1,720,976 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
Augmented coronary vascular smooth muscle response to endothelin-1 exacerbates cardiac injury following pulmonary exposure to engineered nanomaterials
No full textMulti-walled carbon nanotubes (MWCNT) and 60-carbon fullerenes (C60) are important engineered nanoparticles (ENP) used across industry. Exposure to ENP potentially promotes cardiovascular detriments. The hypotheses that exposure to either MWCNT or C60 would exacerbate cardiac ischemia/reperfusion (I/R) injury and promote enhanced coronary artery contraction in response to endothelin-1 (ET-1) by a cyclooxygenase-mediated mechanism were tested. One day following intratracheal instillation of vehicle, 1, 10 or 100 [mu]g MWCNT in male Sprague-Dawley rats, hearts were isolated and mounted on a Langendorff perfusion apparatus. Hearts from animals exposed to 100 [mu]g MWCNT exhibited 3x more premature ventricular contractions during perfusion at baseline. Cardiac perfusion was stopped to induce ischemia for 20 minutes and then restarted to study injuries induced by I/R. Post-reperfusion myocardial infarction expanded 18% in the 100 [mu]g MWCNT group compared to the vehicle group. We also noted that post-ischemia cardiac release of ET-1 was increased 4-fold and coronary reperfusion flow was reduced 30% in the 100 [mu]g MWCNT group compared to the vehicle group. We next evaluated isolated coronary artery ET-1-mediated stress (mN/mm2) generation by wire myography, 24 hours after intratracheal instillation of 100 [mu]g MWCNT or vehicle. Coronary artery stress generation in response to ET-1 was increased 35% in the MWCNT group compared to the vehicle group and was dependent on cyclooxygenase/thromboxane signaling. Similar endpoints were examined following C60 exposure. We measured myocardial infarction following I/R in situ and coronary artery ET-1-mediated stress responses by wire myography, 24 hours after intratracheal or intravenous administration of vehicle or 28 [mu]g C60. Myocardial infarction expanded between 70% and 110% across all C60 groups. Coronary artery stress generation in response to ET-1 was elevated by 56% in the male intratracheal C60 group compared to the vehicle group and was dependent on cyclooxygenase signaling. ET-1 responses in all other C60 groups were not different than vehicle. These results support the potential for pulmonary exposure to carbon-based ENP to exacerbate cardiac I/R injury and promote dysfunction in coronary arteries associated with ET-1/cyclooxygenase axis. Our results indicate that therapeutic targeting of ET-1 or cyclooxygenase signaling might prevent cardiovascular detriments associated with ENP exposure.Ph.D
Influence of carbon nanomaterial exposure on pro-constrictor mechanisms during pregnancy
No full textEngineered carbon based nanoparticles (CNP) such as fullerenes and multiwalled carbon nanotubes (MWCNTs) are increasingly used in industries and in nanomedicine as a platform for drug delivery. Following environmental/occupational exposure through inhalation CNP are translocated to extra-pulmonary sites, raising concerns on their potential effects on vasculature particularly in vulnerable life-stages such as pregnancy. Distribution of intravenously delivered C60 in maternal organs varies between pregnant and non-pregnant life-stages, presumed to be associated with changes in reactivity of various vascular beds during pregnancy. The overall goal of this dissertation was to describe and elucidate intracellular mediators driving changes in contractility of vascular segments from three distinct vascular beds following exposure to CNP during pregnancy. In vitro experiments on aortic endothelial cells and wire myographic studies on vessel segments from Sprague Dawley rats exposed to C60/PVP (polyvinylpyrorrolidone formulated C60) or MWCNTs were used to identify changes in vascular tissue contractility and to determine the contribution of Rho-kinase pathway. Intravenous administration of C60/PVP increased contraction in the uterine artery, aorta and umbilical vein while pulmonary exposure to MWCNTs increased contraction in the uterine artery. These changes were confined to pregnancy, suggesting a higher susceptibility of the uterine vasculature to CNP mediated changes during pregnancy. Both in vitro and wire myographic studies suggested an increase in Rho-kinase activity with C60/PVP exposure (but not with MWCNT exposure), suggesting that C60/PVP mediated increase in contractility may be driven by a common pathway involving Rho-kinase via activation of endothelium and/or altering signaling within smooth muscle. MWCNT exposure induced contractions may be mediated by inflammatory mechanisms as suggested by the increased inflammatory endothelial markers. Our comparisons with naïve rats and untreated endothelial cells indicated a critical role played by the dispersion medium used for CNP delivery in determining contractile effects. These CNP exposures may be detrimental to fetal growth resulting in the observed reduction of fetal weight gain following acute exposure to both CNP. The conclusions drawn from this work contribute to both nanomedicine and nanotoxicology, focusing on safe applications of nanotechnology. It also widens our understanding on the life-stage related changes in susceptibility to environmental insults. Ph.D
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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