3,260 research outputs found

    Hierarchically Clustered Representation Learning

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    The joint optimization of representation learning and clustering in the embedding space has experienced a breakthrough in recent years. In spite of the advance, clustering with representation learning has been limited to flat-level categories, which often involves cohesive clustering with a focus on instance relations. To overcome the limitations of flat clustering, we introduce hierarchically-clustered representation learning (HCRL), which simultaneously optimizes representation learning and hierarchical clustering in the embedding space. Compared with a few prior works, HCRL firstly attempts to consider a generation of deep embeddings from every component of the hierarchy, not just leaf components. In addition to obtaining hierarchically clustered embeddings, we can reconstruct data by the various abstraction levels, infer the intrinsic hierarchical structure, and learn the level-proportion features. We conducted evaluations with image and text domains, and our quantitative analyses showed competent likelihoods and the best accuracies compared with the baselines.Comment: 10 pages, 7 figures, Under review as a conference pape

    Adversarial Dropout for Supervised and Semi-supervised Learning

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    Recently, the training with adversarial examples, which are generated by adding a small but worst-case perturbation on input examples, has been proved to improve generalization performance of neural networks. In contrast to the individually biased inputs to enhance the generality, this paper introduces adversarial dropout, which is a minimal set of dropouts that maximize the divergence between the outputs from the network with the dropouts and the training supervisions. The identified adversarial dropout are used to reconfigure the neural network to train, and we demonstrated that training on the reconfigured sub-network improves the generalization performance of supervised and semi-supervised learning tasks on MNIST and CIFAR-10. We analyzed the trained model to reason the performance improvement, and we found that adversarial dropout increases the sparsity of neural networks more than the standard dropout does.Comment: submitted to AAAI-1

    Suppression of vascular endothelial growth factor expression at the transcriptional and post-transcriptional levels

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    Gene expression is regulated at the transcriptional and post-transcriptional levels. Therefore, in order to achieve a high level of silencing, which includes minimizing any residual expression of a target gene, suppression at both the transcriptional and post-transcriptional levels is required. In this study, we describe a new method for highly efficient gene silencing that combines zinc finger protein-mediated transcriptional repression and small interfering RNA (siRNA)-mediated inhibition of post-transcriptional events. To measure the amount of gene expression under various conditions, we used a luciferase reporter gene that was driven by a variety of promoters, including that of the human vascular endothelial growth factor-A (VEGF-A) gene. We also measured expression of the endogenous VEGF-A gene. Inhibition of gene expression by each of the two individual technologies was effective, but in-depth analyses revealed residual expression of the target gene. The combination of specific zinc finger transcription factors and siRNAs greatly enhanced the silencing of the human VEGF-A gene, not only when cells were grown in the presence of normal amounts of oxygen but also under conditions of hypoxic stimulation. These results suggest that a bi-level approach to the silencing of VEGF-A expression may be clinically beneficial as part of a cancer treatment protocol

    A Study on the Effect of Consumer Involvement and Affect Intensity before and after Plagiarism Suspicion on the Purchase Intention of Music Goods

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    This study aims to examine the effect of consumers' involvement and affect intensity on the purchase intention of music items. In particular  domestically, there is no clear standard for judgment of plagiarism, and thus it is expected that plagiarism suspicion is likely to affect consumers' involvement and affect intensity, and as a result, their purchase intention as well. Accordingly, consumer characteristics (involvement, affect intensity) were chosen as independent variables, and consumers' purchase intention on music items as a subordinate variable, respectively. The first questionnaire-based survey was conducted before the awareness of plagiarism suspicion, followed by the second survey after the awareness of plagiarism suspicion. It turned out that the higher level of involvement and affect intensity, both of which are consumer characteristics, the higher level of purchase intention of music goods. While plagiarism suspicion caused C.R values to decrease in every item, a significant difference was observed only in the relation of ‘involvement - purchase intention’. This study shows that music items which involve plagiarism suspicion result in changes in consumers' purchase intention, which will cause damage to the creators and performers of related music items. Thus, for the development of the music industry and creative activity, tools and standards that can clearly distinguish plagiarism need to be developed

    Increased arterial stiffness in healthy subjects with high-normal glucose levels and in subjects with pre-diabetes

