Search results for " manipulation"
showing 10 items of 113 documents
Effet de l'environnement sur l'interaction entre les gammares (Crustacea : Amphipoda) et leurs parasites manipulateurs acanthocéphales
2016
Many parasites with complex life cycle have developed the ability to alter the phenotype of their hosts. It is recognized that such changes in appearance and behavior are responsible for an increase in the probability of predation of their intermediate hosts by their definitive hosts. This phenomenon of parasite manipulation can have numerous consequences at the scale of the ecosystem, modifying the interactions between host populations and altering their ecological role. However, manipulative parasites received little attention from an ecological point of view. Thus, the effect of the environment on the interaction between these parasites and their hosts, in particular in terms of manipula…
Grip Force Adjustments Reflect Prediction of Dynamic Consequences in Varying Gravitoinertial Fields
2018
International audience; Humans have a remarkable ability to adjust the way they manipulate tools through a genuine regulation of grip force according to the task. However, rapid changes in the dynamical context may challenge this skill, as shown in many experimental approaches. Most experiments adopt perturbation paradigms that affect only one sensory modality. We hypothesize that very fast adaptation can occur if coherent information from multiple sensory modalities is provided to the central nervous system. Here, we test whether participants can switch between different and never experienced dynamical environments induced by centrifugation of the body. Seven participants lifted an object …
Jürgen Habermas and the risk of liberal eugenics for the ethical self-understanding of species
2016
El artículo analiza el problema de la naturaleza humana que presenta Jürgen Habermas en su obra El futuro de la naturaleza humana, ¿Hacia una eugenesia liberal? Los vertiginosos avances biotecnológicos reclaman una rigurosa reflexión bioética que el filósofo alemán afronta superponiendo a su ética del discurso una ética de la especie. Habermas esboza un modelo de naturaleza humana construido sobre preceptos como la dignidad humana y de la vida humana, la simetría de las relaciones intersubjetivas y, a resultas de estas, la autocomprensión ética de la especie. Respecto a la eugenesia liberal, el autor se posiciona criticando la eugenesia positiva y amparando la negativa, para lo que basa su …
BlockSee: Blockchain for IoT video surveillance in smart cities
2018
The growing demand for safety in urban environments is supported by monitoring using video surveillance. The need to analyze multiple video-flows from different cameras deployed around the city by heterogeneous owners introduces vulnerabilities and privacy issues. Video frames, timestamps, and camera settings can be digitally manipulated by malicious users; the positions of cameras, their orientation and their mechanical settings can be physically manipulated. Digital and physical manipulations may have several effects, including the change of the observed scene and the potential violation of neighbors' privacy. To face these risks, we introduce BlockSee, a blockchain-based video surveillan…
Application of Chemical Cues in Arthropod Pest Management for Orchards and Vineyards
2013
This chapter reviews the literature on semiochemical-parasitoid systems in perennial crops. The first part of the chapter analyses the possible effects of pheromone-based tactics on parasitoid efficacy. In both orchards and vineyards, the most successful application of synthetic sex pheromones has been their use as mating disruptants. It also discusses the possibility of using parasitoid pheromones to directly affect parasitoid behaviour. The second part of the chapter summarizes research in orchards and vineyards that has tested whether synthetic chemical cues such as herbivore-induced plant volatiles (HIPVs) and host-associated volatiles (HAVs) can be used to manipulate parasitoid behavio…
Differential influence of Pomphorhynchus laevis (Acanthocephala) on brain serotonergic activity in two congeneric host species.
2007
The physiological mechanisms by which parasites with complex life cycles manipulate the behaviour of their intermediate hosts are still poorly understood. In Burgundy, eastern France, the acanthocephalan parasitePomphorhynchus laevisinverses reaction to light in its amphipod hostGammarus pulex, but not inGammarus roeseli, a recent invasive species. Here, we show that this difference in manipulation actually reflects a difference in the ability of the parasite to alter brain serotonergic (5-HT) activity of the two host species. Injection of 5-HT in uninfected individuals of both host species was sufficient to inverse reaction to light. However, a difference in brain 5-HT immunocytochemical s…
Balance training versus balance training and foot and ankle mobilization: a pilot randomized trial in community-dwelling older adults
2019
Background: Balance limitations and foot and ankle problems are common in older adults. Objective: To determine the impact of augmented balance training with foot and ankle mobilizations (FAMs) on ...
Maternal investment in relation to sex ratio and offspring number in a small mammal – a case for Trivers and Willard theory?
2009
1. Optimal parental sex allocation depends on the balance between the costs of investing into sons vs. daughters and the benefits calculated as fitness returns. The outcome of this equation varies with the life history of the species, as well as the state of the individual and the quality of the environment. 2. We studied maternal allocation and subsequent fecundity costs of bank voles, Myodes glareolus, by manipulating both the postnatal sex ratio (all-male/all-female litters) and the quality of rearing environment (through manipulation of litter size by -2/+2 pups) of their offspring in a laboratory setting. 3. We found that mothers clearly biased their allocation to female rather than ma…
''Active Collisions in Altered Gravity Reveal Eye-Hand Coordination Strategies''
2012
White, Olivier | Lefevre, Philippe | Wing, Alan M. | Bracewell, R. Martyn | Thonnard, Jean-Louis; International audience; ''Most object manipulation tasks involve a series of actions demarcated by mechanical contact events, and gaze is usually directed to the locations of these events as the task unfolds. Typically, gaze foveates the target 200 ms in advance of the contact. This strategy improves manual accuracy through visual feedback and the use of gaze-related signals to guide the hand/ object. Many studies have investigated eye-hand coordination in experimental and natural tasks; most of them highlighted a strong link between eye movements and hand or object kinematics. In this experime…
Behavioural and physiological effects of the trophically transmitted cestode parasite, Cyathocephalus truncatus, on its intermediate host, Gammarus p…
2007
SUMMARYSome parasites with complex life-cycles are able to manipulate the behaviour of their intermediate hosts in a way that increases their transmission to the next host. Gammarids infected by the tapeworm Cyathocephalus truncatus (Cestoda: Spathebothriidea) are known to be more predated by fish than uninfected ones, but potential behavioural manipulation by the parasite has never been investigated. In this study, we tested the hypothesis that C. truncatus is able to manipulate the behaviour of one of its intermediate hosts, Gammarus pulex (Crustacea: Amphipoda). To assess if any behavioural change was linked to other phenotypic alterations, we also measured the immunity of infected and u…