1,720,960 research outputs found
Spatial and temporal patterns of global freshwater use for food production and trade
Get PDFL'abstract è presente nell'allegato / the abstract is in the attachmen
The globalization of riverine environmental resources through the food trade
Get PDFWe quantify the impact of food consumption on local and foreign water resources through an indicator of the environmental value of the riverine water. This indicator takes into account both the local environmental relevance of the fluvial area where water is withdrawn (biodiversity richness, riparian vegetation, sediment transport, etc) and the downstream effects of water withdrawals. In the 1986–2013 period, food consumption has more than doubled its impact on foreign riverine environments, but still the international trade reduces the pressure of food consumption on global river system by 11%, as compared to an ideal situation where all food is produced locally. We also show the geography of country (or individual) responsibility on the environmental changes of world rivers. Hotspots of food-related river-environment degradation are found in Australia, Pakistan, South Africa, and Spain
The environmental cost of a reference withdrawal from surface waters: Definition and geography
Get PDFWorld freshwater ecosystems are significantly deteriorating at a faster rate than other ecosystems. Water
withdrawals are recognized as one of the main drivers of growing water stress in river basins worldwide. Over
the years, much effort has been devoted to quantify water withdrawals at a global scale; however, comparisons
are not simple because the uneven spatiotemporal distribution of surface water resources entails that the same
amount of consumed water does not have the same environmental cost in different times or places. In order to
account for this spatiotemporal heterogeneity, this work proposes a novel index to assess the environmental cost
of a withdrawal from a generic river section. The index depends on (i) the environmental relevance of the
impacted fluvial ecosystem (e.g., bed-load transport capacity, width of the riparian belt, biodiversity richness)
and (ii) the downstream river network affected by the water withdrawal. The environmental cost has been
estimated in each and every river section worldwide considering a reference withdrawal. Being referred to a
unitary reference withdrawal that can occur in any river section worldwide, our results can be suitably arranged
for describing any scenario of surface water consumption (i.e., as the superposition of the actual pattern of
withdrawals). The index aims to support the interpretation of the volumetric measure of surface water withdrawal with a perspective that takes into account the fluvial system where the withdrawal actually occurs. The
application of the index highlights the river regions where withdrawals can cause higher environmental costs,
with the challenge of weighting each water withdrawal considering the responsibilities that it has on downstream freshwater ecosystems
CWASI database: virtual water trade and water footprint of agricultural products (1961-2016)
No full textThe CWASI database is a unique and harmonized database of water footprint (WF) and virtual water trade (VWT) data in the period 1961-2016 (detailed trade starts in 1986). The database includes 370 agricultural products among which are crops, crop-based and animal-based products, both edible and non-edible. The database has been developed within the EU-funded CWASI project
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
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
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
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