Éditeur(s) : 3e Rencontres Scientifiques Internationales du contrat de baie de la rade de Brest. Brest 14-16 mars 1995
Résumé : Aquaculture production of scallop has been identified by a series of technical operations during the past ten years programme under a partnership involving the fishermen organizations with regional and national grants. 3 million juveniles have been produced annually, giving a potential recapture by fishing of 100 to 120 tonnes 3 years later. Results in terms of technical and economical approach have pointed out the principal unknown factors responsable for high costs. 7he pilot programme aims to increase the production to reach a level of 5 million juveniles to support the fishery of the rade de Brest and induce new management of the resources. Two priorities were selected, control of the reproduction in the hatchery to obtain reliable larval and postlarval rearing during a larger period of the year, mainly during summer, and improvement of survival rate of the juveniles by minimizing stress when manipulating the animals. But biological and ecological mechanisms are still poorly understoodfor scallop and generally bibvalves and the last two years have shown unchanged results. The technical pathways shows interactions between the different steps of the production of juveniles where different teams operate separately. Management of the livestock has to be developed to increase the survival rate by better breeding but also to reduce the loss by adapted and coordinated practices. Recapture results indicate that fishery strategies depend also on the production of juvenile, and could orientate the management of the hatchery.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00044/15494/12860.pdf
http://archimer.ifremer.fr/doc/00044/15494/

Éditeur(s) : HAL CCSD
Résumé : 12 pages, in French. Colloque international et interdisciplinaire pour les enjeux et usages des technologies de l'information et de la communication, 2015 (EUTIC 2015)
International audience
The emergence of new communication media such as blogs, online newspapers and social networks allow us to go further in the understanding of human behavior. Indeed, these public exchange spaces are now firmly planted in our modern society and appear to be powerful sensors of social behavior and opinion movements. In this paper, we focus on information spreading and attempt to understand what are the conditions in which a person decides to speak on a subject. For this purpose, we propose a set of measures that aim to characterize the diffusion behavior. Our measures have been used on messages related to two events that took place in January 2015: presentation by Microsoft of a new virtual reality headset and the election of a political party of radical left in Greece.
Colloque international et interdisciplinaire pour les enjeux et usages des technologies de l'information et de la communication, 2015 (EUTIC 2015)
Schoelcher, France

hal-01514258
https://hal.archives-ouvertes.fr/hal-01514258
ARXIV : 1602.00252

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The geologic evolution of the South Armenian Block (SAB) in the Mesozoic is reconstructed from a structural, metamorphic, and geochronologic study including U–Pb and 40Ar/39Ar dating. The South Armenian Block Crystalline Basement (SABCB) outcrops solely in a narrow tectonic window, NW of Yerevan. The study of this zone provides key and unprecedented information concerning closing of the Northern Neotethys oceanic domain north of the Taurides-Anatolides platform from the Middle Jurassic to the Early Cretaceous. The basement comprises of presumed Proterozoic orthogneiss overlain by metamorphosed pelites as well as intrusions of granodiorite and leucogranite during the Late Jurassic and Early Cretaceous. Structural, geochronological and petrological observations show a multiphased evolution of the northern margin of the SAB during the Late Jurassic and Early Cretaceous. A south-dipping subduction under the East Anatolian Platform-South Armenian Block (EAP-SAB) is proposed in order to suit recent findings pertaining emplacement of relatively hot subduction related granodiorite as well as the metamorphic evolution of the crystalline basement in the Lesser Caucasus area. The metamorphism is interpreted as evidencing: (1) M1 Barrovian MP–MT conditions (staurolite–kyanite) at c. 157–160 Ma and intrusion of dioritic magmas at c. 150–156 Ma, (2) near-adiabatic decompression is featured by partial melting and production of leucogranites at c. 153 Ma, followed by M2 HT–LP conditions (andalusite–K-feldspar). A phase of shearing and recrystallization is ascribed to doming at c. 130–150 Ma and cooling at 400 °C by c. 123 Ma (M3). Structural observations show (1) top to the north shearing during M1 and (2) radial extension during M2. The extensional event ends by emplacement of a thick detrital series along radial S, E and W-dipping normal faults. Further, the crystalline basement is unconformably covered by Upper Cretaceous-Paleocene series dated by nannofossils, evolving from Maastrichtian marly sandstones to Paleocene limestones.
ISSN: 0743-9547

hal-01174077
https://hal.archives-ouvertes.fr/hal-01174077
DOI : 10.1016/j.jseaes.2014.07.018

