1,720,967 research outputs found
Provenance of the transparent gypsum crystals (Lapis specularis) and gypsum mortars in the windows from the churches of Rome: S. Sabina sull'Aventino and S. Giorgio al Velabro
Full text linkThe latest example of the traditional Roman use of lapis specularis crystals in windows panels instead of glass are represented by the Paleochristian- Early Medieval churches of Rome. The churches of S. Sabina sull’Aventino and S. Giorgio al Velabro were characterized by some of the most ancient examples of windows frameworks built using gypsum mortar. The light was penetrating the panels throughout openings covered by two or more embricated gypsum cleveage fragments less than 15 cm across and up to 7 mm-thick, a technique unknown in older Roman examples, which is clearly related to the availability of small and low-quality crystals. The petrography of the gypsum mortars and the strontium and sulfur isotope analyses of the crystals indicate two diff erent supply sources. A large group of window frameworks were produced using selenite rocks and lapis specularis crystals probably quarried from Tuscany, Sicily or Cyprus, whereas a window in S. Sabina was built using alabastrine gypsum and lapis specularis crystals quarried in Emilia-Romagna, Sicily, Cyprus or Southern Turkey
A New Messinian 87Sr/86Sr Curve for the Ain El Beida Section (Morocco): An Atlantic Perspective of the Mediterranean Salinity Crisis
No full textWe present a new 87Sr/86Sr curve for the time interval between 6.5 and 5.5 Ma of the Ain El Beida section (AEB, Atlantic side of Morocco). The location and the precessional-scale resolution of our curve allow to investigate the possible relationships between global paleoclimatic and palaeoceanographic trends and the high-amplitude hydrological changes of the Mediterranean during the Messinian salinity crisis (MSC). The values, obtained from planktic foraminifers, plot in the upper portion of the global ocean curve and show long- (at eccentricity scale) and short-term (precessional scale) oscillations; the latter are more evident during the maximum of eccentricity for both the 100 and 400 ka components, between 6.00 and 5.85 Ma. Negative 87Sr/86Sr anomalies are observed at insolation minima in phase with δ18O maxima, marking the glacial stages from TG34 to TG26. It is unclear whether these oscillations originated from local (river runoff) or global (glacial/interglacial) climatic forcing. Conversely, the evaporites of the coeval Primary Lower Gypsum (5.97–5.62 Ma) accumulated in the Mediterranean at insolation minima show positive anomalies at glacial stages TG32, 30, 28, and 26. Such an opposite trend is possibly related to the greater sensitivity of the Mediterranean Sea to river runoff during insolation maxima compared to the global ocean, as recorded at the Moroccan Atlantic margin. These observations and the deviation toward lower values of the Mediterranean Sr isotope curve starting at around 6.5 Ma, support the hypothesis of a progressive restriction of the Atlantic connections since the early Messinian, leading to the MSC
I trattati conclusi dall'Unione europea
No full textThis contribution looks at the impact determined by the Ukraine conflict on the European Union’s treaty-making power. The main objective is to assess the extent to which this conflict has affected the agreements concluded by the EU with the parties directly involved– primarily Ukraine and the Russian Federation. Still, reference will also be made to the treaty-based relations with Belarus, considering the position taken by this State during the armed aggression against Ukraine.
In the light of the above, the analysis is structured as follows. First, the impact of the conflict on the effectiveness of the agreements concluded by the Union will be examined (Sections 2 and 3). It will then be examined whether and to what extent the agreements concluded by the Union can be applied to the parts of Ukrainian territory occupied by Russian armed forces (Sect. 4). The analysis is completed by some concluding remarks (Sect. 5)
Le pietre naturali dei pavimenti musivi di Savignano.
No full textIl ritrovamento di significativi esempi di arte musiva romana a Savignano sul Panaro, oltre a rappresentare un'importante scoperta dal punto di vista archeologico, si è rivelato una preziosa occasione per ampliare le conoscenze riguardo i materiali lapidei utilizzati dai Romani nel contesto geografico emiliano, in particolare nel modenese1. Le grandi porzioni di pavimentazione a mosaico rinvenute hanno permesso di indagare la natura dei differenti litotipi utilizzati e definirne le principali località di approvvigionamento
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
Le pietre naturali rinvenute nello scavo del Parco Novi Sad
No full textAnalisi dei materiali lapidei archeologici rinvenuti nello scavo del Parco Novi Sad a Modena
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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