53 resultados para Demons


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n this paper we present a novel hybrid approach for multimodal medical image registration based on diffeomorphic demons. Diffeomorphic demons have proven to be a robust and efficient way for intensity-based image registration. A very recent extension even allows to use mutual information (MI) as a similarity measure to registration multimodal images. However, due to the intensity correspondence uncertainty existing in some anatomical parts, it is difficult for a purely intensity-based algorithm to solve the registration problem. Therefore, we propose to combine the resulting transformations from both intensity-based and landmark-based methods for multimodal non-rigid registration based on diffeomorphic demons. Several experiments on different types of MR images were conducted, for which we show that a better anatomical correspondence between the images can be obtained using the hybrid approach than using either intensity information or landmarks alone.

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In this paper we propose a variational approach for multimodal image registration based on the diffeomorphic demons algorithm. Diffeomorphic demons has proven to be a robust and efficient way for intensity-based image registration. However, the main drawback is that it cannot deal with multiple modalities. We propose to replace the standard demons similarity metric (image intensity differences) by point-wise mutual information (PMI) in the energy function. By comparing the accuracy between our PMI based diffeomorphic demons and the B-Spline based free-form deformation approach (FFD) on simulated deformations, we show the proposed algorithm performs significantly better.

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Osteoarticular allograft transplantation is a popular treatment method in wide surgical resections with large defects. For this reason hospitals are building bone data banks. Performing the optimal allograft selection on bone banks is crucial to the surgical outcome and patient recovery. However, current approaches are very time consuming hindering an efficient selection. We present an automatic method based on registration of femur bones to overcome this limitation. We introduce a new regularization term for the log-domain demons algorithm. This term replaces the standard Gaussian smoothing with a femur specific polyaffine model. The polyaffine femur model is constructed with two affine (femoral head and condyles) and one rigid (shaft) transformation. Our main contribution in this paper is to show that the demons algorithm can be improved in specific cases with an appropriate model. We are not trying to find the most optimal polyaffine model of the femur, but the simplest model with a minimal number of parameters. There is no need to optimize for different number of regions, boundaries and choice of weights, since this fine tuning will be done automatically by a final demons relaxation step with Gaussian smoothing. The newly developed synthesis approach provides a clear anatomically motivated modeling contribution through the specific three component transformation model, and clearly shows a performance improvement (in terms of anatomical meaningful correspondences) on 146 CT images of femurs compared to a standard multiresolution demons. In addition, this simple model improves the robustness of the demons while preserving its accuracy. The ground truth are manual measurements performed by medical experts.

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Non-linear image registration is an important tool in many areas of image analysis. For instance, in morphometric studies of a population of brains, free-form deformations between images are analyzed to describe the structural anatomical variability. Such a simple deformation model is justified by the absence of an easy expressible prior about the shape changes. Applying the same algorithms used in brain imaging to orthopedic images might not be optimal due to the difference in the underlying prior on the inter-subject deformations. In particular, using an un-informed deformation prior often leads to local minima far from the expected solution. To improve robustness and promote anatomically meaningful deformations, we propose a locally affine and geometry-aware registration algorithm that automatically adapts to the data. We build upon the log-domain demons algorithm and introduce a new type of OBBTree-based regularization in the registration with a natural multiscale structure. The regularization model is composed of a hierarchy of locally affine transformations via their logarithms. Experiments on mandibles show improved accuracy and robustness when used to initialize the demons, and even similar performance by direct comparison to the demons, with a significantly lower degree of freedom. This closes the gap between polyaffine and non-rigid registration and opens new ways to statistically analyze the registration results.

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This article provides an analysis of R v Vollmer and Others, Australia’s most famous ‘exorcism-manslaughter’ case, in which a woman, Joan Vollmer, underwent an ‘exorcism’ performed by four people, resulting in her death. We examine how taken-for-granted distinctions were collapsed during the resulting trial - distinctions between crime and punishment, exorcism and punishment, church and state, the past and the present, law and religion, reason and unreason and between a demon and a woman. We show how the defence argument for the reality of demonic possession normalized the bizarre, while simultaneously exoticizing the mundane or ‘traditional’ criminal case involving a husband defendant and a dead wife. The apparent assumption on the part of the police and the media that this case was bizarre serves to veil the fact of its relative ordinariness. A wife is killed, and the lethal punishing violence inflicted on her body downplayed, to be reinterpreted in the legal context as somehow a consequence of something she herself precipitated. Our analysis of the Vollmer case provides a novel perspective on that always intriguing conundrum of crime and punishment.

