1,720,966 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
Critical evaluation of ambient mass spectrometry coupled with chemometrics for the early detection of adulteration scenarios in Origanum vulgare L
No full textNowadays, most of the screening methods in food manufacturing are based on spectroscopic techniques. Ambient Mass Spectrometry is a relatively new field of analytical chemistry which has proven to offer similar speed and ease-of-use when compared to other fingerprinting techniques, alongside the advantages of good selectivity, sensitivity and chemical information. Numerous applications have been explored in food authenticity, based either on the target detection of adulteration markers or, less frequently, on the development of multivariate classification models. The aim of the present work was to evaluate and compare the capabilities of Direct Analysis in Real Time (DART) and Atmospheric Solid Analysis Probe (ASAP) Mass Spectrometry (MS) for the high-throughput authenticity screening of commercial herbs and spices products. The gross addition of bulking material to dried Mediterranean oregano was taken as case study. First, a pilot sample set, constituted by authentic dried oregano, olive leaves (a frequently reported adulterant) and mixtures thereof at different levels (i.e. 10, 20, 30 and 50% w/w) was used. Each sample was fingerprinted by both ambient-MS techniques. After appropriate pre-processing, the whole mass spectra were used for the subsequent multivariate data analysis. Soft Independent Modelling of Class Analogy was adopted as classification algorithm and the model was challenged with both new authentic oregano and in-house prepared blends. To the best of our knowledge, this is the first report of DART-MS and ASAP-MS used in full scan mode and coupled to chemometric modelling as rapid fingerprinting approach for food authentication. Although both the techniques provided satisfactory results, ASAP-MS clearly showed greater potential, leading to reproducible, diagnostic feature-rich mass spectra. For this reason, ASAP-MS was further tested under a more convoluted scenario, where the training and validation sets were enlarged with additional authentic oregano samples and a wider range of adulterant species, respectively. Overall good results were achieved, with 93% model predictive accuracy, and screening detection capability estimated between 5−20% (w/w) addition, depending on the adulterant considered with the only exception of majorana. Investigation of Q residuals could highlight the statistically-relevant chemical markers which could be tentatively annotated by coupling the ASAP probe with a high resolution mass analyser. The results from the validation study confirmed the great potential of ASAP-MS in combination with chemometrics as fast MS-based screening solution and demonstrated its feasibility for classification model building
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
GC-IMS and FGC-Enose fingerprint as screening tools for revealing extra virgin olive oil blending with soft-refined olive oils: A feasibility study
No full textThe undeclared blending of EVOO with soft-refined oils is one of the main issue in the olive oil sector. Despite the efforts, reliable markers related to soft-refinement processes have not been found yet. In the present work, two rapid headspace-based techniques, namely gas-chromatography ion mobility spectrometry and flash gas chromatography electronic nose, were proposed and tested as rapid screening tools for the detection of this fraud practice. Since real counterfeited samples are not commercially available, soft refined and deacidified olive oils were recreated at a laboratory scale and mixed with EVOO at different percentages. Commercial EVOOs sampled over three harvesting seasons (2015/2016, 2016/2017 and 2017/2018), along with the in-house prepared blends, were analysed by means of the above-mentioned techniques. SIMCA was chosen as classification algorithm to discern the illicit mix from the authentic EVOOs. Both the analytical techniques exhibited notable robustness and stability over the time in terms of intra- and inter-day reproducibility. Concerning the samples discrimination, the final outcome was found to be greatly affected by the inclusion (or exclusion) of the EVOO15/16 group in the model training. When EVOO from more recent harvests (i.e. EVOO16/17, EVOO17/18) were used to calibrate the model, a practically 100% specificity was achieved by both the techniques and even the lowest-percentage adulterated samples (i.e. 10%) were recognized to be non-authentic EVOOs. On the other hand, poorer classification was achieved including the EVOO15/16 in the model training. The present work demonstrated that focusing on the volatile fraction might be the right strategy to overcome the lack of clear and specific process-related marker formed upon soft-refinement processes. At the same time, it highlighted how the EVOO chemical (in)stability would be a crucial aspect to be considered in the development of fingerprinting methods
Analytical issue related to fumonisins: A matter of sample comminution?
No full textThe aim of the present work was to evaluate the effect of sample particle size on fumonisins recovery during the extraction step. Four maize samples were ground and the resulted flours were separated in six different fractions according to their particle size (1000-250 μm). Fumonisin B1 and B2 were quantified on each fraction, as well as on the unfractionated sample by HPLC-MS/MS. Furthermore, the proximate analysis was carried out to exclude the influence of macro-constituent on the mycotoxins distribution. Although the six maize fractions were found to be characterized by the same macro-constituent composition, a significant increase (p < 0.000) of fumonisins content was observed in all the analysed samples. Extraction yields up to five times higher were found in the finer flours. From the above, it is clear that the sample particle size has a significant impact on the fumonisins recovery. The outcomes suggest that sample granulometry should be standardized for ensuring accuracy and reliability of the analysis results. Overall, the results of this study, although still preliminary, may offer a reliable analytical solution to finally address the “hidden fumonisin issue”
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