Affine Registration of label maps in Label Space

Two key aspects of coupled multi-object shape\ud analysis and atlas generation are the choice of representation\ud and subsequent registration methods used to align the sample\ud set. For example, a typical brain image can be labeled into\ud three structures: grey matter, white matter and cerebrospinal\ud fluid. Many manipulations such as interpolation, transformation,\ud smoothing, or registration need to be performed on these images\ud before they can be used in further analysis. Current techniques\ud for such analysis tend to trade off performance between the two\ud tasks, performing well for one task but developing problems when\ud used for the other.\ud This article proposes to use a representation that is both\ud flexible and well suited for both tasks. We propose to map object\ud labels to vertices of a regular simplex, e.g. the unit interval for\ud two labels, a triangle for three labels, a tetrahedron for four\ud labels, etc. This representation, which is routinely used in fuzzy\ud classification, is ideally suited for representing and registering\ud multiple shapes. On closer examination, this representation\ud reveals several desirable properties: algebraic operations may\ud be done directly, label uncertainty is expressed as a weighted\ud mixture of labels (probabilistic interpretation), interpolation is\ud unbiased toward any label or the background, and registration\ud may be performed directly.\ud We demonstrate these properties by using label space in a gradient\ud descent based registration scheme to obtain a probabilistic\ud atlas. While straightforward, this iterative method is very slow,\ud could get stuck in local minima, and depends heavily on the initial\ud conditions. To address these issues, two fast methods are proposed\ud which serve as coarse registration schemes following which the\ud iterative descent method can be used to refine the results. Further,\ud we derive an analytical formulation for direct computation of the\ud "group mean" from the parameters of pairwise registration of all\ud the images in the sample set. We show results on richly labeled\ud 2D and 3D data sets

Les deux corps du monarque dans la pensée élisabéthaine

En 1562 est représenté devant Élisabeth Ire Gorboduc, pièce historique de Norton et Sackville. À l’heure où le corps du roi est celui d’une femme et où est débattue la pérennité dynastique d’une reine non mariée, la fiction dramatique démultiplie le corps royal à travers différents dispositifs (pantomime, action, chœur). Par là est donnée à voir une réflexion sur le droit de succession, sur le sang royal et le pouvoir naturel, éclairant le statut paradoxal d’un corps à la fois unique et multipleOn january 18 1562, Gorboduc, an historical play by Norton and Sackville, is performed before Queen Elizabeth I. The monarch’s body is at the time one of an unmarried woman, causing various debates amongst politicians. The play uses a range of theatrical devices (pantomime, action, chorus) in order to put on stage a plural royal body, exposing new thoughts on inheritance, royal blood and natural power, and therefore exploring the paradoxical state of a complex and unique bod

A Component Model for Transmission and Processing of Synchronized Multimedia Data Flows

International audienceOur research deals with distributed multimedia applications built on software components. Currently, multimedia data are omnipresent on the Internet. However, this network is not designed to support and transmit multimedia data. In this perspective, it is necessary to introduce quality of service management in this kind of applications. In this paper, we are particularly interested in the inter-flow synchronization (e.g. audio and image flows of a video). We develop a component model in order to tackle the synchronization between multimedia flows from the source (e.g. media capture) to the destination (e.g. media player). This model is named OSAGAIA* and is made of two entities. The first one is called elementary processor. It is used as the runtime environment (component container) for multimedia components. The second one is called conduit. It is used to transport synchronous multimedia flows between elementary processors. So, distributed applications are composed of multimedia components (within containers) connected by multimedia flows (within conduits). We are working on a distributed prototype which validates the synchronization algorithms that we use. It is implemented with Java language using JMF (Java Media Framework) API and TCP/IP as network protocol

A Multimedia Oriented Component Model.

International audienc

L’interprétation de la loi par le juge

Les différentes théories de l’interprétation, la méthode de l'Exégèse, de la Libre recherche scientifique, la théorie réaliste de l'interprétation, ne sont opposées qu'en apparence. Elles sont en réalité conciliables. L’interprétation peut être envisagée tout à la fois comme un acte de connaissance et de volonté. C’est un acte de connaissance car elle est aiguillée par des méthodes et des règles pratiques. Elle est également un acte de volonté en ce que ce cadre ne permet pas de découvrir un seul et véritable sens de la règle ; le sens donné est choisi pour être appliqué, les méthodes servant simplement à guider la décision du juge

Multiculturalité et plurilinguisme : défis pour la formation des professeurs des écoles

Ce travail est le résultat d’une étude comparative sur la formation reçue par les enseignants Espagnols, Français, Italiens et Grecs de l’Enseignement Primaire en compétences multiculturelles et multilingues et leur perception de la diversité des élèves pour pouvoir élaborer des propositions méthodologiques adaptées à leurs besoins. Grâce à une méthode quantitative, comparative et de révision théorique et épistémologique, on peut constater la nécessité d’améliorer la formation initiale et continue des enseignants en termes de multiculturalité et de multilinguisme dans les pays participant au projet.Este trabajo es el resultado de un estudio comparado sobre la formación recibida por los profesores españoles, franceses, italianos y griegos de Educación Primaria en competencias multiculturales y plurilingües y su percepción ante la diversidad del alumnado para poder elaborar propuestas metodológicas adecuadas a sus necesidades. A través de un método cuantitativo, comparativista y de revisión teórica y epistemológica se puede constatar la necesidad de mejorar la formación inicial y continua del profesorado en cuanto a multiculturalidad y plurilingüismo en los países participantes del proyecto.This work is the result of a comparative study on the training received by Spanish teachers, French, Italian and Greek Primary Education in multicultural and multilingual competences and their perception of the diversity of students in order to develop methodological proposals appropriate to their needs. Through a quantitative, comparative and theoretical and epistemological review method, we can see the need to improve the initial and continuing training of teachers in multiculturalism and multilingualism in the countries participating in the project

Fibrinolytic Therapy in Acute Stroke

Acute ischemic stroke is a major cause of morbidity and mortality in Europe, North America, and Asia. Its treatment has completely changed over the past decade with different interventional approaches, such as intravenous trials, intra-arterial trials, combined intravenous/intra-arterial trials, and newer devices to mechanically remove the clot from intracranial arteries. Intravenous thrombolysis with tissue plaminogen activator (tPA) within 4.5 hours of symptoms onset significantly improved clinical outcomes in patients with acute ischemic stroke. Pharmacological intra-arterial thrombolysis has been shown effective until 6 hours after middle cerebral artery occlusion and offers a higher rate of recanalization compared with intravenous thrombolysis, whereas combined intravenous/ intra-arterial thrombolysis seems to be as safe as isolated intravenous thrombolysis. The more recent advances in reperfusion therapies have been done in mechanical embolus disruption or removal. Merci Retriever and Penumbra System have been approved for clot removal in brain arteries, but not as a therapeutic modality for acute ischemic stroke since it is no clear whether mechanical thrombectomy improves clinical outcome in acute stroke. However, mechanical devices are being used in clinical practice for patients who are ineligible for tPA or who have failed to respond to intravenous tPA. We summarize the results of the major thrombolytic trials and the latest neurointerventional approaches to ischemic stroke