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This is a highly original study of possession by demons and their exorcism, which was rife in early modern times, focussing on the place where they were most prevalent, France. Catholics at the time believed that the devil was present everywhere, in the rise of the heretics, in the activities of witches, and even in the bodies of the pious young women. The rite of exorcism was intended to heal the possessed and show the power of the church - but it generated as many problems as it resolved. Possessed nuns endured frequently violent exorcisms, exorcists were suspected of conjuring devils, and possession itself came to be seen as a form of holiness, elevating several women to the status of living saints. Sarah Ferber offers a challenging study of one of the most intriguing phenomena of early modern Europe; looking also at the present day, it argues that early modern conflicts over the devil still carry an unexpected force and significance for western Christianity (from publisher).

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A imagem por tensor difusão (DTI) é uma extensão da imagem por ressonância magnética que permite a caraterização microestrutural dos tecidos, sendo um destes, os músculos esqueléticos. No entanto, dadas as grandes dimensões dos mesmos, a aquisição de volumes DTI deste tipo de tecidos é comumente realizada em mais que uma sessão. A não linearidade dos gradientes de codificação espacial e a presença de magnetizações parasitas levam a que ocorram distorções que impossibilitam, quando unidos, a continuação de volumes na sua transição. No mercado já existem sotwares que permitem estas correções, no entanto, o seu objetivo tem como fim estudos populacionais aplicados na neurologia, não estando preparados para o alinhamento e união de volumes contíguos. Ao recorrer a algoritmos aplicados nestes softwares, com a devida preparação, é possível garantir a continuidade de volumes. Um desses algoritmos, demons, foi aplicado em pontos de sobreposição de imagens de volumes contíguos. A transformada resultante deste algoritmo foi aplicado ao volume considerado a transformar e unido ao volume de referência. Mostra-se ser possível a aplicação destes algoritmos para a continuação de volumes, sendo observada a preservação da coerência anatómica das fibras quando comparadas aos grupos de controlo. Numa versão futura, recomenda-se a utilização de algoritmos mais robustos, que tomam partido da informação direcional que a imagem por tensor de difusão fornece.

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En français (Fouet des 'fascinateurs' hérétiques) dont l'objectif est de prouver la réalité du sabbat des sorciers, dans le contexte du début de la répression de la sorcellerie démoniaque et des contestations qu'elle suscite dans certains lieux et milieux. Il y démontre en particulier la réalité des apparitions démoniaques et expose les moyens de ses protéger des assauts des démons. Il illustre son propos au moyen d'exemples scripturaires et surtout de récits des premiers martyrs et des Pères du désert empruntés au Speculum historiale de Vincent de Beauvais, qu'il recopie textuellement ou résume. Nicolas Jacquier montre ainsi une bonne connaissance d'ensemble de cette oeuvre. En Anglais "An attentive reader of Vincent de Beauvais' Speculum historiale in the XVth century : the Burgundian inquisitor Nicolas Jacquier and the reality of demonic apparitions." In 1458, the Dominican inquisitor Nicolas Jacquier writes his Flagellum hereticorum fascinariorum (Scourge of Heretical Witches), which aims at proving the reality of the witches' Sabbath. He pens this work in the context of the onset of the repression of diabolical witchcraft and the disputes which arise from it in certain places and circles. He in particular demonstrates the reality of demonic apparitions and exposes the means by which one is to protect oneself from the assaults of demons. He illustrates his subject by means of scriptural examples, making particular reference to the narratives of the first martyrs and of the Fathers of the desert borrowed from Vincent de Beauvais' Speculum historiale, that he either reproduces word for word, or summarizes. Nicolas Jacquier thus demonstrates a good knowledge of the entirety of this work.

