1,721,108 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
Studio Raman e SERS dei complessi metallici di Ibuprofen.
No full textL'Ibuprofen è un principio attivo del gruppo dei farmaci non steroidei dotati di proprietà anti infiammatorie, in cui il sito di interazione attraverso cui si sviluppano le proprietà farmacologiche è costituito dal gruppo carbossilato, che può anche essere disponibile per interazioni legante-metallo. L'interesse per lo studio strutturale dei complessi metallici deriva dall'osservazione che la complessazione con ioni metallici può favorire il trasporto del farmaco, rendendolo più efficace; inoltre alcuni autori riportano che i complessi di antiinfiammatori con il Cu(II) presentano un effetto anti-ulcera. Gli spettri Raman dei complessi metallici di Ibu hanno diversa struttura: il complesso Cu-Ibu presenta struttura bidentata a ponte (si osservano infatti le bande attribuite al legame Cu-O e del ponte Cu-Cu2), mentre il complesso Ibu-Zn ha una struttura bidentata 2:1 semplice. La tecnica 'Surface Enhanced Raman Spectroscopy' (SERS), consentendo una notevole amplificazione dell'intensità degli spettri Raman, estende l'uso delle spettroscopie vibrazionali alle concentrazioni bioattive dei farmaci (ppm) in soluzione. Gli spettri SERS mostrano bande intense nella regione 1350-1600 cm-1, attribuibili ai modi vibrazionali degli anelli aromatici e del gruppo COO-. Si nota che gli spettri Raman dei solidi sono alquanto diversi da quelli SERS degli stessi composti, poiché solo le bande dovute alle vibrazioni dei gruppi direttamente interagenti con la superficie delle particelle colloidali di Ag sono amplificate e questo spiega la relativa semplicità degli spettri SERS. L'elevata amplificazione delle bande dovute allo ione carbossilato e agli anelli aromatici conferma che, per tutti i composti considerati, l'interazione con la superfìcie di Ag è dovuta alle coppie di elettroni degli atomi di ossigeno e che le molecole si chemiadsorbono sulla superficie delle particelle di colloide
Productivity variations in a wild boar Sus scrofa population in central Italy
No full textThe study has been carried out on a wild boar Sus scrofa population in southern Tuscany (Italy). We aimed to estimate the
trend in population structure and productivity of a harvested and high-density population. From 1990 to 1996 we examined
2773 harvested wild boars, assessing age, sex, and number of foetuses per females. We highlighted an increase of the
proportions of yearling following a season with a peak of two-year individuals. Neither significant differences in mean foetus
numbers among age classes nor among seasonal variations have been pointed out. Productivity peaks seemed to be related
to peaks in sub-adult females in previous seasons, while food availability and harvest could have been responsible for
fluctuations of sub-adult females. Fluctuations seemed more likely linked to an alternation of high and low frequency in the
recruitment of females in the breeding pool than to individual differences in prolificity. Massive harvesting could bring subadult
females and males to reproduction when adult individuals are scarce, incrementing the overall productivity, but young
individuals are possibly more sensitive to environmental variations. We suggest that these studies should last longer and be
strictly associated to a contemporary monitoring of trophic resources
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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