257 research outputs found

    Ontology-based context representation and reasoning for object tracking and scene interpretation in video

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    Computer vision research has been traditionally focused on the development of quantitative techniques to calculate the properties and relations of the entities appearing in a video sequence. Most object tracking methods are based on statistical methods, which often result inadequate to process complex scenarios. Recently, new techniques based on the exploitation of contextual information have been proposed to overcome the problems that these classical approaches do not solve. The present paper is a contribution in this direction: we propose a Computer Vision framework aimed at the construction of a symbolic model of the scene by integrating tracking data and contextual information. The scene model, represented with formal ontologies, supports the execution of reasoning procedures in order to: (i) obtain a high-level interpretation of the scenario; (ii) provide feedback to the low-level tracking procedure to improve its accuracy and performance. The paper describes the layered architecture of the framework and the structure of the knowledge model, which have been designed in compliance with the JDL model for Information Fusion. We also explain how deductive and abductive reasoning is performed within the model to accomplish scene interpretation and tracking improvement. To show the advantages of our approach, we develop an example of the use of the framework in a video-surveillance application.This work was supported in part by Projects CICYT TIN2008- 06742-C02-02/TSI, CICYT TEC2008-06732-C02-02/TEC, SINPROB, CAM MADRINET S-0505/TIC/0255 and DPS2008–07029-C02–02.Publicad

    Which medical technology and/or local treatment is most conducive, as of 2012, to pressure sore debridement ? Developing French guidelines for clinical practice

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    AbstractIntroductionImplementation of a curative strategy at the debridement stage associates systemic therapy with local therapy.ObjectivesTo determine which medical devices and technology other than support surfaces and what kinds of drugs to use in order to cleanse a pressure ulcer in 2012.MethodA systematic review of the literature querying the databases PASCAL Biomed, Cochrane Library and PubMed from 2000 to 2010 along with a compendium of prevailing professional practices.ResultsPressure sore debridement is based on local care and on the use of alginates, hydrogels and hydrocolloids.DiscussionThe analyzed articles do not take into account any specific stage of pressure ulcer debridement. Data that might favor some kinds of dressings show a low level of evidence. Were it possible to decide on the dressing to be used for a given indication, professionals would be better able to orient and narrow down their choices.ConclusionUse of alginates and hydrogels in pressure ulcer debridement is of real interest. According to expert opinion, other dressings (irrigo-absorbents, for instance) seem promising, but have yet to receive adequate scientific validation

    Functional Magnetic Resonance Imaging of Rats with Experimental Autoimmune Encephalomyelitis Reveals Brain Cortex Remodeling.

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    UNLABELLED: Cortical reorganization occurring in multiple sclerosis (MS) patients is thought to play a key role in limiting the effect of structural tissue damage. Conversely, its exhaustion may contribute to the irreversible disability that accumulates with disease progression. Several aspects of MS-related cortical reorganization, including the overall functional effect and likely modulation by therapies, still remain to be elucidated. The aim of this work was to assess the extent of functional cortical reorganization and its brain structural/pathological correlates in Dark Agouti rats with experimental autoimmune encephalomyelitis (EAE), a widely accepted preclinical model of chronic MS. Morphological and functional MRI (fMRI) were performed before disease induction and during the relapsing and chronic phases of EAE. During somatosensory stimulation of the right forepaw, fMRI demonstrated that cortical reorganization occurs in both relapsing and chronic phases of EAE with increased activated volume and decreased laterality index versus baseline values. Voxel-based morphometry demonstrated gray matter (GM) atrophy in the cerebral cortex, and both GM and white matter atrophy were assessed by ex vivo pathology of the sensorimotor cortex and corpus callosum. Neuroinflammation persisted in the relapsing and chronic phases, with dendritic spine density in the layer IV sensory neurons inversely correlating with the number of cluster of differentiation 45-positive inflammatory lesions. Our work provides an innovative experimental platform that may be pivotal for the comprehension of key mechanisms responsible for the accumulation of irreversible brain damage and for the development of innovative therapies to reduce disability in EAE/MS. SIGNIFICANCE STATEMENT: Since the early 2000s, functional MRI (fMRI) has demonstrated profound modifications in the recruitment of cortical areas during motor, cognitive, and sensory tasks in multiple sclerosis (MS) patients. Experimental autoimmune encephalomyelitis (EAE) represents a reliable model of the chronic-progressive variant of MS. fMRI studies in EAE have not been performed extensively up to now. This paper reports fMRI studies in a rat model of MS with somatosensory stimulation of the forepaw. We demonstrated modifications in the recruitment of cortical areas consistent with data from MS patients. To the best of our knowledge, this is the first report of cortical remodeling in a preclinical in vivo model of MS.This work was supported by grants from the National Multiple Sclerosis Society (NMSS; RG-4001-A1 to SP), the Italian Multiple Sclerosis Foundation (FISM; RG 2010/R/31 to SP and FISM Grant 10/12/F14/2011 to PM), the Italian Ministry of Health (GR08/7 to SP), the European Research Council (ERC) 2010-SIG (RG 260511-SEM_SEM to SP), the European Community (EC) 7th Framework Programme (FP7/2007-2013; RG 280772-iONE to SP), The Evelyn Trust (RG 69865 to SP), The Bascule Charitable Trust (RG 75149 to SP). LPJ is supported by a Wellcome Trust Research Training Fellowship (RRZA/057).This is the final version of the article. It first appeared from Society for Neuroscience via http://dx.doi.org/10.1523/JNEUROSCI.0540-15.201

