1,720,999 research outputs found
Disrupted and chaotic rock units
No full textMany important geological concepts and features were first recognized and described in the Apennines and Sicily. In these areas, among the most distinctive features are rock units characterized in outcrop by variably disrupted strata or blocks
of diverse sizes disposed in a clay-rich matrix. The stratal disruption and the intense weathering give an overall chaotic or non-bedded appearance to these units, and various names have been used for
them, including argille scagliose, argille brecciate, caotico eterogeneo, Chaotic Complex, Undifferentiated Complex, Ligurian mélange, and olistostrome. Some of these terms, such as argille scagliose and olistostrome, have been applied to mélanges in
other mountain chains, even while Apennine geologists continued to debate whether local examples resulted from tectonic or gravitational processes. The purpose of this chapter is to provide a brief review of past and current research on disrupted rock units in the Apennines. First, we briefly review how the nomenclature originated and evolved. Second, we summarize the criteria that are
currently being used in the Northern Apennines to subdivide these units into two major types, tectonosomes and olistostromes, which originated by in situ tectonic deformation and by gravitational
mass movements, respectively
Late thrust propagation and sedimentary response in the thrust belt-foredeep system of the Southern Apennines (Pliocene-Pleistocene)
No full textLandscape Influences on the Development of the Medieval–Early Renaissance City-states of Pisa, Florence, and Siena, Italy
No full textThe objective of this chapter is to analyze how the
local landscape and environmental conditions influenced
the evolution of the city-states of Pisa, Florence
(Firenze), and Siena, primarily from the High (∼1000–
1300 AD) to Late Medieval Age and early Renaissance
(∼1300–1500 AD). The three cities are located in the
province of Tuscany in the central north-western part
of Italy
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
Characterization of seasonal backscatter change in subarctic wetlands and river ice breakup using Radarsat data
No full textThe first objective of this research was to describe the backscatter response of Radarsat images to seasonal changes in the Hudson Bay Lowland. The second objective was to evaluate the potential of Radarsat images for predicting river ice cover breakup. Six Standard Mode images from spring, summer and fall, 1996 were used for the first objective. The backscatter response from numerous land covers was assessed and plotted over time. Environmental changes influenced backscatter more than incidence angle. Backscatter was low in spring due to the wet snow cover. Backscatter increased to a June peak because of the disappearance of snow and the increasing moisture content of vegetation. A decline into August was tied to declining amounts of water in vegetation and surface layers and a further backscatter decline into November was tied to deposition of new wet snow. Spring was found to be the best time of year for distinguishing between the land covers. Five Fine Mode images were used for the second objective. Three were pre-breakup and two were post-breakup. The images show many features indicative of approaching breakup including cracks, shear zones and texture changes from consistently mottled to distinctly patchy with circular, transverse and longitudinal bright features. Ice backscatter declined 2 to 4 dB from three weeks prior to just before breakup
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