1,721,005 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
Reconstructing Late Quaternary environmental change on the southern Cape coast of South Africa: A 30,000-year geochemical record from Pearly Beach
No full textA dissertation submitted in fulfilment of the academic requirements for the degree of Master of Science, to the Faculty of Science, School of Chemistry, University of the Witwatersrand, Johannesburg, 2023.The southern Cape coast of South Africa has undergone complex and dynamic climate changes due to its position at the boundary of major atmospheric and oceanic systems. However, climate changes that occurred in the region during the Last Glacial Maximum (30,000 – 18,000 cal yr BP) and the deglaciation period that followed (18,000 – 11,000) are still not fully understood. Climatic change along the southern Cape coast is of archaeological, cultural and environmental significance given the ecological diversity and hominin fossil, richness of the region. Moreover, predictions of future climate change and water scarcity management issues in the southern Cape make it vital to understand and response to future climate scenarios. To address this gap, this study investigated the geochemical composition of a 5.42 m sediment record (KSV 1) extracted from a freshwater coastal wetland near Pearly Beach on the southern Cape coast. The wetland, situated in the winter rainfall zone, is influenced by the southern westerly storm track, the South Atlantic anticyclone, and Agulhas-Benguela interactions, making it an ideal location to investigate changes to large-scale atmospheric and oceanic circulation systems. Using a combination of inorganic elemental (X-ray fluorescence, XRF) and stable carbon isotope (δ13C) analysis, this study presents a 30,000 year record of palaeoenvironemental change from Pearly Beach and considers these in relation to broad-scale climatic perturbations that occurred in southern Africa over this period. A chronology for the core was derived from radiocarbon dating of 8 bulk sediment samples. Sedimentation rates over the record averaged 0.02 cm/yr, giving the XRF analyses which were conducted at 2 cm intervals, an average temporal resolution of ~ 110 years. Sediments deposited 30,000 – 15,000 cal yr BP consist primarily of quartz-rich (60 – 90% SiO2) silt and fine sand with relatively low quantities of clay material. An increase in the relative proportion of Al2O3 from ~15,000 cal yr BP, coupled with a rise in sedimentation rate, marks an increase in the accumulation of fine-grained material within the wetland that is associated with a rise in global sea levels following deglaciation. A distinct shift to higher δ13C values around this time points to a change in vegetation community, with an increase in contribution from C4 drought-tolerant plants. The presence of calcium carbonate in sediments provides a strong indicator for marine intrusions at site and a pronounced increase in marine influence is inferred from ~8,500 cal yr BP, corresponding with the stabilisation of sea levels near to present-day levels. Variations in elements typically associated with heavyminerals (titanium and zirconium) are used to infer changes in depositional energy at the site. Enrichments in Ti and Zr suggest a period of enhanced transport energy between 18,800 and 14,500 cal yr BP. This is coupled with an increase in the Si/Al ratio and linked to enhanced aeolian activity. An increase in wind intensity during this period is attributed to the intensification in the Southern Hemisphere westerly winds at this time. This corresponds with available fossil pollen records, which suggest an increase in moisture at Pearly Beach 18,500 to 15,000 cal yr BP that was possibly linked to a slowdown in the Atlantic Meridional Overturning Circulation (AMOC) and build-up of heat in the southeast Atlantic. It is possible that a build-up of heat in the southeast Atlantic brought on by a slowdown in the AMOC increased moisture uptake in the frontal storms, resulting in stronger low-pressure systems and intensified storms, as reflected in the KSV-1 record. Comparisons with other records from South Africa, including Mfabeni, Cold Air Cave and Cango Caves, indicate that the central and eastern parts of the country experienced a cooling event ~18,500 and 14,500 cal yr BP. New geochemical data from Pearly Beach suggests that this cooling may have been linked to intensification of westerly winds at this time. An apparent lag effect in the warming of South Africa after deglaciation may be attributed to the enhanced influence of westerly winds during the glacial-interglacial period, which pushed cold air masses across the interior of the country. The complex interplay between local sea level changes, westerly wind dynamics, and regional climatic conditions underscores the significance of the geochemical record from Pearly Beach in understanding past environmental changes and their broader implications for southern Africa.PAST (Paleontological Scientific Trust)MMM202
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
Geochemical Investigation Into Holocene Palaeoenvironmental Change Along The Southern Cape Coast, South Africa
No full textA dissertation is submitted following the requirements for the degree of Master of Science, to the Faculty of Science, School of Chemistry, at the University of the Witwatersrand, Johannesburg, 2023.Climatic conditions across southern Africa are affected by the complex interaction of different atmospheric and oceanic circulation systems, the understanding of which is important to predicting future climate change. Palaeoenvironmental reconstruction is an essential tool to understand long-term environmental change and the response of ecosystems to such changes. This study examines the geochemical composition of a sediment core (WR1-1) extracted from a freshwater wetland located near Plettenberg Bay on the southern Cape coast. The wetland is located ~4 m above present sea level and positioned ~500 m from the modern coast. Situated within the year-round rainfall zone, the site is influenced by tropical easterly flow and the southern westerlies. Elemental and stable isotope geochemistry are used to reconstruct the palaeoenvironmental change at the site over the last ~8000 cal yr BP. Variations in CaO/Al2O3, Sr/Al2O3 and δ13C indicate that marine conditions dominated from 7300 to 6400 cal yr BP. Marine influence at the site decreased dramatically from ~6300 cal yr BP, as the system transitioned to a freshwater back-barrier wetland. Enrichments in SiO2/Al2O3 and Zr/Al2O3 track changes in depositional energy and suggest that the period 3800 – 3200 cal yr BP was associated with increased aeolian activity. This is interpreted to reflect increased aridity and is consistent with geochemical and pollen records from nearby sites at Eilandvlei and Voëlvlei. This suggests that a shift to more arid conditions during this time was a broad feature of the climate in the year-round rainfall zone of South Africa. The timing of this event corresponds with a marked decrease in Antarctic sea ice and pronounced aridity along the east coast of South Africa, suggesting that mid to late Holocene aridity in the YRZ was likely driven by declines in moisture from both westerly and easterly wind systems.Tritisano Trust.MM202
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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