388 research outputs found

    2011 German Escherichia coli outbreak: Alignment-free whole-genome phylogeny by feature frequency profiles

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    Accuracy of SNP-based whole-genome phylogeny reconstruction relies heavily on quality of sequence alignment which is particularly hindered by poorly assembled genomes. Alignment-free methods might provide additional insights. Here, we constructed a whole-genome phylogeny of 9 E.coli isolates from the 2011 German outbreak against existing E. coli genomes using the alignment-free feature frequency profile method. In addition, we looked for gene elements that distinguish the outbreak group from the other E. coli strains and possibly accounted for the emergence of the outbreak isolates using the distinguishing feature analysis

    Building Trust in Online Shopping: The Moderating Effect of Individualism and Collectivism

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    As online shopping becoming more global, consumers with different culture had different consideration when shopping online. Thus, this study attempts to investigate how one specific dimension of culture, individualism-collectivism, moderates the relationship between online trust and its determinants The determinant factors under investigation include perceived risk, privacy, security, social exchange and information content. Data collected from customers of online shops from Hong Kong and Switzerland were used to test the research model. The result indicated that perceived risk had a negative relationship with Trust. Perceived risk had a stronger effect on trust for collectivists than individualists. Also, Security had a positive relationship with trust. The study showed that information content was positively related to trust of online vendors. Information content had a stronger effect on trust for individualists then collectivists

    Effects Of Supply Chain Strategies And Practices On Firm Performance

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    A number of studies have looked at the impacts of supply chain strategies on firm performance. Yet, how different supply chain practices translate to firm performance remains unclear. Drawing from the resource based view, this study investigates the role of supply chain capabilities in mediating the relationships between supply chain practices and firm performance. A survey was conducted with 171 manufacturing firms in five Chinese cities to empirically validate the research model. Our findings suggest that, supply chain practices, as driven by supply chain strategies, create different supply chain capabilities and lead to firm performance. The findings shed some lights on the mechanism in which supply chain strategies and practices translate into firm performance

    The Enhanced metastatic potential of hepatocellular carcinoma (HCC) cells with sorafenib resistance

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    Acquired resistance towards sorafenib treatment was found in HCC patients, which results in poor prognosis. To investigate the enhanced metastatic potential of sorafenib resistance cells, sorafenib-resistant (SorR) cell lines were established by long-term exposure of the HCC cells to the maximum tolerated dose of sorafenib. Cell proliferation assay and qPCR of ABC transporter genes (ABCC1-3) were first performed to confirm the resistance of cells. Migration and invasion assays, and immunoblotting analysis on the expression of epithelial to mesenchymal transition (EMT) regulatory proteins were performed to study the metastatic potential of SorR cells. The expression of CD44 and CD133 were studied by flow cytometry and the gene expressions of pluripotency factors were studied by qPCR to demonstrate the enrichment of cancer stem cells (CSCs) in SorR cells. Control (CTL) and SorR cells were also injected orthotopically to the livers of NOD-SCID mice to investigate the development of lung metastasis. Increased expressions of ABCC1-3 were found in SorR cells. Enhanced migratory and invasive abilities of SorR cells were observed. The changes in expression of EMT regulatory proteins demonstrated an activation of the EMT process in SorR cells. Enriched proportion of CD44+ and CD44+CD133 + cells were also observed in SorR cells. All (8/8) mice injected with SorR cells demonstrated lung metastasis whereas only 1/8 mouse injected with CTL cells showed lung metastasis. HCC cells with sorafenib resistance demonstrated a higher metastatic potential, which may be due to the activated EMT process. Enriched CSCs were also demonstrated in the sorafenib resistant cells. This study suggests that advanced HCC patients with acquired sorafenib resistance may have enhanced tumor growth or distant metastasis, which raises the concern of long-term sorafenib treatment in advanced HCC patients who have developed resistance of sorafenib. © 2013 Chow et al.published_or_final_versio

