1,721,025 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
Climate change impacts on soil organic carbon stocks of Mediterranean agricultural areas: A case study in Northern Egypt
No full text11 páginas.- 4 figuras.- 3 tablas.- referencias.- Supplementary data associated with this article can be found, in
the online version, at http://dx.doi.org/10.1016/j.agee.2016.09.001Mediterranean agricultural areas are characterised by low soil organic C (SOC) contents and as a consequence they are often degraded and highly vulnerable to environmental changes. Climate change is expected to have a large impact upon these areas but they may be key for mitigation of its effects given their potential for soil C sequestration. Several approaches have been proposed to evaluate climate change impacts on SOC stocks, being soil C models amongst the most effective tools to assess C stocks, dynamics and distribution and to predict trends under climate change scenarios. In this study, we applied the CarboSOIL model and global climate models to predict and analyse the effects of short- (2030), medium- (2050) and long-term (2100) climate changes on SOC contents at standard soil depths (0–25, 25–50 and 50–75 cm) in a Mediterranean arid area (El Fayoum, Northern Egypt) for different land use types. The validation of CarboSOIL with field data proved the consistency of the model. Overall decreases of SOC contents in the topsoil soil layer and increases in the subsoil layers are expected in the short, medium and long term. However, intensity of these changes will depend on the land use type and our results suggest that agricultural land uses relying on irrigation will be particularly vulnerable to losses of SOC stocks. This study demonstrates the importance of assessing SOC contents and dynamics along the soil profile and the potential for soil C sequestration particularly in the subsoil. The methods used in this research can be applied in other Mediterranean areas with available information on soil, land use and climate.N
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
Soil physicochemical and microbiological indicators of short, medium and long term post-fire recovery in semi-arid ecosystems
No full text© 2015 Elsevier Ltd. All rights reserved. Natural disturbances such as wildfires cause significant alterations to the structure and functioning of semi-arid ecosystems. After such disturbances, the recovery of the soil ecosystem as a whole, and more specifically the belowground microbial communities, is poorly understood. In this study, we aimed to (a) assess the short, medium and long term changes in soil physicochemical and microbiological indicators and indices after a wildfire in a semi-arid environment, (b) analyse the key relationships of multiple soil parameters and indices, and (c) identify the most suitable indicators of post-fire recovery. The study was conducted across a wildfire chronosequence spanning sites recently burnt (three months) through to 14 years after fire in a semi-arid hummock grassland ecosystem of northern Western Australia. Immediate effects of the fire on the soil system were evident with increases in pH, electrical conductivity, and available nutrients. These chemical indicators showed a strong correlation with fire age and were consistent in the direction of change. Variations in the microbial composition were apparent one year after the fire, with a higher proportional abundance of bacterial communities. The fungi to bacteria ratio and the microbial quotient (proportion of microbial C to total organic C) proved to be significant indices to reflect the recovery of soils in these semi-arid environments. Overall, this study highlights the importance of understanding the post-fire response of belowground ecosystems, and particularly changes and recovery of soil microbial communities, at different time periods. The approach and methods followed in this research can be effectively extrapolated to other areas. This study can be used to inform better soil management of degraded systems in a rapidly changing climate
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
Ecophysiological Indicators to Assess Drought Responses of Arid Zone Native Seedlings in Reconstructed Soils
No full text10 páginas.- 2 figuras.- 4 tablas.- 66 referencias.- This article also appears in: Restoration and Rehabilitation of Degraded Land in Arid and Semi-Arid Environments.- En ResearchGate pueden encontrar el pdf de originalRestoration of degraded arid and semi-arid land faces the challenge of reinstating vegetation communities exposed to limited and variable rainfall events that in combination with a deficit of original topsoil may exceed thresholds for seedling development. In a series of glasshouse experiments, we evaluated variation in drought responses of (i) 21 arid zone plant species from the mining intensive Pilbara region of Western Australia in an original topsoil substrate and (ii) four selected species (Acacia inaequilatera, Acacia spondylophylla, Eucalyptus leucophloia and Triodia epactia) in three different soil substrates (topsoil, overburden material and a blend of both soil materials) that may be considered as an alternative substrate for restoration. Seedling drought responses were tested using ecophysiological indicators (e.g. stomatal conductance and leaf water potential (Ψleaf) at the time of stomatal closure, among others) during soil drying. Our results showed that plant life form and morphological traits interact with ecophysiological indicators to show that trees are significantly less tolerant to drought-related stress than shrubs and herbs (p ≤ 0·05). When grown in overburden material seedlings experienced a decline in overall plant growth (87% in T. epactia and 62% in E. leucophloia) and ecophysiological drought tolerance. These responses are evidence of the low quality of the overburden substrate, which has a depleted nutrient content and low water retention capacity. Overall, this study highlights the sensitivity of early seedling development and the importance of facilitating seedling recruitment and survival to secure successful arid zone restoration. Copyright © 2016 John Wiley & Sons, Ltd.This research was supported by a BHP Billiton Iron OreCommunity Development Project under the auspices of theRestoration Seedbank Initiative, a partnership betweenBHP Billiton Iron Ore, The University of WesternAustralia and Botanic Gardens and Parks Authority.Peer reviewe
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