1,722,962 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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
Palaeozoic black shales: how much should we trust the Recent to reconstruct the Past?
No full textOrganic-carbon-rich sediments were widely deposited during multiple intervals of Mesozoic and Palaeozoic time or even earlier; on the contrary, sediments rich in organic carbon are today restricted to small areas along continental margins and have rarely accumulated during the Cenozoic. Global marine deposits document that episodes of accumulation of OC-rich sediments occurred in different regions and at different times.These episodes were linked to climatic and palaeoceanographic perturbations that resulted in massive fluctuations in hydrologic and nutrient cycles and in ocean chemistry and that recurred throughout geologic time.The whole Palaeozoic is punctuated by a profusion of episodes of black shale deposition that represent a common and not unusual sediment for that time. Furthermore, the abundance of organic matter does not, per se, imply black shales. The Palaeozoic, in fact, is also characterized by fossiliferous OC-rich limestones, e.g. the Silurian–Devonian “Orthoceras limestones” bordering northern Gondwana. However, the paucity of survivingPalaeozoic and earlier black shale sections makes it difficult to impossible to recognize the internal structure of global events that are common in younger OC-rich sedimentary sequences. Going ever deeper into the past, in fact, two factors appear playing a more and more fundamental role: preservation and time resolution. OC-rich sediments, either in form of black shales or limestones, do not necessarily reflect periods of elevateddeposition of high organic matter but may paradoxically simply represent times of better organic matter preservation. Then, even well-dated sequences do not offer the high resolutionrecords needed to fully document or delineate short-time processes. In the Palaeozoic the length of individual biozones is generally on the order of millions of years, which is in the same range as third-order sea-level changes. Thus, an important question in Palaeozoic sequences is whether episodes occur at different scales or belong to cycles of diverse order.Also according to this premise, too often was exasperate the use of the uniformitarianism principle in which models or opinions derived from recent examples are simplistically applied to any of the older “timeboxes”. In actuality, physical and biological conditions (e.g., oxygen and CO2) have strongly varied through time. Palaeozoic black shales were clearly deposited in a CO2-dominated setting (see Berner, 1994, 1998), whereas youngerdeposits reflect a lower concentration of the same gas. Again, the nature of primary producers is not yet completely defined for pre-Jurassic production of organic matter.Furthermore, palaeogeographic scenarios reveal completely different worlds in terms of land masses, oceans, palaeolatitudes, etc. According to this, any attempt to model the deposition of OC-rich sediments through the Phanerozoic must necessarily be tuned with all these variables. Another relevant point is that some of the Phanerozoic OC-rich sediments are defined as global events, like the Cretaceous OAE1a and OAE2, but some othersappear to have had a more restricted and even localized significance. These differences require the application of different approaches in search of possible interpretations and perhaps diverse mechanisms leading to the deposition of OC-rich sequences.Finally, many of the most significant black shale episodes in the Palaeozoic strictly match with major crises in the history of life. Understanding what drives global diversity may be used to explain processes, such as mass extinctions, that control diversity and turnover at a variety of geographic and temporal scales.The main issues described here need to be further investigated and are certainly worth answering. The Scientific Community must come to a multiple-time scale approach and to a constructive dialogue that better integrates data and models in order to be even more successful. These efforts, with an emphasis on the upscaling/downscaling of processes and effects/feedbacks, will lead to the identification of methodologies that may be used uniformly in the Palaeozoic, Mesozoic and Cenozoic. In that case the scientific community will be able to test the validity of processes in the recent as well as its application in the past, to obtain real progress in the knowledge of OC-rich sediments, and to gain credibility for delineating true perspectives for the future.REFERENCESBERNER R.A. (1994). GEOCARB II: a revised model for atmospheric CO2 over Phanerozoic time. American Journal of Science, 294: 56-91.BERNER R.A. (1998). The carbon cycle and CO2 over Phanerozoic time: the role of land plants. Philosophical Transactions of the Royal Society of London, B 353: 75-82.NEGRI A., FERRETTI A., WAGNER T. & MEYERS P.A. (2009). Organic-carbon-rich sediments through the Phanerozoic: Processes, progress, and perspectives. Palaeogeography, Palaeoclimatology, Palaeoecology, Special Issue, 273 (3-4): 197 pp
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