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Notre travail porte sur le Videvdad, texte avestique nommé d'après unmot avestique Videvdad-data-, c'est-à-dire la « Un qui tient éloignés les demons ». Ce recueil comprend 22 chapitres édictant des lois religieuses, des préceptes rituels et des mesures de purification Ces prescriptions ont pour but de repousser l'impureté des elements purs de la création d'Ahura Mazda. Notre thèse est une édition du chapitre 19 de ce recueil complétée de sa traduction commentée. Ce chapitre raconte la tentation de Zarathustra par le Mauvais Esprit et sa victoire sur ce dernier Le texte a été traduit et commenté sémantiquement, phonétiquement et philologiquement afin d'en dégager les particularités linguistiques.L'édition de référence du texte avestique est celle de Geldner, qui date de la fin du 19 siècle Dans la mesure où il a été démontré durant ces dernières années quil fallait revoir ce travail, nous avons fait une édition du texte en collationnant 13 manuscits. Notre étude nous a permis à la fois de proposer pour certains termes une autre lecture que celle de Geldner et decontinuer les recherches sur la filiation des manuscrits.De plus le texte avestique a été mis en regard de la version pehlevie. L'intérêt de cette dernière traduction réside dans ses gloses : parfois un long commentaire parfois une simple énonciation de synonymes en pehlevie. le traducteur lui-même comprenant mal le sens du mot original. L'édition du texte pehlevi a également été refaite à partir des deux manuscrits lesplus anciens (L4 et Kl).Videvdad 19 :Critical Edition, Translation and Commentary of the Avestan and Pahlavi TextsWe worked on the Videvdad, an Avestan text whose title is a Middle Persian word coming from the Avestan Videvdad-data- "the law that keeps demons away" This anthology contains 22 chapters dealing with religious laws, ritual precepts and measures of purification. These prescriptions aim ft rejecting impurity from pure elements in Ahura Mazda's creation. Our dissertation is an edition and translation with commentary of chapter 19 of this anthology. lt relates the temptation of Zarathustra by the Bad Evil and how Zarathustra overcame him. The text was translated and annotated semantically, phonetically and philologically to highlight linguistic features.Until today, Geldner's edition, which dates back to the end of the 19th century has been the edition of reference. However, in recent years, scholars have shown that this edition must be revised Therefore, we prepared an edition of the Avestan text by collating 13 manuscripts. This work led us to propose new readings for several words and pursue research onmanuscripts filiation.Furthermore, we also studied the Middle Persian text. This translation is interesting in that it contains glosses that can either be long commentaries or simple synonyms. We also made the edition of the Middle Persian text on the basis of the two oldest manuscripts (L4 and Kl).

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In this paper, we present an efficient numerical scheme for the recently introduced geodesic active fields (GAF) framework for geometric image registration. This framework considers the registration task as a weighted minimal surface problem. Hence, the data-term and the regularization-term are combined through multiplication in a single, parametrization invariant and geometric cost functional. The multiplicative coupling provides an intrinsic, spatially varying and data-dependent tuning of the regularization strength, and the parametrization invariance allows working with images of nonflat geometry, generally defined on any smoothly parametrizable manifold. The resulting energy-minimizing flow, however, has poor numerical properties. Here, we provide an efficient numerical scheme that uses a splitting approach; data and regularity terms are optimized over two distinct deformation fields that are constrained to be equal via an augmented Lagrangian approach. Our approach is more flexible than standard Gaussian regularization, since one can interpolate freely between isotropic Gaussian and anisotropic TV-like smoothing. In this paper, we compare the geodesic active fields method with the popular Demons method and three more recent state-of-the-art algorithms: NL-optical flow, MRF image registration, and landmark-enhanced large displacement optical flow. Thus, we can show the advantages of the proposed FastGAF method. It compares favorably against Demons, both in terms of registration speed and quality. Over the range of example applications, it also consistently produces results not far from more dedicated state-of-the-art methods, illustrating the flexibility of the proposed framework.

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The present article examines the meaning and function of olfactory remnants, often repugnant, linked to demons in the context of late medieval witchcraft and demonology. This reflection is developed within the framework of a «make believe» logic sustained by the doctrinal, theological, narrative and judiciary constructions of the witches' Sabbath. Incorporated within the order of sensory perception, references to the fetid smell of demons - who are by nature devoid of odour because they are pure spirits - constitute further proofs bearing witness to demonic presence, and thus testifying to the ignominy of the crime of witchcraft and to the guiltiness of the accused. According to those who attacked demon worshippers, the devil truly revealed himself physically; human beings were able to touch, hear, see and smell him. Sensory faculties were therefore perceived as being instrumental in corroborating the existence and reality of the Sabbath and the presence of the devil in bodily form. These considerations bring us to examine the olfactory fields associated with the devil's odour: odour of corpses, hell, sin, deviance, but also of defilement, impurity, corruption and excrements. These fetid odours are embedded in a logic of moral, spiritual and religious inversion of positive odours, such as the «sweet fragrance» of the saints, the «pure odour» of Christ or the «soft perfume» of virtue.