243 research outputs found

    Document segmentation by interest areas detection

    Get PDF
    This paper presents a new approach of document structuring by the description of a foveated vision system implied in extracting visual and eye-catching information of a document . The simulation system is based on psycho-perceptive rules for visual data capturing. It allows us to obtain a representation of segmented document by using simple low-level processing . The low-level process is based on a visual integrative memory which displays the unequal importance of information in the visual field . The resulting segmentation enhances the fact that the access of information is directly linked to the search of attractive areas . The technical approach of the segmentation (using a space-variant geometry and a multiresolution process) lays a sound basis for elaborating the kinetic of the ocular displacement on a document. It provides not only a document representation in blocks, but shows a unified view corresponding to the integration of time-variant representations of the same visual field . The resulting blocks (text, graphs, image) are determined and localized all the better, such that the number of fixation points increases and yields a more complete and detailed description of components .Cette étude présente une nouvelle approche de la structuration de documents imprimés basée sur l'exploitation de la dynamique du regard dans le repérage de l'information. Le système qui a été mis en place nous permet d'obtenir une représentation du document segmenté en faisant appel à des procédures d'extraction de primitives géométriques simples (traitements de bas niveau) relevant de la prise en compte de certains comportements caractéristiques chez l'homme dans l'extraction d'information. Il utilise une série de représentations de type multirésolution du document où la nature du sous-échantillonnage est une fonction de la position du regard. Cette approche est basée sur la recherche des zones de focalisation de l'attention permettant de conserver une description précise des éléments dans les zones de fixation, tout en résumant les régions présentant un « intérêt » moindre. La simulation du parcours de l'oeil sur le document que nous avons retenue traduit la segmentation que ferait un lecteur qui aborde le document sans a priori sur ce qu'il veut trouver. Pour cela, nous nous sommes inspirés d'une stratégie exploratoire particulière : le survol. Celle-ci s'appuie essentiellement sur l'aspect visuel du document, c'est-à-dire sur les caractéristiques visuelles de bas niveau de l'image. Elle permet en outre une perception équilibrée des données en privilégiant l'organisation globale du document. La technique mise en oeuvre s'appuie sur un partitionnement évolutif de l'espace, en zones centrées aux points de fixation successifs. C'est sur la base de ce partitionnement, que la description des différentes régions ciblées du document évolue et converge vers une représentation segmentée

    Cell-seeded thermoreversible hydrogel-polyurethane composites for nucleus pulposus augmentation

    Get PDF
    Tissue engineering represents an alternative approach to the current invasive surgical procedures for the intervertebral disc (IVD) repair. The combination of injectable hydrogels and elastic biomaterials allow three-dimensional cell cultures and provide mechanical stability. In the present study a thermoreversible hyaluronan (HA) hydrogel as well as fibrin glue were mixed with polyurethane (PU) and their effect was investigated on the proliferation and differentiation of human IVD (hIVD cells) and mesenchymal stem cells (hMSCs) by in vitro and ex-vivo experiments

    Associations between lamb survival and prion protein genotype: analysis of data for ten sheep breeds in Great Britain

    Get PDF
    BACKGROUND: Selective breeding programmes, based on prion protein (PrP) genotype, have been introduced throughout the European Union to reduce the risk of sheep transmissible spongiform encephalopathies (TSEs). These programmes could have negative consequences on other important traits, such as fitness and production traits, if the PrP gene has pleiotropic effects or is in linkage disequilibrium with genes affecting these traits. This paper presents the results of an investigation into associations between lamb survival and PrP genotype in ten mainstream sheep breeds in Great Britain (GB). In addition, the reasons for lamb deaths were examined in order to identify any associations between these and PrP genotype. RESULTS: Survival times from birth to weaning were analysed for over 38000 lambs (2427 dead and 36096 live lambs) from 128 flocks using Cox proportional hazard models for each breed, including additive animal genetic effects. No significant associations between PrP genotype and lamb survival were identified, except in the Charollais breed for which there was a higher risk of mortality in lambs of the ARR/VRQ genotype compared with those of the ARR/ARR genotype. Significant effects of birth weight, litter size, sex, age of dam and year of birth on survival were also identified. For all breeds the reasons for death changed significantly with age; however, no significant associations between reason for death and PrP genotype were found for any of the breeds. CONCLUSION: This study found no evidence to suggest that a selective breeding programme based on PrP genotype will have a detrimental effect on lamb survival. The only significant effect of PrP genotype identified was likely to be of little consequence because an increased risk of mortality was associated with a genotype that is selected against in current breeding strategies

