1,721,015 research outputs found
Risk Based Prioritization of Organic Chemicals within the Chesapeake Bay Watershed
Full text linkDetection of chemicals of emerging concern (CECs) in aquatic systems is raising concern about exposure limits and environmental health. New Approach Methodologies (NAMs), which include a range of molecular and computational techniques, are being developed to help reduce animal-intensive toxicity testing with risk-based prioritization approaches. Certain NAMs are aimed at translating concentration data into risk assessment by comparing target chemical concentrations to a range of available toxicity data, including high-throughput bioassays and whole-organism toxicity endpoints, to prioritize “high risk” chemicals. This thesis applies such a geographic-based chemical prioritization approach to forecast risk in tributaries of the Chesapeake Bay and identify problematic contaminants for further research. Our study encompasses two distinct geographic scales: a micro-scale analysis focusing on a Potomac River tributary, assessing the impact of a local wastewater treatment plant (WWTP) and combined sewer overflows (CSOs); and a macro-scale analysis across multiple Chesapeake Bay tributaries, evaluating urban and agricultural land-use contributions to contaminant risk. In the micro-scale study, we identified several “high risk” chemicals that exceeded toxicity thresholds, especially psychotropic compounds. We found the highest potential risk near the WWTP and CSO outfalls at the Potomac River tributary; however, the risk levels dramatically decreased in the mainstem Potomac River, likely due to its greater flow. In the macro-scale study, we also identified several “high risk” chemicals that exceeded toxicity thresholds. We found greater chemical concentrations, especially hormone and pesticide compounds, with highest potential risk at sites where land-use was predominantly agricultural. These results support the need for further organism-specific and landscape studies to research the biological effects of “high risk” chemicals and risk correlations to agricultural land-use and WWTP sources
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
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
Evaluation of in vivo fish and amphibian endocrine test guideline assays: current status and future needs
No full textAbstract Endocrine pathways are crucial in regulating physiological functions in organisms, including growth and development, metabolism, tissue function, and reproduction. Exposure to endocrine disrupting chemicals (EDCs) can interfere with normal hormonal function and lead to adverse effects in organisms and/or their offspring. As a result, regulatory testing and assessment requirements have been implemented to identify and regulate EDCs—defined by the World Health Organization as chemicals that alter the function of an endocrine system and cause “subsequent adverse effects in an intact organism, its progeny, or (sub)populations” - although the approaches taken for assessment vary worldwide. As such, the current typical ecotoxicological assessment paradigm for EDCs involves initial testing for endocrine activity using in vitro and lower-tier in vivo assays, followed by higher-tier in vivo testing which can provide additional endocrine mechanistic data and establishes any consequent adversity. The Organisation for Economic Cooperation and Development and the United States Environmental Protection Agency, among other entities, have validated and adopted standardized in vivo test guidelines for mammals, fish, and amphibians. These tests can be challenging and take months to perform, and many require the use of large numbers of laboratory animals. This paper summarizes the current state of the science for evaluating the endocrine disrupting potential of chemicals in fish and amphibians using in vivo test guideline assays across the estrogen, androgen, thyroid, and steroidogenesis modalities. Current challenges associated with conducting and interpreting the in vivo assays are discussed. Opportunities and potential next steps to strengthen this growing area of testing are explored, including potential to inform development and application of new approach methodologies and thereby reduce reliance on using laboratory animals
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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