1,525 research outputs found

    Extragenital Blaschkoid lichen sclerosus et atrophicus in a child

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    Lichen sclerosus et atrophicus is a chronic inflammatory skin disease that typically affects prepubertal girls and peri- or post-menopausal women in genital and perineal areas. In some cases, it can also manifest as extragenital lesions. Extragenital Blaschkoid lesions have infrequently been reported. Here, we report a case of extragenital Blaschkoid lichen sclerosus et atrophicus in a child

    An Atypical Presentation of a Rare Disease

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    A 76-year-old white woman presented for evaluation of asymptomatic skin lesions on her right shin, right buttock, and left arm. All lesions initially underwent slow growth and plateaued and then remained stable in size. A complete review of systems revealed normal results. She had 3 well-demarcated erythematous round plaques ranging from 1.5 to 3 cm, all with a central depression, yellow hue, and prominent telangiectasias (Figs 1 and 2). An excisional biopsy was performed. Histologically, there were palisading granulomas within the papillary and reticular dermis, predominantly composed of a histiocytic cell population with multiple large giant cells (S100-; Fig 3)

    Rapid Determination of Receiver Sensitivity via Integral Search

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    Receiver sensitivity is a measure of the lowest signal strength that a receiver can detect. Receiver sensitivity is typically measured by linearly incrementing the received power level until a target packet error rate (PER) is reached. Linear search is slow and can occupy substantial test resources such as test stations and instruments. This disclosure describes techniques to rapidly determine the receiver sensitivity of a device-under-test (DUT) by learning the ensemble characteristics of devices under test, building a packet error rate (PER) model, performing limited-range measurements of the DUT, and using the PER model and the results of the measurements to predict the sensitivity of the DUT. By speeding up the determination of receiver sensitivity, the described techniques reduce test cycle times and enable improvement of the units per hour (UPH) of a factory, resulting in a lower cost of owning and operating test stations and instruments

    Sparse Approximate Multifrontal Factorization with Butterfly Compression for High Frequency Wave Equations

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    We present a fast and approximate multifrontal solver for large-scale sparse linear systems arising from finite-difference, finite-volume or finite-element discretization of high-frequency wave equations. The proposed solver leverages the butterfly algorithm and its hierarchical matrix extension for compressing and factorizing large frontal matrices via graph-distance guided entry evaluation or randomized matrix-vector multiplication-based schemes. Complexity analysis and numerical experiments demonstrate O(Nlog2N)\mathcal{O}(N\log^2 N) computation and O(N)\mathcal{O}(N) memory complexity when applied to an N×NN\times N sparse system arising from 3D high-frequency Helmholtz and Maxwell problems

    A Parallel Hierarchical Blocked Adaptive Cross Approximation Algorithm

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    This paper presents a hierarchical low-rank decomposition algorithm assuming any matrix element can be computed in O(1)O(1) time. The proposed algorithm computes rank-revealing decompositions of sub-matrices with a blocked adaptive cross approximation (BACA) algorithm, followed by a hierarchical merge operation via truncated singular value decompositions (H-BACA). The proposed algorithm significantly improves the convergence of the baseline ACA algorithm and achieves reduced computational complexity compared to the full decompositions such as rank-revealing QR decompositions. Numerical results demonstrate the efficiency, accuracy and parallel efficiency of the proposed algorithm

    Physical appearance perfectionism explains variance in eating disorder symptoms above general perfectionism

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    Physical appearance perfectionism is a domain-specific form of perfectionism comprising two components: hope for perfection and worry about imperfection (Yang & Stoeber, 2012). Previous studies found that physical appearance perfectionism is related to eating disorder symptoms, particularly the worry about imperfection component, but did not address the question of whether physical appearance perfectionism explains variance in eating disorder symptoms above general perfectionism. The present study investigated the question examining 559 female university students. Physical appearance perfectionism explained an additional 9-17% of variance in eating disorder symptoms above the 11-20% variance explained by general perfectionism. The findings suggest that physical appearance perfectionism plays an important role in disordered eating beyond general perfectionis
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