Éditeur(s) : Université des Antilles Études caribéennes
Résumé : This study explores weather perceptions, evaluations and behavior of holiday-tourists to the French Caribbean island of La Martinique. Herein, the importance of selected weather parameters for a ‘typical’ summer holiday, for the choice that was made in coming to Martinique and for planned activities is examined. 32 snapshot interviews were held in two brief time periods within a month. Results illustrated slight differences in climate preferences for respondents depending whether they come from a cold or from a warm climate country, that activity patterns seemed overall little influenced by changing weather conditions and that the experienced weather, which was marked by heavy rains in the first data collection period and by changeable weather in the second, appeared to take only a limited impact on return intentions. Albeit the limited possibility of a pilot study to produce valid and reliable findings, variables and factors which are critical to consider when examining weather perceptions and behaviors have been pointed out and presented in a conceptual model for further research.
Cette étude explore les perceptions et les évaluations des conditions météorologiques et les comportements des vacanciers sur l'île de la Martinique. A ce sujet, l´étude examine l'influence de certains paramètres météorologiques sélectionnés sur des vacances d'été «typiques», sur le choix de la destination Martinique et sur les activités envisagées sur lieu. 32 interviews instantanées ont eu lieu en deux courtes périodes de temps pendant un mois. Les résultats illustraient qu´il y avait de légères différences concernant les préférences climatiques selon que les répondants venaient d'un pays au climat froid ou chaud, que les schémas d'activité semblaient généralement peu influencés par les changements météorologiques et que le temps - marquées par de fortes pluies dans la première période de la collecte de données et par un temps variable dans la seconde période - semblait n´avoir qu´un impact limité sur les intentions à revenir à la Martinique. Bien que l´étude pilote n´ait que des possibilités limitées de fournir des résultats valides et fiables, elle identifie les variables et les facteurs qui sont essentiels à considérer lors d´un projet de recherche qui examine la perception des conditions météorologiques par les touristes et les comportements qui en résultent. Ces facteurs sont présentés dans un modèle conceptuel.
Martinique

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.5323
http://journals.openedition.org/etudescaribeennes/5323

Éditeur(s) : HAL CCSD Cambridge University Press (CUP)
Résumé : The natural 15N abundance method for estimating symbiotic biological N2-fixation was tested on legume trees from two rain forests on contrasting soils (oxisols and spodosols) in French Guiana. When possible, the significance of N2-fixing species in the plant community was evaluated in terms of density, biomass and contribution of N2-fixation to the building up of the total nitrogen mass in the leaves. Of the two sites, the rain forest on spodosols was the less favourable for application of the [delta]15N method: the available soil nitrogen was isotopically similar to fixed-N2. Hence, the results showed that a reliable estimate of N2-fixation could not be obtained. A substantial contribution of fixed-N2 to the nitrogen nutrition of legumes was found on oxisols, with an average value of 54 % Ndfa (Nitrogen derived from the atmosphere). The contribution of the N2-fixing legumes to the biomass of the stand was estimated to be 2 t ha[minus sign]1 for the leaf biomass and 136 t ha[minus sign]1 for the total above-ground plant biomass. With 7.5 % of trees in the stand able to fix N2 (462 out of 6156), N2-fixation was estimated to be 7 kg ha[minus sign]1 y[minus sign]1. These results are the first use of the [delta]15N method to estimate nitrogen input by N2-fixing legumes to a natural rain forest. The inter-site variability observed in the [delta]15N of the non-fixing plants suggested different nitrogen-cycling processes in the two soils. The [delta]15N of the non-N2-fixing plants could be related to the soil nitrogen availability and be used as an indicator of efficient or non-efficient nitrogen-cycling rain forests. The spatial variability of the [delta]15N in the plant-available soil nitrogen pool and the nitrogen balance in tropical rain forests are discussed.
ISSN: 0266-4674

hal-01032201
https://hal.archives-ouvertes.fr/hal-01032201
DOI : 10.1017/S0266467499000644

Éditeur(s) : HAL CCSD Elsevier
Résumé : Analyses of tree diversity and community composition in tropical rain forests are usually based either on general herbarium data or on a restricted number of botanical plots. Despite their high taxonomic accuracy, both types of data are difficult to extrapolate to landscape scales. Meanwhile, forestry surveys provide quantitative occurrence data on large areas, and are thus increasingly used for landscape-scale analyses of tree diversity. However, the reliability of these approaches has been challenged because of the ambiguity of the common (vernacular) names used by foresters and the complexity of tree taxonomy in those hyper-diverse communities.We developed and tested a novel approach to evaluate taxonomic reliability of forestry surveys and to propagate the resulting uncertainty in the estimates of several diversity indicators (alpha and beta entropy, Fisher-alpha and Sørensen similarity). Our approach is based on Monte-Carlo processes that simulate communities by taking into account the expected accuracy and reliability of common names. We tested this method in French Guiana, on 9 one-hectare plots (4279 trees – DBH ⩾ 10 cm) for which both common names and standardized taxonomic determinations were available. We then applied our method of community simulation on large forestry inventories (560 ha) at the landscape scale and compared the diversity indices obtained for 10 sites with those computed from precise botanical determination situated at the same localities.We found that taxonomic reliability of forestry inventories varied from 22% (species level) to 83% (family level) in this Amazonian region. Indices computed directly with raw forestry data resulted in incorrect values, except for Gini–Simpson beta-diversity. On the contrary, our correction method provides more accurate diversity estimates, highly correlated with botanical measurements, for almost all diversity indices at both regional and local scales. We obtained a robust ranking of sites consistent with those shown by botanical inventories.These results show that (i) forestry inventories represent a significant part of taxonomic information, (ii) the relative diversity of regional sites can be successfully ranked using forestry inventory data using our method and (iii) forestry inventories can valuably contribute to the detection of large-scale diversity patterns when biases are well-controlled and corrected.The tools we developed as R-functions are available in supplementary material and can be adapted with local parameters to be used for forest management and conservation issues in other regional contexts
ISSN: 0378-1127

hal-01204219
https://hal.archives-ouvertes.fr/hal-01204219
DOI : 10.1016/j.foreco.2014.05.045
PRODINRA : 286554

