Éditeur(s) : Direction Générale des Travaux Publics Direction Générale des Travaux Publics ( Haiti )
Résumé : This collection of over 5,000 black and white photographs held by the National Archives of Haiti dates from 1918 to 1945. It contains images of public buildings before and after restoration, public works, monuments, and the visits of U.S. Presidents and other officials.
Haiti

Droits : All rights reserved by the National Archives of Haiti.
W-C.N.P.C-82

North America -- Puerto Rico -- Puerto Rico -- San Juan -- San Juan
Caribbean

Droits : 2007, Erich Kesse - CC: at-nc-sa (Creative Commons license requiring attribution, prohibiting commercial uses, and requiring rights-share for use of this image.)

Éditeur(s) : HAL CCSD European Geosciences Union
Résumé : International audience
Earth deformation is a multi-scale process ranging from seconds (seismic deformation) to millions of years (tectonic deformation). Bridging short- and long-term deformation and developing seismotectonic models has been a challenge in experimental tectonics for more than a century. Since the formulation of Reid's elastic rebound theory 100 years ago, laboratory mechanical models combining frictional and elastic elements have been used to study the dynamics of earthquakes. In the last decade, with the advent of high-resolution monitoring techniques and new rock analogue materials, laboratory earthquake experiments have evolved from simple spring-slider models to scaled analogue models. This evolution was accomplished by advances in seismology and geodesy along with relatively frequent occurrences of large earthquakes in the past decade. This coincidence has significantly increased the quality and quantity of relevant observations in nature and triggered a new understanding of earthquake dynamics. We review here the developments in analogue earthquake modelling with a focus on those seismotectonic scale models that are directly comparable to observational data on short to long timescales. We lay out the basics of analogue modelling, namely scaling, materials and monitoring, as applied in seismotectonic modelling. An overview of applications highlights the contributions of analogue earthquake models in bridging timescales of observations including earthquake statistics, rupture dynamics, ground motion, and seismic-cycle deformation up to seismotectonic evolution.
ISSN: 1869-9510

hal-01553120
https://hal.archives-ouvertes.fr/hal-01553120
https://hal.archives-ouvertes.fr/hal-01553120/document
https://hal.archives-ouvertes.fr/hal-01553120/file/rosenau2017.pdf
DOI : 10.5194/se-8-597-2017

Éditeur(s) : Pergamon-elsevier Science Ltd
Résumé : Society's needs for a network of in situ ocean observing systems cross many areas of earth and marine science. Here we review the science themes that benefit from data supplied from ocean observatories. Understanding from existing studies is fragmented to the extent that it lacks the coherent long-term monitoring needed to address questions at the scales essential to understand climate change and improve geo-hazard early warning. Data sets from the deep sea are particularly rare with long-term data available from only a few locations worldwide. These science areas have impacts on societal health and well-being and our awareness of ocean function in a shifting climate. Substantial efforts are underway to realise a network of open-ocean observatories around European Seas that will operate over multiple decades. Some systems are already collecting high-resolution data from surface, water column, seafloor, and sub-seafloor sensors linked to shore by satellite or cable connection in real or near-real time, along with samples and other data collected in a delayed mode. We expect that such observatories will contribute to answering major ocean science questions including: How can monitoring of factors such as seismic activity, pore fluid chemistry and pressure, and gas hydrate stability improve seismic, slope failure, and tsunami warning? What aspects of physical oceanography, biogeochemical cycling, and ecosystems will be most sensitive to climatic and anthropogenic change? What are natural versus anthropogenic changes? Most fundamentally, how are marine processes that occur at differing scales related? The development of ocean observatories provides a substantial opportunity for ocean science to evolve in Europe. Here we also describe some basic attributes of network design. Observatory networks provide the means to coordinate and integrate the collection of standardised data capable of bridging measurement scales across a dispersed area in European Seas adding needed certainty to estimates of future oceanic conditions. Observatory data can be analysed along with other data such as those from satellites, drifting floats, autonomous underwater vehicles, model analysis, and the known distribution and abundances of marine fauna in order to address some of the questions posed above. Standardised methods for information management are also becoming established to ensure better accessibility and traceability of these data sets and ultimately to increase their use for societal benefit. The connection of ocean observatory effort into larger frameworks including the Global Earth Observation System of Systems (GEOSS) and the Global Monitoring of Environment and Security (GMES) is integral to its success. It is in a greater integrated framework that the full potential of the component systems will be realised. Crown Copyright (C) 2011 Published by Elsevier Ltd. All rights reserved.
Progress In Oceanography (0079-6611) (Pergamon-elsevier Science Ltd), 2011-10 , Vol. 91 , N. 1 , P. 1-33

