1,720,959 research outputs found
Methodological approach to assessment of groundwater contamination risk in an agricultural area
No full textWater contamination by nitrates of agricultural origin is a major problem in Sardinia (Italy) where Nitrate Vulnerable Zones (NVZs) has been identified in the Arborea reclamation area (W. Sardinia), where intensive agriculture and farming are the mainstays of the local economy. Agricultural practices have seen an increase in the use of animal and chemical fertilizers for enhancing soil productivity. This, accompanied by the intensive use of groundwater resources for irrigation has led to the deterioration of groundwater quality, in areas particularly vulnerable to nitrate contamination. In the test area, the intrinsic nitrate contamination risk from agricultural sources has been evaluated through the combined application of the parametric methods, SINTACS, SI and IPNOA. Risk assessment, using vulnerability and hazard mapping, is considered a fundamental aspect of sustainable groundwater management. All parameters used in this risk assessment were prepared, classified, weighted and integrated in a GIS environment. Results show that nitrate concentrations are located in those areas where agricultural and livestock farming are concentrated. These results could, consequently, be interesting for future development and long term planning of groundwater protection management. The risk methods adopted, verified by comparing the distribution of nitrates in the groundwater with the different vulnerability classes, proved to be a valid tool. In fact the areas with nitrate concentration of more than 100 mg/l coincide well with those at high risk identified by the model and the areas with nitrate concentration of less than 25 mg/l closely match those areas with low and moderate risk
Monitoring erosion risk with ERMIT model: a case study in North Sardinia, Italy
No full textWildfires are one of the most widespread factors of ecosystem degradation around the world. The present note reports the first experimental results of a wider-scale research project, whose aim is to develop methods for the analysis and the collection of field data, by means of a multidisciplinary approach, to evaluate land erosion hazard. The experimental area is located in Mediterranean basin, on a steep slope in a hilly area of north-western Sardinia (Municipality of Ittiri, Italy), where a human caused fire occurred in August 2013. The area is mainly covered by the typical Mediterranean vegetation. The forest fire spread through the study area in August 2013 and the burn severity has been moderate, according to USDA burn severity classification system. After the fire, sediment fences were installed to trap sediments eroded by natural rainfall. Precipitations were recorded using tipping bucket rain gauge installed at the site. Soil erosion rates from experimental plots were measured and estimated with silt fences technique taking into account different slopes and vegetation distribution. The study aims to compare the results obtained by ERMIT (Erosion Risk Management Tool) model application and post-fire sediment yields measured in the study area. The application of the model shows that the area experienced most of erosion after the first rain events after fire occurring. Comparing experimental and model estimated data, there is evidence of ERMiT model overestimating in respect of sampled data for the first year. Future experimental data are needed to confirm this assumption and to contribute to calibrate ERMiT in a Mediterranean typical vegetation and climate environment
Incorporating the visibility analysis of fire lookouts for old-growth wood fire risk reduction in the Mediterranean island of Sardinia
Full text linkSardinia is subject to many fire events each year. A visibility analysis of old-growth woods from the network of fire lookouts was performed; the visibility of fires from lookouts and the level of old-growthness of woods were then implemented to the common information of wildfire hazard maps to obtain a vulnerability map. The results show that 78% of Sardinian old-growth woods are visible from lookouts and that 99% of them fall into the network of protected areas. However, old-growth woods are unevenly protected from fires, with visibility coverages ranging from 40% in the Sulcis macro-area to 100% in others. Compared with the wildfire hazard map, the vulnerability map led to different outputs in terms of fire protection prioritization, allowing better risk assessment and improved fire control planning. The integration of other parameters into wildfire hazard maps is a replicable focus-oriented approach that might be tested in other contexts
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
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