1,720,989 research outputs found
1H, 15N and 13C chemical shift assignments of the C-Ala domain of the alanyl-tRNA synthetase of the psychrophilic bacterium Bizionia argentinensis sp. nov.
No full textA gene encoding a protein classified as alanyl-tRNA synthetase (AlaRS) was found in the genome of the psychrophilic bacteria Bizionia argentinensis. The enzyme is constituted by three domains with an evolutionarily conserved modular arrangement: the N-terminal aminoacylation domain, the editing domain and the C-terminal domain (C-Ala). Herein we report the near complete NMR resonance assignment of the 122 amino acid C-Ala domain from B. argentinensis. The chemical shift data, reported for the first time for a C-Ala domain, constitute the basis for NMR structural studies aimed at elucidating the cold-adaptation mechanism of AlaRS
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
A proton nuclear magnetic resonance-based metabolomic approach in IgA nephropathy urinary profiles
No full textAbstract
Immunoglobulin A nephropathy (IgAN) is the most common form of primary glomerulonephritis worldwide. Both one-dimensional NOESY and transverse-relaxation filter CPMG NMR spectra were recorded to investigate the urine metabolome of 24 IgAN patients and to detect altered metabolic profiles in comparison with 68 healthy matched controls. The spectral data were analyzed using multivariate statistical techniques. The analysis revealed that the NMR spectra of IgAN patients were statistically different from those of the controls (P = 4 × 10−7 for 1D-NOESY and P = 2 × 10−7 for CPMG). The robustness of the determined statistical model was confirmed by its predictive performance (for the 1D-NOESY dataset: sensitivity = 67 %, specificity = 95 %; for the CPMG dataset sensitivity = 60 %, specificity = 94 %). For the first time we found metabolites, including betaine and citrate, that are differentially modulated in IgAN patients compared to controls and that may be directly involved in the pathogenesis of IgAN. These metabolites may influence, directly or indirectly, the TNF-α, a regulating factor of the Th1/Th2 cell balance that is relevant in the pathology. The involvement of metabolites such as betaine and citrate in TNF-α regulation supports the power of the identified metabolic profiles to discern IgAN from controls
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Semisynthetic modification of tau protein with di-ubiquitin chains for aggregation studies
Full text linkUbiquitin, a protein modifier that regulates diverse essential cellular processes, is also a component of the protein inclusions characteristic of many neurodegenerative disorders. In Alzheimer’s disease, the microtubule associated tau protein accumulates within damaged neurons in the form of cross-beta structured filaments. Both mono-and polyubiquitin were found linked to several lysine residues belonging to the region of tau protein that forms the structured core of the filaments. Thus, besides priming the substrate protein for proteasomal degradation, ubiquitin could also contribute to the assembly and stabilization of tau protein filaments. To advance our understanding of the impact of ubiquitination on tau protein aggregation and function, we applied disulfide-coupling chemistry to modify tau protein at position 353 with Lys48-or Lys63-linked di-ubiquitin, two representative polyubiquitin chains that differ in topology and structure. Aggregation kinetics experiments performed on these conjugates reveal that di-ubiquitination retards filament formation and perturbs the fibril elongation rate more than mono-ubiquitination. We further show that di-ubiquitination modulates tau-mediated microtubule assembly. The effects on tau protein aggregation and microtubule polymerization are essentially independent from polyubiquitin chain topology. Altogether, our findings provide novel insight into the consequences of ubiquitination on the functional activity and disease-related behavior of tau protein
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