831 research outputs found

    On Stein's Identity and Near-Optimal Estimation in High-dimensional Index Models

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    We consider estimating the parametric components of semi-parametric multiple index models in a high-dimensional and non-Gaussian setting. Such models form a rich class of non-linear models with applications to signal processing, machine learning and statistics. Our estimators leverage the score function based first and second-order Stein's identities and do not require the covariates to satisfy Gaussian or elliptical symmetry assumptions common in the literature. Moreover, to handle score functions and responses that are heavy-tailed, our estimators are constructed via carefully thresholding their empirical counterparts. We show that our estimator achieves near-optimal statistical rate of convergence in several settings. We supplement our theoretical results via simulation experiments that confirm the theory

    Automatic 3D Model Generation based on a Matching of Adaptive Control Points

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    Abstract The use of a 3D model helps to diagnosis and accurately locate a disease where it is neither available, nor can be exactly measured in a 2D image. Therefore, highly accurate software for a 3D model of vessel is required for an accurate diagnosis of patients. We have generated standard vessel because the shape of the arterial is different for each individual vessel, where the standard vessel can be adjusted to suit individual vessel. In this paper, we propose a new approach for an automatic 3D model generation based on a matching of adaptive control points. The proposed method is carried out in three steps. First, standard and individual vessels are acquired. The standard vessel is acquired by a 3D model projection, while the individual vessel of the first segmented vessel bifurcation is obtained. Second is matching the corresponding control points between the standard and individual vessels, where a set of control and corner points are automatically extracted using the Harris corner detector. If control points exist between corner points in an individual vessel, it is adaptively interpolated in the corresponding standard vessel which is proportional to the distance ratio. And then, the control points of corresponding individual vessel match with those control points of standard vessel. Finally, we apply warping on the standard vessel to suit the individual vessel using the TPS (Thin Plate Spline) interpolation function. For experiments, we used angiograms of various patients from a coronary angiography in Sanggye Paik Hospital

    Variation of quercetin glycoside derivatives in three onion (Allium cepa L.) varieties

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    AbstractThe aim of this study was to quantify the contents of individual quercetin glycosides in red, yellow and chartreuse onion by High Performance Liquid Chromatography (HPLC) analysis. Acid hydrolysis of individual quercetin glycosides using 6M hydrochloric acid guided to identify and separate quercetin 7,4ā€²-diglucoside, quercetin 3-glucoside, quercetin 4ā€²-glucoside, and quercetin. The contents of total quercetin glycosides varied extensively among three varieties (ranged from 16.10 to 103.93mg/g DW). Quercetin was the predominant compound that accounted mean 32.21mg/g DW in red onion (43.6% of the total) and 127.92mg/g DW in chartreuse onion (78.3% of the total) followed by quercetin 3-glucoside (28.83 and 24.16mg/g DW) respectively. Quercetin 3-glucoside levels were much higher in yellow onion (43.85mg/g DW) followed by quercetin 30.08mg/g DW. Quercetin 4ā€²-glucoside documented the lowest amount that documented mean 2.4% of the total glycosides. The varied contents of glycosides present in the different onion varieties were significant

    Long-term evaluation of the prognosis of super hydrophilic surface treated CA implants: a retrospective clinical study

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    This study was performed to evaluate the long-term clinical efficacy of the CA implants (Osstem Implant, Busan, Korea), calcium-modified surfaced treated implants on acid-etched surfaces sandblasted with alumina. From January 2013 to December 2015, 258 implants of 120 patients placed between 2013 and 2015 were retrospectively studied. Using medical records and periapical radiographs, sex, age, location, fixture width and length of placed implants, presence or absence of bone graft, types of bone substitutes and membrane used for bone grafting, primary and secondary stability, initial and delayed complications, and marginal bone loss were investigated. The success rate and survival rate of the implants in each group were analyzed retrospectively based on the criteria suggested by Albrektsson et al. Between 2013 and 2015, with a follow-up longer than 5years, 258 implants with an average diameter of 4.63mm (3.5ā€“5.5mm) and an average length of 9.94mm (7.0ā€“13.0mm) were placed in a total of 120 patients (61 males and 59 females) with a mean age of 63.7years for an average of 62months of observation period. The survival rate was 97.3%, the success rate was 94.2%, and the average final marginal bone loss was 0.074mm. The CA implants manufactured with the improved surface treatment method exhibited a survival rate of 97.3% and a success rate of 94.2% over an average observation period of 62months. The implants were not affected by most factors and had very high survival and success rates over a long period of observation. In particular, the stability of the implant was excellent, with no cases of failed implants in delayed placement after bone grafting and a healing period

    TSLP Induces Mast Cell Development and Aggravates Allergic Reactions through the Activation of MDM2 and STAT6

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    Thymic stromal lymphopoietin (TSLP) is known to promote T helper type 2 cellā€“associated inflammation. Mast cells are major effector cells in allergic inflammatory responses. We noted that the population and maturation of mast cells were reduced in TSLP-deficient mice (TSLP-/-). Thus, we hypothesized that TSLP might affect mast cell development. We found that TSLP induced the proliferation and differentiation of mast cells from bone marrow progenitors. TSLP-induced mast cell proliferation was abolished by depletion of mouse double minute 2 (MDM2) and signal transducers and activators of transcription 6 (STAT6), as an upstream activator of MDM2. TSLP-/-, in particular, had a considerable deficit in the expression of MDM2 and STAT6. Also, the TSLP deficiency attenuated mast cellā€“mediated allergic reactions through the downregulation of STAT6 and MDM2. In an antibody microarray chip analysis, MDM2 expression was increased in atopic dermatitis patients. These observations indicate that TSLP is a factor for mast cell development, and that it aggravates mast cellā€“mediated immune responses
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