    Recent Developments in Identification of Genuine Odor- and Taste-Active Compounds in Foods

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    Both aroma and taste are important quality criteria for food products, and they have a great influence on our consumption behaviours. In recent years, a significant increase in the number of studies related to the identification of the characteristic odor- and taste-active compounds of particular foods has been observed.In this book, you can find nine valuable scientific contributions, which deal with the more recent analytical developments for the identification of some compounds responsible for odor and taste in foods such as ham, beer, strawberry, Amontillado sherry wine and others, in order to authenticate them or evaluate the effect of different techniques or making stages on their aroma and taste

    Web interaction environments : characterising Web accessibility at the large

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    Tese de doutoramento, Informática (Engenharia Informática), Universidade de Lisboa, Faculdade de Ciências, 2012Accessibility quality on the Web is essential for providing a good Web experience to people with disabilities. The existence of virtual ramps aid these users grasping and interacting withWeb content, just like the experience of those who are unimpaired. However, more often than not, Web pages impose accessibility barriers, usually centred on the unavailability of tailored content to specific perceptual abilities (e.g., textual description of images, enabling grasping information with assistive technologies), as well as on proper HTML structural elements that adequate the semantics of a Web page. When evaluating the accessibility quality of Web pages, the resulting analysis is often focused on a small sample set (e.g., a single Web page or a selection of pages from a Web site). While this kind of analysis gets the gist of accessibility quality, it misses the big picture on the overall accessibility quality of the Web. This thesis addresses the challenge of observing accessibility phenomena on the Web, through the experimental evaluation of large collections of Web pages. This resulted on new findings about the accessibility quality of the Web, such as its correlation with HTML element count, and the erroneous perception of accessibility quality by developers. Small-scale experiments have been verified also at large scale, such as the correlation between the usage of HTML templates and accessibility quality. Based on the challenges raised by the experimental evaluation, this thesis proposes a novel approach for large scale Web accessibility evaluation based on Linked Data, as well as the establishment of metrics to assess the truthfulness and coverage of automated evaluation methods.A qualidade da acessibilidade é um factor crucial para as pessoas com deficiências terem uma boa experiência de interacção com a Web.A qualidade da acessibilidade é um factor crucial para as pessoas com deficiências terem uma boa experiência de interacção com a Web. A existência de rampas virtuais ajuda estas pessoas a compreender e interagir com conteúdos Web, a par do que o utilizador comum já experiencia. Porém, a maioria das páginas Web ainda contêm barreiras à acessibilidade. Estas barreiras centram-se normalmente na indisponibilidade de conteúdos perceptíveis por diferentes tipos de capacidades (e.g., descrições textuais de imagens), bem como no uso incorrecto de elementos HTML de acordo com a semântica de uma página Web. Nos dias de hoje, a avaliação da qualidade de acessibilidade de páginas Web é ainda efectuada em pequena escala (e.g., uma página Web ou, no melhor caso, um conjunto de páginas representativas de um sítio Web). Apesar deste tipo de avaliações resultarem na compreensão de alguns fenómenos do estado da acessibilidade na Web, ainda não se sabe qual o seu impacto em larga escala. Esta tese discute os principais desafios na observação da acessibilidade da Web, tendo por base um conjunto de avaliações experimentais de colecções de grande dimensão de páginas Web. Destes estudos destacam-se as seguintes contribuições e resultados:a diferença drástica na interpretação dos avisos resultantes de avaliações de acessibilidade Web: um dos resultados principais da avaliação experimental em larga escala destaca a diferença na interpretação dos avisos (warnings) da aplicação de técnicas da norma WCAG, onde a interpretação optimista (i.e., a visão da maioria dos criadores de páginas Web) se distancia amplamente da interpretação conservadora (onde os avisos são interpretados como erros); a correlação entre a qualidade da acessibilidade de uma página Web e a sua complexidade: este mesmo estudo de larga escala revelou uma correlação entre a complexidade de uma página Web (no que diz respeito ao número de elementos HTML que contém) e a qualidade da acessibilidade. Quanto menor a complexidade de uma página Web, mais certa se torna a alta qualidade da acessibilidade dessa página; o benefício do uso de templates e sistemas de gestão de conteúdos na melhoria da acessibilidade de páginas Web: em ambos os estudos experimentais de acessibilidade foi detectada uma correlação entre a qualidade de acessibilidade das páginas Web e