Éditeur(s) : HAL CCSD
Résumé :   Diffusion du document : INRA Antilles-Guyane, UMR ECOFOG, F97387 Kourou, Guyane (France) Diplôme : DEA
il s'agit d'un type de produit dont les métadonnées ne correspondent pas aux métadonnées attendues dans les autres types de produit : DISSERTATION
This work on tropic al humid forest of Paracou includes 16 permanent sample plots covering a total surface of 119 hectares. Ten hectares of them are taken up by floodplains which characteristic is a continuous no-deep underground water level with phases of strong surface water logging. Three items have been studied : (i) Checking that during dry season the maps of the underground water level including its limits are reliable, (ii) Characterising the most suitable ecological niches for certain species, (iii) Additional updating the floodplains characterisation by precisely analysing the chemical soil content as well as the physiological reaction of the Symphonia Globulifera . Checking the underground water level in dry season enabled to put down to a quite good measurement reliability by GIS. The classification ecological of species proposed in this work is based on the relative density in floodplain and drain soil very similar to that which concerns a surface located ten or more kilometres further. This lets us assess that this classification is of a good reliability as long as the climate conditions are quite similar to ours in Paracou. Furthermore the presence of pneumatophores in the Symphonia Globulifera is a good biological criterion as long as it shows a long time ground moisture saturation. By analysing the life litter and the soil we mentioned that the leaf content and the soil content indicate a better nutritional value (phosphorus, calcium and potassium) in the floodplains. For phosphorus the relation between the life litter and the soil results put forward that the Olsen method gives a better explanation of the real phosphorus availability for the trees.
Le dispositif de recherche sur la forêt tropicale humide de Paracou est composé de 16 parcelles permanentes couvrant au total 119 ha, dont 10 ha sont occupés par des bas-fonds, caractérisés par l'existence permanente d'une nappe peu profonde et par des périodes de fort engorgement en surface. Notre étude avait trois objectifs : (i) vérifier la fiabilité des cartes de la profondeur de nappe en saison sèche, qui délimitent ces bas-fonds, (ii) caractériser les préférences écologiques de quelques espèces et (iii) compléter la caractérisation des bas-fonds par l'analyse de la richesse chimique du sol et l'étude de la réaction physiologique du Symphonia globulifera. La vérification sur la profondeur de nappe en saison sèche a montré que les imprécisions des cartes étaient d'ampleur limitée, sans incidence forte par rapport à l'ensemble des données. Le classement écologique des espèces proposé dans cette étude, basé sur leurs densités relatives dans les bas-fonds et hors des bas-fonds, est très similaire à celui présenté par une autre étude, dans un dispositif situé à plusieurs dizaines de kilomètres. Cela suggère que ce classement a une bonne validité, tant que les conditions climatiques ne diffèrent pas trop de celles rencontrées à Paracou. Par ailleurs, la présence des pneumatophores du Symphonia globulifera est un bon critère biologique signalant un engorgement hydrique prolongé du sol. Au niveau des analyses de la litière et du sol, les teneurs foliaires et les teneurs dans le sol semblent indiquer que la nutrition en phosphore, calcium et potassium est meilleure en bas-fonds. Au niveau de la méthode de mesure du phosphore assimilable, les relations entre les résultats de la litière et celles du sol suggèrent que la méthode d'Olsen rend mieux compte de la disponibilité effective du phosphore pour les arbres de la forêt tropicale humide que la méthode de Duchaufour.
https://hal.archives-ouvertes.fr/hal-01189229

hal-01189229
https://hal.archives-ouvertes.fr/hal-01189229
PRODINRA : 17050

Éditeur(s) : HAL CCSD IOP Publishing
Résumé : Radioactive pollutants are naturally present in microelectronic device materials and can be an issue for the reliability of devices. The main concern is alpha emitters that produce high-energy particles (a few MeV) that ionize the semiconductor and then trigger soft errors. The question is to know what kinds of radionuclides are present in the device, their location in the device and the abundance of each species. In this paper we describe tools that are required to address the issue of radioactive pollutants in electronic devices.
ISSN: 0268-1242

hal-01504448
https://hal.archives-ouvertes.fr/hal-01504448
DOI : 10.1088/1361-6641/aa5479

