Éditeur(s) : Public Library Science
Résumé : The blue mussel, Mytilus edulis, is a commercially important species, with production based on both fisheries and aquaculture. Dynamic Energy Budget (DEB) models have been extensively applied to study its energetics but such applications require a deep understanding of its nutrition, from filtration to assimilation. Being filter feeders, mussels show multiple responses to temporal fluctuations in their food and environment, raising questions that can be investigated by modeling. To provide a better insight into mussel–environment interactions, an experiment was conducted in one of the main French growing zones (Utah Beach, Normandy). Mussel growth was monitored monthly for 18 months, with a large number of environmental descriptors measured in parallel. Food proxies such as chlorophyll a, particulate organic carbon and phytoplankton were also sampled, in addition to non-nutritious particles. High-frequency physical data recording (e.g., water temperature, immersion duration) completed the habitat description. Measures revealed an increase in dry flesh mass during the first year, followed by a high mass loss, which could not be completely explained by the DEB model using raw external signals. We propose two methods that reconstruct food from shell length and dry flesh mass variations. The former depends on the inversion of the growth equation while the latter is based on iterative simulations. Assemblages of food proxies are then related to reconstructed food input, with a special focus on plankton species. A characteristic contribution is attributed to these sources to estimate nutritional values for mussels. M. edulis shows no preference between most plankton life history traits. Selection is based on the size of the ingested particles, which is modified by the volume and social behavior of plankton species. This finding reveals the importance of diet diversity and both passive and active selections, and confirms the need to adjust DEB models to different populations and sites.
Plos One (1932-6203) (Public Library Science), 2014-10 , Vol. 9 , N. 10 , P. 1-13

Droits : 2014 Picoche et al. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
http://archimer.ifremer.fr/doc/00218/32895/31380.pdf
http://archimer.ifremer.fr/doc/00218/32895/31381.pdf
http://archimer.ifremer.fr/doc/00218/32895/31382.pdf
http://archimer.ifremer.fr/doc/00218/32895/31383.pdf
http://archimer.ifremer.fr/doc/00218/32895/31384.pdf

Éditeur(s) : HAL CCSD Public Library of Science
Résumé : International audience
RATIONALE: Optimal management of complicated parapneumonic effusions (CPPE) remains controversial. OBJECTIVES: to assess safety and efficacy of iterative therapeutic thoracentesis (ITTC), the first-line treatment of CPPE in Rennes University Hospital. METHODS: Patients with CPPE were identified through our computerized database. We retrospectively studied all cases of CPPE initially managed with ITTC in our institution between 2001 and 2010. ITTC failure was defined by the need for additional treatment (i.e. surgery or percutaneous drainage), or death. RESULTS: Seventy-nine consecutive patients were included. The success rate was 81% (n = 64). Only 3 patients (4%) were referred to thoracic surgery. The one-year survival rate was 88%. On multivariate analysis, microorganisms observed in pleural fluid after Gram staining and first thoracentesis volume ≥450 mL were associated with ITTC failure with adjusted odds-ratios of 7.65 [95% CI, 1.44-40.67] and 6.97 [95% CI, 1.86-26.07], respectively. The main complications of ITTC were iatrogenic pneumothorax (n = 5, 6%) and vasovagal reactions (n = 3, 4%). None of the pneumothoraces required chest tube drainage, and no hemothorax or re-expansion pulmonary edema was observed. CONCLUSIONS: Although not indicated in international recommendations, ITTC is safe and effective as first-line treatment of CPPE, with limited invasiveness.
ISSN: 1932-6203

hal-00945622
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00945622
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00945622/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-00945622/file/fetchObject.pdf
PUBMED : 24400113

