1,720,963 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
Conformational and electronic interaction studies of some alpha-ethylsulfinyl p-substituted acetophenones
No full textThe preferred conformations of the α-ethylsulfinyl p-substituted acetophenones Y_PhC(O)CH2S(O)Et ( Y=OMe 1, Me 2, H 3, Cl 4, Br 5, CN 6, NO2 7) are determined by νCO IR analysis and ab initio HF/6-31G** computations. In solvents of low relative permittivity, carbon tetrachloride and chloroform, the cis2 rotamer prevails over the gauche3 one, excepting for 6 and 7, in chloroform, for which the gauche3 rotamer becomes the most stable. In both solvents the c2/g3 population ratio gradually increases on going from electron-attracting to electron-donating substituents. These trends are discussed in terms of the increasing contribution of the CT and electrostatic and interactions which stabilise the cis2 rotamer along with the simultaneous decreasing contribution of the , orto- and interactions which stabilise the gauche3 rotamer. In the high relative permittivity acetonitrile the gauche3 rotamer becomes the most stable one for the whole series. The good linear correlation of the c2/g3 ratio with both the σp+ substituent constants and the negative cis2 carbonyl frequency shifts (Δνc2), in chloroform indicate that the cis2-gauche3 equilibrium is mainly determined by the interactions which act in the cis2 rotamer, and only to a minor extent by those which operate in the gauche3 rotamer
Comparative spectroscopic and theoretical studies on the conformation of some alpha-diethoxyphosphoryl carbonyl compounds and their alpha-ethylsulfonyl analogues
No full textThe comparative νCO IR analysis between β-carbonylphosphonates [XC(O)CH2 P(O)(OR)2: X=Me 1, Ph 2, OEt 3 , NEt2 4 and SEt 5; R=Et] (series I) and β-carbonylsulfones [XC(O)CH2SO2R: X=Me 6, Ph 7, OEt 8 , NEt2 9 and SEt 10; R=Et] (series II) along with ab initio 6-31G** calculations of 1a and 6a (R=Me) suggest the existence of only a single gauche conformer for I. The negative carbonyl frequency shifts for both series follow approximately the electron-affinities of the π*CO orbital of the parent compounds MeC(O)X 11-15. The less positive asymmetric sulfonyl frequency shifts (ΔνSO2) for II in relation to the phosphoryl frequency shifts (ΔνPO) for I and the larger negative carbonyl frequency shifts for II with respect to the corresponding values for I are in line with the upfield 13C NMR chemical shifts of the carbonyl carbon for II compared to I. These trends agree with the shorter O(SO2)...C(CO)¬ contact in comparison with the O(PO)...C(CO)¬ one and are discussed in terms of Olp * π *CO charge transfer and electrostatic interactions which are stronger for series II than for I, indicating that the sulfonyl oxygen atom is a better electron donor than the phosphoryl oxygen atom. Intrinsic geometrical parameters of O=S-CH2 and O=P-CH2¬ moieties seems to be responsible for this behaviour indicated by X-ray and ab initio calculations of dialkyl methylsulfonylmethanephosphonate MeSO2CH2P(O)(OR)2 (R=Et 18, Me 18a)
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
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