1,721,272 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
Simulation of Electrochemiliminescence Produced by a High Frequency Square Wave Potential Waveform. Effects of the Ohmic Drop and of the Cell Time constant on the Electrode Potential, the Current and the Light Emission
No full textDifferent aspects of the electrochemiluminescence process produced by a high frequency square-wave polarization at ultramicroelectrodes were studied by means of the digital simulation technique employing the finite difference Hopscotch algorithm in one dimension. The simulation allowed the deconvolution of the charging and faradaic currents and provided the real polarization potential. In particular, the theoretical study demonstrated that the IR drop and the cell time constant, R(u)C(dl), affect the shape of the potential waveform which delay and modify the faradaic current and therefore the light emission peaks correspondingly. Suitable plots enable systems characterized by values of the dimensionless annihilation constant (lambda = kt(s)c(A)) greater than 1000 to be distinguished when the responses around the peak maxima are considered, The influence of lambda on the shape and position of the reaction layer was also rationalized together with the influence of different diffusion coefficients. The existence of multiple emitting zones, which arise from the reaction layers of previous steps, was also observed
A recombinant chromosome 15 with duplication of the Prader-Willi/Angelman syndrome critical region arising from a familial intrachromosomal insertion, previously described as a paracentric inversion of 15q11-q15
No full textEvaluation of Ion-Annihilation Reaction Kinetics Using High-Frequency Generation of Electrochemiluminescence
No full textThe bimolecular rate constants for the annihilation reactions of the radical ions of 9,10-diphenylanthracene (DPA), 9,10-dimethylanthracene (DMA), and ruthenium(II) tris(bipyridine) (Ru(bpy)3(2+)) in acetonitrile and DPA in propylene carbonate have been measured using electrogenerated chemiluminescence (ECL). In this work, a high-frequency multicycle square wave was applied to a microelectrode and the resulting luminescence curves were fit to an appropriate computer simulation. The analysis was complicated by the direct interaction of the emission with the metallic electrode due to the close proximity of the ECL reaction layer to a reflecting surface. Significant deviations between theory and experiment were apparent during the rising portion of the ECL curve and when high frequencies (short step times) were used. Under these conditions, the ECL reaction layer is within a distance of 200 nm from the electrode surface. These effects were least apparent with carbon-fiber microelectrodes consistent with their lower electrode reflectivity and density-of-states. Diffusion-controlled ion-annihilation rates of (2 +/- 1) x 10(10) M(-1) s(-1) were measured far DPA, DMA, and Ru(bpy)3(2+) in acetonitrile and (4 +/- 1) x 10(9) M(-1) s(-1) for DPA in propylene carbonate, a more viscous solvent. The unimolecular rate constant for singlet formation for DPA in acetonitrile and propylene carbonate was calculated to be ca. 3 x 10(9) and 5 x 10(8) s(-1), respectively. The ca. 6-fold smaller unimolecular rate for DPA in propylene carbonate can be attributed to the longer solvent relaxation time for propylene carbonate compared to acetonitrile. The rate to form the tripler state proceeds at the diffusion-controlled limit for DMA, DPA, and Ru(bpy)(3)(2+) consistent with the predictions based on electron-transfer theory
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
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
- …
