211 research outputs found

    A Replica Inference Approach to Unsupervised Multi-Scale Image Segmentation

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    We apply a replica inference based Potts model method to unsupervised image segmentation on multiple scales. This approach was inspired by the statistical mechanics problem of "community detection" and its phase diagram. Specifically, the problem is cast as identifying tightly bound clusters ("communities" or "solutes") against a background or "solvent". Within our multiresolution approach, we compute information theory based correlations among multiple solutions ("replicas") of the same graph over a range of resolutions. Significant multiresolution structures are identified by replica correlations as manifest in information theory overlaps. With the aid of these correlations as well as thermodynamic measures, the phase diagram of the corresponding Potts model is analyzed both at zero and finite temperatures. Optimal parameters corresponding to a sensible unsupervised segmentation correspond to the "easy phase" of the Potts model. Our algorithm is fast and shown to be at least as accurate as the best algorithms to date and to be especially suited to the detection of camouflaged images.Comment: 26 pages, 22 figure

    Systemic and immune manifestations in myelodysplasia: a multicenter retrospective study

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    OBJECTIVE: The presence of systemic and/or immune manifestations in myelodysplasia has been currently reported. The influence of these manifestations on the natural outcome of myelodysplastic syndrome has to be considered. We present a multicenter retrospective study (2002-2009) of patients with myelodysplastic syndrome disclosing systemic and/or immune manifestations. METHODS: Forty-six patients with myelodysplasia presenting with systemic and/or immune manifestations were compared in terms of survival with 189 patients with myelodysplasia lacking these features. RESULTS: The clinical picture in these cases consisted of fever (13%), arthralgia or arthritis (13%), and cutaneous manifestations (67%). Four cases of systemic vasculitis have been reported in our series, and they have a worse prognosis. Immune anomalies were recorded in 29% of the cases, and the presence of cryoglobulins was also associated with a worse prognosis. CONCLUSION: A difference in survival between patients with myelodysplastic syndrome with systemic manifestations and patients lacking these manifestations has been observed in the presence of systemic vasculitis and/or cryoglobulins

    Crystal structures of self-assembled nanotubes from flexible macrocycles by weak interactions

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    8 páginas, 7 figuras, 2 tablas, 2 esquemas.Herein we report the crystal structures of tubular self-assemblies of flexible macrooligolides. The assembly is driven by the propensity of the macrocycles to create nearly flat structures displaying a void space within them and the cooperativity of weak directional interactions such as dipole–dipole interactions and CH***Ohydrogen bonds and non-directional interactions such as van der Waals contacts. The significance of the stereochemistry and the size of the cavity in the formation of the nanotubes are also studied.This research was supported by the Spanish MICINN-FEDER (CTQ2008-03334/BQU, CTQ2008-06806-C02-01/BQU and CTQ2008-06754-C04-01/PPQ), the MSC (RTICC RD06/0020/ 1046) and the Canary Islands FUNCIS (PI 01/06).Peer reviewe

    Anti-Ku antibodies: Clinical, genetic and diagnostic insights

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    Anti-Ku antibodies are reported in various connective tissue diseases and the Ku complex can be responsible for a very strong autoimmune answer in autoimmune disease. Nowadays, anti-Ku antibodies are detected by ELISA, counterimmunoelectrophoresis (CIE), immunoblot (IB) and new highly performant techniques. Although the prevalence of anti-Ku antibodies is not homogenous, depending on several features such as disease type, genetic and geographical clustering, and also method of detection, they could be found in 55% overlap PM/systemic sclerosis patients. Moreover, anti-Ku antibodies are not associated with a particular clinical outcome, and especially with cancer related to myositis

    Dépistage des troubles visuels et auditifs chez l'enfant. Application des recommandations chez les médecins généralistes du Maine-et-Loire

