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[Midland Railway, Engine Drawing Card, Sketch No. 6267]
No full textThis engine drawing card was created for Midland Terminal Railway, Class 10-26 D. Section J-10D. Sketch 6267. Copy Spec. C-2778
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
Vertical distribution of methane oxidation and methanotrophic response to elevated methane concentrations in stratified waters of the Arctic fjord Storfjorden (Svalbard, Norway)
Get PDFThe bacterially mediated aerobic methane oxidation (MOx) is a key mechanism in controlling methane (CH₄) emissions from the world’s oceans to the atmosphere. In this study, we investigated MOx in the Arctic fjord Storfjorden (Svalbard) by applying a combination of radio-tracerbased incubation assays (³H-CH₄ and ¹⁴C-CH₄), stable CCH₄ isotope measurements, and molecular tools (16S rRNA gene Denaturing Gradient Gel Electrophoresis (DGGE) fingerprinting, pmoA- and mxaF gene analyses). Storfjorden is stratified in the summertime with melt water (MW) in the upper 60m of the water column, Arctic water (ArW) between 60 and 100 m, and brine-enriched shelf water (BSW) down to 140 m. CH₄ concentrations were supersaturated with respect to the atmospheric equilibrium (about 3–4 nM) throughout the water column, increasing from ~20nM at the surface to a maximum of 72nM at 60m and decreasing below. MOx rate measurements at near in situ CH₄ concentrations (here measured with ³H-CH₄ raising the ambient CH₄ pool by >2 nM) showed a similar trend: low rates at the sea surface, increasing to a maximum of ~2.3nMday⁻¹ at 60 m, followed by a decrease in the deeper ArW/BSW. In contrast, rate measurements with ¹⁴C-CH₄ (incubations were spiked with ~450nM of ¹⁴C-CH₄, providing an estimate of the CH₄ oxidation at elevated concentration) showed comparably low turnover rates (>1nMday⁻¹) at 60 m, and peak rates were found in ArW/BSW at ~100m water depth, concomitant with increasing ¹³C values in the residual CH₄ pool. Our results indicate that the MOx community in the surface MW is adapted to relatively low CH₄ concentrations. In contrast, the activity of the deep-water MOx community is relatively low at the ambient, summertime CH₄ concentrations but has the potential to increase rapidly in response to CH⁴ availability. A similar distinction between surface and deepwater MOx is also suggested by our molecular analyses. The DGGE banding patterns of 16S rRNA gene fragments of the surface MW and deep water were clearly different. A DGGE band related to the known type I MOx bacterium Methylosphaera was observed in deep BWS, but absent in surface MW. Furthermore, the Polymerase Chain Reaction (PCR) amplicons of the deep water with the two functional primers sets pmoA and mxaF showed, in contrast to those of the surface MW, additional products besides the expected one of 530 base pairs (bp). Apparently, different MOx communities have developed in the stratified water masses in Storfjorden, which is possibly related to the spatiotemporal variability in CH₄ supply to the distinct water masses
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
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