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Wind energy production is very sensitive to instantaneous wind speed fluctuations. Thus rapid variation of wind speed due to changes in the local meteorological conditions can lead to electrical power variations of the order of the nominal power output. The high variability of this renewable energy source can caused a disruptive effect on power quality and reliability, in non-interconnected island networks as in Guadeloupe (French West Indies). To palliate these difficulties, it is essential to identify and characterize the wind speed distribution over very short time intervals. This allows anticipating the eventuality of power shortage or power surge. Therefore, it is of interest to categorize wind speed fluctuations into distinct classes and to estimate the probability of a distribution to belong to a class. This paper presents a method for classifying wind speed distributions by estimating a finite mixture of Dirichlet distributions. The SAEM algorithm that we use provides a fine distinction between three wind speed distribution classes. It is a new nonparametric method for wind speed classification.
ISSN: 0960-1481

hal-01527881
https://hal.archives-ouvertes.fr/hal-01527881
DOI : 10.1016/j.renene.2011.03.024

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
An intensive water vapour intercomparison effort, involving airborne and ground-based water vapour lidar systems, was carried out in the framework of the COPS experiment. The main objective of this paper is to provide accurate error estimates for these systems. Comparisons between the ground-based Raman lidar BASIL and the airborne CNRS DIAL (Differential Absorption Lidar) indicate a mean relative bias between the two sensors, calculated with respect to the mean value of −2.13% (−0.034 g kg−1) in the altitude region 0.5-3.5 km, while comparisons between BASIL and the airborne DLR DIAL lead to a mean relative bias of 1.87% (0.018 g kg−1) in this same altitude region. Comparisons between the ground-based UHOH DIAL and the CNRS DIAL indicate a bias of −3.2% (−0.37 × 1022 m−3) in the altitude range 1.5-4.5 km, while comparisons between the UHOH DIAL and the DLR DIAL indicate a bias of 0.83% (0.06 × 1022 m−3) in this same altitude range. Based on the available comparisons between the ground-based Raman lidar BERTHA and the CNRS DIAL, the mean relative bias is found to be −4.37% (−0.123 g kg−1) in the altitude region 0.5-4.5 km. Comparisons between the ground-based IGN Raman lidar and the CNRS DIAL indicate a bias of 3.18% (0.55 g kg−1) in the altitude range from 0.5 to 4.5 km, while comparisons between the CNRS DIAL and DLR DIAL result in a mean relative bias of 3.93% (1.1 × 1022 m−3) in the altitude interval 0.5-4.0 km. Based on the available statistics of comparisons, benefiting from the fact that the CNRS DIAL was able to be compared with all other lidar systems, and putting equal weight on the data reliability of each instrument, overall relative values for BASIL, BERTHA, IGN Raman lidar, UHOH DIAL, DLR DIAL, and CNRS DIAL, with respect to the mean value, are found to be −0.38, −2.60, 4.90, −1.43, −2.23 and 1.72%, respectively.
ISSN: 0035-9009

hal-00572576
https://hal.archives-ouvertes.fr/hal-00572576
DOI : 10.1002/qj.697

Résumé : Les fourmis sont des organismes cibles appropriés pour les études environnementales. Au cours de notre étude, nous nous sommes focalisés sur les fourmis de la litière via l'application de deux méthodes de récolte complémentaires selon le protocole all (ants of leaf litter). Dans les forêts naturelles de Guyane française, l'hétérogénéité environnementale et les perturbations structurent les communautés de fourmis de la litière en influençant la richesse, la diversité, l'abondance et la densité en espèces ainsi que les compositions taxonomique et fonctionnelle. Chaque type de formation végétale possède une communauté spécifique. La fragmentation et la conversion des forêts en plantations ont entrainé une altération plus ou moins profonde des communautés; cette variabilité est fonction du type d’agriculture et des espèces d'essences cultivées. Bien que l'altération des communautés se soit révélée maximale dans la plupart des monocultures, les plantations de cacaoyers ont un potentiel de conservation réel. Enfin, dans un contexte ou il est urgent de simplifier l'intégration des arthropodes dans les études de conservation, de contrôle et de suivi de la santé des écosystèmes terrestres, la méthode des réseaux de neurones est apparue comme un outil puissant pour mettre en évidence et analyser les patrons des communautés de fourmis.
Ants are reliable and relevant target organisms for environmental surveys. In our study, we focused on litter-dwelling ants through the use of two complementary sampling methods that were implemented according to the ants of leaf litter (all) protocol. In pristine forests of french guiana, leaf-litter ant communities are structured by environmental heterogeneity and natural perturbations - which influence species richness, diversity, abundance and density, as well as taxonomic and functional composition. This results in habitat-specific communities for each vegetal formation. Forest fragmentation and conversion into monocultures have led to a more or less deep alteration of the ant communities; this variability depends on the type of agricultural system and cultivated tree species. Although the intensity of community alteration peaked in tree monocultures, cocoa plantation exhibited a real potential for native species conservation. Finally, in the current context where simplifying the integration of arthropods into conservation programs as well as into surveys designed to monitor and manage the environment is critical, the use of neural networks appears to be a powerful tool for reliably highlighting and analyzing ant communities patterns.