Droits : 2011 Published by Elsevier Ltd. All rights reserved.
http://archimer.ifremer.fr/doc/00044/15557/15923.pdf
DOI:10.1016/j.pocean.2011.05.001
http://archimer.ifremer.fr/doc/00044/15557/

Éditeur(s) : HAL CCSD Wiley
Résumé : 1. Functional traits are posited to explain interspecific differences in performance, but these relationships are difficult to describe for long-lived organisms such as trees, which exhibit strong ontogenetic changes in demographic rates. Here, we use a size-dependent model of tree growth to test the extent to which of 17 functional traits related to leaf and stem economics, adult stature and seed size predict the ontogenetic trajectory of tree growth.[br/] 2. We used a Bayesian modelling framework to parameterize and contrast three size-dependent diameter growth models using 16 years of census data from 5524 individuals of 50 rain forest tree species: a size-dependent model, a size-dependent model with species-specific parameters and a size-dependent model based on functional traits.[br/] 3. Most species showed clear hump-shaped ontogenetic growth trajectories and, across species, maximum growth rate varied nearly tenfold, from 0.58 to 5.51 mm year(-1). Most species attained their maximum growth at 60% of their maximum size, whereas the magnitude of ontogenetic changes in growth rate varied widely among species.[br/] 4. The Trait-Model provided the best compromise between explained variance and model parsimony and needed considerably fewer parameters than the model with species terms.[br/] 5. Stem economics and adult stature largely explained interspecific differences in growth strategy. Maximum absolute diameter growth rates increased with increasing adult stature and leaf delta(13)C and decreased with increasing wood density. Species with light wood had the greatest potential to modulate their growth, resulting in hump-shaped ontogenetic growth curves. Seed size and leaf economics, generally thought to be of paramount importance for plant performance, had no significant relationships with the growth parameters.[br/] 6. Synthesis. Our modelling approach offers a promising way to link demographic parameters to their functional determinants and hence to predict growth trajectories in species-rich communities with little parameter inflation, bridging the gap between functional ecology and population demography.
ISSN: 0022-0477

hal-01032387
https://hal.archives-ouvertes.fr/hal-01032387
DOI : 10.1111/j.1365-2745.2011.01883.x

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : Cette étude démontre que l’écriture du roman The Swinging Bridge constitue une action de récupération de la mémoire féminine indienne qui réactive les liens entre Indo-Trinidadiens du Canada et Indo-Trinidadiens vivant à Trinidad tout en rétablissant une relation avec l’Inde des origines. Elle montre que, dans l’espace du roman, des relations s’établissent entre le centre historique réel ou mythique des établissements dispersés, et des sociétés d’installation par le biais d’une intrigue qui amène personnages et lecteurs à la conscience de former un peuple en diaspora.Elle analyse les procédés littéraires d’une récupération de la mémoire qui révèle, rectifie et réorganise dans une nouvelle cohérence des fragments épars réintroduisant dans la mémoire collective les qualités ancestrales d’indépendance de la femme indienne. Elle révèle le caractère hybride de l’identité culturelle diasporique qui se construit tout au long du roman puis analyse les enjeux pour l’écrivain féminin postcolonial diasporique de cet acte de représentation.Elle conclut que cette représentation constitue une réécriture contre discursive de l’Histoire trinidadienne et qu’elle introduit la définition d’un continuum identitaire indo-américain qui contribue à résorber la dislocation et la fragmentation qui caractérisent cet espace essentiellement diasporique.
This work proposes to read The Swinging Bridge as a process by which a hybrid Indo-Trinidadian Diaspora is created. It argues that the novel’s recovery of memory constitutes a process by which individual memories turn into a collective diasporic memory which re-establishes links between Indo-Trinidadians dispersed in Canada and Trinidad. We demonstrate that rebinding to the Trinidadian space and recovering part of the memory of the Indian historical centre set the three spaces in a diasporic relation.This study also demonstrates that the novel’s narrative semantics rejects cultural conflict, as well as essentialism and creates a hybrid cultural identity. It establishes that the construction of diaspora at work in The Swinging Bridge advocates for the appreciation routes rather than roots and is compatible with the idea of a multi-locational diasporic consciousness.
Caraïbes
Trinité

