Éditeur(s) : HAL CCSD Elsevier
Résumé : International audience
Geographical distribution of parasite species can provide insights into the evolution and diversity of parasiticcommunities. Biogeography of marine parasites is poorly known, especially because it requires anunderstanding of host-parasite interactions, information that is rare, especially over large spatial scales.Here, we have studied the biogeographical patterns of dactylogyrid parasites of chaetodontids, one of themost well-studied fish families, in the tropical Indo-west Pacific region. Dactylogyrid parasites were collectedfrom gills of 34 butterflyfish species (n = 560) at nine localities within an approximate area of62 million km2. Thirteen dactylogyrid species were identified, with richness ranging from 6 to 12 speciesat individual localities. Most dactylogyrid communities were dominated by Haliotrema angelopterum orHaliotrema aurigae, for which relative abundance was negatively correlated (q = !0.59). Parasite richnessand diversity were highest in French Polynesia and the Great Barrier Reef (Australia) and lowest in Palau.Three biogeographic regions were identified based on dactylogyrid dissimilarities: French Polynesia,characterised by the dominance of H. angelopterum, the western Pacific region dominated by H. aurigae,and Ningaloo Reef (Australia), dominated by Euryhaliotrema berenguelae. Structure of host assemblageswas the main factor explaining the dissimilarity (turnover and nestedness components of the Bray-Curtis dissimilarity and overall Bray-Curtis dissimilarity) of parasite communities between localities,while environment was only significant in the turnover of parasite communities and overall dissimilarity.Spatial structure of localities explained only 10% of the turnover of parasite communities. The interactionof the three factors (host assemblages, environment and spatial structure), however, explained the highestamounts of variance of the dactylogyrid communities, indicating a strong colinearity between the factors.Our findings show that spatial arrangement of chaetodontid dactylogyrids in the tropical Indo-westPacific is primarily characterised by the turnover of the main Haliotrema spp., which is mainly explainedby the structure of host assemblages.
ISSN: 0020-7519

hal-01562156
https://hal-univ-perp.archives-ouvertes.fr/hal-01562156
DOI : 10.1016/j.ijpara.2017.01.006

Éditeur(s) : HAL CCSD Royal Society, The
Résumé : Plant leaf litter generally decomposes faster as a group of different species than when individual species decompose alone, but underlyingmechanisms of these diversity effects remain poorly understood. Because resource C : N: P stoichiometry (i.e. the ratios of these key elements) exhibits strong control on consumers, we supposed that stoichiometric dissimilarity of litter mixtures (i.e. the divergence in C : N: P ratios among species) improves resource complementarity to decomposers leading to faster mixture decomposition. We tested this hypothesis with: (i) a wide range of leaf litter mixtures of neotropical tree species varying in C : N: P dissimilarity, and (ii) a nutrient addition experiment (C, N and P) to create stoichiometric similarity. Litter mixtures decomposed in the field using two different types of litterbags allowing or preventing access to soil fauna. Litter mixture mass loss was higher than expected from species decomposing singly, especially in presence of soil fauna. With fauna, synergistic litter mixture effects increased with increasing stoichiometric dissimilarity of litter mixtures and this positive relationship disappeared with fertilizer addition. Our results indicate that litter stoichiometric dissimilarity drives mixture effects via the nutritional requirements of soil fauna. Incorporating ecological stoichiometry in biodiversity research allows refinement of the underlying mechanisms of how changing biodiversity affects ecosystem functioning.
ISSN: 0962-8452

hal-01204222
https://hal.archives-ouvertes.fr/hal-01204222
DOI : 10.1098/rspb.2014.1682
PRODINRA : 289918

Éditeur(s) : Blackwell science
Résumé : The trophic level mean and variance, and the degree of omnivory for five Celtic Sea fish predators were estimated using a database of stomach content records characterized by a high level of taxonomic resolution. The predators occupied a high position in the food web, i.e. 4.75 for Atlantic cod Gadus morhua, 444 for haddock Melanogrammus aeglefinus, 4.88 for European hake Merluccius merluccius, 5.00 for megrim Lepidorhombus whiffiagonis and 5.27 for whiting Merlangius merlangus. The level of taxonomic resolution of the prey did not greatly affect mean T-L predator values; an effect on variance was evident, low resolution masking intra-population variability in T-L. Generalized additive models (GAM) were used to explain the variability of predator T-L caused by environmental variables (international Council for the Exploration of the Sea, ICES, division and season) and predator characteristics (total length, L-T). Significant year, location season and interaction effects were found for some species and with L-T, at the scale of ICES subdivision. The species-specific variability of T-L could be due to spatio-temporal variations in prey availability and in predator selectivity following ontogenetic changes. Omnivorous fish T-L. was less affected by spatio-temporal variations. In addition, results showed that the omnivory index and T-L variability provide dissimilar information on predator feeding strategy. Combining information on T-L. variability and omnivory allowed between within individual and between-individual components contributing to trophic niche width to be separated and the type of generalization of fish predators to be identified. (c) 2008 The Authors Journal compilation (c) 2008 The Fisheries Society of the British Isles.
Journal of Fish Biology (0022-1112) (Blackwell science), 2008-09 , Vol. 73 , N. 4 , P. 763-781

