1,720,961 research outputs found
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
Variations 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
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
Lithostratigraphy and lithogeochemistry of Ediacaran alkaline basaltic rocks of the Musgravetown Group, Bonavista Peninsula, northeastern Newfoundland, Canada: an extensional volcanogenic basin in the type-Avalon terrane
Get PDFVolcanic rocks of the Ediacaran Musgravetown Group on Bonavista Peninsula, Avalon terrane, Newfoundland, include basal ca. 600 Ma calc-alkaline basalt succeeded by continental tholeiite and alkaline rhyolite of the ca. 592 Ma Plate Cove volcanic belt (Bull Arm Formation), indicating a change from subduction-related to extensionrelated tectonic regimes during that interval. Alkalic basalts on northeastern (Dam Pond area) and southwestern (British Harbour area) Bonavista Peninsula occur below and above, respectively, the ca. 580 Ma glacial Trinity facies. Dam Pond basalt occurs in a structural dome intercalated with and flanked by fine-grained, siliciclastic deposits (Big Head Formation) overlain by Trinity facies. The British Harbour basalt occurs above the Trinity facies, in an upward- coarsening sandstone sequence (Rocky Harbour Formation) overlain by red beds of the Crown Hill Formation (uppermost Musgravetown Group). The Rocky Harbour and Big Head formations are likely stratigraphically interfingered proximal and distal deposits, respectively, derived from erosion of the Bull Arm Formation and older Avalonian assemblages.The Big Head basalts have lower SiO2, Zr, FeOT, P2O5, TiO2 and higher Mg#, Cr, V, Co and Ni contents, and are therefore more primitive than the more FeOT-, TiO2-, and P2O5-rich British Harbour basalts. Large-ionlithophile and rare-earth-element concentrations and ratios indicate that both suites originated from low degree partial melts of deep, weakly garnet-bearing, undepleted asthenospheric peridotite sources, with magma conduits likely focused along regional extensional faults. The protracted and episodic extension-related volcanic activity is consistent with a geodynamic setting that evolved from a mature arc into extensional basins with slowly waning magmatism, possibly involving slab rollback and delamination followed by magmatic underplating. The duration and variation of both volcanism and sedimentation indicate that the Musgravetown Group should be elevated to a Supergroup in order to facilitate future correlation of its constituent parts with other Avalonian basins.Les roches volcaniques du groupe d’Ediacara de Musgravetown sur la péninsule de Bonavista, terrane d’Avalon, à Terre-Neuve, comprennent des basaltes calcoalcalins basaux d’environ 600 Ma auxquels ont succédé de la tholéiite continentale et de la rhyolite alcaline de la ceinture volcanique d’environ 592 Ma de Plate Cove (Formation de Bull Arm), ce qui révèle un passage d’un régime tectonique de subduction à un régime d’extension durant cet intervalle. Les basaltes alcalins dans le nord-est (secteur de Dam Pond) et le sud-ouest (secteur de British Harbour) de la péninsule de Bonavista se manifestent au- dessous et au-dessus, respectivement, du faciès glaciaire d’environ 580 Ma de Trinity. Le basalte de Dam Pond apparaît dans un dôme interstratifié et flanqué de dépôts silicoclastiques à grains fins (Formation de Big Head) recouverts du faciès de Trinity. Les basaltes de British Harbour se trouvent au-dessus du faciès de Trinity, dans une séquence de grès à granulométrie croissante vers le haut (Formation de Rocky Harbour) recouverte de couches rouges de la Formation de Crown Hill (partie sommitale du groupe de Musgravetown). Les Formations de Rocky Harbour et de Big Head sont vraisemblablement stratigraphiquement interdigitées de dépôts proximaux et distaux, respectivement, provenant de l’érosion de la Formation de Bull Arm et d’assemblages avaloniens plus anciens.Les basaltes de Big Head ont des teneurs inférieures de SiO2, de Zr, de FeOT, de P2O5 et de TiO2, et des teneurs supérieures de Mg#, de Cr, de V, de Co et de Ni; ils sont en conséquence plus primitifs que les basaltes plus riches en FeOT, en TiO2 et en P2O5 de British Harbour. Les ratios et les concentrations d’éléments lithophiles à grand rayon ionique et de métaux des terres rares signalent que les deux suites proviennent de fontes partielles de faible degré de sources de péridotite asthénosphérique non appauvrie, faiblement grenatifère, profondes, avec des conduits magmatiques probablement concentrés le long de failles d’extension régionales. L’activité volcanique apparentée à l’extension, prolongée et épisodique, correspond à un milieu géodynamique ayant évolué d’un arc à maturité en bassins d’extension au magmatisme s’affaiblissant lentement, comportant possiblement un repositionnement de dalles et une délamination suivis d’un sous-placage magmatique. La durée et la variation du volcanisme et de la sédimentation révèlent que le groupe de Musgravetown devrait être reclassé en un supergroupe pour faciliter la corrélation future de ses composantes avec d’autres bassins avaloniens