http://www.theses.fr/2011AGUY0475/document

Résumé : Les réseaux de capteurs constituent un axe de recherche très fertile ces dernières années. Cette technique se développe dans différents domaines comme l'environnement, l'industrie, le commerce, la médecine, l'armée, etc. Les réseaux de capteurs sont difficiles à concevoir parce qu'ils sont fortement contraints en énergie et que tous les éléments ont potentiellement une influence sur la durée de vie du système. Nous proposons un outil permettant l'aide au bon paramétrage et aux choix de paramètres optimaux pour la stabilité des applications.Dans cette thèse, nous nous sommes intéressés à deux problématiques : une classification des paramètres pour un outil d'aide à la décision pour la configuration d'un réseau de capteurs et la seconde, un outil de test de conformité du système dans un environnement réel. Le document est divisé en deux parties où la première partie est un état de l'art de différents protocoles existants et la deuxième partie décrit notre contribution dans ces deux problématiques.Dans la première contribution, nous avons analysé l'impact de la couverture radio puis de la topologie sur les performances d'un réseau de capteurs. Nous étudions le taux de perte et le niveau d'énergie pour en déduire la stabilité d'une application. Puis nous avons proposé une étude menant à une classification pour notre outil d'aide à la décision. Notre classification est basée sur une étude de divers paramètres de la couche MAC, physique, protocole de routage, nombre de nœuds et type d'application.Dans la deuxième contribution, nous nous sommes focalisés sur une approche pragmatique permettant de tester la conformité d'un réseau de capteurs dans un environnement réel. Pour tester la conformité dans un environnement réel, nous proposons une architecture d'exécution de test sur un réseau de capteurs réel. Ceci dans un but d'assurer un niveau correct de conformité et la stabilité de celui-ci durant son fonctionnement.
Wireless sensor networks is one of the hotest research topic in the last few years. This technology can be applied for different fields such as environment, industry, trading, medicine, military etc. Wireless sensor networks are hard to conceive because they require a lot of energy and because each of its component may have an influence on the lifetime of the whole system. What we suggest is a tool allowing to choose the correct and optimal parameters for the reliability of the applications.In this thesis, we focused on two major problems : firstly, a classification of the parameters for a tool allowing to make decisions about the configuration of a wireless sensors network, and secondly, a tool testing the compliance of the system with a real environment. The document is divided into two parts : the first part states the different protocols that exist, and the second part describes our contributions to those topics.In the first contribution, we analyzed how influential the radio cover and the network topology are on the network performances. Then, we deduced from the study of the loss rate and of the level of energy, the reliability of the application. Next, we suggested a study leading to a classification for our decision making tool. For this classification, we studied various parameters related to the MAC layer, the Physical layer, the network layer, the application layer the number of nodes involved in the network.In the second contribution, we adopted a pragmatic approach so we could test the conformity of a wireless sensors network in a real environment. In order to test its conformity in a real environment, we suggested a structured test execution on a real wireless sensor network. This task has been suggested in order to check the conformance level of the network while it was working.

http://www.theses.fr/2012AGUY0586/document

Éditeur(s) : HAL CCSD
Résumé : This work is devoted to the theoritical research and to the numerical calculus of weak solutions (in the sens of generalized functions) for the non linear transport equation((∂u)/(∂t))(x,y,t)+a(x,y,t)((∂f(u))/(∂x))(x,y,t)+b(x,y,t)((∂g(u))/(∂y))(x,y,t)=0 pour t>0with the initial condition u(x,y,0)=u₀(x,y) where the functions {(x,y,t)→a(x,y,t)} and {(x,y,t)→b(x,y,t)} belong to L^{∞}(R²×R⁺) (but can be discontinuous), the functions f and g are smooth and monotonous, the function {(x,y)→u₀(x,y)} belongs to L^{∞}(R²). We recall the necessary notions on nonlinear generalized functions for introducing their tensorial product. The main results (to determine the weak solutions) are sufficient conditions so that, when a sum of généralized functions (like Heaviside or Dirac products) is associated with zero, each terms of the sum is equal to zero. Thanks to these theoretical results, we can solve the Riemann problem with the help of a solver written like tensorial product of Heaviside functions (or like a sum of tensorial product of Heaviside functions) in order to obtain the weak solutions. These weak solutions allow to develop two dimensional numerical Godunov type schemes. Then, numerical tests are performed which give a comparison between the results obtained by these 2D schemes and the ones of the splitting method. These tests prove that the 2D numerical schemes are as reliable as the ones obtained by splitting. They are also more simple in their expression. Moreover, a more detailed comparative study of the two types of numerical schemes show that the 2D schemes are far less expensive in the linear case as well as in the non linear case. They are stable for the L^{∞} norm, unlike the splitting schemes. At least some perspectives as well as an existence theorem of a strong solution "almost eveywhere" for linear hyberbolic systems are studied.
Nous nous intéressons à la recherche et au calcul numérique de solutions faibles (au sens des fonctions généralisées) de l'équation de transport non linéaire((∂u)/(∂t))(x,y,t)+a(x,y,t)((∂f(u))/(∂x))(x,y,t)+b(x,y,t)((∂g(u))/(∂y))(x,y,t)=0 pour t>0complétée de la condition initiale : u(x,y,0)=u₀(x,y) où les fonctions {(x,y,t)→a(x,y,t)} et {(x,y,t)→b(x,y,t)} appartiennent à L^{∞}(R²×R⁺) (mais peuvent être discontinues), les fonctions f et g sont lisses et monotones, la fonction {(x,y)→u₀(x,y)} appartient à L^{∞}(R²). Des rappels sur les fonctions généralisées nous permettent d'introduire leur produit tensoriel. Un des résultats clés (pour déterminer ultérieurement les solutions faibles cherchées) donne des conditions suffisantes pour que, lorsqu'une somme de fonctions généralisées (de type produit d'Heaviside ou de Dirac) est associée à 0, chacun des termes de la somme est nul. Grâce à ces résultats théoriques, on résout le problème de Riemann 2D à l'aide d'un solveur s'écrivant comme produit tensoriel de fonctions type Heaviside (ou comme somme de produit tensoriel de fonctions type Heaviside) afin d'obtenir les solutions faibles. Ces solutions faibles permettent la construction des schémas numériques de type Godunov 2D. Nous les validons par des test numériques comparant les résultats obtenus par ces schémas 2D et ceux de la méthode du splitting. Ces tests montrent que les schémas numériques 2D sont aussi fiables que ceux par splitting, alors qu'ils sont plus simples dans leur écriture. Une étude comparative plus complète entre les deux types de schémas numériques montre de plus que les schémas 2D sont nettement moins coûteux à la fois dans les cas linéaire et non linéaire et qu'ils sont stables pour la norme L^{∞}, contrairement aux schémas par splitting. Enfin des perspectives ainsi qu'un théoréme d'existence de solutions fortes "presque partout" pour des systèmes hyperboliques linéaires sont abordés.
https://hal.archives-ouvertes.fr/tel-01487366

