1,720,953 research outputs found
Stima della qualità degli ambienti fluviali in aree urbane attraverso l’uso di bioindicatori ai fini della costituzione di corridoi ecologici. Caso di studio: fiume Aniene
No full textEstimating the environmental river quality in urban areas using bioindicators to restore ecological corridors. Case study: Aniene river
Rosalba Tamburro
Abstract
The present thesis aimed first to compare the application of a broad set of indicators founded on the plant and animal components of the river ecosystem with the scientific purpose to evaluate the goodness of the indices, their possible correlations, and their limits. Second, the study was conducted to assess the Aniene environmental quality inside Rome to provide fundamental knowledge on river quality useful for making proposals improving the urban ecological corridor.
The investigation was focused on the riparian vegetation, the river ecological state and his functionality inside Rome, from the Great Ring Road to the confluence with the Tiber river.
Twenty sampling sites were selected where vegetation survey was carried out and inside them other seven sites were chosen to conduct studies on macrobenthic (RQE_STAR_ICMi) and macrophyte (IBMR) communities. Physical-chemical parameters of water were carried out too. Finally, the Fluvial Functionality Index (IFF) was applied to establish a broader environmental value of the river that enclosed the urban pressure too.
All these investigations were carried out from April 2014 to October 2016. The floristic composition was analysed by means of transects comprising both water and riparian belts. Two bioindication models based on the plant species were applied to assess the habitat quality. They are represented by Ellenberg indicators and Hemeroby index for the evaluation of anthropogenic disturbance. The floristic matrix of 245 species X 104 relevès was subjected to multivariate statistical analysis for a first data exploration through Cluster Analysis (CA) and Principal Component Analysis (PCA). To identify and analyse the existence of the ecological gradients a bivariate Pearson correlation test was performed between the significative coordinates of the PCA and the 7 indicators set (Ellenberg and Hemeroby). The Pearson correlation analysis also was performed to verify the possible correspondence between the vegetation and the other indices and between them. Chemical analysis revealed a very poor percentage of water saturation of Oxygen concentration showing a lower water quality resulting from domestic, agricultural and factories pollutants. The most significant correlations between the indices of Ellenberg and Hemeroby is the one existing between indicators of luminosity and Hemeroby whose increase is accompanied by degradation of forest vegetation rearing towards more heliophilous conditions. These conditions seem to favour the continental indicators, when the mitigation effects of the shrub and the ocean species that accompany the riparian forests decrease. IBMR and emerobia calculated on the same list of species used for the calculation of the IBMR, are correlated by showing a parallel trend. The correlation of the IBMR with H calculated on the 25 species of the IBMR list and not with the total H, calculated on the whole set of species detected by Phytosociological detection, shows the limits of this European index which does not entirely correspond to the local flora. Especially about the quota of Mediterranean species that are missing or are underestimated in the databases currently available. The RQE_STAR_ICMi was inversely correlated with ecological disturbance conditions meaning that when Hemeroby decreases the macroinvertebrates presence rises.
The index of macroinvertebrates, on the other hand, had the same low values on all sites, indicating that the water quality everywhere was polluted. This finding confirms what in previous studies had already been demonstrated: the quality of water expressed by the macrobenthic community may not coincide with that expressed by the plant community. This identifies a different behaviour of fauna and flora compared to ecological factors. The Nutrient indicators (N) of Ellenberg were also correlated to NO3 confirming that domestic and agricultural pollutants contaminated the water.
Among the contaminants sodium and magnesium appear to be significantly related to the IBMR RQE. The work carried out identifies the need to use more indicators to identify the ecological state of the watercourses considering overall existing gradients and temporal variations, especially of macrophyte and spondal vegetation, that are most sensitive to environmental variables. It also identifies the need to consider faunistic data separately from floristic ones as the response to environmental variables is different. Finally, the investigation carried out on vegetation shows a fair resumption of near-natural formations to Populus nigra and Ulmus minor, which, though very fragmented, support the hope of reconstituting a wider riparian forest that can act as an ecological corridor in the urban area. The IFF has highlighted in detail the most compromised tracts that need riverway restoration. These results show that Mediterranean rivers, characterized by wide and well drained basins with dense and deep waters, develop a limited macrophyte diversity, while a self-purification function is surely exerted by the riparian vegetation, which is instead removed.
Therefore, it would be more appropriate to include the IFF, Ellenberg and Hemeroby indices to make the assessment of the ecological quality of the watercourse more reliable
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
Author Under Sail The Imagination of Jack London, 1893-1902
No full textIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Intro -- Title Page -- Copyright Page -- Dedication -- Contents -- Acknowledgments -- Introduction -- 1. Spirit Truth -- 2. From Absorption to Theatricality and Back Again -- 3. "I Will Build a New Present" -- 4. Sons as Authors -- 5. Fathers as Publishers -- 6. The Daughter as Author -- 7. Lovers as Authors -- 8. At Sea with the Family -- 9. Yellow News, Yellow Stories -- 10. The Return Home -- Notes -- Bibliography -- Index -- About Jay WilliamsIn Author Under Sail, Jay Williams offers the first complete literary biography of Jack London as a professional writer engaged in the labor of writing. It examines the authorial imagination in London's work, the use of imagination in both his fiction and nonfiction, and the ways he defined imagination in the creative process in his business dealings with his publishers, editors, and agents. In this first volume of a two-volume biography, Williams traverses the years 1893 to 1902, from London's "Story of a Typhoon" to The People of the Abyss. The Jack London who emerges in the pages of Author Under Sail is a writer whose partnership with publishers, most notably his productive alliance with George Brett of Macmillan, was one of the most formative in American literary history. London pioneered many author models during the heyday of realism and naturalism, blurring the boundaries of these popular genres by focusing on absorption and theatricality and the representation of the seen and unseen. London created an impassioned, sincere, and extremely personal realism unlike that of other American writers of the time. Author Under Sail is a literary tour de force that reveals the full range of London as writer, creative citizen, and entrepreneur at the same time it sheds light on the maverick side of machine-age literature.Description based on publisher supplied metadata and other sources.Electronic reproduction. Ann Arbor, Michigan : ProQuest Ebook Central, YYYY. Available via World Wide Web. Access may be limited to ProQuest Ebook Central affiliated libraries
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