982 research outputs found

    Homophily-Driven Sanitation View for Robust Graph Contrastive Learning

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    We investigate adversarial robustness of unsupervised Graph Contrastive Learning (GCL) against structural attacks. First, we provide a comprehensive empirical and theoretical analysis of existing attacks, revealing how and why they downgrade the performance of GCL. Inspired by our analytic results, we present a robust GCL framework that integrates a homophily-driven sanitation view, which can be learned jointly with contrastive learning. A key challenge this poses, however, is the non-differentiable nature of the sanitation objective. To address this challenge, we propose a series of techniques to enable gradient-based end-to-end robust GCL. Moreover, we develop a fully unsupervised hyperparameter tuning method which, unlike prior approaches, does not require knowledge of node labels. We conduct extensive experiments to evaluate the performance of our proposed model, GCHS (Graph Contrastive Learning with Homophily-driven Sanitation View), against two state of the art structural attacks on GCL. Our results demonstrate that GCHS consistently outperforms all state of the art baselines in terms of the quality of generated node embeddings as well as performance on two important downstream tasks

    Biološka karakterizacija izolata golubljeg paramiksovirusa 1 i analiza njegove patogenosti u SPF pilića

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    Pigeon paramyxovirus type 1 (PPMV-1) is considered as an antigenic variant of Newcastle Disease leading to high mortality and significant economic losses to the poultry industry. However, the pathogenicity of PPMV-1 to chickens is still unclear. Herein, we reported the biological characterization of the isolated PPMV-1 from the diseased pigeons suspected to Newcastle Disease and studied its pathogenicity in SPF chickens. The phylogenetic tree and evolution distances revealed that the new isolate belonged to a VI.2.1.1.2.2 sub-genotype of NDV. Despite the cleavage motif of the F protein containing the 112RRQKR↓F117 sequence associated with virulent NDV strains, and the value of MDT and ICPI of the isolate showing mesogenic characteristics, the challenge trial showed that the isolate had weak pathogenicity to chickens while causing lesions in multiple tissues and organs in pigeons.Golublji paramiksovirus tipa 1 (PPMV-1) smatra se antigenskom varijantom njukaslske bolesti koja uzrokuje visoku smrtnost i znatne ekonomske gubitke u peradarskoj industriji. Patogenost virusa PPMV-1 u pilića međutim još uvijek nije jasna. U ovom je radu provedena biološka karakterizacija PPMV-1 izoliranog iz golubova za koje se sumnja da su oboljeli od njukaslske bolesti te je istražena njihova patogenost u SPF pilića. Filogenetsko stablo i evolucijske udaljenosti otkrili su da novi izolat pripada podgenotipu VI.2.1.1.2.2 virusa njukaslske bolesti (NDV). Unatoč motivu u mjestu cijepanja F-proteina koji sadržava sekvenciju 112RRQKR↓F117 povezanu s virulentnim sojevima NDV-a, vrijednosti MDT-a i ICPI-ja izolata pokazale su mezogene značajke. Ovo probno istraživanje je pokazalo da su izolati PPMV-1 slabo patogeni u pilića, dok u golubova uzrokuju lezije na više organa i tkiva

    Analysis of only 0-1 min clip or 1-4 min Clip for focal liver lesions during contrast-enhanced ultrasonography

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    Purpose: To evaluate the reliability of analysis of only 0-1min clips and 1-4min clips versus the entire clips in performing contrast-enhanced ultrasonography (CEUS) of focal liver lesions (FLLs).Methods: Contrast-enhanced ultrasonography (CEUS) examinations of 43 single FLLs were performed. All clips were analyzed in three ways, the entire clips, 0-1 min clips and 1-4 min clips, benign or malignant diagnosis and pathological diagnosis of each FLL were concluded by the three ways subsequently.Results: The results of correct diagnosis were assessed using Chi-square test. There was no difference with regard to benign or malignant diagnosis, between 0-1min clips and the entire clips, or between 1-4 min clips and the entire clips (p = 0.243 and p = 0.747, respectively). Moreover, no significant differences in pathological diagnosis existed between 0-1min clips and the entire clips, and 1- 4min clips versus entire clips (p=0.808 and p = 0.808, respectively). No significant differences existed among CEUS entire clip, 0-1min clip and 1-4min clip in identifying FLLs, and based on which the diagnosis of two different FLLs during CEUS with only one injection of contrast agent can be available.Conclusion: Only 0-1min clips or 1-4 min clips can be used to instead of the entre clip in performing CEUS of FLLs.Keywords: Focal liver lesions, Contrast-enhanced ultrasonography, Ultrasonic diagnosis, Clip

