1,720,992 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
Diffusion Hindrance and Geometry of Filament Crossings Account for the Complex Interactions of F-Actin with α-Actinin from Chicken Gizzard
No full textThe interaction of alpha-actinin from chicken gizzard with F-actin is quite complex. The apparent dissociation constant, C, increases with the increase of actin concentration according to the following expression: C = Ko + a[actin] - c[actin]5/2. At pH 7.5 and 37 degrees C, in the presence of 0.1 M KCl and 2 mM MgCl2, the dissociation constant at infinite actin dilution, Ko, is 2.17 microM. The binding of alpha-actinin to actin is related by the term a[actin] to the diffusion of actin filaments and by the term c[actin]5/2 to the crossing number concentration of the F-actin network. Especially at low actin concentration, the binding of alpha-actinin to actin is increased by gelsolin, which fragments actin filaments and increases their diffusion. The different binding isotherms of alpha-actinin to actin filaments and to actin bundles are discussed
Protein cross talking through osmotic work : the free energy of formation of the MgADP-myosin complexes at the muscle protein osmotic pressure
No full textA method is presented to determine the energy of formation of the myosin-ADP complexes at the muscle protein osmotic pressure. It is found that, at 18 kP, the putative protein osmotic pressure in skeletal muscle, the increase of MgADP from 0.05 to 2 mmolal, increases the free energy of myosin-ADP and of myosin-(ADP)2 by 0. 756 and by 9.85 kJ/mol, respectively, and decreases the free energy of myosin by 8.34 kJ erg/mol. It is pointed out that the local changes of water chemical potential, induced by the binding of MgADP to myosin, can be sensed by other structures of the contractile machinery, which per se may even be insensitive to MgADP. Cross talking between macromolecules can thus be achieved by changes of the water chemical potential
α-Actinin from chicken gizzard: At low temperature, the onset of actin-gelling activity correlates with actin bundling
No full textThe effect of alpha-actinin from chicken gizzard on the properties of F-actin solutions at 37 degrees C and at 4 degrees C was investigated. Beside the well-known increase of the gelling activity of alpha-actinin, it was found that lowering temperature to 4 degrees C: (a) modifies the shape of the alpha-actinin-F-actin binding isotherm; (b) increases the light scattering of the alpha-actinin-F-actin mixtures; (c) induces the formation of ribbons and bundles of F-actin. It was also observed that, by warming to 37 degrees C, the bundles of F-actin formed at 4 degrees C were dissociated into quasi-parallel actin filaments running at a distance of 25-42 nm from each other. On subsequent cooling to 4 degrees C, these parallel filaments were rapidly assembled into bundles. As at 37 degrees C, alpha-actinin displays a potent gelling activity on bundles but not on filaments of actin, and as the gelling activity at 4 degrees C is accompanied by the formation of actin bundles, it is concluded that actin bundling is a necessary condition to promote the actin-gelling activity
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
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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