1,720,997 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
Fish ecology of mesophotic coral ecosystems
Full text linkMesophotic coral ecosystems (MCEs; reefs 30-150 m depth) are largely unstudied. This thesis uses the shallow reef to MCE depth gradient around Utila, Honduras, to address research questions in three themes: (i) understanding fish community ecological processes on MCEs; (ii) evaluating effective survey techniques for MCE fish research; and (iii) exploring the role of MCEs in the western Atlantic lionfish invasion. Around Utila, herbivorous reef fish declined with increasing depth, but remained present on MCEs, suggesting a possible role in structuring mesophotic benthic communities. To test this I artificially excluded fish from areas of the reef with controls for changing light levels. The results indicate strong effects of light availability on MCE hard coral, macroalgal and sponge coverage, while little detectable effects of fish exposure. Fish surveys play a crucial role in informing reef management, yet few studies consider how biases in survey techniques varies across depth gradients. I explored differences between baited-remote underwater video (BRUV) and diver-operated video (DOV) finding BRUVs consistently recorded more species regardless of depth, but that DOV is likely better for surveys of herbivores. I also assessed fish responses to divers using open-circuit SCUBA or closed-circuit rebreathers (CCR) and, while both recorded similar fish abundances, CCR divers were able to approach fish more closely. In addition, I conducted a meta-analysis identifying widespread invasion of western Atlantic MCEs by Indo-Pacific lionfish, with similar relative abundance distributions across the depth gradient to native range sites. Around Utila, MCE lionfish occurred at greater densities than on shallow reefs, with MCE individuals larger and more mature than their shallow counterparts. This suggests deeper lionfish populations may represent an extension of ontogenetic migrations, and act as a disproportionately large source of new lionfish recruits. Overall, this thesis provides insights applicable to the western Atlantic region more generally and highlights the need for MCEs to be considered by reef managers.</p
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
Three-dimensional modelling of coral reefs for structural complexity analysis
Full text linkCoral reefs are some of Earthâs most biodiverse and economically valuable ecosystems. Simultaneously they are among the most threatened by anthropogenic factors including global climate change. Their unique three-dimensional (3D) structural complexity is part of what enables them to provide their ecosystem services. It strongly affects species richness, abundance, and other indicators of ecosystem health.
This thesis explores the relationship between coral reef 3D structural complexity and ecosystem features. It has developed a new, low-cost method for creating and analysing photogrammetric 3D models of shallow reefs from diver-held camera footage. 3D models are analysed at scales 1-175 cm in terms of point-to-point distances, linear rugosity (R), fractal dimension (D), and vector dispersion (1/k). The 3D modelsâ accuracy and precision were determined by comparisons with ground truths. The 3D models have root mean square errors of 1.35-1.48 cm in the X, Y and Z dimensions. Values of R from the 3D models were 86.8% accurate compared to in-situ chain-and-tape measurements. Values of D and 1/k were 86.9-99.6% accurate compared with ground truths from 3D printed objects modelled underwater. Data collected around Utila, Bay Islands, Honduras in the Caribbean showed that 3D metrics automatically calculated from the 3D models had the same predictive power for fish abundance and diversity as the more traditional Habitat Assessment Score (HAS). Like HAS, the 3D metrics explained 12-34% of variation in the fish data. A controlled experiment furthermore tested how 1/k affected sessile epibenthic organism settlement around Utila after one year. Results from approximately 200 3D printed recruitment tiles showed that 1/k significantly affected algae settlement, but not coral spat, polychaete, sponge, or bryozoan settlement. The results suggested that the surfaces of artificial reefs can be designed to minimise algal recruitment and that the availability of sheltered, reef-facing area influences epibenthic settlement more strongly than 1/k at the 1 cm scale. Finally, a convolutional neural network (CNN) learned patterns between the 3D models and fish data with just 85 data points. The CNN is a promising approach for analysing larger data sets without 3D metrics.
We suggest 3D models become a standard approach for measuring reef structural complexity. Not only can they explain as much variation in fish abundance and diversity as traditional measurements, but also they can nondestructively produce a variety of 3D metrics at numerous spatial scales and keep a permanent record of reef structure over time.</p
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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