Éditeur(s) : HAL CCSD Springer Verlag/EDP Sciences
Résumé : International audience
Background : This study examines the radial trend in wood stiffness of tropical rainforest trees. The objective was to determine if the type of growing environment (exposed plantation or dense primary forest) would have an effect on this radial trend. Methods : The axial elastic modulus of wood samples, representing a pith to bark cross-section, of six trees from several French Guianese species (two of Eperua falcata, one of Eperua grandiflora, two of Carapa procera and one of Symphonia gloubulifera) was measured using a dynamic "forced vibration" method. Results : Primary forest trees were observed to have a decrease in wood stiffness from pith to bark, whereas plantation trees, from the same genus or species, displayed a corresponding increase in wood stiffness. Juvenile wood stiffness appears to vary depending on the environment in which the tree had grown. Conclusion : We suggest that the growth strategy of primary forest trees is to produce wood resistant to selfbuckling so that the height of the canopy may be obtained with the maximum of efficiency. In contrast, the growth strategy of the trees growing in an exposed plantation is to produce low-stiffness wood, important to provide flexibility in wind. Further experiments to study the behaviour of more species, with more individuals per species, growing across a range of physical environments, are required.
ISSN: 1286-4560

hal-00644335
https://hal.archives-ouvertes.fr/hal-00644335
https://hal.archives-ouvertes.fr/hal-00644335/document
https://hal.archives-ouvertes.fr/hal-00644335/file/McLean_al.pdf
DOI : 10.1007/s13595-011-0085-z

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
Radial trends of vibrational properties, including the specific dynamic modulus (E'/r) and damping coefficient (tand), were investigated for 3 tropical rainforest hardwood species, Simarouba amara, Carapa procera and Symphonia globulifera by free-free flexural vibration test. The microfibril angle (MFA) was estimated through X-Ray diffraction. Consistent patterns of radial variations were observed for all studied properties. E'/r was found to decrease from pith to bark, which is strongly related to the increasing pith-bark trend of MFA. The variation of tand along the radius can be partly explained by MFA, and partly by the gradient of extractives due to heartwood formation. The coupling effect of MFA and extractives could be separated through the analysis of log(tand) - log(E'/r) diagram. For the studied species, the extractive content putatively associated to heartwood formation generally tends to decrease the wood damping coefficient. However, this weakening effect of extractives was not observed for inner part of the heartwood, suggesting the mechanical action of extractives was reduced during their chemical ageing.
ISSN: 1435-0211

hal-00797055
https://hal.archives-ouvertes.fr/hal-00797055
https://hal.archives-ouvertes.fr/hal-00797055/document
https://hal.archives-ouvertes.fr/hal-00797055/file/Radial_variations_vibrational_Zhang_al.pdf

Éditeur(s) : HAL CCSD Oxford Scholarship Online
Résumé : Brain aromatase in fish is an exciting research topic because of several unconventional features that challenge the established view based on studies in other vertebrates. First, the brain of teleost fish exhibits a high degree of aromatase activity, especially in sexually mature animals. Given the emerging roles of estrogens in neurogenesis, the unique features of the adult fish brain suggest that, in addition to classical functions on brain sexual differentiation and sexual behavior, aromatase expression in radial glial cells could be involved in the modulation of the high proliferative activity in the brain of fish.
Brain Aromatase, Estrogens, and Behavior

ISBN : 9780199841196
hal-00905522
https://hal.archives-ouvertes.fr/hal-00905522
DOI : 10.1093/acprof:oso/9780199841196.003.0007

