1,720,964 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
Chemistry of a family of osmium(II) metallacycles incorporating isonitrile coordination
No full textThe reaction of Os(RL)(PPh3)2(CO)Br (3) with CNBut in dichloromethane solution has furnished the cationic complex [Os(RL)(PPh3)2(CO)(CNBut)]+ isolated as PF6-salt, 4 which behaves as a 1:1 electrolyte in acetone solution (RL is C6H2O-2-CHNHC6H4R(p)-3-Me-5 and R is Me, OMe and Cl). The presence of significant Os-CNBut back-bonding in 4 is reflected in the blue shift of both the MLCT transition maximum (~500 nm) and CºO stretching frequency (~1930 cm-1) compared to those in 3 (~550 nm and ~1870 cm-1, respectively). For the same reason, the OsIII/OsII reduction potential (~0.8 V vs. SCE) in 4 is ~100 mV higher than those in 3. The complex 4·2CH2Cl2 (R = Me) represents the first example of a structurally characterized cyclometallated osmium(II) isonitrile system. In the distorted octahedral OsC3OP2 coordination sphere of 4·2CH2Cl2 (R = Me), the Os-P, Os-CO and Os-O bond lengths are closely similar to those in a analogue of 3. Due to the trans influence of the CNBut ligand, the Os-C(aryl) bond is however lengthened by ~0.15 Å in 4·2CH2Cl2 (R = Me). The type 3 complexes stand in strong contrast to the corresponding ruthenium system, which undergoes halide substitution as well as insertion into the Ru-O bond upon treatment with CNBut. This happens because the Os-O bond (2.166(6) Å) is stronger than the Ru-O bond (2.235(4) Å)
Carbonylation of four-membered ruthenium and osmium metallacycles incorporating an orthometallated phenolic function: new acylruthenium and arylosmium complexes
No full textThe solution reaction of Ru(QL1)(PPh3)2(CO)Cl (3) and Os(QL1)(PPh3)2(CO)Br (4) with carbon monoxide at one atmosphere pressure has respectively afforded the orange acylruthenium system Ru(QL2)(PPh3)2(CO)Cl (5) and the yellow arylosmium dicarbonyl system Os(QL3)(PPh3)2(CO)2Br (6) in excellent yields. (QL1 is C6H2O-2-CHNHC6H4Q(p)-3-Me-5, QL2 is C6H2(CO-1)O-2-CHNHC6H4Q(p)-3-Me-5 and QL3 is C6H2OH-2-CHNC6H4Q(p)-3-Me-5 and Q is Me, OMe and Cl.) It is proposed that in the case of 3 a dicarbonyl complex similar to 6 is formed as an intermediate which rapidly undergoes aryl migration with concomitant phenolato coordination furnishing 5. The stability of 6 is consistent with the greatly diminished ability of osmium in promotion of migratory reactions. In the reaction 4 → 6 the Os-O(phenolato) bond is cleaved and the Schiff base moiety undergoes iminium-phenolato → imine-phenol tautomerization. The observed cis geometry of 6 may arise by a concerted route involving edge displacement of the halide ligand. The crystal and molecular structure of 5(Q = Cl) has revealed the presence of a distorted octahedral RuC2P2OCl coordination sphere and a highly planar acyl chelate ring characterized by a Ru-C distance of 2.013(4) A. In the hydrogen bonded zwitterionic iminium-phenolato ring the N O distance is 2.561(6) Å. The acyl complexes of type 5 display an MLCT band near 500 nm which is absent in 6. The Schiff base C=N stretch in 5 (~1630 cm-1) is significantly higher than that in 6 (~1600 cm-1) which displays two strong CO stretches near 2020 and 1940 cm-1 (cis-Os(CO)2 configuration). A single 31P NMR signal occurs in both 5 and 6 near 37 and -6 ppm, respectively (trans-M(PPh3)2 configuration). The voltammetric reduction potentials of the MIII/MII couple is observed near 1.0 and 0.8 V vs. SCE in 5 and 6, respectively. Both are significantly higher than those in parent complexes (3 and 4) due to stabilization of the bivalent state upon carbonylation
Chemistry of a family of osmium(II) metallacycles incorporating isonitrile coordination
No full textThe reaction of Os(RL)(PPh3)2(CO)Br (3) with CNBut in dichloromethane solution has furnished the cationic complex [Os(RL)(PPh3)2(CO)(CNBut)]+ isolated as PF6-salt, 4 which behaves as a 1:1 electrolyte in acetone solution (RL is C6H2O-2-CHNHC6H4R(p)-3-Me-5 and R is Me, OMe and Cl). The presence of significant Os-CNBut back-bonding in 4 is reflected in the blue shift of both the MLCT transition maximum (~500 nm) and CºO stretching frequency (~1930 cm-1) compared to those in 3 (~550 nm and ~1870 cm-1, respectively). For the same reason, the OsIII/OsII reduction potential (~0.8 V vs. SCE) in 4 is ~100 mV higher than those in 3. The complex 4·2CH2Cl2 (R = Me) represents the first example of a structurally characterized cyclometallated osmium(II) isonitrile system. In the distorted octahedral OsC3OP2 coordination sphere of 4·2CH2Cl2 (R = Me), the Os-P, Os-CO and Os-O bond lengths are closely similar to those in a analogue of 3. Due to the trans influence of the CNBut ligand, the Os-C(aryl) bond is however lengthened by ~0.15 Å in 4·2CH2Cl2 (R = Me). The type 3 complexes stand in strong contrast to the corresponding ruthenium system, which undergoes halide substitution as well as insertion into the Ru-O bond upon treatment with CNBut. This happens because the Os-O bond (2.166(6) Å) is stronger than the Ru-O bond (2.235(4) Å)
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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