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.5757
http://journals.openedition.org/etudescaribeennes/5757

Éditeur(s) : HAL CCSD American Geophysical Union
Résumé : International audience
A CO2-rich brine core-flood experiment in calcite limestone for conditions representative of underground storage (P = 12 MPa and T = 100°C) was performed in order to explore the dissolution mechanisms arising at moderate CO2 partial pressure (0.3 MPa). An increase of the total porosity (φT) accompanied by a persistent permeability (k) decrease was measured. The mechanisms controlling this atypical anticorrelated k − φT relationship were investigated from the analysis of high-resolution X-ray microtomography images of the sample acquired before and after the experiment. All the evidences converge to the conclusion that the ubiquitous decrease of permeability measured during the 44 h of dissolution is due to the clogging of a fraction of the macroporosity by microporous material triggered by the rearrangement of the detached undissolved particles. This mechanism results in the development of low permeability zones bridging the macroporosity.
ISSN: 0094-8276

hal-00903585
https://hal.archives-ouvertes.fr/hal-00903585
DOI : 10.1002/grl.50595

Éditeur(s) : HAL CCSD
Résumé : This paper develops a two-way director-firm fixed effect model to study the relationship between independent directors’ individual heterogeneity and firm operating performance, using French data. This strategy allows considering and differentiating in a unified empirical framework mechanisms related to board functioning and mechanisms related to director selection. We first show that the independence status, netted out unobservable individual heterogeneity, is negatively related to performance. This result suggests that independent board members experience a strong informational gap that outweighs other monitoring benefits. However, we show that industry-specific expertise as well as informal connections inside the boardroom may help to bridge this gap. Second, we provide evidence that independent directors have higher intrinsic ability as compared to affiliated board members, consistent with a reputation-based selection process.
https://hal.archives-ouvertes.fr/hal-01060211

hal-01060211
https://hal.archives-ouvertes.fr/hal-01060211
https://hal.archives-ouvertes.fr/hal-01060211v2/document
https://hal.archives-ouvertes.fr/hal-01060211/file/cahier%202014-29.pdf

Éditeur(s) : Amer Soc Biochemistry Molecular Biology Inc
Résumé : Scleractinian corals are the most basal eumetazoan taxon and provide the biological and physical framework for coral reefs, which are among the most diverse of all ecosystems. Over the past three decades and coincident with climate change, these phototrophic symbiotic organisms have been subject to increasingly frequent and severe diseases, which are now geographically widespread and a major threat to these ecosystems. Although coral immunity has been the subject of increasing study, the available information remains fragmentary, especially with respect to coral antimicrobial responses. In this study, we characterized damicornin from Pocillopora damicornis, the first scleractinian antimicrobial peptide (AMP) to be reported. We found that its precursor has a segmented organization comprising a signal peptide, an acidic proregion, and the C-terminal AMP. The 40-residue AMP is cationic, C-terminally amidated, and characterized by the presence of six cysteine molecules joined by three intramolecular disulfide bridges. Its cysteine array is common to another AMP and toxins from cnidarians; this suggests a common ancestor, as has been proposed for AMPs and toxins from arthropods. Damicornin was active in vitro against Gram-positive bacteria and the fungus Fusarium oxysporum. Damicornin expression was studied using a combination of immunohistochemistry, reverse phase HPLC, and quantitative RT-PCR. Our data show that damicornin is constitutively transcribed in ectodermal granular cells, where it is stored, and further released in response to nonpathogenic immune challenge. Damicornin gene expression was repressed by the coral pathogen Vibrio coralliilyticus. This is the first evidence of AMP gene repression in a host-Vibrio interaction.
Journal Of Biological Chemistry (0021-9258) (Amer Soc Biochemistry Molecular Biology Inc), 2011-06 , Vol. 286 , N. 25 , P. 22688-22698

