1,720,984 research outputs found
Geoepidemiology of the Inhalable Airborne Particulate Matter (PM10): interpretation of the compositional data using Multivariate Statistical Analysis
No full textThirty-year changes (1970 to 2000) in bathymetry and sediment texture recorded in the Lagoon of Venice sub-basins, Italy.
Full text linkA detailed comparison was made of two bathymetric charts of the Lagoon of Venice (LV) from 1970 and 2000, in tandem with a comparison of sediment grain size data. Analysis of the data revealed marked changes in both morphology and sedimentation, with more than 50% of the 400 km2 assessed in this study 15-20 cm shallower in 1970 than in 2000. The four sub-basins into which the LV is subdivided saw different patterns of change.
The Northern basin A was identified as “pristine”, i.e. still in quasi-natural condition, with slight clay enrichment and a small degree of deepening (4-5 cm), essentially due to sea level rise (SLR).
The bathymetry and sedimentology of the northern-central sub-basin B (identified as “urban”) and the southern-central basin C (identified as “open”) were affected by infill activities and excavation of industrial navigation channels in the 1970s, causing the loss of ~ 60 km2 of mudflats, and creating an “open” lagoon.
The southernmost basin D (identified as “exploited-subsiding”) of the LV was found to be relatively unchanged and still in semi-natural condition.
Comparison of sediment types showed depletion of fine-grained fractions (< 22 µm) in all sub-basins except the northernmost one. Consequent enrichment in sand (> 63 µm) was recorded, except in the southern-central sub-basin C where medium and coarse sand fractions declined.
The results suggest that climate-related SLR accounts for a small fraction of bathymetric change, whilst variations in hydrodynamics (currents and wind patterns) and sediment supply are likely causal factors for the different evolution of the four sub-basins.
Definition of the attributes of each sub-basin provided data that was essential not only for the LV but also for predicting the fate of transitional environments facing both anthropic (fishing, navigation, land use changes) as well natural (SLR, eustatism) forcing factors
Inorganic Geochemical Indicators in Glacial Marine Sediments :Applications to the Paleoclimatic Fluctuations Recorded by Late Quaternary Squences in Antartica
No full textEvidence of climatic fluctuations by multivariate geochemical analysis: the case of a sedimentary record in the Ross Sea, Antartica
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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
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