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Palynological characterisation of the Lower Carnian of the Kea5 borehole (Koudiat El Halfa Dome; Central Atlas, Tunisia)
No full textIn Central Tunisia, the Triassic outcrops of the Koudiat El Halfa and Rheouis Domes are mainly composed of an evaporite-dominated succession.
The scarce biostratigraphic data available to date assign a Ladinian-Carnian age for the outcropping strata. The present palynological study data demonstrate an Early Carnian (Julian) age for the Triassic sediments penetrated by the KEA5 borehole in the Koudiat El Halfa Dome, which were previously considered to represent Middle Triassic. The palynological record mainly consists of Enzonalasporites vigens, Patinasporites densus,
Vallasporites ignacii, Brodispora striata, Samaropollenites speciosus, Ovalipollis pseudoalatus in association with Circumpolles species such as Praecirculina granifer, Camerosporites secatus and Duplicisporites granulatus. In addition, Lagenella martini and Aulisporites astigmosus occur in the upper part of the drilled succession and their first appearance could indicate a Julian-Early Tuvalian age. These new data allow a palynostratigraphic correlation with the Rheouis Formation cropping out along the structural ‘‘North–South Axis’’ of Central Tunisia, particularly in the Jebel Rheouis Dome. The drilled succession can be correlated with the Black Dolostones (Tr3) and the Middle Gypsum (Tr4) members of the Rheouis Formation
A Carnian (Julian) microflora from the Djerba Melita 1 borehole (Gulf of Gabes, South-eastern Tunisia)
No full textThis study represents a contribution to the biostratigraphic characterization of the Gulf of Gabes Triassic series. Diverse and well preserved palynological assemblages from the Djerba Melita 1 (DJM1) well in the Djerba Island (Gulf of Gabes, Southern Tunisia) are here presented and discussed. A Carnian microflora is recorded in the Triassic portion of the drilled succession. The co-occurrence of Ladinian-lower Carnian taxa in association with typical Carnian elements allows to refer the microflora to the lower part of the Duplicisporites continuus palynological assemblage (late Julian, Austrotrachyceras austriacus Subzone). A semi-quantitative analysis of the assemblages also seems to document the occurrence, in the middle-upper part (units 3 and 4) of DJM1 well of the Aulisporites-Aratrisporites Acme Zone, an ammonoid-calibrated palynological event occurring in several European successions, referring to the late Julian/early Tuvalian. The occurrence of this acme zone in Southern Tunisia encourages its application also to Triassic sedimentary records belonging to the southern Tethyan margin
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Probiotic properties of Brevibacillus brevis and its influence on sea bass (Dicentrarchus labrax) larval rearing
No full textVariations on the Author
Get PDF“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
Get PDFWe 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
Get PDFWe 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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