111 research outputs found

    REGIONAL AND URBAN SCIENCE IN FRANCE: RANKINGS OF AUTHORS AND INSTITUTIONS AND PUBLICATION PATTERNS DURING THE NINETIES

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    This article analyses the evolution experienced by research in urban and regional science in France between 1991 and 2000, comparing these changes with wider international trends. Nine of the leading international journals of regional and urban studies were used in drawing up rankings of countries, authors and institutions and in exploring publication patterns. We examine the strategy adopted by the French in establishing themselves within the world's top five in regional and urban research and report a number of interesting findings when comparisons are drawn internationally.REGIONAL AND URBAN SCIENCE, BIBLIOMETRICS, RANKINGS

    Two-dimensional multiscale entropy analysis: applications to image texture evaluation

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    Complexity measures, defined as measures of irregularity over time scales, are the subject of a growing number of studies as the information they reveal can find utility in a large field of applications. One of the most popular complexity measures is the multiscale entropy. Nevertheless, more and more algorithms dedicated to complexity analyses are proposed to improve the existing ones. However, such measures are available only for one-dimensional time series. For bidimensional data (images), no equivalent algorithm has been proposed to analyze irregularity over spatial scales. We herein introduce a new framework that extends the one-dimensional multiscale entropy (MSE1D) to the bidimensional case (MSE2D). Moreover, a variant of MSE2D is also ModMSE2D). The two new algorithms are tested as new texture analysis frameworks. They are applied to simulated and real data. Our results show that, compared with other existing texture analysis algorithms, MSE2D and ModMSE2D are suitable and powerful tools for image analysis and classification according to their texture patterns. While MSE2D is computationally faster than ModMSE2D, ModMSE2D is more robust to small image sizes. The two methods present interesting performances, and can be as useful as their unidimensional versions in two-dimensional applications

    Network-based dissolution

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    We introduce a novel graph-theoretic dissolution model which applies to a number of redistribution scenarios such as gerrymandering or work economization. The central aspect of our model is to delete some vertices and redistribute their "load" to neighboring vertices in a completely balanced way. We investigate how the underlying graph structure, the pre-knowledge about which vertices to delete, and the relation between old and new "vertex load" influence the computational complexity of the underlying easy-to-describe graph problems, thereby identifying both tractable and intractable cases

    Use of colonoscopy as a primary screening test for colorectal cancer in average risk people

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    The use of colonoscopy as a primary screening test for colorectal cancer (CRC) in average risk adults is a subject of controversy. Our primary objective was to build a predictive model based on a few simple variables that could be used as a guide for identifying average risk adults more suitable for examination with colonoscopy as a primary screening test. METHODS: The prevalence of advanced adenomas was assessed by primary screening colonoscopy in 2210 consecutive adults at least 40 yr old, without known risk factors for CRC. Age, gender, and clinical and biochemical data were compared among people without adenomas, those with non-advanced adenomas, and those with any advanced neoplasm. A combined score to assess the risk of advanced adenomas was built with the variables selected by multiple logistic regression analysis. RESULTS: Neoplastic lesions were found in 617 subjects (27.9%), including 259 with at least one neoplasm that was 10 mm or larger, villous, or with moderate-to-severe dysplasia, and 11 with invasive cancers. Advanced lesions were more frequent among men, older people, and those with a higher body mass index (BMI). These three variables were independent predictors of advanced adenomas in multivariate analysis. A score combining age, sex, and BMI was developed as a guide for identifying individuals more suitable for screening colonoscopy. CONCLUSIONS: Age, gender, and BMI can be used to build a simple score to select those average risk adults who might be candidates for primary screening colonoscop

    Afectación de colon en el síndrome de Klippel Trenaunay Weber

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    We report the case of a 12-year-old boy, diagnosed of Klippel Trenaunay Weber syndrome, with hemangiomas and venous varicosities in the right leg, who complaint about incidental hernatochezia. In the colonoscopy some violet and plain angiodisplastic lesions like in the skin, were observed in rectum and distal sigmoid colon. We think this case is interesting, because of the unusual afectation of the gut in this disease and the importance of considering the endoscopic procedures in the evaluation of these patients
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