Droits : 2011 by The American Society for Biochemistry and Molecular Biology, Inc.
http://archimer.ifremer.fr/doc/00039/14996/12433.pdf
DOI:10.1074/jbc.M110.216358
http://archimer.ifremer.fr/doc/00039/14996/

Résumé : Les forêts tropicales contiennent dans leur biomasse aérienne un stock de carbone important à l’échelle de la planète. Mesurer ce stock et comprendre son fonctionnement permet de mieux saisir les enjeux liés à sa protection, sa destruction ou sa modification, ainsi que son rôle dans le cycle du carbone et les mécanismes climatiques globaux. Dans le cadre des problématiques économiques et écologiques liés au climat, les forêts sont progressivement prises en compte dans les programmes internationaux de mesures visant à réduire l’impact anthropique sur le climat (Protocole de Kyoto, 1998 ; Accord de Copenhague, 2009). L’intégration des forêts dans les mécanismes financiers liés au marché du carbone est clairement envisagée dans les années à venir (marché de carbone « d’origine forestière »).L’estimation de la biomasse aérienne d’une parcelle de forêt inventoriée nécessite l’utilisation successive de plusieurs modèles. Dans ces parcelles, le diamètre et l’espèce de chaque arbre sont renseignés. Ensuite, ces parcelles sont utilisées comme références pour l’extrapolation spatiale des valeurs de biomasse. Cette extrapolation repose souvent sur le traitement de signaux aériens (avions, satellites). Il est aussi possible d’utiliser covariables environnementales (climat, géologie, …).L’incertitude associée à l’estimation de la biomasse d’une région est le résultat de toutes les incertitudes associées à ces différents processus. Les connaissances actuelles ne nous permettent pas de quantifier cette incertitude. L’objectif de la thèse est de développer une méthodologie d’estimation de la biomasse qui permette la propagation des incertitudes ainsi que l’identification des sources de cette incertitude.Modèle de hauteur : Nous proposons un nouveau modèle de hauteur pour les forêts tropicales. Les paramètres de ce modèle ont un sens écologique et peuvent être prédits par des variables décrivant le peuplement sur lequel il est appliqué. Nous avons utilisé les données des projets Amalin et Bridge et sélectionné 42 parcelles réparties en Guyane dans lesquelles le diamètre et la hauteur de chaque arbre ont été mesurés.Modèle de densité de bois : Un modèle à été conçu pour associer à chaque espèce une distribution de densité de bois et non une valeur fixe. Nous avons utilisé les données du projet Bridge dans lequel la densité de bois a été mesurée sur 2504 arbres représentant 466 espèces.Modèle de biomasse: Nous avons montré par une analyse de sensibilité que les incertitudes des prédictions de hauteur et de densité de bois n’avaient qu’une part négligeable dans l’incertitude des prédictions de biomasse. L’amélioration de la précision de ces modèles n’est donc pas une priorité. En revanche, le modèle de hauteur peut être une source de biais.Modélisation spatiale : Les modèles développés ont été appliqués à différents réseaux de parcelles couvrant bien la zone littorale guyanaise : inventaires papetiers de l’ONF, réseau Guyafor, projet Amalin… Les prédictions de biomasse de ces parcelles sont utilisées dans un modèle spatiale. Nous produisons ainsi une carte de biomasse guyanaise associée à une carte de l’incertitude de cette estimation.
Tropical forest yield and important part of the aerial vegetation carbon stock on earth. Measuring and understanding this stock distribution is crucial for the management of the tropical forests facing the actual environmental challenges (REDD+, carbon market).Aerial Biomass estimation of forest census plots requires few models depending on the precision of the inventory: diameter models, height models, wood density models. Spatial extrapolation between census plots relies on aerial data (satellite measurements, images) or ground-based data (geology, altitude).The uncertainty of the estimation of a region’s biomass is the result of the uncertainty brought by all these models. The aim of the thesis is to develop models and methods to estimate the biomass of a region while propagating the uncertainties. This is applied to the neo-tropical forest of French Guiana (South America, Guianas Plateau).