Droits : info:eu-repo/semantics/OpenAccess
tel-01487366
https://hal.archives-ouvertes.fr/tel-01487366
https://hal.archives-ouvertes.fr/tel-01487366/document
https://hal.archives-ouvertes.fr/tel-01487366/file/th%C3%A8se_olivier_jouannelle_HAL.pdf

Éditeur(s) : HAL CCSD Springer Verlag (Germany)
Résumé : International audience
*Context: Tree orientation is controlled by asymmetric mechanical stresses set during wood maturation. The magnitude of maturation stress differs between longitudinal and tangential directions, and between normal and tension woods. * Aims: We aimed at evaluating patterns of maturation stress on eucalypt plantation trees and their relation with growth, with a focus on tangential stress evaluation. * Methods: Released maturation strains along longitudinal and tangential directions were measured around the circumference of 29 Eucalyptus nitens trees, including both straight and leaning trees. * Results: Most trees produced asymmetric patterns of longitudinal maturation strain but more than half of the maturation strain variability occurred between trees. Many trees produced high longitudinal tensile stress all around their circumference. High longitudinal tensile stress was not systematically associated with the presence of gelatinous layer. The average magnitude of released longitudinal maturation strain was found negatively correlated to the growth rate. A methodology is proposed to ensure reliable evaluation of released maturation strain in both longitudinal and tangential directions. Tangential strain evaluated with this method was lower than previously reported. * Conclusion: The stress was always tensile along longitudinal direction and compressive along tangential direction, and their respective magnitude was positively correlated. This correlation does not result from a Poisson effect but may be related to the mechanism of maturation stress generation.
Annals of Forest Science

hal-00913611
https://hal.archives-ouvertes.fr/hal-00913611
https://hal.archives-ouvertes.fr/hal-00913611/document
DOI : 10.1007/s13595-013-0318-4

Éditeur(s) : HAL CCSD Elsevier Masson
Résumé : International audience
Introduction. - Temocillin is an alternative to treat urinary tract infections with bacteria producing extended spectrum beta-lactamase (ESBL). The objective is to evaluate the use of temocillin in urinary tract infections. Materials and methods. - A systematic review of literature was carried out according to PRISMA criteria. All national and international recommendations have been reviewed regarding the indication of the use of temocillin in urology. Data collection on the use of temocillin in urinary tract infection has been performed from the Cochrane, LILACS and the Medline database. The following keywords were used: temocillin, extended spectrum. beta-lactamase, urinary tract infections, urine, prostate, epididymis, testis, diffusion, pharmacokinetics, pharmacodynamics. The selection was based on the methodology, language of publication (English/French), relevance to the topic and date of publication of the articles collected. The endpoint was to provide exhaustive scientific information allowing urologists to use this antibiotic in febrile urinary infections. Results. - Bacteria producing ESBL has a relatively high susceptible to temocillin, ranging from 61 % to 90 %. These rates would allow its use in probabilistic. The dosage recommended is currently, in the normo-renal patient, 4 g per day by intermittent infusion or continuously after a loading dose of 2g. Some studies argue, particularly in case of difficult clinical situations or obese patients, for administration of high doses (6 g/24 h) rather continuous infusion. There is no evident relationship between high doses and side effects. With an excellent urinary and prostatic diffusion, temocilllin might be recommend for the treatment of ESBL prostatitis. Conclusion. - Temocillin is known to have good urinary and prostatic diffusion. According to our results, this antibiotics is now a reliable alternative for the treatment of documented ESBL urinary tract infections. (C) 2017 Elsevier Masson SAS. All rights reserved.
ISSN: 1166-7087

hal-01659245
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01659245
DOI : 10.1016/j.purol.2017.07.242
PUBMED : 28869169

Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Marine Protected Areas (MPAs) are increasingly used for biodiversity conservation and the management of sustainable fisheries. The use of taxonomic surrogates in routine monitoring of the reserve effects on fish assemblages may represent a promising method due to its substantial technical and economic benefits. However, higher taxonomic ranks should be used as surrogates with caution, especially for fish, where the approach is still virtually undocumented. This study aims to shed light on relationships between taxonomic relatedness and ecological similarity, which is crucial to assess the relevance of species surrogacy to reflect species-level information and detect changes in fish related to protection regimes. By analyzing data from a Mediterranean MPA, we show that rather being related to taxonomic relationships, the ability of higher taxa to reflect species-level patterns was explained in terms of aggregation level and distribution of species within taxa. Null models using random aggregations of species were created to identify the best surrogates able to depict changes in responses of assemblages to protection observed at the species-level. Comparison of null model predictions with the more classical higher-taxon approach revealed that the latter was not reliable because, unlike null model outcomes, surrogates determined empirically were not relevant for other subsequent independent monitoring. The effectiveness of species surrogates to depict changes in responses of assemblages to protection observed at the species-level depended (1) on the numerical resolution of the aggregation and (2) the magnitude of differences between protected and unprotected locations. Such findings suggest that surrogacy approaches may be applied for routine monitoring of Mediterranean reef fish communities, although mere empirical determinations of sufficient taxonomy seems to be not reliable, legitimizing the use of alternative methods based on null models. Guidelines for the careful use of species surrogacy in the ecological evaluation of MPAs on fish assemblages are provided.
ISSN: 0006-3207