Éditeur(s) : HAL CCSD Geological Society of America
Résumé : International audience
In this study, a novel application of a statistical approach is utilized for analysis of downhole logging data from Miocene-aged siliciclastic shelf sediments on the New Jersey Margin (eastern USA). A multivariate iterative nonhierarchical cluster analysis (INCA) of spectral gamma-ray logs from Integrated Ocean Drilling Program (IODP) Expedition 313 enables lithology within this siliciclastic succession to be inferred and, through comparison with the 1311 m of recovered core, a continuous assessment of depositional sequences is constructed. Signifi cant changes in INCA clusters corroborate most key stratigraphic surfaces interpreted from the core, and this result has particular value for surface recognition in intervals of poor core recovery. This analysis contributes to the evaluation of sequence stratigraphic models of large-scale clinoform complexes that predict depositional environments, sediment composition, and stratal geometries in response to sea-level changes. The novel approach of combining statistical analysis with detailed lithostratigraphic and seismic refl ection data sets will be of interest to any scientists working with downhole logs, especially spectral gamma-ray data, and also provides a reference for the strengths and weaknesses of multi component analysis applied to continental margin lithofacies. The method presented here is appropriate for evaluating successions elsewhere and also has value for hydrocarbon exploration where sequence stratigraphy is a fundamental tool.
EISSN: 1553-040X

insu-00858238
https://hal-insu.archives-ouvertes.fr/insu-00858238
DOI : 10.1130/GES00913.1

Éditeur(s) : HAL CCSD
Résumé : International audience
The Corinth Rift is the most seismically active zone in Europe. The area is characterized by very localized NSextension at a rate of1.5cm/year, the occurrence of frequent and intensive microseismic crises and occasionalmoderate to large earthquakes like in 1995 (Mw=6.1).Since the year 2000, the Corinth Rift Laboratory (CRL, http://crlab.eu) consisting in a multidisciplinary naturalobservatory, aims at understanding the mechanics of faulting and earthquake nucleation in the Rift. Recent studieshave improved our view about fault geometry and mechanics within CRL, but there is still a critical need for a betterknowledge of the structure at depth both for the accuracy of earthquake locations and for mechanical interpretationof the seismicity.In this project, we aim to analyze the complete seismological database (13 years of recordings) of CRL by usingrecently developed methodologies of structural imaging, in order to determine at the same time and with highresolution, the local 3D structure and the earthquake locations.We perform an iterative joint determination of 3D velocity model and earthquake coordinates. In a first step, Pand S velocity models are determined using first arrival time tomography method proposed by Taillandier et al.(2009). It consists in the minimization of the cost function between observed and theoretical arrival times which isachieved by the steepest descent method (e.g. Tarantola 1987). This latter requires computing the gradient of thecost function by using the adjoint state method (Chavent 1974). In a second step, earthquakes are located in thenew velocity model with a non-linear inversion method based on a Bayesian formulation (Gesret et al. 2015). Step1 and 2 are repeated until the cost function no longer decreases.We present preliminary results consisting in: (1) the adjustement of a 1D velocity model that is used as initialmodel of the 3D tomography and (2) a first attempt of the joint determination of 3D velocity model and earthquakelocation.In addition to the tomographic imaging, we perform a preliminary receiver function analysis of teleseismic datarecorded by the broadband stations of the CRL network. The RF analysis should provide the interface depthsbeneath seismometers and increase the imaging resolution of the upper crustal structures provided by the 3Dtomography. In this first attempt, we adjust the 1D velocity model that produces a synthetic RF as similar aspossible to the observed RF for a subset of data. We compare the identified interfaces with structures imaged bythe tomography.
EGU general assembly 2016
Vienne, Austria