http://www.theses.fr/2012AGUY0567/document

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
: Previously, we demonstrated that eicosapentaenoic acid enhanced ethanol-induced oxidative stress and cell death in primary rat hepatocytes via an increase in membrane fluidity and lipid raft clustering. In this context, another n-3 polyunsaturated fatty acid, docosahexaenoic acid (DHA), was tested with a special emphasis on physical and chemical alteration of lipid rafts. Pretreatment of hepatocytes with DHA reduced significantly ethanol-induced oxidative stress and cell death. DHA protection could be related to an alteration of lipid rafts. Indeed, rafts exhibited a marked increase in membrane fluidity and packing defects leading to the exclusion of a raft protein marker, flotillin. Furthermore, DHA strongly inhibited disulfide bridge formation, even in control cells, thus suggesting a disruption of protein-protein interactions inside lipid rafts. This particular spatial organization of lipid rafts due to DHA subsequently prevented the ethanol-induced lipid raft clustering. Such a prevention was then responsible for the inhibition of phospholipase C-γ translocation into rafts, and consequently of both lysosome accumulation and elevation in cellular low-molecular-weight iron content, a prooxidant factor. In total, the present study suggests that DHA supplementation could represent a new preventive approach for patients with alcoholic liver disease based upon modulation of the membrane structures.
ISSN: 0278-6915

hal-00860153
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00860153
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00860153/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00860153/file/Sergent-et-al-incl-figures-accepted.pdf
DOI : 10.1016/j.fct.2013.07.061

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
The shallow-water bivalve Codakia orbiculata which harbors gill-endosymbiotic sulfur-oxidizing ?-proteobacteria can lose and acquire its endosymbionts throughout its life. Long-term starvation and recolonization experiments led to changes in the organization of cells in the lateral zone of gill filaments. This plasticity is linked to the presence or absence of gill-endosymbionts. Herein, we propose that this reorganization can be explained by three hypotheses: (a) a variation in the number of bacteriocytes and granule cells due to proliferation or apoptosis processes, (b) a variation of the volume of these two cell types without modification in the number, and (c) a combination of both number and cell volume variation. To test these hypotheses, we analyzed cell reorganization in terms of proliferation and apoptosis in adults submitted to starvation and returned to the field using catalyzed reporter deposition fluorescence in situ hybridization, immunohistochemistry, and structural analyses. We observed that cell and tissue reorganization in gills filaments is due to a variation in cell relative abundance that maybe associated with a variation in cell apparent volume and depends on the environment. In fact, bacteriocytes mostly multiply in freshly collected and newly recolonized individuals, and excess bacteriocytes are eliminated in later recolonization stages. We highlight that host tissue regeneration in gill filaments of this symbiotic bivalve can occur by both replication of existing cells and division of undifferentiated cells localized in tissular bridges, which might be a tissue-specific multipotent stem cell zone.
ISSN: 1059-910X

hal-01545915
https://hal.archives-ouvertes.fr/hal-01545915
DOI : 10.1002/jemt.22041