o uso de templates e sistemas de gestão de conteúdo. Esta propriedade foi verificada quer em pequena escala (sobre uma colecção de páginas Web da Wikipedia), quer em larga escala; o incumprimento das regras mais elementares e mais conhecidas da acessibilidade: estes estudos experimentais permitiram também verificar que, apesar de toda a envagelização e educação sobre as questões de acessibilidade na Web, a maioria das regras de acessibilidade são incessantemente quebradas pela maioria das páginas Web.Esta problemática verifica-se, em particular, nas regras de cumprimento de acessibilidade mais conhecidas, tal como por exemplo a disponibilidade de textos alternativos a conteúdos multimédia. Com base nestas experiências e resultados, esta tese apresenta um novo modelo de estudo da acessibilidade na Web, tendo por base o ciclo de estudos da Web em larga escala. Deste modelo resultaram as seguintes contribuições: um modelo para a avaliação distribuída de acessibilidade Web, baseado em propriedades tecnológicas e topológicas: foi concebido um modelo de avaliação de acessibilidade Web que permite a concepção de sistemas de avaliação com base em propriedades tecnológicas e topológicas. Este modelo possibilita, entre outras características, o estudo da cobertura de plataformas e avaliadores de acessibilidade, bem como da sua aplicação em larga escala; uma extensão às linguagens e modelos EARL e Linked Data, bem como um conjunto de definições para extrair informação destes: este modelo de avaliação de acessibilidade Web foi sustentado também pela sua concretização em linguagens e modelos já existentes para o estudo de acessibilidade (EARL) e da Web em larga escala (Linked Data), permitindo assim a sua validação; definição dos limites da avaliação de acessibilidade Web: por fim, este modelo de avaliação de acessibilidade permitiu também delinear uma metodologia de meta-avaliação da acessibilidade, na qual se poderão enquadrar as propriedades dos avaliadores de acessibilidade existentes. Todas estas contribuições resultaram também num conjunto de publicações científicas, das quais se destacam: Rui Lopes and Luís Carriço, A Web Science Perspective of Web Accessibility, in submission for the ACM Transactions on Accessible Computing (TACCESS), ACM, 2011; Rui Lopes and Luís Carriço, Macroscopic Characterisations of Web Accessibility, New Review of Hypermedia and Multimedia – Special Issue on Web Accessibility. Taylor & Francis, 2010; Rui Lopes, Karel Van Isacker and Luís Carriço, Redefining Assumptions: Accessibility and Its Stakeholders, The 12th International Conference on Computers Helping People with Special Needs (ICCHP), Vienna, Austria, 14-16 July 2010; Rui Lopes, Daniel Gomes and Luís Carriço, Web Not For All: A Large Scale Study of Web Accessibility, W4A: 7th ACM International Cross-Disciplinary Conference on Web Accessibility, Raleigh, North Carolina, USA, 26-27 April 2010; Rui Lopes, Konstantinos Votis, Luís Carriço, Dimitrios Tzovaras, and Spiridon Likothanassis, The Semantics of Personalised Web Accessibility Assessment, 25th Annual ACM Symposium on Applied Computing (SAC), Sierre, Switzerland, 22-26 March, 2010 Konstantinos Votis, Rui Lopes, Dimitrios Tzovaras, Luís Carriço and Spiridon Likothanassis, A Semantic Accessibility Assessment Environment for Design and Development for the Web, HCI International 2009 (HCII 2009), San Diego, California, USA, 19-24 July 2009 Rui Lopes and Luís Carriço, On the Gap Between Automated and In-Vivo Evaluations of Web Accessibility, HCI International 2009 (HCII 2009), San Diego, California, USA, 19-24 July 2009; Rui Lopes, Konstantinos Votis, Luís Carriço, Spiridon Likothanassis and Dimitrios Tzovaras, Towards the Universal Semantic Assessment of Accessibility, 24th Annual ACM Symposium on Applied Computing (SAC),Waikiki Beach, Honolulu, Hawaii, USA, 8-12 March 2009; Rui Lopes and Luís Carriço, Querying Web Accessibility Knowledge from Web Graphs, Handbook of Research on Social Dimensions of Semantic Technologies, IGI Global, 2009; Rui Lopes, Konstantinos Votis, Luís Carriço, Spiridon Likothanassis and Dimitrios Tzovaras, A Service Oriented Ontological Framework for the Semantic Validation of Web Accessibility, Handbook of Research on Social Dimensions of Semantic Technologies, IGI Global, 2009; Rui Lopes and Luís Carriço, On the Credibility of Wikipedia: an Accessibility Perspective, Second Workshop on Information Credibility on the Web (WICOW 2008), Napa Valley, California, USA, 2008; Rui Lopes, Luís Carriço, A Model for Universal Usability on the Web, WSW 2008: Web Science Workshop, Beijing, China, 22 April 2008; Rui Lopes, Luís Carriço, The Impact of Accessibility Assessment in Macro Scale Universal Usability Studies of the Web, W4A: 5th ACM International Cross-Disciplinary Conference on Web Accessibility, Beijing, China, 21-22 April 2008. Best paper award; Rui Lopes, Luís Carriço, Modelling Web Accessibility for Rich Document Production, Journal on Access Services 6 (1-2), Routledge, Taylor & Francis Group, 2009; Rui Lopes, Luís Carriço, Leveraging Rich Accessible Documents on the Web, W4A: 4th ACM International Cross-Disciplinary Conference on Web Accessibility, Banff, Canada, 7-8 May 2007.Fundação para a Ciência e a Tecnologia (FCT, SFRH/BD/29150/2006

