1,720,995 research outputs found
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
Probing the effect of mutations on cytochrome c stability RID A-4573-2009
No full textAlthough the tertiary structures of mitochondrial cytochromes c (cyts c) seem to be remarkably similar, there are variations in their amino acid sequences, stability and functional properties. GdnHCl-induced unfolding experiments on engineered yeast and horse cyt c were carried out with the aim to to clarify, at molecular level, some aspects concerning the stability of this class of proteins. The results obtained are discussed in the light of the three-dimensional structures of the two proteins
Conversion of cytochrome c into a peroxidase: Inhibitory mechanisms and implication for neurodegenerative diseases
No full textA further function of cytochrome c (cyt c), beyond respiration, is realized outside mitochondria in the apoptotic program. In the early events of apoptosis, the interaction of cyt c with a mitochondrion-specific phospholipid, cardiolipin (CL), brings about a conformational transition of the protein and acquirement of peroxidase activity. The hallmark of cyt c with peroxidase activity is its partial unfolding accompanied by loosening of the Fe sixth axial bond and an enhanced access of the heme catalytic site to small molecules like H2O2. To investigate the peroxidase activity of non-native cyt c, different forms of the protein were analyzed with the aim to correlate their structural features with the acquired enzymatic activity and apoptogenic properties (wt cyt c/CL complex and two single cyt c variants. H26Y and Y67H, free and bound to CL). The results suggest that cyt c may respond to different environments by changing its fold thus favouring the exertion of different biological functions in different pathophysiological cell conditions. Transitions among different conformations are regulated by endogenous molecules such as ATP and may be affected by synthetic molecules such as minocycline, thus suggesting a mechanism explaining its use as therapeutic agent impacting on disease-associated oxidative and apoptotic mechanisms. (C) 2012 Elsevier Inc. All rights reserved
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
Salt-induced formation of the A-state of ferricytochrome c--effect of the anion charge on protein structure
Full text linkStructural information on partially folded forms is important for a deeper understanding of the folding mechanism(s) and the factors affecting protein stabilization. The non-native compact state of equine cytochrome c stabilized by salts in an acidic environment (pH 2.0-2.2), called the A-state, is considered a suitable model for the molten globule of cytochrome c, as it possesses a native-like alpha-helix conformation but a fluctuating tertiary structure. In this article, we extend our knowledge on anion-induced protein stabilization by determining the effect of anions carrying a double negative charge; unlike monovalent anions (which are thought to exert an 'ionic atmosphere' effect on the macromolecule), divalent anions are thought to bind to the protein at specific surface sites. Our data indicate that divalent anions, in comparison to monovalent ions, have a greater tendency to stabilize the native-like M-Fe(III)-H coordinated state of the protein. The possibility that divalent anions may bind to the protein at the same sites previously identified for polyvalent anions was evaluated. To investigate this issue, the behavior of the K88E, K88E/T89K and K13N mutants was investigated. The data obtained indicate that the mutated residues, which contribute to form the binding sites of polyanions, are important for stabilization of the native conformation; the mutants investigated, in fact, all show an increased amount of the misligated H-Fe(III)-H state and, with respect to wild-type cytochrome c, appear to be less sensitive to the presence of the anion. These residues also modulate the conformation of unfolded cytochrome c, influencing its spin state and the coordination to the prosthetic group
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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