1,721,653 research outputs found
The coral fauna of Vitigliano: qualitative and quantitative analysis in a back reef environment (Castro Limestone, Late Oligocene, Salento Peninsula, Southern Italy)
No full textThe Castro Limestone, Middle Chattian in age, consists of various reef facies and has been described as a fringing reef complex. The reef facies outcropping near Vitigliano and the associated coral fauna, which have been previously interpreted to be part of a back-reef subenvironment, are here defined both qualitatively and quantitatively. Three main quantitative methods have been used for the characterization of the back reef facies: 1) counts of coral colonies on a subvertical measured surface, 2) line-transects, 3) quadrats. The results obtained from the various quantitative methods are compared and discussed. Moreover the coral density has been quantified from both linear and areal measurements and has been evaluated to be around 20%. However, corals occur as scattered colonies and do not form a true framework
REEFCORAL: an efficient tool for evaluating the taxonomic and palaeoecological evolution of z-coral communities in the Cenozoic Mediterranean realm
No full textCon lo scopo di valutare ed interpretare l’evoluzione delle comunità a coralli della regione mediterranea durante il Cenozoico, è stato recentemente messo a punto il REEFCORAL database. Attualmente il database contiene più di 3000 presenze di generi di coralli ottenuti da 285 località oligo-miocenichedi regioni circum-mediterranee (incluso l’attuale Bacino del Mediterraneo, la Paratetide, e alcune aree del Medio-Oriente ed europee affacciate sull’Atlantico). Attraverso i dati ottenuti dal database è stato possibile ricostruire le variazioni nella ricchezza dei generi per l’intera regione mediterranea durante l’Oligo-Miocene. Inoltre, applicando la relazione quantitativa che lega la ricchezza tassonomica dei coralli di scogliera attuali alla temperatura media annuale dell’acqua (evidenziata dalla cosiddetta “Energy Hypothesis”), i dati relativi a 102 località selezionate sono stati testati come strumento per la stima di paleotemperature
REEFCORAL: a database for assessing the spatio-temporal distribution of z-coral carbonate producers.
No full textEstimating sea-surface palaeotemperatures from shallow-water carbonates: the example of Mediterranean Oligocene-Miocene corals.
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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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