Droits : 2008 Wiley Blackwell Publishing, Inc. The Fisheries Society of the British Isles
http://archimer.ifremer.fr/doc/2008/publication-4699.pdf
DOI:10.1111/j.1095-8649.2008.01938.x
http://archimer.ifremer.fr/doc/00000/4699/

Éditeur(s) : Université des Antilles Études caribéennes
Résumé : La zona del sudeste de la provincia de Buenos Aires (Argentina), se vislumbra como territorio fértil para los estudios culturales debido a su densidad histórica, social y patrimonial, en un marco de disímiles condiciones geográficas. Dos ciudades bonaerenses intermedias, Mar del Plata y Tandil, se han destacado por sus procesos de construcciones socio-culturales asociadas al ocio y al turismo. El estudio propuesto abarca la primera mitad del siglo XX para reconocer las transformaciones acontecidas en el hábitat y en el habitar, observando las prácticas sociales y las renovadas relaciones entre cuerpo y espacio que darán lugar a propuestas diferenciadas en relación con la estadía costera o serrana. Para ello se hará hincapié en la lectura de la revista ilustrada Caras y Caretas, en particular, en las imágenes de notas y avisos publicitarios.
The southeast zone of the province of Buenos Aires (Argentina), it is glimpsed as fertile territory for the cultural studies due to its historical, social and heritage density, in a frame of dissimilar geographical conditions. Two intermediate cities, Mar del Plata and Tandil, have been outlined for their processes of sociocultural constructions associated with leisure and tourism. The proposed study includes the first half of the XXth century to recognize the transformations happened in the habitat and the living, observing the social practices and the renewed relations between body and space that will give place to different proposals in relation with the coastal or highland demurrage. For this, it will be emphisized in the reading of the illustrated magazine Caras y Caretas, especially, the images of notes and advertising notices.
La zone du sud-est de la province du Buenos Aires (Argentine) est perçue comme un territoire fertile pour les études culturelles pour des raisons historique, sociale et patrimoniale, avec des conditions géographiques dissemblables. Deux villes intermédiaires, Mar del Plata et Tandil, se distinguent par leur processus de construction socioculturelle associée aux loisirs et au tourisme. L'étude proposée concerne la première moitié du XXe siècle. Elle s’attache à reconnaître les transformations des habitats et des modes de vie, en observant les pratiques sociales et les relations renouvelées entre le corps et l'espace en relation avec l’environnement du lieu de séjour, côtier ou montagnard. Pour cela, on mettra l'accent sur la lecture de la revue illustrée Caras y Caretas, en particulier les illustrations et les avis publicitaires.
Argentine
Buenos Aires
Mar del Plata
Tandil

Droits : info:eu-repo/semantics/openAccess
urn:doi:10.4000/etudescaribeennes.7626
http://journals.openedition.org/etudescaribeennes/7626

Éditeur(s) : HAL CCSD
Résumé : International audience
In this paper we describe the various steps of a method using local descriptors in order to classify freehand sketches, which are drawn in an unconstrained manner and recorded online. Our final objective is to simultaneously allow classification, comparison or clustering of those elements according to their Visuo spatial properties, their realization strategies, their structural or temporal parameters, or any combination of two or more of those parameters. The context and the motivation of this work-in-progress are described. First, we'll explain the detection step: we decided to use a mixed segmentation process. Indeed recognition methods based on local descriptor are not fully adapted to our types of shapes and to the one-line context. Later, we will show how we plan to give a global perception of the shape to our local descriptor by using segmentation results. Then we will introduce the local descriptor and how it is computing. Next we'll explain how we calculate the dissimilarity between two descriptors. Finally, we'll describe the approach we have chosen to determine the dissimilarity between shapes represented by sets of local descriptors.
Proceedings of the 14th Biennial Conference of the International Graphonomics Society

hal-00514930
https://hal.archives-ouvertes.fr/hal-00514930

Éditeur(s) : HAL CCSD Wiley
Résumé : Over the past three decades, many small-scale floristic studies of white-sand forests across the Amazon basin have been published. Nonetheless, a basin-wide description of both taxonomic and phylogenetic alpha and beta diversity at regional scales has never been achieved. We present a complete floristic analysis of white-sand forests across the Amazon basin including both taxonomic and phylogenetic diversity. We found strong regional differences in the signal of phylogenetic community structure with both overall and regional Net Relatedness Index and Nearest Taxon Index values found to be significantly positive leading to a pattern of phylogenetic clustering. Additionally, we found high taxonomic dissimilarity but low phylogenetic dissimilarity in pairwise community comparisons. These results suggest that recent diversification has played an important role in the assembly of white-sand forests causing geographic neo-endemism patterns at the regional scale.
ISSN: 0006-3606

hal-01532549
https://hal.archives-ouvertes.fr/hal-01532549
DOI : 10.1111/btp.12298
PRODINRA : 353398