    Differential impact of affective and cognitive attributes on preference under deliberation and distraction

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    Two experiments were designed to test the hypothesis that affective information looms relatively larger than cognitive information when individuals are distracted for a period of time compared to when they engage in deliberative thinking. In two studies, participants were presented with information about 4 decision alternatives: An affective alternative that scored high on affective attributes but low on cognitive attributes, a cognitive alternative with the opposite trade-off, and two fillers. They were then asked to indicate their attitudes toward each of four decision alternatives either immediately, after a period of deliberation, or after a period of distraction. The results of both experiments demonstrated that participants significantly preferred the affective alternative to the cognitive alternative after distraction, but not after deliberation. The implications for understanding when and how unconscious thought may lead to better decisions are being discussed

    Generalized Cassie-Baxter equation for wetting of a spherical droplet within a smooth and heterogeneous conical cavity

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    Introducing the concepts of both Gibbs’s dividing surface and Rusanov’s dividing line, the wettability behaviors of spherical drops inside a smooth and heterogeneous conical cavity are studied. A new generalized Cassie-Baxter equation for contact angles including the influences of the line tension is derived thermodynamically. Additionally, various approximate formulae of this generalized Cassie-Baxter equation are also discussed correspondingly under some assumptions

    A COMPARISON OF EMG AND KINEMATIC ANALYSIS BETWEEN GROUND AND TREADMILL RUNING FOR CHINESE ELITE SPRINTER-PU FAN FANG

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    Ms. Pu Fan-fang, a Chinese National championship, has been training on simulated treadmill for 4 years to improve her ability of velocity endurance. The purpose of the present study was to compare the changes of her movement structures in ground and treadmill running. EMG and' kinematical analysis were used in the test. The kinematical data results show that significant differences were noted between the two conditions for the take off angle, minimum knee angle of swing leg, the minimum angle between thigh and horizontal line, soar high and soar time. The EMG result revealed that the obvious differences of EMG distribution of eight muscles existed in the two conditions. According to the testing results, it should be considered that more using treadmill training could influence her movement structure although it is a good method to improve velocity endurance

    Mutagenesis of the fusion peptide-like domain of hepatitis C virus E1 glycoprotein: involvement in cell fusion and virus entry

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    <p>Abstract</p> <p>Background</p> <p>Envelope (E) glycoprotein E2 of the hepatitis C virus (HCV) mediates binding of the virus to target cell receptors. Nevertheless, the precise role of E1 in viral entry remains elusive.</p> <p>Methods</p> <p>To understand the involvement of the fusion peptide-like domain positioned at residues 264 to 290 within envelope glycoprotein E1 in HCV infection, mutants with Ala and Asn substitutions for residues conserved between HCV and E proteins of flaviviruses or the fusion proteins of paramyxoviruses were constructed by site-directed mutagenesis and their effects on membrane fusion and viral infectivity were examined.</p> <p>Results</p> <p>None of these mutations affected the synthesis or cell surface expression of envelope proteins, nor did they alter the formation of a non-covalent E1-E2 heterodimer or E2 binding to the large extracellular loop of CD81. The Cys residues located at positions 272 and 281 were unlikely involved in intra- or intermolecular disulfide bond formation. With the exception of the G267A mutant, which showed increased cell fusion, other mutants displayed reduced or marginally inhibited cell fusion capacities compared to the wild-type (WT) E1E2. The G267A mutant was also an exception in human immunodeficiency virus type 1 (HIV-1)/HCV E1E2 pseudotyping analyses, in that it showed higher one-cycle infectivity; all other mutants exhibited greatly or partially reduced viral entry versus the WT pseudotype. All but the G278A and D279N mutants showed a WT-like profile of E1E2 incorporation into HIV-1 particles. Since C272A, C281A, G282A, and G288A pseudotypes bound to Huh7 cells as effectively as did the WT pseudotype, the reduced infectivity of these pseudotypes was due to their ability to inhibit cell fusion.</p> <p>Conclusion</p> <p>Our results indicate that specific residues, but not the structure, of this fusion peptide-like domain are required for mediating cell fusion and viral entry.</p
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