1,720,966 research outputs found
Seismic characterization of Pizzoli (Central Italy) to estimate site effects induced by near-fault earthquakes
No full textSedimentological and palynological analyses of a last glacial sediment core from Corvaro (central Italy).
No full textCartografia geomorfologica alla scala 1: 50.000: un esempio nell’area del Golfo di Orosei (Sardegna orientale)
No full textPlio-Quaternary geological evolution of the high Salto River Valley (Central Italy): the Marano De’ Marsi Unit
No full textThis paper summarizes the results of multidisciplinary researches carried out in a wide span of time on the earliest continental deposits
of the high Salto River valley. The study led us to characterize sedimentary environments, to analyze their relationships and to propose
a chronological attribution. Facies are referable to a complex depositional system consisting of a Gilbert-type lacustrine delta
and of slope-type partly interfingered fan deltas coming from the eastern border of the basin. The geological data collected allowed us
to refer the succession to a single sedimentary cycle; in Marano de’ Marsi area the paleodrainage and progradation directions were
also recognized.
To better constrain the chronological, paleoclimatic and paleoenvironmental context, detailed investigations have been conducted on
pelitic facies of the deltaic-lacustrine system in two sampling sites (an artificial outcrop at Marano de’ Marsi village and a borehole
near Borgorose village). Paleomagnetic analyses show that Marano de’ Marsi and Borgorose successions have a normal polarity and
generally low magnetic susceptibility values. Pollen diagrams from both sites mainly record a mid to high elevation forest pollen rain.
The existence of trees from different vegetation belts suggests the presence of a well developed mountain system in the surroundings.
In the case of Marano de’ Marsi section, these vegetation phases alternate with sudden, strong and short spreads of temperate and
subtropical taxa. These alternations suggest that important climate changes occurred, with cyclical forest variations typical of glacial /
interglacial periods of Pliocene and Early Pleistocene. Pollen and paleomagnetic data led us to refer both records to the Olduvai subchron,
at the end of the Pliocene; nevertheless, the possibility that the records deposited during the Gauss chron cannot be, definitely,
excluded.
Field geological data and magnetic fabric results suggest that the Marano de’ Marsi unit sedimentation took place in a basin developed
under extensional tectonic regime
Pollen and macrofossil analyses of Pliocene lacustrine sediments (Salto river valley, Central Italy)
No full textThe study of two sedimentary records sampled in the fluvio-lacustrine succession of high Salto river
valley (Rieti, central Italy) was originated in the frame of the Geomorphologic Map of Italy (APAT, 2008)
field survey and improved with a multidisciplinary approach addressed to a better knowledge of the Plio-
Pleistocene continental environments of central Apennines. The two successions are associated to
different sedimentary facies, with lateral heteropic relations: the deposits cropping out at Marano de’
Marsi are thought to represent deposition in the distal portion of a lacustrine delta, while those of
Borgorose took place in a frankly lacustrine environment.
The sediment succession from Marano de’ Marsi (11 m) was sampled from an outcrop, the one from
Borgorose (24.5 m) from a drillhole. Palaeomagnetic investigations carried out on both sediment records
indicate a normal magnetic polarity and very low magnetic susceptibility values.
In the record from Marano de’ Marsi section, gymnosperm pollen is prevailing. Four main and short
angiosperm arboreal pollen oscillations can however be observed, the oldest of which more marked. The
gymnosperms are mainly represented by Pinus haploxylon type, Pinus sylvestris type, Cedrus, Picea, Abies,
Cathaya, Tsuga, Taxodium type. Among angiosperms the dominant taxa, some of which at present extinct
in Italy, are Quercus, Zelkova, Ulmus, Carya and Pterocarya. The presence of pollen of subtropical taxa as
Nyssa, cfr. Rhoiptelea, Liquidambar, Engelhardia is worth to be mentioned. The investigation was integrated
also by a preliminary study of macrofossils. Fossil impressions with some organic matter of
angiosperm and gymnosperm leaves and seeds/fruits were ascribed to Acer cfr. monspessulanum, Carpinus
cfr. orientalis, Engelhardia, Fagus, Hedera, Liquidambar, Quercus, Rosa, Abies and Pinus.
The 24.5 m long sediment core from Borgorose resulted very poor in pollen, with the same list of
arboreal taxa, at present extinct in Italy, found at Marano de’ Marsi, and a diagramwas drawn only for the
stretch of the core between 3 and 8.2 m. Gymnosperms (P. haploxylon type is dominant, and accompanied
by P. sylvestris type, Picea, Taxodium type, Cedrus, and Tsuga) are always prevailing.
The results obtained by this interdisciplinary investigation indicate that Marano de’ Marsi and Borgorose
successions can be possibly attributed to the Upper Pliocene (normal polarity Olduvai subchron)
even if an older age, considering the present state of the art on Pliocene continental records, and the
peculiarity of the site and of the region, cannot be excluded
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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