1,720,993 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
RE L(3) x-ray absorption study of REO(1-x)F(x)FeAs (RE = La, Pr, Nd, Sm) oxypnictides RID A-4797-2009
No full textRare earth L(3)-edge x-ray absorption near-edge structure (XANES) spectroscopy has been used to study REOFeAs (RE = La, Pr, Nd, Sm) oxypnictides. The Nd L(3) XANES due to the 2p(3/2) -> 5 epsilon d transition shows a substantial change in both white line (WL) spectral weight and the higher energy multiple scattering resonances with the partial substitution of O by F. A systematic change in the XANES features is seen due to varying lattice parameters with ionic radius of the rare earth. On the other hand, we hardly see any change across the structural phase transition. The results provide timely information on the local atomic correlations showing the importance of the local structural chemistry of the REO spacer layer and interlayer coupling in the competing superconductivity and itinerant striped magnetic phase of the oxypnictides
Influence of the extra layer on the transport properties of NdFeAsO1-0.14F0.14 and FeSe0.88 superconductors from magneto dynamic analysis
No full textIn this letter, the electromagnetic response of the NdFeAsO 1-0.14F 0.14 (Tc = 49 K) superconductor system, characterized by FeAs and NdO alternating layers, has been compared with that of FeSe 0.88.We have studied the flux dynamics of these two systems by means of ac multi-harmonic magnetic susceptibility. The analysis shows that although characterized by larger thermal fluctuations due to its higher Tc, NdFeAsO 1-0.14F 0.14 exhibits a stronger pinning force relative to FeSe 0.88. The further Irreversibility Line (IL) analysis also points out that both superconductors have a 3D flux pinning behavior.We associate the stronger pinning force in the NdFeAsO 1-0.14F 0.14 structure to the presence of the extra NdO layer. Different pinning contributions can be associated to the structural stress associated to FeAs superconducting layers and/or to the Nd3+ ions magnetic moment (μ ∼ 3.6 μB) contribution on the flux cores. We will also show that these pinning are over imposed to a weak collective contribution due to the dopant F atoms. ©Springer Science+Business Media, LLC 2012
Si, Al and Zn biomineralization processes in plant roots of Euphorbia pithyusa
No full textIn the abandoned mine of Ingurtosu (SW Sardinia, Italy) a field experimental trial was carried out in the frame of the
UMBRELLA project (7FP EU). The idea of this project was to couple microorganisms with plants to favour metals
accumulation in plants and reduce the effects of metal pollution in soils of heavy metals contaminated sites. Euphorbia
pithyusa was selected as an endemic pioneer plant. About two years after the beginning of the experiment, exploration
of the processes occurring at the soil-root interface was carried out by combing X-ray fluorescence mapping (S-XRF)
and X-ray absorption spectrometry (XAS) to X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM), and
Transmission Electron Microscopy (TEM). We observed that Si and Al are mainly concentrated in the epidermis of the
roots forming a rim that represent a physico-chemical barrier against organic and inorganic stresses. In addition, Si is
able to bind Zn by forming an amorphous Zn-silicate in the epidermis zone. This process leads to the decrease of Zn
concentration from the epidermis to the internal part of the root, where Zn is bonded to other Zn atoms. In the case of
Fe, the Si-Al rim seems to be more efficient and, as observed in LEXRF maps, Fe is mainly concentrated in the external
zone of the roots. EXAFS analysis reveals that the coordination environment of Fe is comparable to that of hematite.
The exact cause of Fe precipitation around roots or in the epidermis zone is unknown, but the oxidizing activity of
roots, together with the action of microorganisms, is thought to be involved. Si and Al particles of the rim can act as a
nucleus for hematite precipitation (Batty et al., 2000) that, in turn, could act as a barrier against metals penetration.
Although Si and Al are not regarded as essential nutrients and the later is an important growth-limiting factor (Rout
et al., 2001), obtained results suggest that these elements are fundamental for controlling metal migration through the
roots, and their beneficial function for plant need to be reassessed. The addition of microorganisms to the soil at the
Ingurtosu mine seems to have no effect on biominerals features, and on Zn and Fe speciation. Our results can be useful
for environmental science because biomineralization in plants can lead to development of specific phytostabilization
techniques, reducing the mobility of the contaminants and prevents their migration to the groundwater or air, thus
decreasing bioavailability for entry into the food chain
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