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The mycotoxin alternariol (AOH), a frequent contaminant in fruit and cereal products, is known to induce DNA damage with subsequent cell cycle arrest. Here we elucidated the effects of AOH on stages of cell cycle progression using the RAW 264.7 macrophage model. AOH resulted in an accumulation of cells in the G2/M-phase (4N). Most cells exhibited a large G2 nucleus whereas numbers of true mitotic cells were reduced relative to control. Both cyclin B1 and p-cdc2 levels increased, while cyclin B1 remained in the cytoplasm; suggesting arrest in the G2/M transition point. Remarkably, after exposure to AOH for 24h, most of the cells exhibited abnormally shaped nuclei, as evidenced by partly divided nuclei, nuclear blebs, polyploidy and micronuclei (MN). AOH treatment also induced abnormal Aurora B bridges, suggesting that cytokinesis was interfered within cells undergoing karyokinesis. A minor part of the resultant G1 tetraploid (4N) cells re-entered the S-phase and progressed to 8N cells.
ISSN: 0378-4274

inserm-00871659
http://www.hal.inserm.fr/inserm-00871659
http://www.hal.inserm.fr/inserm-00871659/document
http://www.hal.inserm.fr/inserm-00871659/file/Alternariol_induces_abnormal_nuclear_morphology_and_cell_cycle_arrest_in_murine_RAW_264.7_macrophages-accepted.pdf
DOI : 10.1016/j.toxlet.2013.02.012

Éditeur(s) : HAL CCSD American Geophysical Union (AGU)
Résumé : New structural, microstructural, and 40Ar/39Ar data from the NW Massif Central (France) provide additional constraints on the timing and tectonic setting of late Variscan granite magmatism. Previous studies had emphasized the role of late orogenic extension in the emplacement of granite plutons in the Limousin region. In contrast, the new data set is consistent with syntectonic emplacement of magma in a dextral simple shear active from 350 to 300 Ma in a transpressional regime. As an alternative hypothesis to late orogenic extension, we propose that magmas migrated into tensional bridges between active P shears associated with a lithospheric shear zone comparable to a pop-up structure. The Galician region, in the western end of the Ibero-Armorican tectonic arc, exhibits major left-lateral ductile shear zones which can be interpreted as conjugate structures to the Limousin and Armorican shear zones. Citation: Ge´belin, A., M. Brunel, P. Monie´, M. Faure, and N. Arnaud (2007), Transpressional tectonics and Carboniferous magmatism in the Limousin, Massif Central, France: Structural and 40Ar/39Ar investigations
ISSN: 0278-7407

hal-00104212
https://hal-insu.archives-ouvertes.fr/hal-00104212
https://hal-insu.archives-ouvertes.fr/hal-00104212/document
https://hal-insu.archives-ouvertes.fr/hal-00104212/file/2005TC001822.pdf
DOI : 10.1029/2005TC001822

Éditeur(s) : HAL CCSD
Résumé : International audience
The French-Dutch island of St Martin, of which the French part became a French Overseas Collectivity on 14 July 2007, is characterized by a multilingual environment and presents the question of which educational and didactic strategies to adopt for French language teaching in these linguistic circumstances. Non-French-speaking children are assessed by the educational team and are given elementary language teaching in CLIN (beginners’ classes for non-French-speaking children). The CLIN teaching relies on methods based on the discipline of French as a Second Language and is presented as a transitional discipline which is needed to ensure comprehension across all educational disciplines. As the CLIN is not in a position to avoid the differences in language, it needs to reinforce the bridges between languages, not only to help the pupils to understand their plural identity but also to reinforce their L1 and TL practices. In these circumstances it is essential to consider the use of multilingual teaching methods.
Interplay : A journal of Languages, Linguistics and Literature