Éditeur(s) : HAL CCSD IOS Press
Résumé : International audience
Sickle cell anemia (SCA) is an inherited red blood cells (RBC) disorder characterized by significantly decreased RBC deformability. The present study aimed to assess whether modulation of RBC Nitric Oxide Synthase (RBC-NOS) activation could affect RBC deformability in SCA.Blood of twenty-five SCA patients was treated for 1 hour at 37°C with Phosphate Buffered Saline (PBS) or PBS containing 1% of Dimethylsulfoxyde as control, L-arginine or N(5)-(1-Iminoethyl)-L-ornithine (L-NIO) to directly stimulate or inhibit RBC-NOS, insulin or wortmannin to indirectly stimulate or inhibit RBC-NOS through their effects on the PI3 Kinase/Akt pathway, and sodium nitroprusside (SNP) and 2-(4-Carboxyphenyl)-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide (cPTIO) as NO donor and NO scavenger, respectively. RBC deformability was measured by ektacytometry at 3 Pa.RBC deformability significantly increased after insulin treatment and significantly decreased after L-NIO and wortmannin incubation. The other conditions did not affect deformability. Significantly increased nitrotyrosine levels, a marker of enhanced free radical generation, were detected by immunohistochemistry in SNP and insulin treated samples.These data suggest that RBC deformability of SCA can be modulated by RBC-NOS activity but also that oxidative stress may impair effectiveness of RBC-NOS produced NO.
ISSN: 1386-0291

hal-01669738
https://hal.univ-antilles.fr/hal-01669738
DOI : 10.3233/CH-162042

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
Brain-derived neurotrophic factor (BDNF), a member of the neurotrophin family, has emerged as an active mediator in many essential functions in the central nervous system of mammals. BDNF plays significant roles in neurogenesis, neuronal maturation and/or synaptic plasticity and is involved in cognitive functions such as learning and memory. Despite the vast literature present in mammals, studies devoted to BDNF in the brain of other animal models are scarse. Zebrafish is a teleost fish widely known for developmental genetic studies and is emerging as model for translational neuroscience research. In addition, its brain shows many sites of adult neurogenesis allowing higher regenerative properties after traumatic injuries. To add further knowledge on neurotrophic factors in vertebrate brain models, we decided to determine the distribution of bdnf mRNAs in the larval and adult zebrafish brain and to characterize the phenotype of cells expressing bdnf mRNAs by means of double staining studies. Our results showed that bdnf mRNAs were widely expressed in the brain of 7 days old larvae and throughout the whole brain of mature female and male zebrafish. In adults, bdnf mRNAs were mainly observed in the dorsal telencephalon, preoptic area, dorsal thalamus, posterior tuberculum, hypothalamus, synencephalon, optic tectum and medulla oblongata. By combining immunohistochemistry with in situ hybridization, we showed that bdnf mRNAs were never expressed by radial glial cells or proliferating cells. By contrast, bdnf transcripts were expressed in cells with neuronal phenotype in all brain regions investigated. Our results provide the first demonstration that the brain of zebrafish expresses bdnf mRNAs in neurons and open new fields of research on the role of the BDNF factor in brain mechanisms in normal and brain repairs situations.
ISSN: 1932-6203

hal-01359562
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01359562
DOI : 10.1371/journal.pone.0158057
PUBMED : 27336917

Éditeur(s) : HAL CCSD National Academy of Sciences
Résumé : International audience
All evolutionary biologists are familiar with evolutionary units that evolve by vertical descent in a tree-like fashion in single lineages. However, many other kinds of processes contribute to evolutionary diversity. In vertical descent, the genetic material of a particular evolutionary unit is propagated by replication inside its own lineage. In what we call introgressive descent, the genetic material of a particular evolutionary unit propagates into different host structures and is replicated within these host structures. Thus, introgressive descent generates a variety of evolutionary units and leaves recognizable patterns in resemblance networks. We characterize six kinds of evolutionary units, of which five involve mosaic lineages generated by introgressive descent. To facilitate detection of these units in resemblance networks, we introduce terminology based on two notions, P3s (subgraphs of three nodes: A, B, and C) and mosaic P3s, and suggest an apparatus for systematic detection of introgressive descent. Mosaic P3s correspond to a distinct type of evolutionary bond that is orthogonal to the bonds of kinship and genealogy usually examined by evolutionary biologists. We argue that recognition of these evolutionary bonds stimulates radical rethinking of key questions in evolutionary biology (e.g., the relations among evolutionary players in very early phases of evolutionary history, the origin and emergence of novelties, and the production of new lineages). This line of research will expand the study of biological complexity beyond the usual genealogical bonds, revealing additional sources of biodiversity. It provides an important step to a more realistic pluralist treatment of evolutionary complexity.
ISSN: 0027-8424

hal-01544803
https://hal.archives-ouvertes.fr/hal-01544803
DOI : 10.1073/pnas.1206541109

