1,720,971 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
Acoustic assessment of the seasonal occurrence and behaviour of Antarctic blue whales Balaenoptera musculus intermedia in the southeastern Atlantic and Southern Oceans
Get PDFThesis (PhD)--University of Pretoria, 2018.With catches of over 360,000 individuals, Antarctic blue whales Balaenoptera musculus intermedia were harvested to near extinction by commercial whaling in the past century. Antarctic blue whales are an important ecological component of marine ecosystems as they ensure the circulation of nutrients in the pelagic environment making such nutrients accessible for primary production. However, their recoveries; distributions; migrations; large-scale response to environmental variabilities are poorly known. This thesis explored the distribution, seasonal occurrence, behaviour and response of Antarctic blue whales to environmental conditions in the high and low latitudes. I used Antarctic circumpolar acoustic data collected from sonobuoys deployed in the austral summers of 1997 through 2009 during the International Whaling Commission’s Southern Ocean Whale and Ecosystem Research (IWC SOWER) line-transect surveys. I also used recent acoustic data from three autonomous acoustic recorders (AARs) deployed between 2014 and 2015; two of these AARs were deployed on oceanographic moorings in the low latitudes and one AAR was deployed on a dedicated mooring in the high latitudes.
Characteristic Z-call and feeding associated D-call of Antarctic blue whales; and sometimes low frequency downsweeping ~28-15 Hz eastern Antarctic fin whale B. physalus calls, were detected using an automated detection template and visual verification methods. I used random forest model to determine pattern of environmental preferences, spatial occurrence and behaviour of Antarctic blue whales. Distance to southern boundary of the Antarctic Circumpolar Current, latitude, longitude and distance from the nearest Antarctic shores were the main geographic predictors of blue whale call occurrence and behaviour during IWC SOWER cruises. Satellite derived sea surface height (SSH), wind stress, wind direction, water depth, sea surface temperature (SST), chlorophyll-a and wind speed were important environmental predictors of blue whale occurrence and behaviour during IWC SOWER cruises. Antarctic blue whale call occurrence and call rates varied significantly in response to inter-annual variabilities of those environmental predictors during those cruises.
Migratory Antarctic blue and fin whales were acoustically detected in South African waters between May and August with fin whales present till November. Diel call rate patterns of both whale species varied between seasons. Wind speed, SSH, SST, chlorophyll-a, time of the day and Ekman upwelling index were important predictors of Antarctic blue and fin whale call occurrence and behaviour off the South African west coast. Off the Maud Rise, Antarctica, call occurrences and rates of Antarctic blue whales peaked in March and were detected throughout the whole year suggesting asynchronous migrations to the low latitudes and part of the population remaining in the Maud Rise during winter. Fin whale calls were only detected in January and March. Wind speed, distance to the sea ice extent, sea surface height, sea surface temperature and time of the day were important predictors of Antarctic blue and fin whale call occurrence and behaviour.
Information emerging from this thesis will improve the management and conservation of these highly depleted species. This thesis provides the first acoustic recordings of Antarctic blue and fin whales in the southern Benguela ecosystem; and provides preliminary information on which to concentrate further research effort to investigate abundance, distribution and seasonality of these large baleen whale populations in both high and low latitudes.National Research FoundationZoology and EntomologyPhDUnrestricte
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
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
The seasonal movements and dynamics of migrating humpback whales off the east coast of Africa
No full textData collected during boat-based and aerial surveys were used to describe population structure, movements, temporal patterns of migration and skin condition of humpback whales in breeding sub-stock C1-S off southern Africa. Results confirmed that the migration route along the south coast of South Africa is linked to the winter ground off Mozambique. A lack of exchange between breeding sub-stocks C1-N and C1-S was found, suggesting that these are independent of each other. Molecular analysis revealed unexpected levels of population structure between the migration route and the winter ground of C1-S, as well as the possibility that this migration route is also utilised by some individuals from breeding sub-stock C3. A skin condition of unknown aetiology that primarily affects humpback whale mother-calf pairs was identified. The first assessment of its prevalence and severity was made, providing a baseline for future monitoring. Humpback whale abundance in an inshore region of Bazaruto Archipelago, Mozambique was estimated and attempts were also made to use the limited information off Plettenberg Bay/Knysna, South Africa. In addition to improving our understanding of humpback whales from Breeding Stock C, knowledge about another baleen whale species utilising the southwest Indian Ocean was extended. The first evidence of southern right whale presence off the coast of Mozambique since the cessation of whaling was documented. It remains unknown whether this is a remnant sub-stock or the recovering South African sub-stock reoccupying its historical range
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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