hal-01532982
https://hal.archives-ouvertes.fr/hal-01532982

Éditeur(s) : HAL CCSD Elsevier
Résumé : Water molecules play a fundamental role in the physics of slow crack propagation in glasses. It is commonly understood that, during stress-corrosion, water molecules that move in the crack cavity effectively reduce the bond strength at the strained crack tip and, thus, support crack propagation. Yet the details of the environmental condition at the crack tip in moist air are not well determined. In a previous work, we reported direct evidence of the presence of a 100 nm long liquid condensate at the crack tip in fused silica glass during very slow crack propagation (10(-9)-10(-10) m/s). These observations are based on in situ AFM phase imaging techniques applied on DCDC glass specimens in controlled atmosphere. Here, we discuss the physical origin of the AFM phase contrast between the liquid condensate and the glass surface in relation to tip-sample adhesion induced by capillary bridges. We then report new experimental data on the water condensation length increase with relative humidity in the atmosphere. The measured condensation lengths were much larger than what predicted using the Kelvin equation and expected geometry of the crack tip.
ISSN: 0022-3093

hal-00412153
https://hal.archives-ouvertes.fr/hal-00412153
DOI : 10.1016/j.jnoncrysol.2007.06.090

Éditeur(s) : HAL CCSD Wiley-Blackwell
Résumé : International audience
The shallow-water bivalve Codakia orbiculata which harbors gill-endosymbiotic sulfur-oxidizing g-proteobacteria can lose and acquire its endosymbionts throughout its life. Longterm starvation and recolonization experiments led to changes in the organization of cells in the lateral zone of gill filaments. This plasticity is linked to the presence or absence of gill-endosymbionts. Herein, we propose that this reorganization can be explained by three hypotheses: (a) a variation in the number of bacteriocytes and granule cells due to proliferation or apoptosis processes, (b) a variation of the volume of these two cell types without modification in the number, and (c) a combination of both number and cell volume variation. To test these hypotheses, we analyzed cell reorganization in terms of proliferation and apoptosis in adults submitted to starvation and returned to the field using catalyzed reporter deposition fluorescence in situ hybridization, immunohistochemistry, and structural analyses. We observed that cell and tissue reorganization in gills filaments is due to a variation in cell relative abundance that maybe associated with a variation in cell apparent volume and depends on the environment. In fact, bacteriocytes mostly multiply in freshly collected and newly recolonized individuals, and excess bacteriocytes are eliminated in later recolonization stages. We highlight that host tissue regeneration in gill filaments of this symbiotic bivalve can occur by both replication of existing cells and division of undifferentiated cells localized in tissular bridges, which might be a tissue-specific multipotent stem cell zone.
Microscopy Research and Technique

hal-00743036
https://hal-uag.archives-ouvertes.fr/hal-00743036

Éditeur(s) : HAL CCSD American Physical Society
Résumé : International audience
It is getting increasingly evident that physical properties such as elastoviscoplastic properties of living materials are quite important for the process of tissue development, including regulation of genetic pathways. Measuring such properties in vivo is a complicated and challenging task. In this paper, we present an instrument, a scanning air puff tonometer, which is able to map point by point the viscoelastic properties of flat or gently curved soft materials. This instrument is an improved version of the air puff tonometer used by optometrists, with important modifications. The instrument allows one to obtain a direct insight into gradients of material properties in vivo. The instrument capabilities are demonstrated on substances with known elastoviscoplastic properties and several biological objects. On the basis of the results obtained, the role of the gradients of elastoviscoplastic properties is outlined for the process of angiogenesis, limb development, bacterial colonies expansion, etc. which is important for bridging the gaps in the theory of the tissue development and highlighting new possibilities for tissue engineering, based on a clarification of the role of physical features in developing biological material.
ISSN: 1539-3755

hal-00666187
https://hal.archives-ouvertes.fr/hal-00666187
https://hal.archives-ouvertes.fr/hal-00666187/document
https://hal.archives-ouvertes.fr/hal-00666187/file/FLEURY_PRE_2010.pdf
DOI : 10.1103/PhysRevE.81.021920

