1,721,051 research outputs found
Development of climate tipping damage metric for life-cycle assessment - the influence of increased warming from the tipping
Full text linkPurpose: The multiple climate tipping points potential (MCTP) is a novel metric in life-cycle assessment (LCA). It addresses the contribution of greenhouse gas emissions to disturb those processes in the Earth system, which could pass a tipping point and thereby trigger large, abrupt and potentially irreversible changes. The MCTP, however, does not represent ecosystems damage. Here, we further develop this midpoint metric by linking it to losses of terrestrial species biodiversity at either local or global scales. Method: A mathematical framework was developed to translate midpoint impacts to temperature increase, first, and then to potential loss of species resulting from the temperature increase, using available data on the potentially disappeared fraction of species due to a unit change in global average temperature. Results and discussion: The resulting damage MCTP expresses the impacts on ecosystems quality in terms of potential loss of terrestrial species resulting from the contribution of GHG emissions to cross climatic tipping points. The MCTP values range from 2.3·10–17 to 1.1·10–15 PDF (potentially disappeared fraction of species) for the global scale and from 2.7·10–17 to 1.1·10–15 PDF per 1 kg of CO2 emitted for the local scale. They are time-dependent, and the largest values are found for emissions occurring between 2030 and 2045, generally declining for emissions occurring toward the end of the century. Conclusions: The developed metric complements existing damage-level metrics used in LCA, and its application is expected to be especially relevant for products where time-differentiation of emissions is possible. To enable direct comparisons between our damage MCTP and the damage caused by other environmental impacts or other climate-related impact categories, further efforts are needed to harmonize MCTP units with those of the compared damage metrics
Impact of Crop Type on Biodiversity Globally
No full textABSTRACT The negative impact of agricultural land on biodiversity is widely recognized. However, there remains a knowledge gap regarding the role of different crop types in maintaining biodiversity within the agricultural landscape. By extracting biodiversity data from global datasets and classifying different crop types, we quantified the contribution of different crop types to biodiversity. Our results indicate that biodiversity levels vary widely among crop types. We found a general loss of biodiversity when natural vegetation is converted to agricultural land, and highest losses in fiber crops, cereals and oil crops, and least in other crops (such as coffee or cocoa) and in mixed crops. In general, perennial crops retain more biodiversity than annual crops. Losses of biodiversity can be mitigated through mixed cropping of multiple crop types, especially by combining annual and perennial crops. The negative impact of converting natural vegetation to agriculture is greater in tropical than in nontropical areas, and hence, the import of commodities from these biodiversity‐rich regions may be particularly detrimental. Given the ongoing increase in biodiversity losses from global intensification and expansion of agricultural land, maintaining or restoring natural vegetation, rating the crop‐type‐specific biodiversity, diversifying crops, and preferring perennial over annual crops, particularly in the tropics, need to be better considered and implemented in global agri‐environmental schemes.National Key Research and Development Program of China https://doi.org/10.13039/501100012166National Natural Science Foundation of China https://doi.org/10.13039/501100001809China Scholarship Council https://doi.org/10.13039/501100004543Natural Environment Research Council https://doi.org/10.13039/50110000027
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
The PREDICTS database: a global database of how local terrestrial biodiversity responds to human impacts
No full textBiodiversity continues to decline in the face of increasing anthropogenic pressures such as habitat destruction, exploitation, pollution and introduction of alien species. Existing global databases of species’ threat status or population time series are dominated by charismatic species. The collation of datasets with broad taxonomic and biogeographic extents, and that support computation of a range of biodiversity indicators, is necessary to enable better understanding of historical declines and to project – and avert – future declines. We describe and assess a new database of more than 1.6 million samples from 78 countries representing over 28,000 species, collated from existing spatial comparisons of local-scale biodiversity exposed to different intensities and types of anthropogenic pressures, from terrestrial sites around the world. The database contains measurements taken in 208 (of 814) ecoregions, 13 (of 14) biomes, 25 (of 35) biodiversity hotspots and 16 (of 17) megadiverse countries. The database contains more than 1% of the total number of all species described, and more than 1% of the described species within many taxonomic groups – including flowering plants, gymnosperms, birds, mammals, reptiles, amphibians, beetles, lepidopterans and hymenopterans. The dataset, which is still being added to, is therefore already considerably larger and more representative than those used by previous quantitative models of biodiversity trends and responses. The database is being assembled as part of the PREDICTS project (Projecting Responses of Ecological Diversity In Changing Terrestrial Systems – www.predicts.org.uk)
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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