116 research outputs found

    A robust nonlinear scale space change detection approach for SAR images

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    In this paper, we propose a change detection approach based on nonlinear scale space analysis of change images for robust detection of various changes incurred by natural phenomena and/or human activities in Synthetic Aperture Radar (SAR) images using Maximally Stable Extremal Regions (MSERs). To achieve this, a variant of the log-ratio image of multitemporal images is calculated which is followed by Feature Preserving Despeckling (FPD) to generate nonlinear scale space images exhibiting different trade-offs in terms of speckle reduction and shape detail preservation. MSERs of each scale space image are found and then combined through a decision level fusion strategy, namely "selective scale fusion" (SSF), where contrast and boundary curvature of each MSER are considered. The performance of the proposed method is evaluated using real multitemporal high resolution TerraSAR-X images and synthetically generated multitemporal images composed of shapes with several orientations, sizes, and backscatter amplitude levels representing a variety of possible signatures of change. One of the main outcomes of this approach is that different objects having different sizes and levels of contrast with their surroundings appear as stable regions at different scale space images thus the fusion of results from scale space images yields a good overall performance

    Interactive ship segmentation in SAR images (SAR görüntülerinde etkileşimli gemi bölütleme)

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    Ship detection from synthetic aperture radar (SAR) images is important for various automatic target recognition (ATR) tasks. Although the ships in offshore areas can be easily detected, the ones near the shores or close to each other are difficult to detect. Furthermore, segmentation and classification of such ships is extremely difficult. In this study, a novel approach is presented for the fast and accurate segmentation of ship boundaries with minimal user interaction. In this approach, the rough location and orientation of a ship is determined by the user. Then, a ship model, which is constructed from synthetic ship images, is fitted on to the ship selected by the user and accurate ship boundaries are extracted. The effectiveness of the proposed algorithm is demonstrated by experimental results

    Pediatric urolithiasis: the current surgical management

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    Children represent about 1% of all patients with urolithiasis, but 100% of these children are considered high risk for recurrent stone formation, and it is crucial for them to receive a therapy that will render them stone free. In addition, a metabolic workup is necessary to ensure a tailored metaphylaxis to prevent or delay recurrence. The appropriate therapy depends on localization, size, and composition of the calculus, as well as on the anatomy of the urinary tract. In specialized centers, the whole range of extracorporeal shock-wave lithotripsy (ESWL), ureterorenoscopy (URS), and percutaneous nephrolithotomy (PCNL) are available for children, with the same efficiency and safety as in adults

    The human keratins: biology and pathology

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    The keratins are the typical intermediate filament proteins of epithelia, showing an outstanding degree of molecular diversity. Heteropolymeric filaments are formed by pairing of type I and type II molecules. In humans 54 functional keratin genes exist. They are expressed in highly specific patterns related to the epithelial type and stage of cellular differentiation. About half of all keratins—including numerous keratins characterized only recently—are restricted to the various compartments of hair follicles. As part of the epithelial cytoskeleton, keratins are important for the mechanical stability and integrity of epithelial cells and tissues. Moreover, some keratins also have regulatory functions and are involved in intracellular signaling pathways, e.g. protection from stress, wound healing, and apoptosis. Applying the new consensus nomenclature, this article summarizes, for all human keratins, their cell type and tissue distribution and their functional significance in relation to transgenic mouse models and human hereditary keratin diseases. Furthermore, since keratins also exhibit characteristic expression patterns in human tumors, several of them (notably K5, K7, K8/K18, K19, and K20) have great importance in immunohistochemical tumor diagnosis of carcinomas, in particular of unclear metastases and in precise classification and subtyping. Future research might open further fields of clinical application for this remarkable protein family

    Unheilige Bücher. Zur Implosion mythischen Erzählens in der ,Prosa Edda‘

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    The so called ‘Prose Edda' or ‘Snorra Edda', usually dated to the third decade of the 13th century, contains after a short prologue two substantial sections dealing mainly with mythography and poetics and a long concluding skaldic poem. In the extant medieval manuscripts from around 1300 and the beginning of the 14th century, additional material like genealogies, grammatical treatises, etc. is included. The present paper focuses on one of the earliest of these manuscripts, codex DG 11 4to, University Library Uppsala, and analyses some central features of the specific way in which it presents different narrative layers. For the first time, this analysis combines a study of textual and visual aspects of the manuscript, and special attention is given to two of the many illustrations in this codex. Together with later scribal notes, the drawings contribute heavily to the process of framing, which is one of the main features of the ‘Prose Edda'. This process of creating potentially endless narrative and visual frames is part of the text‘s ambition to establish a distance to the traditional pagan myths and to facilitate new fictional possibilitie

    Risk factors influencing the complication rates of tension-free vaginal tape-type procedures

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    Purpose of review Tension-free vaginal tape (TVT)-type procedures are gradually becoming the new gold-standard treatment for female stress urinary incontinence. Studies trying to determine the influence of possible risk factors on complications of TVT surgery are needed in order to achieve more favorable results in the future.'This review at ' tempts to summarize the current studies which address the possible risk factors influencing the complication rates of TVT-type procedures
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