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    Going Beyond Counting First Authors in Author Co-citation Analysis

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    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

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    “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

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    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

    Point-bar brink and channel thalweg trajectories depicting interaction between vertical and lateral shifts of microtidal channels in the Venice Lagoon (Italy)

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    Although in tidal point bars, the point-bar brink (i.e. the break-in-slope between bar top and bar slope) and the channel thalweg (i.e. the deepest part of the channel) are thought to shift horizontally toward the outer bank, the occurrence of stable to slow-migrating channels in high-aggradational settings, e.g. salt marshes, is likely to promote a mixed, latero-vertical shift of meandering channel systems. The present study focuses on the trajectories of point-bar brink and channel thalweg of eight point bars located in the salt marshes of the Venice Lagoon, in order to understand how vertical aggradation can interact with lateral migration to shape their stratal geometries. High resolution facies-analysis carried out on closely-spaced sediment cores, collected along the bar axis, allowed us to define specific trajectories, which were classified either as ascending or descending, and linear or non-linear. All the analyzed brink trajectories are ascending, and show evidence of lateral shift of the bar brink under aggradational conditions of surrounding marshes. Development of non-linear brink trajectories is linked with changes in the ratio between vertical and lateral shift rates of the brink, which is in turn dictated by changes in local base level due to substrate compaction. Conversely, the thalweg trajectories can be either ascending or descending, reflecting an interaction between rates of lateral shift and aggradation/degradation of the channel floor. The brink and thalweg can either shift consistently (e.g., both trajectories are ascending) or incongruously (e.g., ascending brink vs. descending thalweg trajectory), reflecting different attitudes of the channel to maintain or increase its cross-sectional area

    Dispelling the Myths Behind First-author Citation Counts

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    We 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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    Control of wind-wave power on morphological shape of salt marsh margins

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    Salt marshes are among the most common morphological features found in tidal landscapes and provide ecosystem services of primary ecological and economic importance. However, the continued rise in relative sea level and increasing anthropogenic pressures threaten the sustainability of these environments. The alarmingly high rates of salt marsh loss observed worldwide, mainly dictated by the lateral erosion of their margins, call for new insights into the mutual feedbacks among physical, biological, and morphological processes that take place at the critical interface between salt marshes and the adjoining tidal flats. We combined field measurements, remote sensing data, and numerical modeling to investigate the interplays between wind waves and the morphology, ecology, and planform evolution of salt marsh margins in the Venice Lagoon of Italy. Our results confirm the existence of a positive linear relationship between incoming wave power density and rates of salt marsh lateral retreat. In addition, we show that lateral erosion significantly decreases when halophytic vegetation colonizes the marsh margins, and that different erosion rates in vegetated margins are associated with different halophytes. High marsh cliffs and smooth shorelines are expected along rapidly eroding margins, whereas erosion rates are reduced in gently sloped, irregular edges facing shallow tidal flats that are typically exposed to low wind-energy conditions. By highlighting the relationships between the dynamics and functional forms of salt marsh margins, our results represent a critical step to address issues related to conservation and restoration of salt marsh ecosystems, especially in the face of changing environmental forcings
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