1,721,182 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
Development of strategies to identify new psychoactive substances and their metabolites in biological samples by LC-QTOF-MS technology
Full text linkNew psychoactive substances (NPS) are emerging in the illegal drug market, which has led to major challenges for analytical laboratories. Keeping screening methods up to date with all relevant drugs is hard to achieve and the risk of missing important findings in biological samples is a matter of concern. Certain groups of NPS, e.g., synthetic opioids including fentanyl analogues, are of special concern due to their high potency. This indicates the possibility of low drug concentrations in vivo and calls for sensitive analytical methods and identification of the most appropriate analytical targets. In this thesis, three studies were carried out to demonstrate the application of liquid chromatography quadrupole time-of-flight mass spectrometry (LC-QTOF-MS) technology in the detection of NPS and their metabolites.
In Study I, a sensitive and quantitative screening method in urine with metabolites of synthetic cannabinoids that were frequently seized in Norway in the current time period (ABFUBINACA, AB-PINACA, AB-CHMINACA, AM-2201, AKB48, 5F-AKB48, BB-22, JWH-018, JWH-073, JWH-081, JWH-122, JWH-203, JWH-250, PB-22, 5F-PB-22, RCS-4, THJ-2201, and UR-144) was developed. The samples were treated with ß-glucuronidase prior to extraction and solid-phase extraction was used. Liquid handling was automated using a robot. Each sample was initially screened for identification and quantification, followed by a second injection for confirmation. The concentrations by which the compounds could be confirmed varied between 0.1 and 12 ng/ml. Overall, the validation showed that the method fulfilled the set criteria and requirements for matrix effect, extraction recovery, linearity, precision, accuracy, specificity, and stability. One thousand urine samples from subjects in drug withdrawal programs were analysed using the presented method. The metabolite ABFUBINACA M3, hydroxylated metabolite of 5F-AKB48, hydroxylated metabolite of AKB48, AKB-48 N-pentanoic acid, 5F-PB-22 3-carboxyindole, BB-22 3-carboxyindole, JWH-018 N- (5-hydroxypentyl), JWH-018 N-pentanoic acid, and JWH-073 N-butanoic acid were quantified and confirmed in 2.3% of the samples. The method was proven to be sensitive, selective, and robust for routine use for the investigated metabolites.
In Study II, the in vitro metabolism of ortho-, meta-, and para-fluorofentanyl - three fluorinated derivatives of fentanyl - was investigated using human hepatocytes and compared to the results from an authentic urine sample from a human individual with a confirmed intake. The three fluorofentanyl isomers were incubated with pooled human hepatocytes at 1, 3, and 5 h. LC-QTOF-MS operating in data-dependent mode was used to analyse the hepatocyte samples, as well as the authentic urine sample. Data were analysed by a targeted approach with a database of potential metabolites. The major metabolite formed in vitro was the N-dealkylation product norfluorofentanyl. In addition, various hydroxylated metabolites, an N-oxide, dihydrodiol metabolites, and a hydroxymethoxy metabolite were found. In the authentic urine sample, the hydroxymethoxy metabolite, norfluorofentanyl, and a metabolite hydroxylated on the ethylphenyl ring were detected. The study showed that the metabolic pattern for ortho-, meta-, and para-fluorofentanyl was close to those previously reported for other fentanyl analogues. The hydroxymethoxy metabolite and the metabolite hydroxylated on the ethylphenyl ring stand out as the metabolites that should be investigated further to determine the most appropriate marker for intake of fluorofentanyl derivatives in urine drug screening for human subjects.
In Study III, a strategy for extended retrospective data analysis of data files acquired by LCQTOF- MS was developed. Diagnostic fragment ions from synthetic cannabinoids (n=251), synthetic opioids (n=88), and designer benzodiazepines (n=26) were obtained from the crowdsourced database HighResNPS.com and converted to a personalized library in a format compatible with the analytical instrumentation. Data files from the analysis of 1314 forensic post-mortem samples performed at the Department of Clinical Pharmacology from January 2014 to December 2018 were retrieved and retrospectively processed with the new personalized library. Potentially positive findings were grouped into category 1 (most confident) and category 2 (less confident) depending on the information available in the files. Five new findings of category 1 were identified: flubromazepam in two data files from 2015 and 2016, respectively, phenibut (4-amino-3-phenylbutyric acid) in one data file from 2015, fluorofentanyl in one data file from 2016, and cyclopropylfentanyl in one data file from 2018. Retention time matches with reference standards further strengthened these findings. One category 2 finding of phenibut was considered plausible after the checking of retention times and signal-to-noise ratios, whereas 34 other potentially category 2 findings were refuted after a closer evaluation. This study showed that new compounds can be detected retrospectively in data files from LC-QTOF-MS using an updated library containing diagnostic fragment ions
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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