hal-01306224
https://hal-mines-paristech.archives-ouvertes.fr/hal-01306224

Éditeur(s) : HAL CCSD
Résumé : Proceedings of the 10th International and Interdisciplinary Conference, CONTEXT 2017, Paris, France, June 20-23, 2017
International audience
This paper presents a research project in science education that is positioned at the intersection of computer science and context in learning. The main objective is to improve learning process by creating a software tool that participates, from the inception to the achievement, in the design of leaning scenarios, based on context effects, and, to show that context effects' learning is an efficient method in the development of student's knowledge regarding a concept. The software will compute differences between two – or more – external contexts based on specific parameters, related to the phenomenon or object that students are expected to study. The elaboration of the calculator (" the MazCalc ") is conducted using the design based research theory, meaning that several iterations of learning field experiments are conducted in order to collect relevant data which are used for the tool creation. In this paper, the design of the scenario involves students from North America and from the French West Indies and the concept studied is about geothermal energy. The instantiation of the context calculator is made with the geothermal object of study, and the differences are computed in the calculator between the two contexts mentioned. This example makes possible to validate the link between context effects predicted and observed, and also to study the impact of external context on the learning process. This study has been conducted thanks to the GEOTREF project support.
Modeling and Using Context

ISBN : 978-3-319-57837-8
hal-01625781
https://hal.univ-antilles.fr/hal-01625781
https://hal.univ-antilles.fr/hal-01625781/document
https://hal.univ-antilles.fr/hal-01625781/file/Elaborating%20the%20context%20calculator%20CONTEXT2017.pdf

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
Relying on the resolvent operator method and using Nadler's theorem, we suggest and analyze a class of iterative schemes for solving multivalued quasi-variational inclusions. In fact, by considering problems involving composition of mutivalued operators and by replacing the usual compactness condition by a weaker one, our result can be considered as an improvement and a significant extension of previously known results in this field.
ISSN: 1385-1292

hal-00780762
https://hal.univ-antilles.fr/hal-00780762
https://hal.univ-antilles.fr/hal-00780762/document
https://hal.univ-antilles.fr/hal-00780762/file/10.1.1.13.5012.pdf
DOI : 10.1023/B:POST.0000023199.34934.9f

Éditeur(s) : HAL CCSD Tsing Hua University
Résumé : International audience
This paper deals with variational inclusions of the form : $0in varphi(z)+F(z)$ where $varphi$ is a single-valued function admitting a second order Fréchet derivative and $F$ is a set-valued map from $R^q$ to the closed subsets of $R^q$. In order to approximate a solution $bar z$ of the previous inclusion, we use an iterative scheme based on a multipoint method. We obtain, thanks to some semistability properties of $bar z$, local superquadratic or cubic convergent sequences
ISSN: 1607-2510

hal-00728816
https://hal.archives-ouvertes.fr/hal-00728816

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
The aim of this paper is twofold. First, it is to extend the sensitivity analysis framework, developed recently for variational inequalities, to mixed equilibrium problems. The second is to propose iterative methods for solving this kind of problems. In the process, we establish an equivalence between an extended version of Wiener-Hopf equations and the given problems relying on a generalization of the Yosida approximation notion. Our results generalize results obtained for optimization, variational inequalities, complementarity problems, and problems of Nash equilibria.
ISSN: 0898-1221

hal-00779234
https://hal.univ-antilles.fr/hal-00779234
DOI : 10.1016/S0898-1221(02)00218-3

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Relying on prox-regularity we suggest and analyze a class of iterative schemes for solving nonconvex variational inequalities, our result can be considered as an improvement and a significant extension of previously known results in this field.
ISSN: 0096-3003

hal-00780630
https://hal.univ-antilles.fr/hal-00780630
DOI : 10.1016/j.amc.2003.06.003

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
Relying on the resolvent operator method and using Nadler's theorem, we suggest and analyze a class of iterative schemes for solving multivalued quasi-variational inclusions. In fact, by considering problems involving composition of mutivalued operators and by replacing the usual compactness condition by a weaker one, our result can be considered as an improvement and a significant extension of previously known results in this field.
ISSN: 1385-1292

hal-00815511
https://hal.univ-antilles.fr/hal-00815511
DOI : 10.1023/B:POST.0000023199.34934.9f