994 resultados para knowledge visualization


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Cardiovascular risk assessment might be improved with the addition of emerging, new tests derived from atherosclerosis imaging, laboratory tests or functional tests. This article reviews relative risk, odds ratios, receiver-operating curves, posttest risk calculations based on likelihood ratios, the net reclassification improvement and integrated discrimination. This serves to determine whether a new test has an added clinical value on top of conventional risk testing and how this can be verified statistically. Two clinically meaningful examples serve to illustrate novel approaches. This work serves as a review and basic work for the development of new guidelines on cardiovascular risk prediction, taking into account emerging tests, to be proposed by members of the 'Taskforce on Vascular Risk Prediction' under the auspices of the Working Group 'Swiss Atherosclerosis' of the Swiss Society of Cardiology in the future.

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In the past three decades, feminists and critical theorists have discussed and argued the importance of deconstructing and problematizing social science research methodology in order to question normalized hierarchies concerning the production of knowledge and the status of truth claims. Nevertheless, often, these ideas have basically remained theoretical propositions not embodied in research practices. In fact there is very little published discussion about the difficulties and limits of their practical application. In this paper we introduce some interconnected reflections starting from two different but related experiences of embodying 'feminist activist research'. Our aim is to emphasise the importance of attending to process, making mistakes and learning during fieldwork, as well as experimenting with personalized forms of analysis, such as the construction of narratives and the story-telling process.

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In the past three decades, feminists and critical theorists have discussed and argued the importance of deconstructing and problematizing social science research methodology in order to question normalized hierarchies concerning the production of knowledge and the status of truth claims. Nevertheless, often, these ideas have basically remained theoretical propositions not embodied in research practices. In fact there is very little published discussion about the difficulties and limits of their practical application. In this paper we introduce some interconnected reflections starting from two different but related experiences of embodying 'feminist activist research'. Our aim is to emphasise the importance of attending to process, making mistakes and learning during fieldwork, as well as experimenting with personalized forms of analysis, such as the construction of narratives and the story-telling process.

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Purpose: To perform in vivo imaging of the cerebellum with an in-plane resolution of 120 mm to observe its cortical granular and molecular layers by taking advantage of the high signal-to-noise ratio and the increased magnetic susceptibility-related contrast available at high magnetic field strength such as 7 T. Materials and Methods: The study was approved by the institutional review board, and all patients provided written consent. Three healthy persons (two men, one woman; mean age, 30 years; age range, 28-31 years) underwent MR imaging with a 7-T system. Gradient-echo images (repetition time msec/echo time msec, 1000/25) of the human cerebellum were acquired with a nominal in-plane resolution of approximately 120 mum and a section thickness of 1 mm. Results: Structures with dimensions as small as 240 mum, such as the granular and molecular layers in the cerebellar cortex, were detected in vivo. The detection of these structures was confirmed by comparing the contrast obtained on T2*-weighted and phase images with that obtained on images of rat cerebellum acquired at 14 T with 30 mum in-plane resolution. Conclusion: In vivo cerebellar imaging at near-microscopic resolution is feasible at 7 T. Such detailed observation of an anatomic area that can be affected by a number of neurologic and psychiatric diseases, such as stroke, tumors, autism, and schizophrenia, could potentially provide newer markers for diagnosis and follow-up in patients with such pathologic conditions. (c) RSNA, 2010.

