Document segmentation by interest areas detection

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

Analyse des orientations pour la caractérisation d'images de documents de la renaissance

Cet article présente une nouvelle méthode de caractérisation d'images de documents imprimés datant de la Renaissance. Notre approche se base sur une extraction des différentes orientations présentes sur la totalité de la surface de la page et qui sont caractéristiques de la présence de différentes entités textuelles, ou graphiques (incluant les enluminures, les ornements et bandeaux, les lettrines, ainsi que diverses illustrations). Cette caractérisation s'appuie sur le calcul et l'exploitation de la fonction d'autocorrélation qui a la particularité, lorsqu'elle est estimée sur une zone de texte ou de dessin, de générer une signature unique facilement identifiable. Ce choix nous permet de séparer le texte des dessins, tout en minimisant la quantité d'a priori relatif aux images traitées

A Stimuli-Responsive Nanocomposite for 3D Anisotropic Cell-Guidance and Magnetic Soft Robotics

Stimuli-responsive materials have the potential to enable the generation of new bioinspired devices with unique physicochemical properties and cell-instructive ability. Enhancing biocompatibility while simplifying the production methodologies, as well as enabling the creation of complex constructs, i.e., via 3D (bio)printing technologies, remains key challenge in the field. Here, a novel method is presented to biofabricate cellularized anisotropic hybrid hydrogel through a mild and biocompatible process driven by multiple external stimuli: magnetic field, temperature, and light. A low-intensity magnetic field is used to align mosaic iron oxide nanoparticles (IOPs) into filaments with tunable size within a gelatin methacryloyl matrix. Cells seeded on top or embedded within the hydrogel align to the same axes of the IOPs filaments. Furthermore, in 3D, C2C12 skeletal myoblasts differentiate toward myotubes even in the absence of differentiation media. 3D printing of the nanocomposite hydrogel is achieved and creation of complex heterogeneous structures that respond to magnetic field is demonstrated. By combining the advanced, stimuli-responsive hydrogel with the architectural control provided by bioprinting technologies, 3D constructs can also be created that, although inspired by nature, express functionalities beyond those of native tissue, which have important application in soft robotics, bioactuators, and bionic devices

Lambs with Scrapie Susceptible Genotypes Have Higher Postnatal Survival

BACKGROUND: Prion protein (PrP) alleles associated with scrapie susceptibility persist in many sheep populations even with high frequencies despite centuries of selection against them. This suggests that scrapie susceptibility alleles have a pleiotropic effect or are associated with fitness or other traits that have been subject to selection. METHODOLOGY/PRINCIPAL FINDINGS: We genotyped all lambs in two scrapie-free Scottish Blackface sheep flocks for polymorphisms at codons 136, 154 and 171 of the PrP gene. We tested potential associations of the PrP genotype with lamb viability at birth and postnatal survival using a complementary log-log link function and a Weibull proportional hazard model, respectively. Here we show there is an association between PrP genotype, as defined by polymorphisms at codons 154 ad 171, and postnatal lamb survival in the absence of scrapie. Sheep carrying the wild-type ARQ allele have higher postnatal survival rates than sheep carrying the more scrapie-resistant alleles (ARR or AHQ). CONCLUSION: The PrP genotypes associated with higher susceptibility to scrapie are associated with improved postnatal survival in the absence of the disease. This association helps to explain the existence, and in many instances the high frequency, of the ARQ allele in sheep populations

Micro-computed tomography (μ-CT) as a potential tool to assess the effect of dynamic coating routes on the formation of biomimetic apatite layers on 3D-plotted biodegradable polymeric scaffolds

This work studies the influence of dynamic biomimetic coating procedures on the growth of bonelike apatite layers at the surface of starch/polycaprolactone (SPCL) scaffolds produced by a 3D-plotting technology. These systems are newly proposed for bone Tissue Engineering applications. After generating stable apatite layers through a sodium silicate-based biomimetic methodology the scaffolds were immersed in Simulated Body Fluid solutions (SBF) under static, agitation and circulating flow perfusion conditions, for different time periods. Besides the typical characterization techniques, Micro-Computed Tomography analysis (μ-CT) was used to assess scaffold porosity and as a new tool for mapping apatite content. 2D histomorphometric analysis was performed and 3D virtual models were created using specific softwares for CT reconstruction. By the proposed biomimetic routes apatite layers were produced covering the interior of the scaffolds, without compromising their overall morphology and interconnectivity. Dynamic conditions allowed for the production of thicker apatite layers as consequence of higher mineralizing rates, when comparing with static conditions. μ-CT analysis clearly demonstrated that flow perfusion was the most effective condition in order to obtain well-defined apatite layers in the inner parts of the scaffolds. Together with SEM, this technique was a useful complementary tool for assessing the apatite content in a non-destructive way

In vitro studies and preliminary in vivo evaluation of silicified concentrated collagen hydrogels

Hybrid and nanocomposite silicacollagen materials derived from concentrated collagen hydrogels were evaluated in vitro and in vivo to establish their potentialities for biological dressings. Silicification significantly improved the mechanical and thermal stability of the collagen network within the hybrid systems. Nanocomposites were found to favor the metabolic activity of immobilized human dermal fibroblastswhile decreasing the hydrogel contraction. Cell adhesion experiments suggested that in vitro cell behavior was dictated by mechanical properties and surface structure of the scaffold. First-to-date in vivo implantation of bulk hydrogels in subcutaneous sites of rats was performed over the vascular inflammatory period. These materials were colonized and vascularized without inducing strong inflammatory response. These data raise reasonable hope for the future application of silicacollagen biomaterials as biological dressings.Fil: Desimone, Martín Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; ArgentinaFil: Hélary, Christophe. Université Pierre et Marie Curie; FranciaFil: Quignard, Sandrine. Université Pierre et Marie Curie; FranciaFil: Rietveld, Ivo B. Universite de Paris; FranciaFil: Bataille, Clement. Université de Versailles Saint-quentin-en-yvelines.; FranciaFil: Copello, Guillermo Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Química y Metabolismo del Fármaco. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Química y Metabolismo del Fármaco; ArgentinaFil: Mosser, Gervaise. Université Pierre et Marie Curie; FranciaFil: Giraud Guille, Marie-Madeleine. Université Pierre et Marie Curie; FranciaFil: Livage, Jacques. Université Pierre et Marie Curie; FranciaFil: Meddahi Pellé, Anne. Université de Versailles Saint-quentin-en-yvelines.; FranciaFil: Coradin, Thibaud. Université Pierre et Marie Curie; Franci