Éditeur(s) : HAL CCSD Taylor & Francis
Résumé : International audience
We provide an inequality relating the radial directional derivative and the subdifferential of proper lower semicontinuous functions, which extends the known formula for convex functions. We show that this property is equivalent to other subdifferential properties of Banach spaces, such as controlled dense subdifferentiability, optimality criterion, mean value inequality and separation principles. As an application, we obtain a first-order sufficient condition for optimality, which extends the known condition for differentiable functions in finite-dimensional spaces and which amounts to the maximal monotonicity of the subdifferential for convex lower semicontinuous functions. Finally, we establish a formula describing the subdifferential of the sum of a convex lower semicontinuous function with a convex inf-compact function in terms of the sum of their approximate epsilon-subdifferentials. Such a formula directly leads to the known formula relating the directional derivative of a convex lower semicontinuous function to its approximate epsilon-subdifferential.
ISSN: 0233-1934

hal-00694601
https://hal.archives-ouvertes.fr/hal-00694601
DOI : 10.1080/02331934.2011.645034

Éditeur(s) : Amer Geophysical Union
Résumé : Recent ROV dives and high-resolution bathymetric data acquired over the Ashadze fields on the Mid-Atlantic Ridge (13 degrees N) allow us to derive constraints on the regional and local geological setting of ultramafic-hosted hydrothermal fields. The active vent fields of Ashadze hydrothermal fields are located in the western axial valley wall, downslope from the termination of a prominent corrugated surface and in a transitional domain with respect to ridge segmentation. The study of the shipboard and ROV bathymetry shows that decameter (100 m by 60 m) to kilometer-scaled rockslides shape the axial valley wall slopes in this region. The Ashadze 1 vent field occurs on a coherent granular landslide rock mass that is elongated in an E-W direction. The Ashadze 1 vent field comprises hundreds of active and inactive sulfide chimneys. The Ashadze 2 vent field is located in a NNE-trending linear depression which separates outcrops of gabbros and serpentinized peridotites. Active black smokers in the Ashadze 2 field are located on ultramafic substratum in a 40-m diameter crater, 5-m deep. This crater recalls similar structures described at some vents of the Logatchev hydrothermal field (Mid-Atlantic Ridge 15 degrees N). We discuss the mode of formation for these craters, as well as that for a breadcrust-like array of radial fissures identified at Ashadze 1. We propose that hydrothermalism at Ashadze can be an explosive phenomena associated with geyser-like explosions. Our study also constrains the geological and geophysical context of the ultramafic-hosted Ashadze hydrothermal system that may use the oceanic detachment fault as a preferred permeability conduit.
Geochemistry Geophysics Geosystems (1525-2027) (Amer Geophysical Union), 2012-11 , Vol. 13 , N. 1 , P. Q0AG14

Droits : 2012. American Geophysical Union. All Rights Reserved.
http://archimer.ifremer.fr/doc/00111/22223/19895.pdf
DOI:10.1029/2012GC004433
http://archimer.ifremer.fr/doc/00111/22223/

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
In this work, we have studied quenching of the fluorescence of two well-known oxygen probes, 1-pyrene butyric acid (PBA) and tris(2,2'-bipyridine)ruthenium ([Ru(bpy)(3)](2+)) by reactive oxygen species (superoxide anion, nitric oxide derivative, hydrogen peroxide) and by the O(2) molecule. Both, time-resolved and steady state fluorescence measurements were performed in solution (ethanol, dimethyl sufoxide, water) and in micelles of Sodium Dodecyl Sulfate that serve as a model for membrane-containing biological structures. We have found that only the free radicals and O(2) can actively quench for the two probes, but not the diamagnetic H(2)O(2). Our data correspond to the classical Stern-Volmer equation. H(2)O(2) has an effect only at high molar concentrations (>0.1 M). In contrast, effective concentrations of free radicals and O(2) that lead to quenching are in millimolar range. In conclusion, our methods allows for detecting global ROS that are small free radicals without interference from the reactive hydroxyl radical. Our data suggest that the method can be used for the quantification of ROS in individual living cells based on the measurement of fluorescence lifetime of those probes
ISSN: 1053-0509

hal-01326234
https://hal.archives-ouvertes.fr/hal-01326234
DOI : 10.1007/s10895-008-0425-z

