1,721,004 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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
The complex process of vitamin A uptake: a first insight by NMR and other biophysical techniques
No full textVitamin A is essential for diverse aspects of life, ranging from embryogenesis to the proper functioning of most adult organs. It circulates in blood bound to serum retinol binding protein (RBP) and is transported into cells by a multitransmembrane receptor termed stimulated by retinoic acid 6 (STRA6)(1). A STRA6-mediated release of retinol from holo-RBP to target organs through a new mechanism has an evolutionary advantage that prevents a possible toxicity deriving from an excessive accumulation of free vitamin A (2). There is also evidence that a specific binding site for the apo-form of the cellular carriers (CRBP) might exist on the cytoplasmic side of the membrane (3).
To gain a first insight into this complex process, we have investigated the effects of biomembrane mimetic systems on CRBP-I and CRBP-II, by means of NMR, Circular Dichroism and Fluorescence measurements.
The interactions of the two homologous proteins with model membranes were studied by recording 15N-HSQC and 15N-TROSY spectra at different molar ratios. Chemical shifts perturbations and line shape analysis provided insights into the interacting residues and proteins conformational dynamics. As the signals were broadened beyond detection at latest steps of the titration, the NMR data have been complemented by CD and Fuorescence measurements.
The results revealed striking differences between the two homologs (4), despite having nearly identical backbone structures (a beta-barrel with two short alpha-helices) and identical retinol-binding motifs. Apo-CRBP-I interacts with model membranes and very likely the helical domain participates in the formation of a protein-membrane “collisional complex” that results in structural changes of the retinol entry site and in a slower protein tumbling. In contrast, NMR data reveal a higher structural flexibility of apo-CRBP-II that allows the existence of more than one conformation. Line shapes analysis performed in the course of the titrations indicated that the protein conformational dispersion is reduced to one preferred state in the presence of phospholipids bilayers. CD spectra showed that the overall structural integrity of the protein is not affected by the presence of the liposomes.
These new evidences complement our earlier results, which had suggested that the two primary cellular retinol carriers exhibit different mechanisms of ligand uptake (5, 6); combined with their distinct tissue distribution this may imply different roles in an intracellular context.
References:
1. Kawaguchi R., Yu J., Honda J., Hu J., Whitelegge J., Ping P., Wiita P., Bok D. and H. Sun Science 315, 820-825 (2007).
2. Kawaguchi R., Yu J., Ter-Stepanian M., Zhong M., Cheng G., Yuan Q., Jin M., Travis G.H., Ong D. and Sun H. ACS Chemical Biology 6, 1041-1051 (2011).
3. Redondo C., Vouropoulou M., Evans J. and Findlay J.B.C. The FASEB J. 22, 1043-1054 (2008).
4. Franzoni L., Baroni F., Cavazzini D., Rossi G.L. and Lücke C., in preparation.
5. Mittag T., Franzoni L., Cavazzini D., Schaffhausen B., Rossi G.L. and Günther U.L. J. Am. Chem. Soc. 128, 9844-9848 (2006).
6. Franzoni L., Cavazzini D., Rossi G.L. and Lücke C. J. Lipid Res. 51, 1332-1343 (2010).
Acknowledgements: the EU-NMR infrastructure HWB●NMR @ Birmingham (UK) is acknowledged for providing access to instrumentation
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