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    <p>Abstract</p> <p>Background</p> <p>Increased fasting plasma glucose (FPG), which includes impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and diabetes, is a risk factor for arterial stiffness. While IFG is widely accepted as a cardiovascular risk factor, recent studies have argued that subjects with high-normal glucose level were characterized by a high incidence of cardiovascular disease. The purpose of this study is to investigate the relationship between FPG and arterial stiffness in non-diabetic healthy subjects.</p> <p>Methods</p> <p>We recruited 697 subjects who visited the health promotion center of a university hospital from May 2007 to August 2008. Age, sex, body mass index (BMI), resting heart rate, smoking habits, alcohol intake, exercise, blood pressure, medical history, FPG, lipid profile, high sensitivity C-reactive protein (hs-CRP), and Brachial-ankle pulse wave velocity (ba-PWV) were measured. We performed correlation and multiple linear regression analyses to divide the research subjects into quartiles: Q1(n = 172), 65 mg/dL ≤FPG < 84 mg/dL; Q2(n = 188), 84 mg/dL ≤FPG < 91 mg/dl; Q3(n = 199), 91 mg/dL ≤FPG < 100 mg/dL; Q4(n = 138), 100 mg/dL ≤FPG < 126 mg/dL.</p> <p>Results</p> <p>FPG has an independent, positive association with ba-PWV in non-diabetic subjects after correcting for confounding variables, including age, sex, BMI, blood pressure, resting heart rate, hs-CRP, lipid profile, and behavioral habits. The mean ba-PWV of the high-normal glucose group (Q3, 1384 cm/s) was higher than that of the low-normal glucose group (1303 ± 196 cm/s vs.1328 ± 167 cm/s, P < 0.05). The mean ba-PWV value in the IFG group (1469 ± 220 cm/s) was higher than that in the normoglycemic group (P < 0.05, respectively).</p> <p>Conclusions</p> <p>An increase in FPG, even within the normal range, was associated with aggravated arterial stiffness. Further research is needed to determine the glycemic target value for the prevention of arterial stiffness in clinical and public health settings.</p

    Meteorin regulates mesendoderm development by enhancing nodal expression

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    During gastrulation, distinct lineage specification into three germ layers, the mesoderm, endoderm and ectoderm, occurs through an elaborate harmony between signaling molecules along the embryonic proximo-distal and anterior-posterior axes, and Nodal signaling plays a key role in the early embryonic development governing embryonic axis formation, mesoderm and endoderm specification, and left-right asymmetry determination. However, the mechanism by which Nodal expression is regulated is largely unknown. Here, we show that Meteorin regulates Nodal expression and is required for mesendoderm development. It is highly expressed in the inner cell mass of blastocysts and further in the epiblast and extra-embryonic ectoderm during gastrulation. Genetic ablation of the Meteorin gene resulted in early embryonic lethality, presumably due to impaired lineage allocation and subsequent cell accumulation. Embryoid body culture using Meteorin-null embryonic stem (ES) cells showed reduced Nodal expression and concomitant impairment of mesendoderm specification. Meteorin-null embryos displayed reduced levels of Nodal transcripts before the gastrulation stage, and impaired expression of Goosecoid, a definitive endoderm marker, during gastrulation, while the proximo-distal and anterior-posterior axes and primitive streak formation were preserved. Our results show that Meteorin is a novel regulator of Nodal transcription and is required to maintain sufficient Nodal levels for endoderm formation, thereby providing new insights in the regulation of mesendoderm allocation.open1113sciescopu

    Transvaginal Endoscopic Appendectomy

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    Since Kalloo and colleagues first reported the feasibility and safety of a peroral transgastric approach in the porcine model in 2004, various groups have reported more complex natural orifice transluminal endoscopic surgery (NOTES) procedures, such as the cholecystectomy, splenectomy and liver biopsy, in the porcine model. Natural orifice access to the abdominal cavity, such as transgastric, transvesical, transcolonic, and transvaginal, has been described. Although a novel, minimally invasive approach to the abdominal cavity is a peroral endoscopic transgastric approach, there are still some challenging issues, such as the risk of infection and leakage, and the method of gastric closure. Hybrid-NOTES is an ideal first step in humans. Human hybrid transvaginal access has been used for years by many surgeons for diagnostic and therapeutic purposes. Here, we report a transvaginal flexible endoscopic appendectomy, with a 5-mm umbilical port using ultrasonic scissors in a 74-year-old woman with acute appendicitis

    A HISTORICAL APPROACH TO SYPHILIS INFECTION IN KOREA

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    From the end of the 15th century, syphilis spread worldwide, posing a serious threat to public health. Venereal syphilis has been a major research topic, not only in clinical medicine but also in paleopathology, especially because it is a disease of questionable origin and of high prevalence until the discovery of antibiotics. Syphilis in history has been studied extensively in Europe and the Americas, though less so in Asia. In this review, based on extant historical documents and available paleopathological data, we pinpoint the introduction and trace the spread of venereal syphilis in Korea to the end of the 19th century. This review provides fundamental information that will be of great help to future research on pre-20th century syphilis in Korea

    EFFECTS OF THREE PREPARATORY MOVEMENTS ON SIDEWARD PROPULSIVE MOVEMENT

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    This study investigated the effects of three preparatory movements (squat, countermovement and hopping) on the sideward propulsive movement. Seven subjects were analyzed in 3-D to determine how fast they reacted to external signals, using three techniques, to reacl1 an aIming spot. The hopping and the countermovement types were considered better than the squat type in the propulsion. The hopping particularly showed the shortest duration from the external signal to take-off and also recorded high extension moments due to the pre-stretch mechanism for the push-off phase
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