62 research outputs found

    Mechanisms of Thermal Adaptation Revealed From the Genomes of the Antarctic Archaea Methanogenium frigidum and Methanococcoides burtonii

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    We generated draft genome sequences for two cold-adapted Archaea, Methanogenium frigidum and Methanococcoides burtonii, to identify genotypic characteristics that distinguish them from Archaea with a higher optimal growth temperature (OGT). Comparative genomics revealed trends in amino acid and tRNA composition, and structural features of proteins. Proteins from the cold-adapted Archaea are characterized by a higher content of noncharged polar amino acids, particularly Gin and Thr and a lower content of hydrophobic amino acids, particularly Leu. Sequence data from nine methanogen genomes (OGT 15degrees-98degreesC) were used to generate IIII modeled protein structures. Analysis of the models from the cold-adapted Archaea showed a strong tendency in the solvent-accessible area for more Gin, Thr, and hydrophobic residues and fewer charged residues. A cold shock domain (CSD) protein (CspA homolog) was identified in M. frigidum, two hypothetical proteins with CSD-folds in M. burtonii, and a unique winged helix DNA-binding domain protein in M. burtonii. This suggests that these types of nucleic acid binding proteins have a critical role in cold-adapted Archaea. Structural analysis of tRNA sequences from the Archaea indicated that GC content is the major factor influencing tRNA stability in hyperthermophiles, but not in the psychrophiles, mesophiles or moderate thermophiles. Below an OGT of 60degreesC, the GC content in tRNA was largely unchanged, indicating that any requirement for flexibility of tRNA in psychrophiles is mediated by other means. This is the first time that comparisons have been performed with genome data from Archaea spanning the growth temperature extremes. from psychrophiles to hyperthermophile

    Extended Theories of Gravity and their Cosmological and Astrophysical Applications

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    We review Extended Theories of Gravity in metric and Palatini formalism pointing out their cosmological and astrophysical application. The aim is to propose an alternative approach to solve the puzzles connected to dark components.Comment: 44 pages, 11 figure

    Use of SMS texts for facilitating access to online alcohol interventions: a feasibility study

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    A41 Use of SMS texts for facilitating access to online alcohol interventions: a feasibility study In: Addiction Science & Clinical Practice 2017, 12(Suppl 1): A4

    Beyond marks: new tools to visualise student engagement via social networks.

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    Evidence shows that engaged students perform better academically than disinterested students. Measurement of engagement with education is difficult and imprecise, especially in large student cohorts. Traditional measurements such as summary statistics derived from assessment are crude secondary measures of engagement at best and do not provide much support for educators to work with students and curate engagement during teaching periods. We have used academic-related student contributions to a public social network as a proxy for engagement. Statistical summaries and novel data visualisation tools provide subtle and powerful insights into online student peer networks. Analysis of data collected shows that network visualisation can be an important curation tool for educators interested in cultivating student engagement

    Organizational Constraints to Realizing Business Value

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    The paradigm of service-oriented computing (SOC) has emerged as an approach to provide flexibility and agility, not just in systems development but also in business process management. This modular approach to defining business flows as technology independent services has gained unanimous popularity among end-users and technology vendors alike. Although there is a significant amount of research ongoing on the technology implementations of service oriented architectures (SOAs), there is a paucity of research literature on the factors affecting the adoption of service-oriented computing and the realization of business value in practice. This paper empirically examines the adoption of SOC as an enterprise strategy across fifteen firms, and discusses the organizational constraints that influence the enterprise adoption and implementation of SOA. In doing so, this paper fills a crucial gap in the academic literature about the practical use of SOA as an enterprise strategy for agility, and lays the groundwork for future work on SOA alignment with organizational strategy. The paper also provides practitioners with guidelines for the successful implementation of SOA to achieve business value
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