1,721,063 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
Per- and polyfluoroalkyl substances (PFAS) determination in shellfish by liquid chromatography coupled to accurate mass spectrometry
No full textPer- and polyfluoroalkyl substances (PFAS) are a numerous class of
chemical compounds characterized by a C-F backbone of variable
length with either a sulfonic acid group (PFSA) or a carboxylic acid
(PFCA), produced for more than 70 years at industrial level.1 PFOS
and PFOA are the predominantly cited molecules of this class. Cur-
rently, these compounds are debated both at scientific and political
levels due to the risks associated to exposure to legacy (PFOA, PFOS,
etc.) and to emerging perfluorinated compounds (HFPO-DA or GenX,
ADONA, C6O4), introduced after the banning in the production/
import/use of PFOA and PFOS.2,3
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
Zwitterionic HILIC stationary phase as a valuable alternative in separative techniques. Application to the analysis of gamma-hydroxybutyric acid and its metabolite in hair
No full textIn this work, the physical and chemical properties of a novel zwitterionic LC stationary phase are applied to the development, validation and application of a new fast and reliable method devoted to the analysis of GHB (gamma-hydroxybutyric acid) and its relatively new discovered glucuronide metabolite in hair. The obtained sensitivity, expressed as limit of detection (LOD) and quantification (LOQ), were 0.033 and 0.10 ng/mg for GHB and 0.11 and 0.37 ng/mg, for GHB-glucuronide respectively. Linearity was assessed between LOQ and 50 ng/mg for both compounds. GHB and GHB-glucuronide extraction from hair matrix was maintained simple and consisted in an acidified-solvent incubation. No samples purification was required before LC–MS/MS analysis. The method was finally applied to 65 real hair sample, 60 adults and 5 children below 2 years old. The obtained results highlighted that GHB concentrations were in the range 0.11–0.96 ng/mg (average 0.38 ± 0.25 ng/mg) in 44 cases (68%) while in 21 samples GHB concentrations were in the range between LOD and LOQ (0.033–0.1 ng/mg). GHB-glucuronide was detected in few samples (n. 3) at levels below LOQ. The interest on these molecules relies on the fact that GHB is both a naturally occurring inhibitory neurotransmitter in the central nervous system and an illicit drug often experienced by victims of drug-facilitated sexual assault. GHB-glucuronide was firstly identified in urine by the group of Petersen in 2013 and, as per analogy to ethyl glucuronide, it was proposed as a longer biomarker for GHB intoxication
Is old stuff back? A fatal case of ethyl chloride sniffing
Full text linkBackground: Ethyl chloride (EC) or chloroethane is a colourless halogenated hydrocarbon gas regularly employed as a topical anaesthetic spray for pain-related injuries and muscle spasm in athletes. However, EC became also popular as a street drug in the 1980s. Brief inhalations of EC vapour can result in dizziness, euphoria, confusion, incoordination, hallucinosis, impairment of short-term memory and narcosis. Inhalation of higher doses, usually employed to “get high”, may be related to severe depression of the central nervous system. Indeed, toxicity and deaths have been reported so far. Case presentation: A 40-year-old man was found unresponsive after EC inhalation. EC determination was performed by dynamic headspace gas chromatography coupled to mass spectrometry. EC was detected in the peripheral blood (0.156 g/L), central blood concentration (0.203 g/L) and the lung and brain (19 and 25 mg/kg). EC in the vitreous humour showed a sensitively lower respect to blood (0.018 vs 0.203 g/L). Conclusions: Considering the results of toxicological analyses of investigations on the death scene besides the absence of any signs of trauma, death was attributed to inhalation of ethyl chloride
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