1,720,972 research outputs found
Risk of groundwater contamination from nitrates in the Po basin (Italy)
No full textIn 1991, the EU promulgated the Nitrates Directive 91/676/EEC, with which it obliged member states to set up monitoring systems, to designate areas vulnerable to nitrate pollution, especially that of agricultural origin, and to activate protection plans, setting the initial target as 1993. After a long delay, Italy assimilated the directive in 1999 with the D.Lgs. 152/99 (legislative decree), which basically transferred responsibility for identifying vulnerable zones to the Regional Authorities. The Po river basin was, and still is, particularly problematical, with its surface aquifers containing generally high levels of particularly in the lower Piedmontese plain, in the Alessandria area, in the upper Milan valley and in the Emilia-Romagna plain. Taking these pollution levels into consideration, along with continual eutrophication of the Adriatic Sea, the EU enjoined Italy to define the entire Po valley as vulnerable, to avoid being penalised. Such a restrictive designation would, however, have had a highly negative effect on agriculture and to avoid this, the Regions of the Po basin, after long delays, set in motion a series of scientific studies in order to be able to limit the areas defined as vulnerable. This paper, in line with Regional policies, proposes a method that can be applied on a regional scale for identifying areas vulnerable to nitrate pollution. It uses a parametric indicator of Pollution Risk, which is the product of the SINTACS R5 and the IPNOA indicators: since the former indicator assesses the vulnerability of an aquifer, that is its susceptibility to absorption and spread of fluid or water-borne pollutant over time, while the latter studies the risk of pollution by nitrates of agricultural origin (that is, the amount of nitrates persisting in the territory), it is clear to us that the product of the two indicates the nitrate that may actually be present in the aquifer waters. The easy availability of input parameters for the model, the reliability of the output data, as compared with the results of monitoring various test sites in the Po valley, and the production of thematic maps, using GIS software, make the method a valid tool for the Regions when identifying zones vulnerable to nitrate pollution. The method is presented here with application to a test site of about 250 km2, situated in the lower Alessandria plain (Eastern Piedmont, Italy)
Groundwater nitrate contamination risk assessment: a comparison of parametric systems and simulation modelling
No full textGroundwater nitrate contamination is a source of rising concern that has been faced throughthe introduction of several regulations in different countries. However the methodologies used in thedefinition of Nitrate Vulnerable Zones are not included in the regulations. The aim of this work was tocompare different methodologies, used to asses groundwater nitrate contamination risks, based onparametric systems or simulation modelling. The work was carried out in Piedmont, Italy, in an areacharacterised by intensive animal husbandry, high N load, a shallow water table and a coarse type ofsub-soil sediments. Only N loads from agricultural non-point sources were considered. Differentmethodologies with different level of information have been compared to determine the groundwaternitrate contamination risk assessment: N load, IPNOA index, the intrinsic contamination risk fromnitrates, leached N and N concentration of the soil solution estimated by the simulation model. Thegood correlation between the IPNOA index and the intrinsic nitrate contamination risk revealed thatthe parameters that describe the soil in this area did not lead to a different classification of the parcels.The intrinsic nitrate contamination risk was greatly influenced by N fertilisation, however the effect ofthe soils increased the variability in comparison to the IPNOA index. The leached N and Nconcentration in the leaching were closely correlated. The dilution effect of percolated water wasalmost negligible. Both methodologies were slightly correlated to the N fertilisation and the twoindexes. The correlations related to the intrinsic nitrate contamination risk was higher than thoserelated to IPNOA, and this means that the effect of taking into account soil parameters increases thecorrelation to the prediction of the simulation mode
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