Résumé : La Petite Mer de Gavres est une zone conchylicole, classée salubre, et exploitée en pêche à pied, avec une commercialisation directe difficile à contrôler. A la suite de problèmes de salubrité rencontrés sur les coquillages de cette zone, une étude bactériologique a été réalisée par IFREMER de juin 1986 à septembre 1987, suivie en 1988 d'une comparaison des contaminations des différentes espèces de coquillages. Ces études montrent que l'insalubrité de certains coquillages de la petite Mer de Gavres est particulièrement évidente pour les fouisseurs (coques et palourdes). Malgré la proximité des sources de pollutions de la Rade de Lorient et la petitesse du bassin versant de la Petite Mer, c'est ce dernier qui la contamine, notamment aux abords du bourg de Riantec qui apparaît nettement insalubre. Cette pollution par les eaux douces d'un bassin versant très limité induit évidemment une forte saisonnalité des contaminations qui augmentent significativement en automne-hiver.

Droits : 1989 Ifremer
http://archimer.ifremer.fr/doc/00128/23945/21903.pdf
http://archimer.ifremer.fr/doc/00128/23945/

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The last step of oestrogen biosynthesis is catalyzed by the enzyme aromatase, the product of the cyp19a1 gene. In vertebrates, cyp19a1 is expressed in the brain resulting in a local oestrogen production that seems important not only for the control of reproduction-related circuits and sexual behaviour, but also for the regulation of neural development, synaptic plasticity and cell survival. In adult amphibians, the precise sites of expression of cyp19a1 in the brain have not been investigated which prevents proper understanding of its potential physiological functions. The present study aimed at examining the precise neuroanatomical distribution of cyp19a1 transcripts in adult brains of both male and female Xenopus. We found that cyp19a1 expression is highly regionalized in the brains of both sexes. The highest expression was found in the anterior part of the preoptic area and in the caudal hypothalamus, but significant levels of cyp19a1 transcripts were also found in the supraoptic paraventricular and suprachiasmatic areas, and in brain regions corresponding to the septum, bed nucleus of the stria terminalis and amygdala. Importantly, no obvious difference between male and female Xenopus was detected at the level of cyp19a1 transcripts. Additionally, in the brain of adult Xenopus, cyp19a1 transcripts were detected in neurons, and not in glial cells. These data and those available in other vertebrates on cyp19a1/aromatase expression suggest that, with the intriguing exception of teleost fishes, cyp19a1 was under strong evolutionary conservation with respect to its sites of expression and the nature of the cells in which it is expressed
ISSN: 0016-6480

hal-01187140
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01187140
DOI : 10.1016/j.ygcen.2015.08.008
PUBMED : 26255686

Éditeur(s) : HAL CCSD Wiley
Résumé :  
1. Relationships between tropical rain forest biomass and environmental factors have been determined at regional scales, e.g. the Amazon Basin, but the reasons for the high variability in forest biomass at local scales are poorly understood. Interactions between topography, soil properties, tree growth and mortality rates, and treefalls are a likely reason for this variability. 2. We used repeated measurements of permanent plots in lowland rain forest in French Guiana to evaluate these relationships. The plots sampled topographic gradients from hilltops to slopes to bottomlands, with accompanying variation in soil waterlogging along these gradients. Biomass was calculated for >175 tree species in the plots, along with biomass productivity and recruitment rates. Mortality was determined as standing dead and treefalls. 3. Treefall rates were twice as high in bottomlands as on hilltops, and tree recruitment rates, radial growth rates and the abundance of light-demanding tree species were also higher. 4. In the bottomlands, the mean wood density was 10% lower than on hilltops, the basal area 29% lower and the height:diameter ratio of trees was lower, collectively resulting in a total woody biomass that was 43% lower in bottomlands than on hilltops. 5. Biomass productivity was 9% lower in bottomlands than on hilltops, even though soil Olsen P concentrations were higher in bottomlands. 6. Synthesis. Along a topographic gradient from hilltops to bottomlands there were higher rates of treefall, which decreased the stand basal area and favoured lower allocation to height growth and recruitment of light-demanding species with low wood density. The resultant large variation in tree biomass along the gradient shows the importance of determining site characteristics and including these characteristics when scaling up biomass estimates from stand to local or regional scales.
ISSN: 0022-0477