hal-01174428
https://hal-univ-perp.archives-ouvertes.fr/hal-01174428
DOI : 10.1016/j.biocon.2015.06.002

Éditeur(s) : Université de Bretagne Occidentale
Résumé : The negative impact of the man on the environment unquestionably increases. The coastal environment as a whole is the maritime environment which is the most exposed to man-made eutrophication. For instance, nitrate loads to coastal waters off Brittany (France) have increased 10 times (from 3 to s 30mg L-1NO3) during the four last decades. Eutrophication of this coastal zone is now a recurrent problem, more and more worrying. This eutrophication exhibits two main forms : " green tides ", which are caused by local proliferations and stranding of green macro-algae (particularly the Ulva species) in nitrogen-enriched areas ; phytoplanktonic blooms, which are responsible for coloured water events, toxic species can be present (Pseudo-Nitzschia, Alexandrium, Dinophysis), and induce banning of shellfish consumption. The objectives of this study are to assess the respective role of various rivers (especially the Loire and the Vilaine) in the eutrophication of the Brittany shelf ecosystem and test the impact of nitrogen enrichment in the triggering of Pseudo-Nitzchia toxicity. For these purposes, a coupled hydrodynamical/ biogeochemical 3D model has been developed and validated against past measured time-series and satellite images. After a brief analysis of primary production over the Brittany shelf under different conditions, we show a description of the real time adaptation of this model. Daily results are currently presented in real time on www.previmer.org web site. The inability of the model to correctly simulate near shore phytoplankton is worsened in this model by the fact that the turbidity field used is a climatological one, made by satellite images averaged on a decadal basis. First, near shore pixels of satellite images are scarcely reliable, secondly a climatological mean cannot represent the sudden bursts or drops of the real turbidity, highly dependent on the actual sea-state : this can explain also why the model at this moment fails to reproduce a sudden bloom occurring in a short period of sunny and calm weather. The simulated Pseudo-Nitzschia biomass and induced risk of toxicity in the water column cannot really be validated offshore, because monitoring measurements are available only near the coast, and deal only with toxicity in benthic filter feeders. To get temporarily rid of that problem, an interesting improvement would be to add to the operational model the bio-accumulation of toxin in the shellfishes : simulated concentrations in shellfish fresh would become directly comparable with usual measurements of the monitoring networks. Our model points out the important impact of Loire river loads on the primary production on the western and southern Brittany. This result is crucial for administrations in charge of reducing the terrestrial loadings responsible for eutrophication, because it can delay reduction programs on small tributaries until the main input from the Loire has been significantly reduced. A question arises, about the reliability of the haline stratification in the model, because the horizontal extent of the Loire plume will be enhanced by a stronger stratification.
L'eutrophisation des milieux marins côtiers, de plus en plus importante, représente un des impacts majeurs des activités humaines sur l'environnement. Les phénomènes d'eutrophisation sont en constante augmentation ; ces dernières décennies ont vu le nombre de sites touchés augmenter de par le monde. La bande côtière bretonne est particulièrement concernée par ce phénomène. L'eutrophisation s'y manifeste de deux façons : "Des phénomènes de marée vertes, très localisées, qui sont provoqués par la croissance excessive et l'échouage de macro-algues du genre Ulva dans ces zones riches en azote ; Des blooms de phytoplancton à l'origine des phénomènes d'eaux colorées, qui peuvent aussi provoquer des interdictions de consommation de coquillages lorsque les espèces mises en jeu sont toxiques (Pseudo-Nitzschia, Alexandrium, Dinophysis). L'objectif de ce travail est multiple : il vise à mettre en évidence et à comprendre l'impact et le rôle des apports en nutriments sur la production primaire et l'eutrophisation des milieux côtiers. Ce travail a aussi pour ambition l'identification et la compréhension des causes des phénomènes d'eutrophisation et permettre ainsi d'apporter des solutions ou des pistes d'amélioration. En n, il a aussi un objectif de prévision à court terme de l'état biologique sur la zone. Pour atteindre ces objectifs, un modèle en temps réel a été mis en oeuvre. Les résultats de simulations numériques et de mesures satellitaires sont présentés sur internet : www.previmer.org. L'outil principal de ce travail est un modèle couplé physique/biogéochimie. La partie hydrodynamique est fournie par le code Mars3D (3D hydrodynamical Model for Application at Regional Scale) développé à IFREMER. Au code hydrodynamique Mars3D est couplé le modèle des cycles de l'azote, du phosphore et du silicium d'IFREMER. Le modèle couplé permet de simuler en 3 dimensions et de manière dynamique les courants, le brassage horizontal et vertical, les champs de température et de salinité, mais aussi les principaux cycles de nutriments, reproduisant ainsi les conditions déterminantes de la production primaire. La croissance des algues est modélisée, et nous permet de voir l'influence des panaches de dilution des principales rivières bretonnes sur leur croissance. Les diffcultés du modèle à correctement simuler les concentrations en phytoplancton près des zones côtières, sont probablement dues à l'utilisation d'une climatologie de concentration en matière en suspension fondée sur des données satellitaires. Tout d'abord, les pixels côtiers des images satellitaires sont entachés d'erreurs, ensuite une climatologie n'est pas capable de représenter les apports soudains des fleuves lors des crues. Cela peut expliquer l'incapacité du modèle a représenter certains blooms liés à des périodes ensoleilées et calmes. A ce modèle de base nous avons ajouté un genre spécifique de phytoplancton : le genre Pseudo-Nitzschia. Certaines espèces de Pseudo-Nitzschia sont réputées toxiques. En effet, ce phytoplancton a la capacité de synthétiser une toxine : l'acide domoïque. Cette toxine est responsable du syndrome ASP (Amnesic Shellfish Poisoning). Le modèle reproduit globalement les mêmes zones de toxicité que les mesures du REPHY, et donne des résultats encourageants. L'étude montre que la Loire influence une large partie de la bande côtière bretonne ; son panache remonte jusqu'au nord de la mer d'Iroise, et contribue pour une grande part à l'enrichissement du sud et de l'ouest de la Bretagne. Le traçage de l'azote en provenance de la Loire au sein des cycles biogéochimiques nous a permis de quantifier cet enrichissement.

