Fusion individuelle de données cérébrales multimodales : informations issues d'images numériques et connaissances expertes

National audienceL'étude de l'activité fonctionnelle cérébrale à partir d'images TEP est difficile à cause de la résolution spatiale limitée et du faible rapport signal sur bruit de celles-ci. Cette étude nécessite l'utilisation conjointe et la fusion d'informations provenant de différentes modalités d'images numériques et de connaissances expertes modélisées dans des atlas. Ces derniers se rapportant à une anatomie standard, il est fondamental de les adapter auparavant à la morphologie spécifique du patient concerné. Pour résoudre au mieux les problèmes rencontrés depuis l'acquisition de l'image à l'identification des différentes zones, nous proposons dans cet article une méthodologie pour obtenir des données individualisées et pour les fusionner. La première étape fait intervenir un processus automatique de recalage de l'image TEP avec une image RM, via une radiographie par Rayons X, par l'introduction d'informations a priori extraites d'un atlas. La seconde étape vise à individualiser les atlas anatomiques pour que la superposition avec les images TEP soit plus précise. Dans cette optique, une méthode d'identification des sillons du cortex d'un patient sur une image RM 3D est présentée. L'accent est mis sur la généralité de la démarche, sur l'explicitation des connaissances et des mécanismes de fusion, et sur l'évaluation des résultats en fonction des images traitées

investigation of the agouti gene for the identification of useful markers for coat colour association studies in domestic rabbits

AbstractIn wild-type mice, it is well known that Agouti is expressed in skin where it controls the banded-hair Agouti phenotype. Molecular genetics and pharmacological studies show that mutually exclusive binding of the melanocortin 1 receptor (MC1R) by the Agouti protein or by -melanocyte-stimulating hormone (a-MSH) signals hair-bulb melanocytes to synthesise preferentially either pheomelanin (yellow-red pigment) or eumelanin (black-brown pigment), respectively. In mice as well as in other species, loss-of-function mutations of the Agouti gene determine only the production of eumelanin while gain-of-function mutations lead to pheomelanin production. A variety of coat colours appear as a result of these alterations that show also epistatic interactions with MC1R mutations. In rabbit, classical studies have suggested the presence of three alleles at the Agouti locus: A (wild type allele), at (black and tan) and a (non-agouti). We recently showed that mutations in the rabbit MC1R gene are associated with c..

Genetic variability of the pattern of night melatonin blood levels in relation to coat changes development in rabbits

To assess the genetic variability in both the nocturnal increase pattern of melatonin concentration and photoresponsiveness in coat changes, an experiment on 422 Rex rabbits (from 23 males) raised under a constant light programme from birth was performed. The animals were sampled at 12 weeks of age, according to 4 periods over a year. Blood samples were taken 7 times during the dark phase and up to 1 h after the lighting began. Maturity of the fur was assessed at pelting. Heritability estimates of blood melatonin concentration (0.42, 0.17 and 0.11 at mid-night, 13 and 15 h after lights-out respectively) and strong genetic correlations between fur maturity and melatonin levels at the end of the dark phase (-0.64) indicates that (i) the variability of the nocturnal pattern of melatonin levels is under genetic control and (ii) the duration of the nocturnal melatonin increase is a genetic component of photoresponsiveness in coat changes

Elastic Scattering by Deterministic and Random Fractals: Self-Affinity of the Diffraction Spectrum

The diffraction spectrum of coherent waves scattered from fractal supports is calculated exactly. The fractals considered are of the class generated iteratively by successive dilations and translations, and include generalizations of the Cantor set and Sierpinski carpet as special cases. Also randomized versions of these fractals are treated. The general result is that the diffraction intensities obey a strict recursion relation, and become self-affine in the limit of large iteration number, with a self-affinity exponent related directly to the fractal dimension of the scattering object. Applications include neutron scattering, x-rays, optical diffraction, magnetic resonance imaging, electron diffraction, and He scattering, which all display the same universal scaling.Comment: 20 pages, 11 figures. Phys. Rev. E, in press. More info available at http://www.fh.huji.ac.il/~dani

Uma visão crítica do soberano: sobre a herança moderna, a lógica atual de soberania e o exercício democrático / A critique sight of sovereignty: about modern heritage exercise, sovereignty logic nowadays and democratic exercise