hal-01032100
https://hal.archives-ouvertes.fr/hal-01032100

Éditeur(s) : HAL CCSD American Chemical Society
Résumé : The distribution of water and ions in nanoporous membranes, in particular close to their surfaces with external reservoirs, is investigated by means of molecular dynamics (MD) simulations using classical polarizable force fields. A sodium iodide (NaI) aqueous solution is considered in uncharged weakly hydrophilic (WH) and highly hydrophilic (HH) nanoporous materials modeled by a single truncated nanopore in contact with two reservoirs. In the inner part of the nanopore, the spatial distribution of water and ions is obtained by coupling semi-infinitesimal longitudinal and semi-infinitesimal radial descriptions. In the HH material, in contrast with the WH material, species are no longer uniformly distributed in the inner nanopore and water molecules are distributed in a nearly frozen axially periodic corona-like structure which leads to the formation of ionic tunnels. In the reservoirs, water molecules and ions attracted by the membrane surface create a necking of the confined solution which acts as a barrier at the entrance of the nanopore. In the WH nanopore subsurface, close to the surface of the membrane, the species distribution is analogous to the interface distribution between an aqueous electrolyte solution and air. In the HH nanopore subsurface, this distribution is modulated by the water corona-like structure. These results provide useful information for predicting properties of nanoporous membranes, in particular the drastic reduction of diffusion coefficients in HH materials, and give a guide to designing synthetic membranes for applications in nanofiltration, etc.
ISSN: 1932-7447

hal-00682155
https://hal.archives-ouvertes.fr/hal-00682155
DOI : 10.1021/jp2078924

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Dental and postcranial remains (an atlas, carpus and metacarpus elements, and a part of the pelvic girdle) of an embrithopod mammal are described from Bir Om Ali, Tunisia, a new late Eocene locality. The enamel microstructure of a tooth fragment found in association shows 'arsinoitheriid radial enamel', an enamel condition which is characteristic of Arsinoitherium (Arsinoitheriidae, Embrithopoda). Although the postcranial elements slightly differ in size and morphology from those of Arsinoitherium zitteli (late Eocene to early Oligocene), we tentatively refer this new Eocene Tunisian material to that genus. These fossils represent the first known embrithopod from the Eocene of Tunisia.
ISSN: 0899-5362

hal-00903435
https://hal.archives-ouvertes.fr/hal-00903435
DOI : 10.1016/j.jafrearsci.2013.07.010

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
We aimed to assess the impact of a postoperative drainage after RPN. A retrospective multicentric study included RPN performed at eight centers between 2010 and 2014. Three centers stopped using postoperative drainage early in their RPN experience, whereas other institutions systematically left a drain. Preoperative characteristics, complication rates, need for postoperative imaging or procedure (surgical or radiological) and length of hospital stay were compared between the two groups [drainage (D) and no drainage (ND)]. Among 636 RPNs, 140 were done without drainage (22 %). In the ND group, surgeons were more experienced (> 50 cases: 55.7 vs. 15.1 %; p < 0.0001), and tumors were more complex (RENAL score: 7.6 vs. 6.5; p < 0.0001). Complication rates were similar in both groups (21.9 vs. 20.2 %; p = 0.67). The omission of postoperative drainage did not increase requirement of CT scan (RR = 1.03; 95 % CI 0.64-1.67). Length of hospital stay was shorter in the ND group (4.5 vs. 5.5 days; p = 0.007). There were six urinary fistulas: four in the D group (0.8 %) and two in the ND group (1.4 %; p = 0.49). A CT scan was done to confirm the diagnosis of fistula in every case. In multivariate analysis, the omission of drainage was not associated with increased need of postoperative CT scan or major complications but was a predictor of decreased length of stay. The omission of postoperative drainage does not seem to increase the risk of postoperative complications and could safely be omitted after RPN.
ISSN: 0724-4983

hal-01361502
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01361502
DOI : 10.1007/s00345-015-1721-2
PUBMED : 26511751