Droits : info:eu-repo/semantics/openAccess
http://archimer.ifremer.fr/doc/00015/12603/9481.pdf
http://archimer.ifremer.fr/doc/00015/12603/

Éditeur(s) : HAL CCSD ACM
Résumé : International audience
Applications over wireless sensor networks are growing quickly. Traditional software development tools are not well adapted to this technology. In particular, adequate testing methodologies are required. Many issues have not been formally addressed as energy-conservation, congestion control, reliability data dissemination, security. In this paper, we present a pragmatic approach to detect some kind of anomalies based on defined scenarios on wireless sensor networks. A scenario is considered as a set of events which should happen on the network in an ordered way. We discuss a formal architecture able to perform these scenarios over the wireless sensor networks and to raise alarms if necessary. This methodology has been implemented on a prototype and has been experimented with various examples. This contribution is a first attempt for a formal testing methodology for wireless sensor networks.
Proceedings of the 6th ACM workshop on QoS and security for wireless and mobile networks

Droits : info:eu-repo/semantics/OpenAccess
hal-00596118
https://hal.archives-ouvertes.fr/hal-00596118
https://hal.archives-ouvertes.fr/hal-00596118/document
https://hal.archives-ouvertes.fr/hal-00596118/file/Q2sWinet_10.pdf
DOI : 10.1145/1868630.1868641

Résumé : Bycatch of marine turtles, vulnerable or endangered species, is a growing issue of all fisheries, including Oceanic purse-seine fishery. The present paper seeks to assess marine turtle bycatch at a spatial and temporal level in the European purse seine fishery operating in the Atlantic and Indian Oceans. The study was based on data collected through French and Spanish observer programs from 1995 to 2011, a period where more than 230 000 fishing sets were realized by the UE fleets in both Oceans. A total of 15 913 fishing sets were observed, including 6 515 on drifting Fish Aggregate Devices (FAD) and 9 398 on Free Swimming Schools (FSC). Over the study period, 597 turtles were caught, 86% being released alive at sea. At the same time, from 2003 to 2011, 14 124 specific observations were carried out on floating objects whether they ended in a set or not. 354 marine turtles were observed upon which 80% were already free or entangled alive and therefore released alive. At the temporal and spatial level, data were organized and analysed by Ocean, fishing mode (FAD vs. FSC) as well as by year, quarter and statistical square of 1°. In order to evaluate the impact if this fishery in both Oceans, bycatch distribution was compared to the total fishing effort of the UE fleet, as well as to the known marine turtle post nesting migration routes, nesting population abundances and known feeding areas. The species composition, the size and sex structure of bycatch are also discussed here. At last, an attempt to raise the data to the total fishing effort was carried out. Based on observation of marine turtle by-catches on sets, we estimated that, globally, 3500 marine turtles were accidentally captured by the EU-PS fleet in the Atlantic Ocean from 1995 to 2010, and around 2000 in the Indian Ocean from 2003 to 2010, with a corresponding annual bycatch rate of 218 (SD=150; survival rate =91%) and 250 (SD=157; survival rate =77%) respectively in the Atlantic and Indian Ocean. However, because of important uncertainties mainly due to the low observation coverage and the scarcity of marine turtle bycatch events, it was impossible to produce solid and reliable global estimates of marine turtle bycatch and mortality due to PS activity.