    Challenges and strategies in the repair of ruptured annulus fibrosus

    Get PDF
    Lumbar discectomy is the surgical procedure most frequently performed for patients suffering from low back pain and sciatica. Disc herniation as a consequence of degenerative or traumatic processes is commonly encountered as the underlying cause for the painful condition. While discectomy provides favourable outcome in a majority of cases, there are conditions where unmet requirements exist in terms of treatment, such as large disc protrusions with minimal disc degeneration; in these cases, the high rate of recurrent disc herniation after discectomy is a prevalent problem. An effective biological annular repair could improve the surgical outcome in patients with contained disc herniations but otherwise minor degenerative changes. An attractive approach is a tissue-engineered implant that will enable/stimulate the repair of the ruptured annulus. The strategy is to develop three-dimensional scaffolds and activate them by seeding cells or by incorporating molecular signals that enable new matrix synthesis at the defect site, while the biomaterial provides immediate closure of the defect and maintains the mechanical properties of the disc. This review is structured into (1) introduction, (2) clinical problems, current treatment options and needs, (3) biomechanical demands, (4) cellular and extracellular components, (5) biomaterials for delivery, scaffolding and support, (6) pre-clinical models for evaluation of newly developed cell- and material-based therapies, and (7) conclusions. This article highlights that an interdisciplinary approach is necessary for successful development of new clinical methods for annulus fibrosus repair. This will benefit from a close collaboration between research groups with expertise in all areas addressed in this review

    ELFE, a database to determine greenhouse gases and ammonia emissions factors from livestock

    Get PDF
    ELFE, a database to determine greenhouse gases and ammonia emissions factors from livestock. 20. Nitrogen Workshop. Coupling C-N-P-S cycle

    Membership categorization, culture and norms in action

    Get PDF
    In this article, we examine the extent to which membership categorization analysis (MCA) can inform an understanding of reasoning within the public domain where morality, policy and cultural politics are visible (Smith and Tatalovich, 2003). Through the examination of three examples, we demonstrate how specific types of category device(s) are a ubiquitous feature of accountable practice in the public domain where morality matters and public policy intersect. Furthermore, we argue that MCA provides a method for analysing the mundane mechanics associated with everyday cultural politics and democratic accountability assembled and presented within news media and broadcast settings

    Inhibition of hypertrophy and improving chondrocyte differentiation by MMP-13 inhibitor small molecule encapsulated in alginate-chondroitin sulfate-platelet lysate hydrogel

    Get PDF
    Background: Mesenchymal stem cells are a promising cell source for chondrogenic differentiation and have been widely used in several preclinical and clinical studies. However, they are prone to an unwanted differentiation process towards hypertrophy that limits their therapeutic efficacy. Matrix metallopeptidase 13 (MMP-13) is a well-known factor regulated during this undesirable event. MMP-13 is a collagen degrading enzyme, which is also highly expressed in the hypertrophic zone of the growth plate and in OA cartilage. Accordingly, we investigated the effect of MMP-13 inhibition on MSC hypertrophy. Methods: In this study, 5-bromoindole-2-carboxylic acid (BICA) was used as an inhibitory agent for MMP-13 expression. After identifying its optimal concentration, BICA was mixed into a hydrogel and the release rate was studied. To prepare the ideal hydrogel, chondroitin sulfate (CS) and platelet lysate (PL) were mixed with sodium alginate (Alg) at concentrations selected based on synergistic mechanical and rheometric properties. Then, four hydrogels were prepared by combining alginate (1.5w/v) and/or CS (1w/v) and/or PL (20v/v). The chondrogenic potential and progression to hypertrophy of human bone marrow-derived mesenchymal stem cell (hBM-MSC)-loaded hydrogels were investigated under free swelling and mechanical loading conditions, in the presence and absence of BICA. Results: Viability of hBM-MSCs seeded in the four hydrogels was similar. qRT-PCR revealed that BICA could successfully inhibit MMP-13 expression, which led to an inhibition of Coll X and induction of Coll-II, in both free swelling and loading conditions. The GAG deposition was higher in the group combining BICA and mechanical stimulation. Conclusions: It is concluded that BICA inhibition of MMP-13 reduces MSC hypertrophy during chondrogenesis. Graphical abstract: Figure not available: see fulltext. © 2020 The Author(s)
    corecore