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La Mediterrània ha estat gresol de la circulació d¿idees i persones des de fa mil·lennis. Durant l¿edat mitjana, però, el moviment més rellevant va ser, tal vegada, el que es va produirentre l¿Orient (Maixriq) i l¿Occident (Magrib) islàmics. Els viatges d¿estudis, íntimament units a les prescripcions religioses,varen convertir els científics musulmans en membres especialment actius en la difusió dels coneixements i dels avenços ques¿anaven adquirint a la capital de l¿imperi, Bagdad. Lluny de ser mers «transportistes» de la ciència, el nivell cultural assolit durantl'edat d'or abbassí els va convertir en un dels clímaxs intel·lectuals de la història. Al principi, tot i restar en un discret segonpla, els científics del nord d¿Àfrica i, especialment, els científicsd'al-Andalus varen tenir un paper essencial en la transmissióde la ciència oriental cap a una Europa que en va recollir el testimoni.Per això l¿aportació de la cultura araboislàmica és un esglaó sense el qual és impossible entendre la ciència posterior.Els camps conreats foren diversos: medicina, agronomia,òptica... però l¿àmbit que presidí la ciència fou, sens dubte,l¿astronomia (relacionada, al seu torn, amb les matemàtiques i la geografia). Els noms dels astrònoms més rellevants (desd¿al-Khwarizmi fins a Azarquiel) i les fites que varen assolir justifiquen que fossin coneguts per un públic ampli. Malgrat tot, continuen essent uns grans desconeguts.

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PURPOSE: To describe the use of anterior segment optical coherence tomography (AS-OCT) to clarify the position and patency of aqueous shunt devices in the anterior chamber of eyes where corneal edema or tube position does not permit a satisfactory view. DESIGN: Noncomparative observational case series. METHODS: Four cases are reported in which aqueous shunt malposition or obstruction was suspected but the shunt could not be seen on clinical examination. The patients underwent AS-OCT to identify the position and patency of the shunt tip. RESULTS: In each case, AS-OCT provided data regarding tube position and/or patency that could not be obtained by slit-lamp examination or by gonioscopy that influenced management. CONCLUSIONS: AS-OCT can be used to visualize anterior chamber tubes in the presence of corneal edema that precludes an adequate view or in cases where the tube is retracted into the cornea. In such cases, AS-OCT is useful in identifying shunt patency and position, which helps guide clinical decision making.

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BACKGROUND: The goal of this study was to characterize the performance of fluorine-19 ((19)F) cardiac magnetic resonance (CMR) for the specific detection of inflammatory cells in a mouse model of myocarditis. Intravenously administered perfluorocarbons are taken up by infiltrating inflammatory cells and can be detected by (19)F-CMR. (19)F-labeled cells should, therefore, generate an exclusive signal at the inflamed regions within the myocardium. METHODS AND RESULTS: Experimental autoimmune myocarditis was induced in BALB/c mice. After intravenous injection of 2×200 µL of a perfluorocarbon on day 19 and 20 (n=9) after immunization, in vivo (19)F-CMR was performed at the peak of myocardial inflammation (day 21). In 5 additional animals, perfluorocarbon combined with FITC (fluorescein isothiocyanate) was administered for postmortem immunofluorescence and flow-cytometry analyses. Control experiments were performed in 9 animals. In vivo (19)F-CMR detected myocardial inflammation in all experimental autoimmune myocarditis-positive animals. Its resolution was sufficient to identify even small inflammatory foci, that is, at the surface of the right ventricle. Postmortem immunohistochemistry and flow cytometry confirmed the presence of perfluorocarbon in macrophages, dendritic cells, and granulocytes, but not in lymphocytes. The myocardial volume of elevated (19)F signal (rs=0.96; P<0.001), the (19)F signal-to-noise ratio (rs=0.92; P<0.001), and the (19)F signal integral (rs=0.96; P<0.001) at day 21 correlated with the histological myocarditis severity score. CONCLUSIONS: In vivo (19)F-CMR was successfully used to visualize the inflammation specifically and robustly in experimental autoimmune myocarditis, and thus allowed for an unprecedented insight into the involvement of inflammatory cells in the disease process.