Droits : 2012 IOTC
http://archimer.ifremer.fr/doc/00149/25991/24087.pdf
http://archimer.ifremer.fr/doc/00149/25991/

Éditeur(s) : HAL CCSD American Geophysical Union (AGU) American Geophysical Union
Résumé : International audience
Environmental magnetism of speleothems is still in its early stage of development. Here we report on our investigation of the environmental and paleomagnetic information that has been recorded in speleothems, and what are the factors that control its preservation and reliability. To address these issues, we used a multidisciplinary approach, including rock magnetism, petrography, scanning electron microscopy, stable carbon and oxygen isotope compositions, and major and trace element concentrations. We applied this to a set of samples from different stages of speleothem evolution: present-day dripwater (glass plates), a weathered stalactite, a fresh stalagmite, cave sediments, and terra rossa soils. These samples come from the Penico and Excentricas caves, located in two distinct aquifers of the Algarve region, South Portugal. Our results show that the main magnetic carriers of the speleothems under study are primary (detrital) and consist of maghemite (and magnetite?). Similarities in coercivity and temperature dependence of the studied set of samples suggest that iron oxides are inherited from the terra rossa soils that cap the cave and were transported to the speleothems by dripwater. Hence, they represent a regional environmental signature. Interestingly, a stable and probably detrital remanent magnetization could be isolated in the fresh stalagmite, whereas the weathered stalactite yielded chaotic magnetic directions and very low remanent intensities. We propose that these low intensities can be the result from (i) different remanence acquisition mechanisms between stalagmite and stalactite and/or (ii) iron dissolution by fungal activity. We also suggest that magnetic properties and color and the content in detrital elements in the fresh speleothem inform about environmental processes acting on the interface of rock (soil)-atmosphere, while oxygen isotope composition and alkaline-earth element concentrations inform about calcite-water interaction processes. These results provide a better understanding of how environmental information is recorded in speleothems and what the factors are that control the reliability of the paleomagnetic and paleo-environmental signal.
ISSN: 0148-0227

hal-01114953
https://hal.archives-ouvertes.fr/hal-01114953
DOI : 10.1002/2014JB011381

Éditeur(s) : HAL CCSD Wiley
Résumé : International audience
The easy-to-use in vivo model, zebrafish larva, is being increasingly used to screen chemical-induced hepatotoxicity, with a good predictivity for various mechanisms of liver injury. However, nothing is known about its applicability in exploring the mechanism called membrane remodeling, depicted as changes in membrane fluidity or lipid raft properties. The aim of this study was, therefore, to substantiate the zebrafish larva as a suitable in vivo model in this context. Ethanol was chosen as a prototype toxicant because it is largely described, both in hepatocyte cultures and in rodents, as capable of inducing a membrane remodeling leading to hepatocyte death and liver injury. The zebrafish larva model was demonstrated to be fully relevant as membrane remodeling was maintained even after a 1-week exposure without any adaptation as usually reported in rodents and hepatocyte cultures. It was also proven to exhibit a high sensitivity as it discriminated various levels of cytotoxicity depending on the extent of changes in membrane remodeling. In this context, its sensitivity appeared higher than that of WIF-B9 hepatic cells, which is suited for analyzing this kind of hepatotoxicity. Finally, the protection afforded by a membrane stabilizer, ursodeoxycholic acid (UDCA), or by a lipid raft disrupter, pravastatin, definitely validated zebrafish larva as a reliable model to quickly assess membrane remodeling involvement in chemical-induced hepatotoxicity. In conclusion, this model, compatible with a high throughput screening, might be adapted to seek hepatotoxicants via membrane remodeling, and also drugs targeting membrane features to propose new preventive or therapeutic strategies in chemical-induced liver diseases.
ISSN: 0260-437X

hal-01526425
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01526425
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01526425/document
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01526425/file/Zebrafish%20larva%20as%20a%20reliable%20model-Podechard%20JAT%202016%20revised.pdf
DOI : 10.1002/jat.3421

Éditeur(s) : HAL CCSD Springer Verlag
Résumé : International audience
Over the years, a number of different models and techniques have been proposed to both quantify and explain the glacial isostatic adjustment (GIA) process. There are serious challenges, however, to obtaining accurate results from measurements, due to noise in the data and the long periods of time necessary to identify the relatively small-magnitude signal in certain regions. The primary difficulty, in general, is that most of the geophysical signals that occur in addition to GIA are nonstationary in nature. These signals are also corrupted by random as well as correlated noise added during data acquisition. The nonstationary characteristic of the data makes it difficult for traditional frequency-domain denoising approaches to be effective. Time-frequency filters present a more robust and reliable alternative to deal with this problem. This paper proposes an extended S transform filtering approach to separate the various signals and isolate that associated with GIA. Continuous global positioning system (GPS) data from eastern Canada for the period from June 2001 to June 2006 are analyzed here, and the vertical velocities computed after filtering are consistent with the GIA models put forward by other researchers.
ISSN: 0033-4553

hal-00795451
https://hal.archives-ouvertes.fr/hal-00795451
DOI : 10.1007/s00024-011-0404-1

Éditeur(s) : HAL CCSD Wiley
Résumé : We report new measurements of the surface ionization Phi(0) for Ge K alpha and L alpha X-rays on an Fe substrate, Ga K alpha and L alpha X-rays on an Ni substrate, and Au M alpha X-rays on Si, W and Ta substrates. The measurements were performed using the tracer technique for electron incident energies ranging from the ionization threshold up to about 40 keV. Improvements in sample preparation and in the X-ray measurement technique enabled surface ionization values to be obtained with uncertainties less than 2%. Simulations of Phi(0) for the studied cases were performed using the general-purpose Monte Carlo (MC) code PENELOPE. Experimental measurements are compared with simulation results and with the results of several predictive formulae widely used in electron probe microanalysis and Auger electron spectroscopy (AES). The accuracy of the reported measurements makes it possible to assess the reliability of the different calculations for incident electron energies below 10 keV.
ISSN: 0049-8246

hal-00617775
https://hal.archives-ouvertes.fr/hal-00617775
DOI : 10.1002/xrs.1294