1,721,558 research outputs found
Decoupling of Tibetan sedimentary sequence and Higher Himalayan Crystallines: Strain and paleotemperature constrains for the South Tibetan detachment system
The South Tibetan Detachment System: Thermal and mechanical transition from deeper to upper structural levels.
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
“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
We 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
Replay to comment on "Strain determinations and tectonic evolution in the Millen Range area (northern Victoria Land, Antarctica)" by R.H. Findaly.
A comparative U-Th-Pb (zircon-monazite) and 40Ar- 39Ar (muscovite-biotite) study of shear zones in northern Victoria Land (Antarctica): Implications for geochronology and localized reworking of the Ross Orogen
Mylonitic granites from two shear zones in northern Victoria Land (Antarctica) were investigated in order to examine the behaviour of the U-Th-Pb system in zircon and monazite and of the 40Ar- 39Ar system in micas during ductile deformation. Meso- and micro-structural data indicate that shear zones gently dip to the NE and SW, have an opposite sense of shear (top-to-the-SW and -NE, respectively) and developed under upper greenschist facies conditions. In situ U-Pb dating by laser-ablation inductively coupled plasma-mass spectrometry of zircon areas with well-preserved igneous zoning patterns (c. 490 Ma) confirm that granites were emplaced during the Early Cambrian to Early Ordovician Ross-Delamerian Orogeny. Monazite from the Bier Point Shear Zone (BPSZ) mainly yielded U-Th-Pb ages of c. 440 Ma, in agreement with in-situ Ar laserprobe ages of syn-shear muscovite and with most Ar ages of coexisting biotite. The agreement of ages derived from different decay schemes and from minerals with different crystal-chemical features suggests that isotope transport in the studied sample was mainly controlled by (re)crystallization processes and that the main episode of ductile deformation in the BPSZ occurred at c. 440 Ma. Cathodoluminscence imaging showed that zircon from the BPSZ contains decomposed areas with faint relics of oscillatory zoning. These areas yielded a U-Pb age pattern which mimics that of monazite but is slightly shifted towards older ages, supporting previous studies which suggest that 'ghost' structures may be affected by inheritance. In contrast, secondary structures in zircon from the Mt. Emison Shear Zone (MESZ) predominantly consist of overgrowths or totally recrystallized areas and gave U-Pb ages of c. 450 and 410 Ma. The c. 450-Ma date matches within errors most monazite U-Th-Pb ages and in-situ Ar ages on biotite aligned along the mylonitic foliation. This again suggests that isotope ages from the different minerals are (re)crystallization ages and constrains the time of shearing in the MESZ to the Late Ordovician. Regionally, results indicate that shear zones were active in the Late Ordovician-Early Silurian and that their development was partially synchronous at c. 440 Ma, suggesting that they belong to a shear-zone system formed in response to ∼NE-SW-directed shortening. Taking into account the former juxtaposition of northern Victoria Land and SE Australia, we propose that shear zones represent reactivated zones formed in response to stress applied along the new plate margin as a consequence of contractional tectonics associated with the early stages (Benambran Orogeny) of the development of the Late Ordovician-Late Devonian Lachlan Fold Belt
The Mangri shear zone in central Himalayas: The role of tectonometamorphic discoutinuities in the exhumation of crystalline units.
Strain determinations and tectonic evolution in the Millen Range area (northern Victoria Land, Antarctica)
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