A field, petrographical and geochemical investigation of the Kennack Gneiss, Lizard Peninsula, southwest England
No full textThe Lizard complex of southwest England is considered to represent a thrust slice of Devonian oceanic crust, emplaced onto the Gramscatho flysch basin during the Middle Devonian. The ophiolite is an incomplete sequence consisting of strongly deformed basaltic lavas and interflow sediments (Landewednack and Old Lizard Head Series schists respectively), overlain by serpentinized peridotites and lherzolites, variable gabbro and a restricted sheeted dyke complex. Intruded into the basal, serpentinized ultramafic rocks are a suite of compositionally banded rocks called the Kennack Gneiss. Excluding some late mafic dykes, the Kennack Gneiss is the youngest rock suite present, because portions of the gneiss intrude and cross-cut the foliations of all the other rock types. -- The banded Kennack Gneiss consists of distinct felsic and mafic fractions. Field relationships with other units indicate an intrusive igneous nature for the Kennack Gneiss and the relationships between the felsic and mafic fractions of the gneiss suggest that magma-mingling and possibly mixing have played a significant role in generation of these rocks. Digestion of plastic gabbroic xenoliths by felsic material, net-veining of silicic material in microgabbro and flame-like interfingering of felsic and mafic fractions all support the proposal of magmatic mingling. -- Field relationships also indicate that the mafic fraction of the Kennack Gneiss is distinct from the hornblende schists, and that some mafic dykes are genetically related to the mafic fraction of the Kennack Gneiss. Variably deformed pegmatitic gabbro within the map area appears to be only slightly older than the Kennack Gneiss and is significantly different in chemistry from the Crousa gabbro. -- Harker variation diagrams for the Kennack Gneiss as a whole show variable trends. The presence of curvilinear trends indicates that a restite separation or in situ metamorphic segregation processes may be discounted as viable hypotheses. Instead, fractional crystallization, thermogravitational diffusion or magma-mixing are favored. The trace element chemistry of the Kennack gneiss indicates that magma-mixing is the most favorable of the three. This is demonstrated through irregular inter end member trends not easily explained through traditional fractional crystallization processes. -- Negative colinear variations with silica dominate the felsic fractions of the Kennack Gneiss. MgO variation diagrams for the mafic fractions of the gneiss show a high degree of scatter, but particular elements (CaO, Na₂O, SiO₂ and Sr) exhibit curvilinear covariance with MgO. These points suggest that the felsic fractions are interrelated through mixing, while the mafic fractions are interrelated through progressive fractional crystallization. This indicates that the chemical and physical evolution of the felsic fractions has been dominated by magmatic mingling and mixing of a silicic magma with a late stage differentiate of the mafic fractions. Although the majority of the chemical data for the felsic rocks supports mixing, a number of elements, Y, Nb, possibly Th and U and the rare earth elements exhibit strong enrichment/depletion trends which are difficult to interpret. However, careful interpretatiqn indicates that the felsic fractions of the gneiss were initially generated through partial melting of a crustal source, intermediate in composition which contained abundant plagioclase and a HFSE bearing phase such as zircon. These crustal melts underwent crystal fractionation of alkali feldspar as well as a LREE bearing phase (monazite?), as indicated by the extreme enrichment of the Y, Nb and possibly the HREE in the most evolved silicic rocks. Following this crystal fractionation, the felsic magma was intruded into a magma chamber containing the mafic fraction of the gneiss. Mixing of the felsic magma and the most differentiated portions of the mafic magma occurred, however, mixing was only local as demonstrated by the mingled state now observed in the field. The mingled and partially mixed magmas were then intruded along the base of and into the Lizard peridotite. Intrusion of the Kennack Gneiss was synchronous with displacement of the Lizard complex from the oceanic regime. The strongly banded character of the Kennack Gneiss resulted from a high strain gradient at the base of the Lizard complex at that time. -- Major element chemistry of the mafic fractions suggest a volcanic arc influence in generation of these rocks. Similarly, trace and rare earth element chemistry in combination with tectonic discrimination diagrams support a volcanic arc setting of generation for the two magmas. These observations have significant implications for the geotectonic history of the Lizard complex.Bibliography: leaves 281-291
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