    2011 German Escherichia coli O104:H4 outbreak: whole-genome phylogeny without alignment

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    <p>Abstract</p> <p>Background</p> <p>A large-scale <it>Escherichia coli </it>O104:H4 outbreak occurred in Germany from May to July 2011, causing numerous cases of hemolytic-uremic syndrome (HUS) and deaths. Genomes of ten outbreak isolates and a historical O104:H4 strain isolated in 2001 were sequenced using different new generation sequencing platforms. Phylogenetic analyses were performed using various approaches which either are not genome-wide or may be subject to errors due to poor sequence alignment. Also, detailed pathogenicity analyses on the 2001 strain were not available.</p> <p>Findings</p> <p>We reconstructed the phylogeny of <it>E. coli </it>using the genome-wide and alignment-free feature frequency profile method and revealed the 2001 strain to be the closest relative to the 2011 outbreak strain among all available <it>E. coli </it>strains at present and confirmed findings from previous alignment-based phylogenetic studies that the HUS-causing O104:H4 strains are more closely related to typical enteroaggregative <it>E. coli </it>(EAEC) than to enterohemorrhagic <it>E. coli</it>. Detailed re-examination of pathogenicity-related virulence factors and secreted proteins showed that the 2001 strain possesses virulence factors shared between typical EAEC and the 2011 outbreak strain.</p> <p>Conclusions</p> <p>Our study represents the first attempt to elucidate the whole-genome phylogeny of the 2011 German outbreak using an alignment-free method, and suggested a direct line of ancestry leading from a putative EAEC-like ancestor through the 2001 strain to the 2011 outbreak strain.</p

    2011 German Escherichia coli outbreak: Prophage analysis of close-assembled TY2482 against 55989 using PHAST

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    Using the Hiseq data of the German E. coli outbreak isolate TY2482, preliminary prophage analyses have been performed by some researchers previously. With the closed assembly of the same isolate being available, another round of analysis might help in resolving questions that remain unclear due to the incompleteness of the dataset

    UNDERSTANDING THE DETERMINANTS OF BLOCKCHAIN ADOPTION IN SUPPLY CHAINS: AN EMPIRICAL STUDY IN CHINA

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    This study adopts affordance approach to understand how supply chain managers interpret the possible benefits that can be performed within blockchain-enabled supply chain applications. With a focus on governance efficiency improvement, the impacts of traceability and transparency affordance on uncertainty reduction were examined from the perspective of transaction cost theory in supply chain industry. Partial least squares – structural equation modelling (PLS-SEM) was used to analyze the data collected from 364 experienced supply chain managers in China. The results revealed that traceability affordance exerted significant impacts on environmental and trading partner uncertainty rather than transparency affordance, which in turn affected the adoption intention. This study contributes to the extant literature by embedding transaction cost in blockchain affordances. The findings are useful in guiding practitioners to improve blockchain system design for reducing uncertainties in supply chain environment, leading to a higher adoption rate of blockchain technology

    The psychophysiological effects of Tai-chi and exercise in residential Schizophrenic patients: a 3-arm randomized controlled trial

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    BACKGROUND: Patients with schizophrenia are characterized by high prevalence rates and chronicity that often leads to long-term institutionalization. Under the traditional medical model, treatment usually emphasizes the management of psychotic symptoms through medication, even though anti-psychotic drugs are associated with severe side effects, which can diminish patients’ physical and psychological well-being. Tai-chi, a mind-body exercise rooted in Eastern health philosophy, emphasizes the motor coordination and relaxation. With these potential benefits, a randomized controlled trial (RCT) is planned to investigate the effects of Tai-chi intervention on the cognitive and motor deficits characteristic of patients with schizophrenia. METHODS/DESIGN: A 3-arm RCT with waitlist control design will be used in this study. One hundred and fifty three participants will be randomized into (i) Tai-chi, (ii) exercise or (iii) waitlist control groups. Participants in both the Tai-chi and exercise groups will receive 12-weeks of specific intervention, in addition to the standard medication and care received by the waitlist control group. The exercise group will serve as a comparison, to delineate any unique benefits of Tai-chi that are independent of moderate aerobic exercise. All three groups will undergo three assessment phases: (i) at baseline, (ii) at 12 weeks (post-intervention), and (iii) at 24 weeks (maintenance). All participants will be assessed in terms of symptom management, motor coordination, memory, daily living function, and stress levels based on self-perceived responses and a physiological marker. DISCUSSION: Based on a promising pilot study conducted prior to this RCT, subjects in the Tai-chi intervention group are expected to be protected against deterioration of motor coordination and interpersonal functioning. They are also expected to have better symptoms management and lower stress level than the other treatment groups. TRIAL REGISTRATION: The trail has been registered in the Clinical Trials Center of the University of Hong Kong (HKCTR-1453)