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Metalloproteases involved in extracellular matrix remodeling play a pivotal role in cell response by regulating the bioavailability of cytokines and growth factors. Recently, the disintegrin and metalloprotease, ADAMTS1 has been demonstrated to be able to activate the transforming growth factor TGF-β, a major factor in fibrosis and cancer. The KTFR sequence from ADAMTS1 is responsible for the interaction with the LSKL peptide from the latent form of TGF-β, leading to its activation. While the atomic details of the interaction site can be the basis of the rational design of efficient inhibitory molecules, the binding mode of interaction is totally unknown. In this study, we show that recombinant fragments of human ADAMTS1 containing KTFR sequence keep the ability to bind the latent form of TGF-β. The recombinant fragment with the best affinity is modeled to investigate the binding mode of LSKL peptide with ADAMTS1 at the atomic level. Using a combined approach with molecular docking and multiple independent molecular dynamics (MD) simulations, we provide the binding mode of LSKL peptide with ADAMTS1. The MD simulations starting with the two lowest energy model predicted by molecular docking shows stable interactions characterized by 3 salt bridges (K3-NH3+ with E626-COO−; L4-COO− with K619-NH3+; L1-NH3+ with E624-COO−) and 2 hydrogen bonds (S2-OH with E623-COO−; L4-NH with E623-COO−). The knowledge of this interaction mechanism paves the way to the design of more potent and more specific inhibitors against the inappropriate activation of TGF-β by ADAMTS1 in liver diseases
ISSN: 1476-9271

hal-01269916
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01269916
DOI : 10.1016/j.compbiolchem.2016.01.012
PUBMED : 26878129

Résumé : Le Brésil et la France partagent une frontière commune sur plus de 700 kilomètres, via la Guyane, région monodépartementale d’Outre-Mer française, et l’Amapá, Etat de la République fédérative du Brésil. Réalité socio-spatiale en marges à toutes les échelles malgré le différentiel socio-économique fort qu’elle marque, la frontière franco-brésilienne est devenue, depuis les années 1990, une interface politique, support de la relance des relations internationales franco-brésiliennes et des relations entre Guyane et Amapá.La thèse pose la question de cet écart en se concentrant sur la partie estuarienne de la frontière fluviale de l’Oyapock, autour des bourgs riverains de Saint-Georges (Guyane française) et d’Oiapoque (Brésil), entre lesquels un pont binational d’envergure est en construction, malgré leur rattachement routier à la marge aux polarités régionales de Cayenne et de Macapá.
Brazil and France share a common border of over 700 km via French Guiana, a French Overseas monodepartmental region, and Amapá, State of the Federal Republic of Brazil. Socio-spatial margin at all scales despite the strong socio-economic differential it marks, the Franco-Brazilian border has become since the 1990s a political interface, support for the revival of the Franco-Brazilian international relations and of the relations between French Guiana and Amapá. The thesis raises the question of this gap, focusing on the estuarine portion of the border river of the Oyapock, around the towns of Saint-Georges (French Guiana) and Oiapoque (Brazil) ; a significant bi-national bridge is under construction between these two towns, despite their road connection as margins to the regional polarities of Cayenne and Macapá.
Brasil e França compartilham uma fronteira comum com mais de 700 km através da Guiana Francesa, Região monodepartamental ultramarina francesa, e do Amapá, Estado da República Federativa do Brasil. Realidade sócio-espacial à margem a todas as escalas, apesar do forte diferencial sócio-econômico que a marca, a fronteira franco-brasileira tornou-se, desde os anos 90, uma interface política, suporte para a retomada das relações internacionais franco-brasileiras e das relações entre a Guiana Francesa e o Amapá. A tese expõe a questão deste desnível, centrando-se na porção estuarina da fronteira fluvial do Oiapoque, ao redor das pequenas cidades de Saint-Georges (Guiana Francesa) e de Oiapoque (Brasil), entre as quais uma ponte binacional de grande porte está em construção, apesar da ligação rodoviária delas como margens aos pólos regionais de Caiena e Macapá.

http://www.theses.fr/2012AGUY0504/document