Resumo: Este ensaio consiste em análise da soberania na atualidade, tendo em vista a herança decorrente das teorias modernas e a intensificação do exercício de poder soberano no cenário político recente. Para tanto, foram consideradas relações de poder que submergem a concepção prevalente de soberania no constitucionalismo democrático e no sistema-mundo da ordem global, pois, segundo a hipótese proposta ainda resta presente o projeto da modernidade e a expansão ocidental atrelada ao exercício de soberania. Assim, foi realizada investigação acerca da herança respectiva ao conceito de soberania, ao relacionar a formação da ordem internacional e o constitucionalismo democrático com a dominação do terceiro mundo pelo continente europeu e dimensão política na atualidade. A matriz teórica insurge da desconstrução pensada por Jacques Derrida seguido da reflexão crítica de Costa Douzinas. Nesse sentido, se fez necessário pensar além dos limites institucionais de proliferação soberana dos estados-nação e da lei internacional, na busca de alternativa capaz de ultrapassar os limites da unidade moderna, bem como inibir a proliferação da sociedade internacional sob o prenúncio universalista. Em sentido contrário, portanto, foi observada o exercício de resistência oposto ao processo legitimado pela violência do direito, o que implica na contínua (re)definição do espaço democrático. Portanto, vislumbrou-se a possibilidade de deslocamento do soberano através da mobilização democrática.Palavras-Chave: Soberano. Democracia. Modernidade. Desconstrução. Abstract: This essay consists on the analysis of sovereignty nowadays, given the legacy from modern theories and intensification of exercised sovereignty in recent political scene. Is taken in consideration power relations which drown the prevalent conception of sovereignty in democratic constitutionalism as in the world system global order. According to the hypothesis proposed remains present the project of modernity and western expansion linked with the exercise of sovereignty. Research was carried out about the heritage of the concept sovereignty, related with the formation of international order and democratic constitutionalism as considered  according to domination of the Third World by Europe and political dimension today. The theoretical bias comes from deconstruction thought by Jacques Derrida followed by critical reflection professed by Costa Douzinas. So it was necessary to think beyond the institutional boundaries of sovereign proliferation of nation-states and international law in the pursuit of alternative able to push the boundaries of modern drive and inhibit the proliferation of international society under the universal harbinger. On the other hand, however, it observed the exercise of resistance opposite to legitimized violence of law, which implies the continuous (re) definition of democratic space. So it is investigated the possibility of displacement of sovereign through democratic mobilization.Keywords: Sovereign. Democracy. Modernity. Deconstruction

DIREITOS HUMANOS E SOBERANIA: ESTUDOS CRÍTICOS SOBRE O PAPEL DO DIREITO NO CENÁRIO POLÍTICO ATUAL

Este artigo traz reflexões sobre a temática de Direitos Humanos relacionada a soberania, em especial, acerca do papel do direito no cenário da política atual. A análise foi feita a partir dos estudos da teoria crítica do direito e da filosofia política, principalmente sob o viés da critical legal theory a partir dos trabalhos de Costas Douzinas. O que se propôs neste trabalho foi delimitar os contornos filosófico-políticos para a investigação dos Direitos Humanos e seus paradoxos, ao relocar a problemática da realização desses direitos e sua importância para a política e manutenção da ordem social. Aqui serão apresentados limites e possiblidades sobre como pensar os Direitos Humanos em meio à conjuntura jurídico-política atual, em atenção aos contornos de afirmação de autoridade, das práticas políticas dominantes e do direito estabelecido, sobretudo, a captura de modos de pensar e de viver pelas democracias liberais e ordem internacional. Nesse contexto, foi feita investigação do problema da soberania e seus desdobramentos, quanto a dinâmica política e relações de poder determinantes à concepção prevalente de Direitos Humanos

Stroke Outcomes in Malawi, a Country with High Prevalence of HIV: A Prospective Follow-Up Study

Peer reviewe

Studies of Diffuse Interstellar Bands. V. Pairwise Correlations of Eight Strong DIBs and Neutral Hydrogen, Molecular Hydrogen, and Color Excess

We establish correlations between equivalent widths of eight diffuse interstellar bands (DIBs), and examine their correlations with atomic hydrogen, molecular hydrogen, and EB-V . The DIBs are centered at \lambda\lambda 5780.5, 6204.5, 6283.8, 6196.0, 6613.6, 5705.1, 5797.1, and 5487.7, in decreasing order of Pearson\^as correlation coefficient with N(H) (here defined as the column density of neutral hydrogen), ranging from 0.96 to 0.82. We find the equivalent width of \lambda 5780.5 is better correlated with column densities of H than with E(B-V) or H2, confirming earlier results based on smaller datasets. We show the same is true for six of the seven other DIBs presented here. Despite this similarity, the eight strong DIBs chosen are not well enough correlated with each other to suggest they come from the same carrier. We further conclude that these eight DIBs are more likely to be associated with H than with H2, and hence are not preferentially located in the densest, most UV shielded parts of interstellar clouds. We suggest they arise from different molecules found in diffuse H regions with very little H (molecular fraction f<0.01). Of the 133 stars with available data in our study, there are three with significantly weaker \lambda 5780.5 than our mean H-5780.5 relationship, all of which are in regions of high radiation fields, as previously noted by Herbig. The correlations will be useful in deriving interstellar parameters when direct methods are not available. For instance, with care, the value of N(H) can be derived from W{\lambda}(5780.5).Comment: Accepted for publication in The Astrophysical Journal; 37 pages, 11 figures, 6 table