1,720,965 research outputs found
Proto-oncogene Pim-1: structural stability of the variants observed in tumor tissues
No full textPim-1 kinase belongs to the family of serine/threonine protein kinases (EC 2.7.11.1) encoded by the pim proto-oncogenes (Saris et al., 1991; Hoover et al., 1991; van der Lugt et al., 1995). Pim-1 kinase, originally identified as a common Proviral insertion site in moloney murine leukemia virus-induced T-cell lymphomas in mice (Cuypers et al., 1984), is involved in several signalling pathways and in the regulation of cell cycle progression and apoptosis. The three Pim family members Pim-1, Pim-2 and Pim-3 identified in humans have been reported as signalling protein kinases playing an important role in tumor biology (Anizon et al., 2010). Pim-1, nearly undetectable in normal tissues, is overexpressed in many haematological malignancies and in the cells of several solid tumor. In several cancer tissues Pim-1 variants have been identified and several databases for patterns of somatic mutation in human cancer genomes report mutations in this oncogene (Yuan et al., 2006; Greenman et al., 2007; Forbes et al., 2008; Akagi et al., 2009). Many of these variants are nonsynonymous single nucleotide polymorphisms (nsSNPs), single nucleotide variations occurring in the coding region and leading to amino acid substitutions (Dixit A et al., 2009). In this study we investigated the effect of amino acid substitution on the structural stability and on the activity of the Pim-1 kinase. We expressed and purified as soluble recombinant proteins some of the mutants identified in cancer and in the nsSNPs database. The mutants show a decreased thermal and thermodynamic stability and decreased activation energy relative to kinase activity, when compared to the wild- type
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
NAD-DEPENDENT GLUTAMATE DEHYDROGENASE FROM THE THERMOPHYLIC EUBACTERIUM Bacillus acidocaldarius.
No full textThe first thermophilic eubacterial glutamate dehydrogenase was purified to homogeneity from Bacillus acidocaldarius to compare its molecular properties with those of the glutamate dehydrogenase from thermophilic archaea. Glutamate dehydrogenase represents 2% of the total soluble proteins of B. acidocaldarius, an amount that may suggest an important role for this enzyme in nitrogen metabolism of the thermophilic eubacterium. The protein is a hexamer (subunit mass 48 kDa) and undergoes dissociation during gel filtration analysis. Isoelectric focusing of the purified enzyme indicated a pI of 4.5. The enzyme is strictly specific for NAD, 2-oxoglutarate, and L-glutamate. The thermal stability of B. acidocaldarius glutamate dehydrogenase is dependent on protein concentration
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
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