1,720,990 research outputs found
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
Sedimentation and preservation of the Miocene Atacama Gravels in the Pedernales-Chañaral Area, Northern Chile: Climatic or Tectonic Control?
No full textIn recent years, longitudinal changes on the thin/thick-skinned tectonic styles of the Central Andes has been
intensively discussedwhile other studies have considered the role ofmass transfers on the unloading of the
orogen, and on the stress regime along the plate interface arising from changes on the volume of sediment
arriving into the Peru–Chile trench. The search for paleo-climate records is therefore crucial for our
understanding of the history of the Central Andes. In this paper, we focus on the Atacama Gravels, an
extensive blanket ofMiocene continental deposits filling a Neogene paleo-valley systemalong the southern
Atacama Desert in northern Chile. An east–west transect, between Pedernales and Chañaral (26°30′S),
enabled us to carry out a sedimentological and tectonic study of the Atacama Gravels, based on logging and
field observations along the Rio Salado canyon. New 39Ar–40Ar ages obtained on intercalated and overlying
ignimbrites date the beginning of the Atacama Gravels sedimentation at around the Oligocene–Miocene
boundary and cessation of sedimentation in the Late Miocene. Thirteen lithofacies, included within five
facies associations (A1 to A5) were identified. Depositional environments vary from proximal alluvial fan
(A1, A2) in the Precordillera through ephemeral fluvial (A3, A4) to distal playa lake (A5) in the Coastal
Cordillera. No evidences of synsedimentary deformation have been found, showing that the change from
sediment removal to sediment preservation cannot be explained by tectonic causes, and climate change
appears to be the dominant controlling factor of sediment preservation. A progressive change from semiarid
towards hyper-arid climatic conditions during theMiocene, led to a reduction on the transport capacity
of the fluvial system and sediment preservation along the paleo-valley system formed during the
Oligocene
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
Preservation of the Miocene Atacama Gravels in the El Salvador area, Northen Chilean Andes: Climate / Depositional-Erosional balance
No full textDispelling 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
Apatite (U–Th)/He thermochronology and Re–Os ages in the Altar region, Central Andes (31°30′S), Main Cordillera of San Juan, Argentina: implications of rapid exhumation in the porphyry Cu (Au) metal endowment and regional tectonics
Full text linkAltar is a large porphyry Cu (Au) deposit located in the Main Cordillera of Argentina, 20 km to the north of the giant Los Pelambres–El Pachón porphyry copper cluster, at the southern portion of the Pampean flat-slab segment of the Andes. Although this region hosts telescoped porphyry-epithermal deposits, the precise temporal relationship between porphyry emplacement, mineralization, cooling, and regional orogenic uplift are still poorly understood. New Re–Os molybdenite ages indicate that Altar orebodies are associated with two magmatic hydrothermal centers: Altar East (11.16 ± 0.06 Ma) and Altar Central (10.38 ± 0.05 Ma) formed at temporally distinct periods. New (U–Th)/He ages from the Early Permian and Late Eocene plutons, and the Middle Miocene subvolcanic stocks associated with Cu–Au mineralization of the Altar region reflect a rapid cooling pulse during the Middle Miocene (15.02 to 10.66 Ma) coeval with a major phase of tectonic shortening and regional uplift. The main pulse of rapid cooling and related tectonic uplift in the Altar region was synchronous with the formation of the hydrothermal systems and resulted in an increased focused metal endowment (Au–Cu grades) due to the telescoping of epithermal mineralization over the rapidly uplifted porphyry system. This 11–10 Ma tectonically triggered exhumation event coincides with the collision of the E-trending segment of the Juan Fernández Ridge with the Peru–Chile trench, at this latitude. Collision and ensuing ridge subduction may have driven a localized pulse of rapid cooling and exhumation of the Main Cordillera that has not been well documented to the north or south of the Altar–Los Pelambres region
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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