Adaptive Resonance Theory for reading modelisation

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Evaluation subjective de la qualité de vidéos encodées MPEG2 dans un contexte de télé-robotique chirurgicale

International audienceLa transmission de vidéos médicales sur de grandes distances est un sujet en plein développement, du fait de la « révolution numérique » que connaît le monde médical actuellement. La contrepartie de cette numérisation réside dans des volumes de données considérables nécessitant des capacités de transmission elles-mêmes très importantes, rendant la compression avec perte en amont inévitable. Celle-ci constitue un défi majeur dans un contexte aussi sensible que le contexte médical, celui de l'impact des pertes sur la qualité des données et leur exploitation. Le travail présenté ici concerne l'évaluation subjective, par un panel de chirurgiens, de séquences vidéo issues d'une application de télé-robotique chirurgicale et compressées avec pertes au format MPEG2. L'évaluation s'appuie sur les recommandations de l'ITU-R1 à travers le protocole DSCQS², l'objectif étant de déterminer un seuil de compression permettant d'avoir une qualité perceptuelle de la vidéo chirurgicale compressée irréprochable, pour le bon déroulement de l'opération et pour assurer la sécurité des patients. Nous montrons qu'il existe un seuil de tolérance à la compression avec pertes de type MPEG2 autour de 3 Mbits/s pour les vidéos utilisées dans cette étude, ce qui équivaut à un taux de compression d'environ 90 :1 du flux vidéo initialement à 270 Mbits/s

Domestic water carrying and its implications for health: a review and mixed methods pilot study in Limpopo Province, South Africa

Background: Lack of access to safe water remains a significant risk factor for poor health in developing countries. There has been little research into the health effects of frequently carrying containers of water. The aims of this study were to better understand how domestic water carrying is performed, identify potential health risk factors and gain insight into the possible health effects of the task. Methods: Mixed methods of data collection from six were used to explore water carrying performed by people in six rural villages of Limpopo Province, South Africa. Data was collected through semi-structured interviews and through observation and measurement. Linear regression modelling were used to identify significant correlations between potential risk factors and rating of perceived exertion (RPE) or self reported pain. Independent t-tests were used to compare the mean values of potential risk factors and RPE between sub-groups reporting pain and those not reporting pain. Results: Water carrying was mainly performed by women or children carrying containers on their head (mean container weight 19.5 kg) over a mean distance of 337 m. The prevalence of spinal (neck or back) pain was 69% and back pain was 38%. Of participants who carried water by head loading, the distance walked by those who reported spinal pain was significantly less than those who did not (173 m 95%CI 2-343; p = 0.048). For head loaders reporting head or neck pain compared to those who did not, the differences in weight of water carried (4.6 kg 95%CI -9.7-0.5; p = 0.069) and RPE (2.5 95%CI -5.1-0.1; p = 0.051) were borderline statistically significant. For head loaders, RPE was significantly correlated with container weight (r = 0.52; p = 0.011) and incline (r = 0.459; p = 0.018). Conclusions: Typical water carrying methods impose physical loading with potential to produce musculoskeletal disorders and related disability. This exploratory study is limited by a small sample size and future research should aim to better understand the type and strength of association between water carrying and health, particularly musculoskeletal disorders. However, these preliminary findings suggest that efforts should be directed toward eliminating the need for water carrying, or where it must continue, identifying and reducing risk factors for musculoskeletal disorders and physical injury