1,720,998 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
Trace element analysis of extraterrestrial metal samples by inductively coupled plasma mass spectrometry: the standard solutions and digesting acids
No full textRATIONALE: Nearly 99% of the total content of extraterrestrial metals is composed of Fe and Ni, but with greatly variable trace element contents. The accuracy obtained in the inductively coupled plasma mass spectrometry (ICP-MS) analysis of solutions of these samples can be significantly influenced by matrix contents, polyatomic ion interference, and the concentrations of external standard solutions.
METHODS: An ICP-MS instrument (X Series 2) was used to determine 30 standard solutions with different concentrations of trace elements, and different matrix contents. Based on these measurements, the matrix effects were determined. Three iron meteorites were dissolved separately in aqua regia and HNO3. Deviations due to variation of matrix contents in the external standard solutions were evaluated and the analysis results of the two digestion methods for iron meteorites were assessed.
RESULTS: Our results show obvious deviations due to unmatched matrix contents in the external standard solutions. Furthermore, discrepancy in the measurement of some elements was found between the sample solutions prepared with aqua regia and HNO3, due to loss of chloride during sample preparation and/or incomplete digestion of highly siderophile elements in iron meteorites.
CONCLUSIONS: An accurate ICP-MS analysis method for extraterrestrial metal samples has been established using external standard solutions with matched matrix contents and digesting the samples with HNO3 and aqua regia. Using the data from this work, the Mundrabilla iron meteorite previously classified as IAB-ung is reclassified as IAB-MG. Copyright (C) 2016 John Wiley & Sons, Ltd
FORMATION OF THE FLOWED CORE IN A LEOVILLE TYPE B CAI: PLASTIC DEFORMATION OR HOT ACCRETION?
No full textkoamabayili/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
Origin of Al-rich chondrules in CV chondrites: Incorporation of diverse refractory components into the ferromagnesian chondrule-forming region
No full textAluminum-rich (Al2O3 > 10 wt%) chondrules (ARCs) are important chondritic components that petrologically link two other major chondritic components, ferromagnesian chondrules (FMCs) and calcium-aluminum-rich inclusions (CAIs), which formed in different regions of the protoplanetary disk. They are closely related to FMCs as indicated by their similar igneous textures, mineral assemblages, and Al-Mg isotope systematics; meanwhile, they have genetic a relationship with CAIs as indicated by their distinctly Al2O3-rich compositions and occasional occurrences of relict CAI minerals. In order to further understand their formation mechanism and genetic relationships to FMCs and CAIs, nine ARCs and three ARC-related objects from Allende (CV3 oxidized), Leoville (CV3 reduced), and the ungrouped Ningqiang carbonaceous chondrites were studied for petrology, mineralogy, bulk compositions, rare earth element (REE) abundances, and in situ oxygen isotopic com- positions. Our results suggest that (i) ARCs crystallized from incompletely molten droplets with crystallization sequences mainly determined based on their bulk compositions. Projection of their bulk compositions onto the forsterite-saturated tridymite-diopside-spinel diagram allows us to classify them into Al-rich [Sp], Al-rich [En], and Al-rich [Plag]; (ii) ARC pre- cursors are mixtures of refractory materials and the precursors of FMCs, in which the refractory materials have diverse sources rather than a single type of CAI/AOA (amoeboid olivine aggregate); this is inferred from the bulk compositions, relict minerals (both coarse- and fine-grained spinel, olivine, and Al-Ti-diopside), and various CAI-like REE patterns (unfraction- ated Group I/III and highly fractionated Group II/II-like) of ARCs. The sources include AOAs and igneous Type B/C CAIs; (iii) ARCs were melted in the FMC-forming region, possibly by the same heating mechanism or during the same transient heating event, which is consistent with the similar oxygen isotopic compositions of their phenocrysts (D17O= −5.2 ± 1.7‰, 2SD). Thus, we consider that ARCs formed by melting of mixtures of diverse refractory components with the FMC precursors in the FMC-forming region
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