    Spiritual Economies of Evangelical Worship: Technology, Stewardship and Experience

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    The present work explores how American evangelicals have learned to use and think about performance technology, such as professional audio, video and lighting technologies as they endeavour to craft worship environments. I track the discourses from trade publications, like Technologies for Worship Magazine (TFWM) and Worship Facilities Magazine and Church Production, in their devotion to bridge the divide between religion and technology to create a house of worship market. Both TFWM and Church Production participate in conferences where they offer education on technology use. Technologies for Worship Magazine is the educational basis for the TFW Pavilion and Worship Facilities and Church Production for an event called Worship Facilities Expo (WFX). Ethnographic research at these events reveals that evangelical worship technicians learn to cultivate dispositions towards stewardship and technical mastery through attending these technology exhibitions and conferences, by taking offered educational seminars. Training at the TFW Pavilion and WFX focussed on two main areas: first, how to use professional performance technologies, like audio amplification and control devices, lighting configurations, and video capture, production and broadcast systems. Second, training addressed the importance for church technicians to use technologies to create excellent and relevant worship experiences. By excellent, trainers meant worship practice that uses performance technologies seamlessly to create immersive experiences. Churches who strive for technological excellence embody the belief that the relevance of the church and its message among believers and non-believers is coupled with the use of technology to enhance the affective potential of the message delivered by the pastor. Yet, as church technicianslike audio or lighting engineersreflect on technology use, they reveal the ways that technology troubles contemporary worship practice as much as it augments the creation of poignant, immersive experiences
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