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    Dépister précocement les troubles visuels et auditifs chez le nourrisson permet une meilleure prise en charge thérapeutique. Ce rôle est en grande partie dévolu aux médecins généralistes et obligatoires lors des examens de santé du 9e et du 24e mois. Nous avons réalisé une enquête prospective auprès de l’ensemble des médecins généralistes d’un département français, afin de connaître leurs habitudes pratiques cliniques en matière de dépistage des troubles sensoriels. Le taux de réponses de 49 % a permis d’exploiter 321 questionnaires. Nous constatons que l’examen clinique n’est pas systématique et qu’il est principalement effectué lors des examens des 4e, 9e et 24e mois ou en cas de doute parental. Si les signes d’alerte sont, dans leur ensemble, bien connus des médecins généralistes, les facteurs de risque sont recherchés de façon incomplète. L’examen clinique reste sommaire avec la réalisation des principaux réflexes pour l’appareil visuel, mais une recherche superficielle du strabisme ou de l’amblyopie. Le dépistage auditif est réalisé principalement avec la voix ou le claquement des mains, bien que deux tiers d’entre eux possèdent des jouets calibrés. L’âge minimum de prise en charge est mal connu des praticiens et cela peut être préjudiciable à la bonne prise en charge des déficits sensoriels. Le nouveau carnet de santé devrait permettre un dépistage plus pertinent des troubles sensoriels chez le nourrisson : une plus large diffusion des informations et des conduites à tenir est nécessaire

    Attribute Controlled Reconstruction and Adaptive Mathematical Morphology

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    ISBN : 978-3-642-38293-2International audienceIn this paper we present a reconstruction method controlled by the evolution of attributes. The process begins from a marker, propagated over increasing quasi-flat zones. The evolution of several increasing and non-increasing attributes is studied in order to select the appropriate region. Additionally, the combination of attributes can be used in a straightforward way. To demonstrate the performance of our method, three applications are presented. Firstly, our method successfully segments connected objects in range images. Secondly, input-adaptive structuring elements (SE) are defined computing the controlled propagation for each pixel on a pilot image. Finally, input-adaptive SE are used to assess shape features on the image. Our approach is multi-scale and auto-dual. Compared with other methods, it is based on a given attribute but does not require a size parameter in order to determine appropriate regions. It is useful to extract objects of a given shape. Additionally, our reconstruction is a connected operator since quasi-flat zones do not create new contours on the image

    DNA Double-Strand Breaks Induced by Cavitational Mechanical Effects of Ultrasound in Cancer Cell Lines

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    Ultrasonic technologies pervade the medical field: as a long established imaging modality in clinical diagnostics; and, with the emergence of targeted high intensity focused ultrasound, as a means of thermally ablating tumours. In parallel, the potential of [non-thermal] intermediate intensity ultrasound as a minimally invasive therapy is also being rigorously assessed. Here, induction of apoptosis in cancer cells has been observed, although definitive identification of the underlying mechanism has thus far remained elusive. A likely candidate process has been suggested to involve sonochemical activity, where reactive oxygen species (ROS) mediate the generation of DNA single-strand breaks. Here however, we provide compelling new evidence that strongly supports a purely mechanical mechanism. Moreover, by a combination of specific assays (neutral comet tail and staining for γH2AX foci formation) we demonstrate for the first time that US exposure at even moderate intensities exhibits genotoxic potential, through its facility to generate DNA damage across multiple cancer lines. Notably, colocalization assays highlight that ionizing radiation and ultrasound have distinctly different signatures to their respective γH2AX foci formation patterns, likely reflecting the different stress distributions that initiated damage formation. Furthermore, parallel immuno-blotting suggests that DNA-PKcs have a preferential role in the repair of ultrasound-induced damage

    Temporal controls on silicic acid utilisation along the West Antarctic Peninsula

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    The impact of climatic change along the Antarctica Peninsula has been widely debated in light of atmospheric/oceanic warming and increases in glacial melt over the past half century. Particular concern exists over the impact of these changes on marine ecosystems, not only on primary producers but also on higher trophic levels. Here we present a record detailing the historical controls on the biogeochemical cycling of silicic acid [Si(OH)4] on the west Antarctica Peninsula margin, a region in which the modern phytoplankton environment is constrained by seasonal sea-ice. We demonstrate that Si(OH)4 cycling through the Holocene alternates between being primarily regulated by sea-ice or glacial discharge from the surrounding grounded ice-sheet. With further climate-driven change and melting forecast for the 21st Century, our findings document the potential for biogeochemical cycling and multi-trophic interactions along the peninsula to be increasingly regulated by glacial discharge, altering food-web interactions
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