Éditeur(s) : HAL CCSDTaylor & Francis (Routledge) Résumé : International audience The influences of task difficulty (index difficulty: 2-4), input device of different length, range of motion and mode of resistance (joystick or rotorcraft stick), and directions of movement (leftward rightward) on motor patterns in a realistic control situation were examined with a multilevel analysis (joint kinematics and muscular variables, and global task performance). Eight subjects controlled the displacements of a virtual object during a slalom task characterized by a realistic inertial model. Pilots adapted the endpoint kinematic organization to increasing accuracy constraints to preserve task success whatever the device and the direction. However, the rotorcraft stick manipulation remains highly complex in comparison to the joystick due to poorer proprioceptive information, higher inertial constraints, and an asymmetrical muscle control. ISSN: 0022-2895
Éditeur(s) : HAL CCSDPublic Library of Science Résumé : International audience As environmental sounds are used by larval fish and crustaceans to locate and orientate towards habitat during settlement, variations in the acoustic signature produced by habitats could provide valuable information about habitat quality, helping larvae to differentiate between potential settlement sites. However, very little is known about how acoustic signatures differ between proximate habitats. This study described within-and between-site differences in the sound spectra of five contiguous habitats at Moorea Island, French Polynesia: the inner reef crest, the barrier reef, the fringing reef, a pass and a coastal mangrove forest. Habitats with coral (inner, barrier and fringing reefs) were characterized by a similar sound spectrum with average intensities ranging from 70 to 78 dB re 1μPa.Hz-1. The ISSN: 1932-6203
Éditeur(s) : HAL CCSDElsevier Résumé : International audience Justafterthereefcolonization,fishspeciescouldusetheacousticcuetosettleondifferentsuitablehabitats.Inthepresent study, we used the auditory evoked potential (AEP) technique to measure and compare the detectionabilities in five coral reef fish species, with some of these species that are found in the same habitat. We also ex-aminedtheeffectoffishsizeonsensitivityatthespecieslevel.Allstudiedspeciesexceptoneshowedsize-relatedchangesinsensitivitycharacterizedbyeitheradecrease(i.e.higherAEPthresholds)oranincrease(i.e.lowerAEPthresholds) in detection abilities with increasing size. The interspecific comparison of audiograms revealed thatsome species are more sensitive than others in terms of sound pressure level and frequency detection.Overall,thisstudy indicatesthattheAEPthresholdandthefrequencybandwidthatearlylifestagesmay vary be-tween andwithin fish species.Thedetectionabilities aredifferent infish species thatarenotphylogeneticallyre-lated, which might suggest that the establishment of their capabilities is not necessarily related to the reefconquest. ISSN: 0022-0981
Livres anciens
Images
Fonds Jean Bernabé
Fonds René Maran
Esclaves de Guyane
Esclavage en Martinique
Catalogue collectif des périodiques
Audio-Vidéo
Études et recherches
Etudes Caribéennes
Tramil
Or
Esclavage et résistances