Search results for "Interaction"
showing 10 items of 5710 documents
Using Semantic Web Technologies to Follow the Evolution of Entities in Time and Space
2013
International audience; In this paper we present the "continuum model". Our work follows a "perdurantism" approach and is designed to handle dynamic phenomena extending the 4D-fluent with the use of semantic web technologies. In our approach we represent dynamic entities as constituted by timeslices each with semantic, geometric, temporal and identity components. Our model is able to link the diverse representations of an entity and allows the inference of qualitative information from quantitative one. The inference results are later added to the ontology in order to improve knowledge about the phenomenon. The model has been implemented using OWL and SWRL. Our preliminary results are promis…
Interaction peripheral device capable of controlling an element for touching and grasping multidimensional virtual objects
2015
An interaction peripheral device capable of controlling an element for touching and grasping multidimensional virtual objects, including at least two interaction modules, each interaction module being intended to be actuated by a finger of an operator and including a control sensor allowing control of displacement, according to a predetermined number of degrees of freedom, of a portion of the element for touching and grasping virtual objects by bending/extending and/or adduction/abduction displacement of the finger of the operator, and a vibrator able to emit a vibration upon touching and/or letting go of a virtual object by a portion of said element for touching and grasping virtual object…
Couplage visuo-haptique en environnement de conduite simulée
2012
Our visual-haptic system is requested as soon as our arms interact with our external environment. There is a coupling between visual and haptic modalities, so that the central nervous system takes in account the reliability and accuracy of both modalities in order to weigh their influence in the visual-haptic integration. Thus there is a rebalancing of the weight of each modality in the context of the visual-haptic solicitation. Typically, psychophysical studies implement short and repeated tasks, with or without sensory conflict, to understand the mechanisms underlying the visual-haptic coupling. Applied in our context, this method is excluded because we have to maintain the ecological cha…
Species-specific song convergence in a moving hybrid zone between two passerines
2003
International audience; Moving hybrid zones are receiving increasing attention. However, so far little is known about the proximate mechanisms underlying these movements. Signalling behaviour, by individuals engaged in interspecific sexual and aggressive interactions, may play a crucial role. In this study, we investigated song variation within a moving hybrid zone between two warblers, Hippolais polyglotta and H. icterina . In these species, song is involved in interspecific territoriality and, probably, in mixed pairings. We showed that allopatric populations of the two species are clearly acoustically differentiated. However, interspecific differences faded out in sympatry as a result of…
Increased susceptibility to predation and altered anti-predator behaviour in an acanthocephalan-infected amphipod.
2007
7 pages; International audience; According to the 'parasitic manipulation hypothesis', phenotypic changes induced by parasites in their intermediate hosts are effective means of increasing trophic transmission to final hosts. One obvious prediction, although seldom tested, is that increased vulnerability of infected prey to an appropriate predator should be achieved by the parasite altering the anti-predator behaviour of its intermediate host. In this study, we tested this prediction using the fish acanthocephalan Pomphorhynchus tereticollis and the freshwater amphipod Gammarus pulex. Firstly, we estimated the relative vulnerability of infected and uninfected gammarids to predation by the b…
Infection with acanthocephalans increases the vulnerability of Gammarus pulex (Crustacea, Amphipoda) to non-host invertebrate predators.
2008
SUMMARYPhenotypic alterations induced by parasites in their intermediate hosts often result in enhanced trophic transmission to appropriate final hosts. However, such alterations may also increase the vulnerability of intermediate hosts to predation by non-host species. We studied the influence of both infection with 3 different acanthocephalan parasites (Pomphorhynchus laevis, P. tereticollis, and Polymorphus minutus) and the availability of refuges on the susceptibility of the amphipod Gammarus pulex to predation by 2 non-host predators in microcosms. Only infection with P. laevis increased the vulnerability of amphipods to predation by crayfish, Orconectes limosus. In contrast, in the ab…
Host manipulation of a freshwater crustacean (Gammarus roeseli) by an acanthocephalan parasite (Polymorphus minutus) in a biological invasion context.
2006
8 pages; International audience; Several gammarid species serve as intermediate hosts for the acanthocephalan parasite Polymorphus minutus. This parasite influences gammarid behaviour in order to favour transmission to its ultimate host, generally a bird. We investigated this host manipulation in Gammarus roeseli, a gammarid species introduced in France 150 years ago which now coexists with several exotic species from different origins. In the field, vertical distribution of G. roeseli revealed a higher proportion of infected individuals close to the water's surface and the size distribution of infected gammarids revealed predation pressure on infected individuals. However, under laboratory…
Introduction. Ecological immunology.
2009
12 pages; International audience; An organism's fitness is critically reliant on its immune system to provide protection against parasites and pathogens. The structure of even simple immune systems is surprisingly complex and clearly will have been moulded by the organism's ecology. The aim of this review and the theme issue is to examine the role of different ecological factors on the evolution of immunity. Here, we will provide a general framework of the field by contextualizing the main ecological factors, including interactions with parasites, other types of biotic as well as abiotic interactions, intraspecific selective constraints (life-history trade-offs, sexual selection) and popula…
Modification of hosts' behavior by a parasite: field evidence for adaptive manipulation.
2007
9 pages; International audience; Parasites relying on trophic transmission to complete their life cycles often induce modifications of their host's behavior in ways that may increase their susceptibility to predation by final hosts. These modifications have often been interpreted as parasite adaptations, but very few studies have demonstrated that host manipulation has fitness benefits for the parasite. The aim of the present study was to address the adaptive significance of parasite manipulation by coupling observations of behavioral manipulation to estimates of trophic transmission to the definitive host in the natural environment. We show that the acanthocephalan parasite Pomphorhynchus …
Manipulative parasites may not alter intermediate host distribution but still enhance their transmission: field evidence for increased vulnerability …
2013
SUMMARYBehavioural alterations induced by parasites in their intermediate hosts can spatially structure host populations, possibly resulting in enhanced trophic transmission to definitive hosts. However, such alterations may also increase intermediate host vulnerability to non-host predators. Parasite-induced behavioural alterations may thus vary between parasite species and depend on each parasite definitive host species. We studied the influence of infection with 2 acanthocephalan parasites (Echinorhynchus truttae and Polymorphus minutus) on the distribution of the amphipod Gammarus pulex in the field. Predator presence or absence and predator species, whether suitable definitive host or …