419 research outputs found

    Intentions to Use Information Technologies: An Integrative Model

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    An integrative model explaining intentions to use an information technology is proposed. The primary objective is to obtain a clearer picture of how intentions are formed, and draws on previous research such as the technology acceptance model (Davis, Bagozzi, & Warshaw, 1989) and the decomposed theory of planned behavior (Taylor & Todd, 1995a). The conceptual model was tested using questionnaire responses from 189 subjects, measured at two time periods approximately two months apart. The results generally supported the hypothesized relationships, and revealed strong influences of both personal innovativeness and computer self-efficacy

    Scaling metagenome sequence assembly with probabilistic de Bruijn graphs

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    Deep sequencing has enabled the investigation of a wide range of environmental microbial ecosystems, but the high memory requirements for {\em de novo} assembly of short-read shotgun sequencing data from these complex populations are an increasingly large practical barrier. Here we introduce a memory-efficient graph representation with which we can analyze the k-mer connectivity of metagenomic samples. The graph representation is based on a probabilistic data structure, a Bloom filter, that allows us to efficiently store assembly graphs in as little as 4 bits per k-mer, albeit inexactly. We show that this data structure accurately represents DNA assembly graphs in low memory. We apply this data structure to the problem of partitioning assembly graphs into components as a prelude to assembly, and show that this reduces the overall memory requirements for {\em de novo} assembly of metagenomes. On one soil metagenome assembly, this approach achieves a nearly 40-fold decrease in the maximum memory requirements for assembly. This probabilistic graph representation is a significant theoretical advance in storing assembly graphs and also yields immediate leverage on metagenomic assembly

    SEQuel: improving the accuracy of genome assemblies

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    Motivation: Assemblies of next-generation sequencing (NGS) data, although accurate, still contain a substantial number of errors that need to be corrected after the assembly process. We develop SEQuel, a tool that corrects errors (i.e. insertions, deletions and substitution errors) in the assembled contigs. Fundamental to the algorithm behind SEQuel is the positional de Bruijn graph, a graph structure that models k-mers within reads while incorporating the approximate positions of reads into the model

    Empirical Examination of the Role of Three Sets of Innovation Attributes for Determining Adoption of IRCTC Mobile Ticketing Service

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    The Indian Railway Catering and Tourism Corporation Limited’s (IRCTC) mobile ticketing was recently introduced in India. In this study of its adoption, three competing attribute-sets are compared. This study aims to reveal the attribute-set best predicting its adoption. The research model was empirically tested and validated using SPSS. Four attributes from the Diffusion of Innovations (DOI) theory, four from the PCI theory, and four from Tornatzky and Klein’s meta-analysis significantly affected behavioral intentions. Only complexity failed to influence use intentions, and behavioral intention and riskiness significantly impacted adoption

    Fellowship training:a qualitative study of scope and purpose across one department of medicine

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    BACKGROUND: Fellowship training follows certification in a primary specialty or subspecialty and focusses on distinct and advanced clinical and/or academic skills. This phase of medical education is growing in prevalence, but has been an "invisible phase of postgraduate training" lacking standards for education and accreditation, as well as funding. We aimed to explore fellowship programs and examine the reasons to host and participate in fellowship training, seeking to inform the future development of fellowship education. METHODS: During the 2013-14 academic year, we conducted interviews and focus groups to examine the current status of fellowship training from the perspectives of division heads, fellowship directors and current fellows at the Department of Medicine, University of Ottawa, Canada. Descriptive statistics were used to depict the prevailing status of fellowship training. A process of data reduction, data analysis and conclusions/verifications was performed to analyse the quantitative data. RESULTS: We interviewed 16 division heads (94%), 15 fellowship directors (63%) and 8 fellows (21%). We identified three distinct types of fellowships. Individualized fellowships focus on the career goals of the trainee and/or the recruitment goals of the division. Clinical fellowships focus on the attainment of clinical expertise over and above the competencies of residency. Research fellowships focus on research productivity. Participants identified a variety of reasons to offer fellowships: improve academic productivity; improve clinical productivity; share/develop enhanced clinical expertise; recruit future faculty members/attain an academic position; enhance the reputation of the division/department/trainee; and enhance the scholarly environment. CONCLUSIONS: Fellowships serve a variety of purposes which benefit both individual trainees as well as the academic enterprise. Fellowships can be categorized within a distinct taxonomy: individualized; clinical; and research. Each type of fellowship may serve a variety of purposes, and each may need distinct support and resources. Further research is needed to catalogue the operational requirements for hosting and undertaking fellowship training, and establish recommendations for educational and administrative policy and processes in this new phase of postgraduate education

    A c-di-GMP Effector System Controls Cell Adhesion by Inside-Out Signaling and Surface Protein Cleavage

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    In Pseudomonas fluorescens Pf0-1 the availability of inorganic phosphate (Pi) is an environmental signal that controls biofilm formation through a cyclic dimeric GMP (c-di-GMP) signaling pathway. In low Pi conditions, a c-di-GMP phosphodiesterase (PDE) RapA is expressed, depleting cellular c-di-GMP and causing the loss of a critical outer-membrane adhesin LapA from the cell surface. This response involves an inner membrane protein LapD, which binds c-di-GMP in the cytoplasm and exerts a periplasmic output promoting LapA maintenance on the cell surface. Here we report how LapD differentially controls maintenance and release of LapA: c-di-GMP binding to LapD promotes interaction with and inhibition of the periplasmic protease LapG, which targets the N-terminus of LapA. We identify conserved amino acids in LapA required for cleavage by LapG. Mutating these residues in chromosomal lapA inhibits LapG activity in vivo, leading to retention of the adhesin on the cell surface. Mutations with defined effects on LapD's ability to control LapA localization in vivo show concomitant effects on c-di-GMP-dependent LapG inhibition in vitro. To establish the physiological importance of the LapD-LapG effector system, we track cell attachment and LapA protein localization during Pi starvation. Under this condition, the LapA adhesin is released from the surface of cells and biofilms detach from the substratum. This response requires c-di-GMP depletion by RapA, signaling through LapD, and proteolytic cleavage of LapA by LapG. These data, in combination with the companion study by Navarro et al. presenting a structural analysis of LapD's signaling mechanism, give a detailed description of a complete c-di-GMP control circuit—from environmental signal to molecular output. They describe a novel paradigm in bacterial signal transduction: regulation of a periplasmic enzyme by an inner membrane signaling protein that binds a cytoplasmic second messenger

    Exploring the impact of the level of absorptive capacity in technology development firms

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    Absorptive capacity (ACAP) is widely recognized as an effective means of obtaining and sustaining a competitive advantage. Although ACAP was globally introduced decades ago, researchers from Central and Eastern Europe have since underestimated its importance. The research objective of this paper is to answer the following questions: how does the level of ACAP influence the performances of technology-driven firms, and how does it catalyse their innovation outputs? Furthermore, we argue that exporting technology-driven firms possess even higher levels of ACAP than those who are weak or not-at-all exporters. ACAP measured value is examined alongside the innovation outputs of firms and their business performance, with an extended focus on exporters. A selected population of >600 Croatian firms were asked to fill in the questionnaire. Out of the 103 firms that completed the survey, 45 were recognized as intensive technology development performers, and 34 were identified as large exporters. Both populations were tested against formulated hypotheses, ultimately proving that higher levels of ACAP can be seen to positively drive innovation performance which, notably, can be seen most clearly with exporters
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