elongated lineaments locally act as boundaries between zones with predominant seaward versus landward vergence. Earth and Planetary Science Letters (0012-821X) (Elsevier), 2008-11 , Vol. 275 , N. 3-4 , P. 201-210 Droits : 2008 Elsevier B.V. All rights reserved. http://archimer.ifremer.fr/doc/2008/publication-5166.pdf DOI:10.1016/j.epsl.2008.04.053 http://archimer.ifremer.fr/doc/00000/5166/ | Partager |
Distribution et taxonomie des Howella (Perciformes, percichthyidae) de l'Atlantique Auteur(s) : Post, A Éditeur(s) : Société Française d'Ichtyologie Résumé : On the basis of geographical distribution and morphological analysis of the Atlantic Howella , two subspecies of H. brodiei have been established, H. brodiei brodiei for the IndoPacific and H. brodiei atlanlica for the tropical and boreal Atlantic. H. sherborni has been recognized as a separate species, probably distributed circumglobally in southern Ocean but presently recorded only from the South Atlantic, the central South Pacific and from off southern and south-eastern Australia respectively. H. b. atlanlica and H. b. brodiei are distinct by having 3 scale rows between the lateral line and the origin of the second dorsal fin, while H. sherborni has 4 scale rows there. H. sherborni is in geographical contact with the two subspecies while H. b. brodiei and H. b. atlantica are geographically isolated from each other. The new subspecies, H. b. atlantica occurs in the North Atlantic and the tropical South Atlantic. Specimens from 75 mm SL and longer, predominantly occur in the boreal areas, while specimens less than that length occur in the tropical areas respectively. A day and night bathymetric distribution and a size-depth stratification have been observed. NOT CONTROLLED OCR L'étude de la distribution et l'analyse des caractères méristiques des Howella de l'Atlantique montre la présence dans les régions tempérées nord et tropicales d'une sous-espèce nouvelle, H. brodiei atlantica, et dans la zone tempérée sud de H. sherborni. H. sherborni, caractérisé par 4 rangées d'écailles entre la ligne latérale et l'origine de la seconde dorsale, est au contact, dans l'Atlantique, de H. b. atlantica et, dans les Océans Indien et Pacifique de H. b. brodiei; ces deux sous-espèces, isolées géographiquement, possèdent 3 rangées d'écailles entre la ligne latérale et l'origine de la seconde dorsale. Les exemplaires d'H. b. atlanlica mesurant 75 mm LS ou plus ont été capturés dans la zone tempérée de l'Atlantique nord et ceux de moins de 75 mm principalement dans l'Atlantique tropical et subtropical nord. Les différences de distribution bathymétrique, le jour et la nuit et selon les tailles, sont étudiées chez H. b. atlanlica et H. sherborni. OCR NON CONTRÔLE Cybium (Société Française d'Ichtyologie), 1991-02 , Vol. 15 , N. 2 , P. 111-128 Droits : 1991 Société Française d'Ichtyologie http://archimer.ifremer.fr/doc/1991/publication-3769.pdf http://archimer.ifremer.fr/doc/00000/3769/ | Partager |
Géographie de la ségrégation ethnique et géopolitique des drogues illicites. L'exemple de la Caraïbe indo-créole Auteur(s) : Figueira, Daurius Cruse, Romain Éditeur(s) : Université des Antilles Études caribéennes Résumé : Cet article discute du lien entre racisme, ségrégation ethnique et trafic de drogues illicites dans trois territoires caribéens caractérisés par une forte représentation des populations d'origine indienne et africaine : Trinidad, le Suriname et le Guyana. Pour des raisons historiques, ces territoires ont connu l'apparition relativement récente d'une classe d'entrepreneurs indo-caribéen prospère. D'un autre côté, pour les mêmes raisons, les populations d'origine afro-caribéennes y représentent l'essentiel de la classe pauvre urbaine. C'est sur cette base que s'est développé, à partir des années 1980, le trafic de cocaïne colombienne. D'où, dans la majorité des cas, une spécialisation ethnique des activités liées au trafic. A la base de la pyramide sociale, les jeunes Afro-caribéens des bidonvilles de Buxton (Guyana) ou de Laventille (Trinidad), par exemple, se retrouvent sur-représentés parmi les coupables de crimes commandités liés au trafic. Et émerge un discours raciste présentant les « noirs » comme plus enclin au crime... This paper focus on an analysis of the relationship between racism, segregation and the illicit drug trade inside three Caribbean territories known for their large share of population of Indian and African origin: Trinidad, Suriname and Guyana. Because of historical reasons, those territories have known the recent growth of a wealthy Indo-Caribbean business class. On the other hand, for similar reasons, Afro-Caribbeans today represent most of the urban poor lower class. From the 1980's Colombian cocaine trafficking affected those territories; hence a drug trafficking activities' ethnical specialization. At the bottom of the pyramid, young Afro-Caribbeans are today overwhelmingly represented amongst perpetrators of crime linked to the traffic. Progressively a racist discourse tends here to present « blacks » as more prone to crime... Guyana Suriname Trinité Droits : info:eu-repo/semantics/openAccess urn:doi:10.4000/etudescaribeennes.5334 http://journals.openedition.org/etudescaribeennes/5334 | Partager |
Discrete element simulation of the Jiufengershan rock-and-soil avalanche triggered by the 1999 Chi-Chi earthquake, Taiwan Auteur(s) : Chang, Kuo Jeng Taboada, Alfredo 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) Éditeur(s) : HAL CCSD American Geophysical Union Résumé : International audience We present Contact Dynamics discrete element simulations of the earthquake-triggered Jiufengershan avalanche, which mobilized a 60 m thick, 1.5 km long sedimentary layer, dipping similar to 22 degrees SE toward a valley. The dynamic behavior of the avalanche is simulated under different assumptions about rock behavior, water table height, and boundary shear strength. Additionally, seismic shaking is introduced using strong motion records from nearby stations. We assume that seismic shaking generates shearing and frictional heating along the surface of rupture, which, in turn, may induce dynamic weakening and avalanche triggering; a simple "slip-weakening'' criterion was adopted to simulate shear strength drop along the rupture surface. We investigate the mechanical processes occurring during triggering and propagation of an avalanche mobilizing shallowly dipping layers. Incipient deformation forms a pop-up structure at the toe of the dip slope. As the avalanche propagates, the pop-up deforms into an overturned fold, which overrides the surface of separation along a decollement. Simultaneously, uphill layers slide at high velocity (125 km/h) and are folded and disrupted as they reach the toe of the dip slope. The avalanche foot forms a wedge that is pushed forward as deformed rocks accrete at its rear. We simulated five cross sections across the Jiufengershan avalanche, which differ in the geometry of the surface of separation. Topographic and simulated surface profiles are similar. The friction coefficient at the surface of separation determined from back analysis is abnormally low (mu(SS) = 0.2), possibly due to lubrication by liquefied soils. The granular deposits of simulated earthquake- and rain-triggered avalanches are similar. ISSN: 0148-0227 hal-00420882 https://hal.archives-ouvertes.fr/hal-00420882 DOI : 10.1029/2008JF001075 | Partager |