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Introduction: The field of Connectomic research is growing rapidly, resulting from methodological advances in structural neuroimaging on many spatial scales. Especially progress in Diffusion MRI data acquisition and processing made available macroscopic structural connectivity maps in vivo through Connectome Mapping Pipelines (Hagmann et al, 2008) into so-called Connectomes (Hagmann 2005, Sporns et al, 2005). They exhibit both spatial and topological information that constrain functional imaging studies and are relevant in their interpretation. The need for a special-purpose software tool for both clinical researchers and neuroscientists to support investigations of such connectome data has grown. Methods: We developed the ConnectomeViewer, a powerful, extensible software tool for visualization and analysis in connectomic research. It uses the novel defined container-like Connectome File Format, specifying networks (GraphML), surfaces (Gifti), volumes (Nifti), track data (TrackVis) and metadata. Usage of Python as programming language allows it to by cross-platform and have access to a multitude of scientific libraries. Results: Using a flexible plugin architecture, it is possible to enhance functionality for specific purposes easily. Following features are already implemented: * Ready usage of libraries, e.g. for complex network analysis (NetworkX) and data plotting (Matplotlib). More brain connectivity measures will be implemented in a future release (Rubinov et al, 2009). * 3D View of networks with node positioning based on corresponding ROI surface patch. Other layouts possible. * Picking functionality to select nodes, select edges, get more node information (ConnectomeWiki), toggle surface representations * Interactive thresholding and modality selection of edge properties using filters * Arbitrary metadata can be stored for networks, thereby allowing e.g. group-based analysis or meta-analysis. * Python Shell for scripting. Application data is exposed and can be modified or used for further post-processing. * Visualization pipelines using filters and modules can be composed with Mayavi (Ramachandran et al, 2008). * Interface to TrackVis to visualize track data. Selected nodes are converted to ROIs for fiber filtering The Connectome Mapping Pipeline (Hagmann et al, 2008) processed 20 healthy subjects into an average Connectome dataset. The Figures show the ConnectomeViewer user interface using this dataset. Connections are shown that occur in all 20 subjects. The dataset is freely available from the homepage (connectomeviewer.org). Conclusions: The ConnectomeViewer is a cross-platform, open-source software tool that provides extensive visualization and analysis capabilities for connectomic research. It has a modular architecture, integrates relevant datatypes and is completely scriptable. Visit www.connectomics.org to get involved as user or developer.

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INTRODUCTION: Delirium is a highly prevalent disorder, with serious consequences for the hospitalised patient. Nevertheless, it remains under-diagnosed and under-treated. We developed evidence-based clinical practice guidelines (CPGs) focusing on prevention, screening, diagnosis, and treatment of delirium in a general hospital. This article presents the implementation process of these CPGs and a before-after study assessing their impact on healthcare professionals' knowledge and on clinical practice. METHODS: CPGs on delirium were first implemented in two wards (Neurology and Neurosurgery) of the Lausanne university hospital. Interactive one-hour educational sessions for small groups of nurses and physicians were organised. Participants received a summary of the guidelines and completed a multiple choice questionnaire, assessing putative changes in knowledge, before and three months after the educational session. Other indicators such as "diagnosis of delirium" reported in the discharge letters, and mean duration of patients' hospital stay before and after implementation were compared. RESULTS: Eighty percent of the nurses and physicians from the Neurology and Neurosurgery wards attended the educational sessions. Both nurses and physicians significantly improved their knowledge after the implementation (+9 percentage-points). Other indicators were not modified by the intervention. CONCLUSION: A single interactive intervention improved both nurses' and physicians' knowledge on delirium. Sustained and repeated interventions are probably needed to demonstrate changes in clinical practice.

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This paper presents a pilot project to reinforce participatory practices in standardization. The INTERNORM project creates an interactive knowledge center based on the sharing of academic skills and experiences accumulated by the civil society, especially consumer associations, environmental associations and trade unions to strengthen the participatory process of standardization. The first objective of the project is action-oriented: INTERNORM provides a common knowledge pool supporting the participation of civil society actors to international standard-setting activities by bringing them together with academic experts in working groups and providing logistic and financial support to their participation in meetings of national and international technical committees. The second objective is analytical: the standardization action provides a research field for a better understanding of the participatory dynamics underpinning international standardization. This paper presents three incentives that explain civil society (non-)involvement in standardization that overcome conventional resource-based hypotheses: an operational incentive related to the use of standards in the selective goods provided by associations to their membership; a thematic incentive provided by the setting of priorities by strategic committees created in some standardization organization; and a rhetorical incentive related to the discursive resource that civil society concerns offers to the different stakeholders.