1,720,961 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
High power ultrasound combined with supercritical carbon dioxide for the drying and microbial inactivation of coriander
Full text linkThis work explores the use of supercritical carbon dioxide (scCO2) drying in combination with High Power Ultrasound (HPU) to enhance both the dehydration efficiency and the microbial inactivation on coriander leaves. ScCO2 drying process alone was compared with a combined drying process (HPU + scCO2) at different powers (10, 40 and 80 W), different drying times (up to 90 min) and two process temperatures (40 and 50 °C). At the most effective condition tested (40 W; 10 MPa; 40 °C), mesophilic bacteria were reduced up to 4 Log, mesophilic spores up to 1 Log, while yeast and molds were never detected (< 2 log CFU/g). 40 W was identified as the threshold HPU value to achieve a beneficial effect on mesophilic bacterial spores reduction. Besides, the use of HPU enhanced the water loss and lowered the water activity of the samples, compared to the ones processed with scCO2 alone. The appearance and color of the dried samples did not show significant differences after the
two processes. Overall, HPU + scCO2 process resulted a promising technology to enhance both the dehydration and microbial inactivation efficiency compared to scCO2 drying alone
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
In situ Raman-analysis of supercritical carbon dioxide drying applied to acellular esophageal matrix
No full textSupercritical (SC) carbon dioxide (CO2) drying has shown potential interest on the production of dry decellularized extracellular matrices for tissue engineering. This work explores the feasibility of Raman spectroscopy as in situ analysis for the SC-CO2 drying monitoring of a decellularized esophagus. Esophagus tissue was dried within an optical accessible high pressure CO2 dryer while the Raman signals of the wet tissue were excited at 785 nm.
Two different experimental procedures were explored: i) single step process (SC-CO2 drying alone) and ii) two steps process (water exchange by ethanol followed by SC-CO2 drying). The quantification of the removal of water or ethanol from the tissue during the drying was obtained evaluating the variation of the Raman signal intensity ratio during time. The measurement of water or ethanol removal curves during the drying process can be easily/successfully exploited for the in situ monitoring of the drying process of a general matrix/tissue
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