1,721,332 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
Cathepsin activities and membrane integrity of zebrafish (Danio rerio) oocytes after freezing to -196 degrees C using controlled slow cooling
No full textDirect detection of high intensity X-ray fluxes with silicon photomultipliers
No full textSilicon Photomultipliers (SiPM) are photodetectors optimized for the detection of infrared to ultraviolet photons and employed in a wide range of fast timing applications for medical imaging and particle detectors. SiPMs are used to detect the passage of ionizing radiation into matter via the collection of secondary photons emitted by the radiator material. In this work, we have investigated the possibility to detect high intensity X-ray fluxes using the DC current produced by SiPMs exposed directly to the X-ray beam, in absence of any passive converter material, to demonstrate the possibility to measure intense radiation fluxes without saturation of the SiPM response. In our application, the signal-to-noise ratio of the SiPM current during the direct exposition to X-rays is typically larger than 100, providing a robust indication of a positive detection. We show that, for a wide range of operational parameters and X-ray flux intensities, the SiPM current can be correlated to the X-ray beam intensity using a parametrization that describes the data with an accuracy of the order or better than 1%. We also show that the SiPM signal current to dark current ratio is maximum for hundreds of mV above the breakdown voltage, with a weak dependence on temperature. These results open the prospects for interesting applications for monitoring intense X-ray beams, for example beam spatial profiling, and possibly real time dosimetry both in medical and industrial applications
Changes in cathepsin gene expression and relative enzymatic activity during gilthead sea bream oogenesis
No full textDispelling 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
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