Éditeur(s) : HAL CCSD
Résumé : International audience
Given the clinical success of commercial amphotericin B lipid products, investigators have begun making generic formulations of liposomal amphotericin B. Generic medicines are an attractive approach to help decrease the cost and accessibility to healthcare, provided that appropriate studies are performed to ensure bioequivalence with the parent product. This is of particular concern for liposomal drugs such as amphotericin B where liposomes are used as a carrier system to reduce the toxicity of the active agent. A favorable therapeutic profile for this form of the drug has to include the proper chemical composition along with strictly controlled manufacturing processes. Studies have shown that a comparison of liposomal amphotericin B products with different or the same chemical compositions, using different methods of production, will vary in size, and have significantly dissimilar in vitro and in vivo toxicities along with reduced efficacy. These results underscore the importance of establishing appropriate bioequivalence testing for liposome products to ensure uniformity of their therapeutic index
Medical Mycology

hal-01259233
https://hal-univ-rennes1.archives-ouvertes.fr/hal-01259233
DOI : 10.1093/mmy/myv111
PUBMED : 26768369

Éditeur(s) : HAL CCSD
Résumé : International audience
The Sigma-Lognormal model of the Kinematic Theory of rapid human movements allows us to represent on-line signatures with an analytical neuromuscular model. It has been successfully used in the past to generate synthetic signatures in order to improve the performance of an automatic verification system. In this paper, we attempt for the first time to build a verification system based on the model parameters themselves. For describing individual lognormal strokes, we propose eighteen features which capture cognitive psychomotor characteristics of the signer. They are matched by means of dynamic time warping to derive a dissimilarity measure for signature verification. Promising initial results are reported for an experimental evaluation on the SUSIG visual sub-corpus, which contains some of the most skilled forgeries currently available for research.
17th Biennial Conference of the International Graphonomics Society
Pointe-à-Pitre, Guadeloupe

hal-01165871
https://hal.univ-antilles.fr/hal-01165871
https://hal.univ-antilles.fr/hal-01165871/document
https://hal.univ-antilles.fr/hal-01165871/file/IGS_2015_submission_11.pdf

Éditeur(s) : HAL CCSD
Résumé : International audience
We present the principle and the main steps of a new method for the visuo-spatial analysis of geometrical sketches recorded online. Visuo-spatial analysis is a necessary step for multi-level analysis. Multi-level analysis simultaneously allows classification, comparison or clustering of the constituent parts of a pattern according to their visuo-spatial properties, their procedural strategies, their structural or temporal parameters, or any combination of two or more of those parameters. The first results provided by this method concern the comparison of sketches to some perfect patterns of simple geometrical figures and the measure of dissimilarity between real sketches. The mean rates of good decision higher than 95% obtained are promising in both cases.
Proceedings of the 2010 International Conference on Image Processing, Computer Vision, & Pattern Recognition

Droits : info:eu-repo/semantics/OpenAccess
hal-00514929
https://hal.archives-ouvertes.fr/hal-00514929
https://hal.archives-ouvertes.fr/hal-00514929/document
https://hal.archives-ouvertes.fr/hal-00514929/file/IPCV2010_-_RRP.pdf
ARXIV : 1305.1520

Éditeur(s) : HAL CCSD Ecological Society of America
Résumé : Herbivores are often implicated in the generation of the extraordinarily diverse tropical flora. One hypothesis linking enemies to plant diversification posits that the evolution of novel defenses allows plants to escape their enemies and expand their ranges. When range expansion involves entering a new habitat type, this could accelerate defense evolution if habitats contain different assemblages of herbivores and/or divergent resource availabilities that affect plant defense allocation. We evaluated this hypothesis by investigating two sister habitat specialist ecotypes of Protium subserratum (Burseraceae), a common Amazonian tree that occurs in white-sand and terra firme forests. We collected insect herbivores feeding on the plants, assessed whether growth differences between habitats were genetically based using a reciprocal transplant experiment, and sampled multiple populations of both lineages for defense chemistry. Protium subserratum plants were attacked mainly by chrysomelid beetles and cicadellid hemipterans. Assemblages of insect herbivores were dissimilar between populations of ecotypes from different habitats, as well as from the same habitat 100 km distant. Populations from terra firme habitats grew significantly faster than white-sand populations; they were taller, produced more leaf area, and had more chlorophyll. White-sand populations expressed more dry mass of secondary compounds and accumulated more flavone glycosides and oxidized terpenes, whereas terra firme populations produced a coumaroylquinic acid that was absent from white-sand populations. We interpret these results as strong evidence that herbivores and resource availability select for divergent types and amounts of defense investment in white-sand and terra firme lineages of Protium subserratum, which may contribute to habitat-mediated speciation in these trees.
ISSN: 0012-9658

hal-01032403
https://hal.archives-ouvertes.fr/hal-01032403
DOI : 10.1890/12-1920.1

Éditeur(s) : HAL CCSD Elsevier Masson
Résumé : International audience
ISSN: 1631-0691

hal-01109725
https://hal-agroparistech.archives-ouvertes.fr/hal-01109725
DOI : 10.1016/j.crvi.2011.03.001