    養龍神話的魔幻化重寫 : 讀也斯 \u3c養龍人師門\u3e

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    在香港,也斯被評為可能是最早譯介當代拉丁美洲小說的譯者,也可能是最早發表帶魔幻色彩的小說的作者。〈養龍人師門〉帶有濃厚的魔幻寫實主義的色彩,業界自然不乏以魔幻寫實主義分析也斯作品,然而似乎只把魔幻寫實視為創作技法,片面理解魔幻寫實主義,忽略其背後的精神。本文嘗試結合學者研究魔幻寫實主義的成果,旁借也斯訪談錄,分析也斯在〈養龍人師門〉如何用魔幻寫實主義重寫神話。本文核心主要是環繞以下兩個問題: 1. 也斯為養龍神話加入/重寫了不少情節和細節,這些故事新質有何意義? 2. 也斯如何以魔幻手法處理重寫,並體驗了怎樣的魔幻寫實主義的特色? 為行文方便,本文將「受魔幻寫實主義影響」、「經過魔幻寫實主義的手 法處理」縮寫成「魔幻化」

    Constructing a new integrated genetic linkage map and mapping quantitative trait loci for vegetative mycelium growth rate in Lentinula edodes

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    The most saturated linkage map for Lentinula edodes to date was constructed based on a mono-. karyotic population of 146 single spore isolates (SSIs) using sequence-related amplified polymorphism (SRAP), target region amplification polymorphism (TRAP), insertion deletion (InDel) markers, and the mating-type loci. Five hundred and twenty-four markers were located on 13 linkage groups (LGs). The map spanned a total length of 1006.1 cM, with an average marker spacing of 2.0 cM. Quantitative trait loci (QTLs) mapping was utilized to uncover the loci regulating and controlling the vegetative mycelium growth rate on various synthetic media, and complex medium for commercial cultivation of L. edodes. Two and 13 putative QTLs, identified respectively in the monokaryotic population and two testcross dikaryotic populations, were mapped on seven different LGs. Several vegetative mycelium growth rate-related QTLs uncovered here were clustered on LG4 (Qmgr1, Qdgr1, Qdgr2 and Qdgr9) and LG6 (Qdgr3, Qdgr4 and Qdgr5), implying the presence of main genomic areas responsible for growth rate regulation and control. The QTL hotspot region on LG4 was found to be in close proximity to:the region containing the mating-type A (MAT-A) locus. Moreover, Qdgr2 on LG4 was detected on different media, contributing 8.07%-23.71% of the phenotypic variation. The present study provides essential information for QTL mapping and marker-assisted selection (MAS) in L. edodes. (C) 2014 The British Mycological Society. Published by Elsevier Ltd. All rights reserved.The most saturated linkage map for Lentinula edodes to date was constructed based on a mono-. karyotic population of 146 single spore isolates (SSIs) using sequence-related amplified polymorphism (SRAP), target region amplification polymorphism (TRAP), insertion deletion (InDel) markers, and the mating-type loci. Five hundred and twenty-four markers were located on 13 linkage groups (LGs). The map spanned a total length of 1006.1 cM, with an average marker spacing of 2.0 cM. Quantitative trait loci (QTLs) mapping was utilized to uncover the loci regulating and controlling the vegetative mycelium growth rate on various synthetic media, and complex medium for commercial cultivation of L. edodes. Two and 13 putative QTLs, identified respectively in the monokaryotic population and two testcross dikaryotic populations, were mapped on seven different LGs. Several vegetative mycelium growth rate-related QTLs uncovered here were clustered on LG4 (Qmgr1, Qdgr1, Qdgr2 and Qdgr9) and LG6 (Qdgr3, Qdgr4 and Qdgr5), implying the presence of main genomic areas responsible for growth rate regulation and control. The QTL hotspot region on LG4 was found to be in close proximity to:the region containing the mating-type A (MAT-A) locus. Moreover, Qdgr2 on LG4 was detected on different media, contributing 8.07%-23.71% of the phenotypic variation. The present study provides essential information for QTL mapping and marker-assisted selection (MAS) in L. edodes. (C) 2014 The British Mycological Society. Published by Elsevier Ltd. All rights reserved
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