1,720,976 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
The resilience of bivalves to environmental stress
No full textHuman activities and climate change are causing irreversible changes in almost all marine environments. In these changing environments, it is the resilience of organisms that may decide whether they succeed or fail. Marine bivalves are habitat forming organisms, the species they support are intrinsically linked to their distribution. This thesis sought to determine whether habitat forming bivalves will be resilient to stressors at a magnitude predicted for the next 100 years. To answer this overarching question, experiments were done to test hypotheses on how stressors will interact to affect bivalves. Oysters currently exist in Sydney Harbour despite a multiple stressor environment including the influence of anthropogenic pollution and construction. These stressors were found to be causing biological impacts at a local scale and influencing patterns of distribution of both native and invasive oysters in Sydney Harbour. How current and future stressors will interact to impact bivalve populations remains unknown. Climate change is predicted too warm and acidify the oceans, which will potentially exacerbate existing environmental stressors. Separate manipulative experiments found that both pollution from anthropogenic sources, and emersion of oysters at low tide will interact with climate change to have synergistically negative effects on the physiology and reproduction of oysters. Intertidal organisms such as oysters are predicted to be resilient. Deep sea organisms are, however, predicted to have a low capacity for resilience. Manipulative experiments on the deep sea bivalve Acesta excavata found that pollution and climate change will interact to cause negative effects on the physiology and energy budget of A. excavata. These results represent important findings into how oyster and other bivalve populations may behave in a future environment that is heavily influenced by anthropogenic practices
Increased abundance of potentially pathogenic Vibrio and a marine heatwave co-occur with a Pacific Oyster summer mortality event
No full textThe Pacific Oyster (Crassostrea gigas) is an important aquaculture species, that has been globally affected by “summer mortality” outbreaks. The causes of summer mortality are often unclear, but several contributing factors have been implicated. To better understand the factors contributing to C. gigas summer mortality, we performed a 24 week experiment in tanks filled by a continuous flow of unfiltered surface seawater during a summer mortality high-risk period. Throughout this period, we measured a suite of environmental parameters, with weekly sampling to characterise the bacterial community composition, the abundance and diversity of the Vibrio genus, and the expression of oyster immune response genes. We observed three clear phases of oyster mortality: Phase 1 (day 0 to 75) was characterised by sporadic and low levels (mean < 1% per week) of oyster mortality; Phase 2 (day 82 to 119) involved constant levels of ongoing mortality (mean < 10% per week); and Phase 3 (day 125 to 161) involved a sharp increase in mortality (mean > 10% per week) reaching up to weekly mortality of 51%. The shift between phase 2 and 3 coincided with heavy rainfall and a marine heatwave (MHW) event at our study site, which lasted 13 days, when the average water temperature was elevated by 0.8 °C when compared to the weeks prior and following the MHW, and a maximum water temperature of 27.7 °C was reached. Oyster mortality was positively correlated with the occurrence of the MHW as well as bacterial and Vibrio abundance, and negatively correlated with seawater salinity that decreased from a salinity of 34.6 to 31.4 psu following rainfall events. In addition, the relative abundance of several Vibrio species, including V. campbellii, V. rotiferianus and V. owensii displayed positive correlations to oyster mortality. Shifts in the oyster-associated bacterial community and oyster immunity gene expression profiles occurred in parallel to increased mortality levels, with genes involved in the regulation of antimicrobial peptides (IkB1 and NF-kB p105) significantly over-expressed during high mortality. Overall, we observed a C. gigas mortality event that coincided with a marine heatwave, rainfall event and a shift in bacterial community composition. Our analyses provides further evidence for the putative role of Vibrio in summer mortality events.</p
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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