1,720,977 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
Rarity in coral reef fish communities
No full text[Extract] One of the greatest challenges in ecology is to explain
the inequality of abundance of taxonomic groups, and, in fact, why a majority of the species in any ecosystem are relatively rare (Preston, 1948; Gaston and Lawton, 1990a; Gaston, 1994a; Kunin and Gaston, 1997). Unfortunately, rare species are rarely
studied, so relatively little information is available on the processes constraining their distributions or limiting their numbers (Kunin and Gaston, 1993). Although the ecological processes influencing rare species may not be fundamentally different from those affecting common species, this cannot be assumed. Direct comparisons of the ecology and life histories of common and rare species, in a range of different taxa, are only now beginning to reveal the essential causes of rarity (Gaston, 1994a), but almost all the progress in this field has come from studies of terrestrial organisms. Gaston's (1994a)
book entitled "Rarity," one of the first attempts to review this subject comprehensively, contained almost no marine examples.
Many factors may explain why the issue of rarity has been avoided by marine ecologists. The taxonomic status of rare species in many marine taxa is uncertain (Ray and Grassle, 1991). It is always difficult to sample rare species and this may be particularly true in aquatic environments. Published accounts
of the geographic distributions of rare marine species are not always reliable because rare species may not be detected by the sampling method. Estimates of the abundances of rare species are almost always unreliable, because typical sample unit sizes and replication are invariably appropriate only for common species (Andrew and Mapstone, 1987). However, there is no fundamental reason why studies on rare marine species cannot make a major contribution to our general understanding of the phenomenon of rarity. Indeed, we cannot assume that the processes leading to rarity in terrestrial organisms apply to their marine counterparts. The prevalence of species with dispersive larval stages and consequently an "open" population structure may require new explanations of rarity. Therefore, comprehensive studies of marine taxa are necessary before a general synthesis of this fundamental ecological issue can be attained
Factors affecting the early life history of the ocean surgeonfish, Acanthurus bahianus.
No full textThe population dynamics of coral reef fishes may be affected by processes acting either on the larvae in the plankton, on the juveniles and adults on the reef, or both. The relative importance of events occurring during the pre-settlement and post-settlement stages has been the subject of much debate in the coral reef fish literature over the past few years. While some workers think that the dynamics of coral reef fish populations are determined primarily by processes acting on the reef, others believe that variation in larval availability is of more significance. Recently, however, it is being recognized that processes occurring during both stages may be important. In this thesis, I examine the effects of abiotic and biotic factors on the early life history of the ocean surgeonfish, Acanthurus bahianus. Evidence that settlement and early post-settlement persistence are mediated by both habitat and other reef residents suggests that larval supply alone is unable to account for the dynamics of local ocean surgeonfish populations. (Abstract shortened by UMI.)Dept. of Biological Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1996 .R57. Source: Masters Abstracts International, Volume: 37-01, page: 0184. Adviser: Peter F. Sale. Thesis (M.Sc.)--University of Windsor (Canada), 1996
Effects of habitat on the recruitment variation of coral reef fishes.
No full textCoral reef fish life cycles have two distinct phases that take place in different parts of their environment. Benthonic or pelagic eggs spawned by adults hatch into larvae that join the water column, after spending some variable time in it they settle back on to a reef. It is well documented that recruitment is highly variable across space and time. This variation can be a reflection of factor occurring during the pelagic larval phase, or during the settlement event. Prior to settlement the number of larvae settling to a given location could be a consequence of oceanographic features, as well as random events taking place during the pelagic larval phase which might affect the survival of larvae. Larvae then have been found to settle differentially to a preferred habitat. These associations have been studied at several spatial scales with contrasting results. In order to explore relationships between habitat and patterns of recruitment, we must first describe the habitat features found at a given location. Chapter two explored the effects that sampling intensity (i.e. number of sampling points or quadrats) and method (point-intercept vs. photo quadrats) have on the comprehensiveness and precision of percent cover estimates of substratum abundances. Chapter three assessed the degree to which habitat type can explain the spatial and temporal variation observed in the recruitment of 2 coral reef species. (Abstract shortened by UMI.)Dept. of Biological Sciences. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2004 .U87. Source: Masters Abstracts International, Volume: 43-01, page: 0150. Adviser: Peter F. Sale. Thesis (M.Sc.)--University of Windsor (Canada), 2004
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
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