Inventory of the free-living marine nematode species from el Bibane Lagoon (Tunisia). A detailed inventory of the free-living nematodes of Tunisia has been made for the northern part of Tunisia, but the southern part of the country is unexplored. El Bibane is the second largest lagoon in Tunisia. It is thus of high importance for future conservation actions, but little is known about its biodiversity. In this study, we identified 71 nematode species, belonging to 68 genera and 22 families. Richness was lowest in the central area of the lagoon where the highest percentages of mud and organic matter were found. The number of species detected in this study is high compared to other transitional environments in the Mediterranean basin, but lower than those reported for North Europe. Most of the species are typical of transitional environments or sediments rich in the fine fraction and detritus. The richest families were Cyatholaimidae and Chromadoridae, but the most frequently found species were Xyalidae, Linhomoeidae and Cyatholaimidae. Six of the species collected are new to science, seven are new records for Tunisian waters, and four are new for the Mediterranean basin. This study adds also important information to the biogeography of the phylum because some of the species detected here were previously known only for other geographical regions. Species that currently appear endemic to the Mediterranean Sea include Chromadorina metulata, Synonchiella edax, Paralongicyatholaimus mastigodes, Trichotheristus setifer and Metalinhomoeus numidicus.

International audienceIn this paper, we present a subjective audiovisual quality assessment experiment realized using a PC based video-conferencing application connected via a local IP network. The experiment was conducted under two different scenarios: a non-interactive and an interactive conversational one. We present the effects of network impairments (packet loss, delay) on perceived audiovisual, audio and video quality. We evaluate the impact of scene complexity on the quality perception in case of video calls. We establish a comparison between the perception of multimedia quality in interactive and non-interactive context. The results presented in this paper show a dependency between the perceived quality and the scene complexity: the perceived quality of a high spatial and temporal complex scene is inferior to that of the less complex one. In addition, our findings show that the audio-video synchronization acceptability do not differ between the interactive and the non-interactive experimental context. © 2016 IEEE

International audienceFor an accurate assessment of media quality, it is essential not only to compute an overall quality measure, but also to identify the type of occurring distortions. In this paper, we focus on a set of no-reference single-artifact based metrics developed by the MOAVI project. We carried out a correlation analysis in order to evaluate the performance of these metrics on three databases with a large sample of distortion types. This study will be used for setting up a video quality monitoring tool box. © 2017 IEEE

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International audienceIn this paper, an audiovisual quality assessment experiment was conducted on audiovisual clips collected using a PC-based videoconferencing application connected via a local IP network. The analyses of experimental results provided a better understanding of the influence of network impairments (packet loss, jitter, delay) on perceived audio and video qualities, as well as their interaction effect on the overall audiovisual quality in videoconferencing applications. We updated the human perception acceptability limits of audio-video synchronization for video conferencing. Further, we investigated the contribution of this synchronization to the audiovisual quality independently and accompanied with network impairments. Finally, we proposed an integration model to estimate the audiovisual quality in the studied context. © 2016 IEEE

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