Éditeur(s) : HAL CCSD Elsevier
Résumé : Among the radionuclides that can migrate from radioactive wastes buried within consolidated argillaceous rocks, I-129 poses a particular problem due to its high mobility in geomedia and its very long half-life of 1.6 10(7) years. Previous studies carried out on such rocks showed the existence of a low iodide retardation regarding the other anion species. The purpose of the present study was two-fold. It was hoped (1) to confirm this retardation by means of radial diffusion experiments and (2) to estimate the influence of the initial iodide concentrations towards the iodide uptake. The results obtained from in-diffusion stage show that (1) no iodide uptake occurs at high initial concentrations and (2) an uptake at low initial concentrations cannot be clearly evidenced. Finally. the most singular behaviour of iodide was highlighted for all the initial iodide concentrations, from the out-diffusion stage. during which some amount of iodide, available for out-diffusion, were not involved in the diffusion process. Although the origin of such phenomenon remains unclear, a kinetic effect for the iodide uptake was proposed, assuming that the period of 55days (corresponding to the in-diffusion stage duration) would be necessary for inducing the iodide uptake. This kinetic effect, already shown elsewhere by (Descostes. M., Blin, V., Bazer-Bachi, F., Meier, P., Grenut, B., Radwan. J., Schlegel, M.L., Buschaert, S.. Coelho, D, Tevissen, E. Diffusion of anionic species in Callovo-Oxfordian argillites and Oxfordian limestones. In press for Appl. Geochem.) on similar materials, needs to be deepened.
ISSN: 0079-1946

hal-00412393
https://hal.archives-ouvertes.fr/hal-00412393
DOI : 10.1016/j.pce.2008.05.020

Éditeur(s) : HAL CCSD
Résumé : International audience
A key element of the biomechanical design of trees is their ability to generate largemechanical stresses in wood at the stem periphery. This function is necessary for the tree tocontrol the orientation of its axes, and therefore to grow in height, maintain its branches at anoptimal angle or achieve adaptive reorientations (Fournier et al., 2013). This “maturationstress” appears in wood fibres during their cellular maturation when their secondary cell wallis thickening. In hardwoods, the stress asymmetry is generated by the formation of specificfibres with a very high tensile growth stress on the upper side of the inclined axis. Theresulting tension wood has microstructural features highly different from the normal wood.Tension wood in almost all temperate species has a specific gelatinous cell wall layer, calledG-layer, that is not lignified and highly mesoporous (Chang et al., 2015). It has been shownrecently, at the macroscopic scale, that cellulose tension appears during maturation and issynchronous with the development of this specific layer (Clair et al., 2011). Tropical species,like simarouba, are able to generate lignified tension wood fibres. The mechanisms of stressgeneration in tension wood fibres are not yet well known. The aim of our study is tounderstand these mechanisms and to know the spatial and temporal kinetics of the differentcell wall layers stiffening during maturation, in parallel with tensile stress generation.Contact-Resonance Atomic Force Microscopy, CR-AFM, was used here to address thisquestion on embedded samples (Arnould and Arinero, 2015) using dual resonance frequencytracking (DRFT, Rodriguez et al., 2007). Change in the contact modulus between, and within,each layer of the cell wall has been measured on several radial lines of developing fibres atdifferent steps. In order to understand the obtained results, and to estimate the sensitivity ofthe AFM indentation-like technique to the different cell wall components stiffness, an elasticanisotropic indentation model was used (Vlassak et al., 2003; Jäger et al., 2011). Finally,these mechanical measurements have been compared to topochemical data obtained on thesame fibres.
8th Plant Biomechanics International Conference
Nagoya, Japan

hal-01436113
https://hal.archives-ouvertes.fr/hal-01436113