1,720,995 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
Combined toxicity of therapeutic pharmaceuticals to duckweed, Lemna minor
No full textPharmaceuticals, which are designed to be biologically active at low concentrations, are found in surface waters, meaning aquatic organisms can be exposed to complex mixtures of pharmaceuticals. In this study, the adverse effects of four pharmaceuticals, 17α-ethynylestradiol (synthetic estrogen), methotrexate (anticancer drug), diclofenac (nonsteroidal anti-inflammatory drug) and fluoxetine (antidepressant), and their binary mixtures at mg/L concentrations were assessed using the 7-day Lemna minor test, with both apical and biochemical markers evaluated. The studied biochemical markers included chlorophyll a, chlorophyll b, carotenoids and oxidative stress enzymes catalase, glutathione-S-transferase and glutathione reductase, with effects compared to solvent controls. The adverse effects on Lemna minor were dose-dependent for frond number, surface area, relative chlorophyll content and activity of glutathione S-transferase for both individual pharmaceuticals and binary mixtures. According to the individual toxicity values, all tested pharmaceuticals can be considered as toxic or harmful to aquatic organisms, with methotrexate considered highly toxic. The most sensitive endpoints for the binary mixtures were photosynthetic pigments and frond surface area, with effects observed in the low mg/L concentration range. The concentration addition model and toxic unit approach gave similar mixture toxicity predictions, with binary mixtures of methotrexate and fluoxetine or methotrexate and 17α-ethynylestradiol exhibiting synergistic effects. In contrast, mixtures of diclofenac with fluoxetine, 17α-ethynylestradiol or methotrexate mostly showed additive effects. While low concentrations of methotrexate are expected in surface water, chronic ecotoxicological data for invertebrates and fish are lacking, but this is required to better assess the environmental risk of methotrexate.Full Tex
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
A Pesticide Decision Support Tool to guide the selection of less environmentally harmful pesticides for the sugar cane industry
No full textPesticides applied to agricultural land have been shown to decrease the quality of water entering the Great Barrier Reef lagoon. This issue is addressed by the Reef 2050 Water Quality Improvement Plan which includes a pesticide reduction target. As part of a wider educational strategy, one method that could help meet the target is to provide stakeholders with information that assists in the selection and use of pesticide active ingredients (PAIs) that pose a lower risk to aquatic environments compared to those currently used. This study developed a Pesticide Decision Support Tool (PDST) in collaboration with stakeholders for the sugar cane industry. The PDST covers all PAIs registered and applied to sugar cane in Australia and four additional PAIs registered for use on crops grown in rotation with sugar cane. The PDST incorporates both the measure of mobility and persistence of a PAI and the measure of effect, which is based on the PAI application rate and ecotoxicity threshold value. The aquatic risk, which is the product of the measure of effect and the measure of mobility and persistence, is a measure of the likelihood that a PAI will reach the aquatic environment and cause harmful effects. Insecticide active ingredients (e.g., cadusafos, chlorpyrifos) posed the greatest aquatic risk, followed by herbicide active ingredients (e.g., MSMA, metolachlor), while fungicide AIs typically had a lower aquatic risk. An interactive spreadsheet allows characteristics, including application rate and tank mixes, to be considered when assessing the potential risk. While focusing on sugar cane, the results are equally appropriate to other crops that use the same PAIs provided the application rates are corrected to the new crop. In addition, the approach used in the PDST can be applied internationally and to any PAIs with sufficient toxicity, mobility, and persistence data.Full Tex
A systematic review of freshwater microplastics in water and sediments: Recommendations for harmonisation to enhance future study comparisons
No full textMicroplastics are contaminants of emerging concern that have been widely detected in aquatic environments over the past decades. While in recent years an increasing number of studies has been published on microplastics in freshwater, there have been questions regarding inconsistency of the results due to large variations in methods and analytical techniques used in the literature. In this study, we adopted a systematic quantitative literature review approach to critically analyse 183 publications reporting microplastics in freshwater ecosystems. We also analysed the current approaches used for sampling, processing and analysis of microplastics in water and sediment, and the findings related to forms, polymer types, colours and sizes. Microplastics are frequently detected in various freshwater ecosystems across six continents, including lakes, rivers, estuaries, and wetlands. The reported microplastic concentrations span eight orders of magnitude in freshwater (1.2 × 10−3 to 5.42 × 105 particles/m3) and six orders of magnitude in sediments (8.1 × 10−1 to 9.5 × 105 particles/kg). Various forms, polymer types, colours and sizes of microplastics have been reported in water and sediment However, the heterogeneity in filter sizes, sampling and sample processing methodologies, and units of reporting between different studies make it difficult to bring together all studies and produce a comprehensive picture of the current state of knowledge. The results also highlight a lack of standardised quality assurance and quality control (QA/QC) protocols, which further makes meaningful assessment of the current literature difficult. We recommend using a consistent language for reporting microplastic concentrations and forms as well as providing more detailed information about sizes and chemical composition of microplastics to facilitate comparisons between studies. In addition, a comprehensive QA/QC protocol needs to be implemented during MP monitoring, especially, negative (field and laboratory) and positive controls, to produce reliable results.Full Tex
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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