1,721,041 research outputs found
Impacts of space, abundance and food web structure on parasite life cycles
No full textThe search for fundamental patterns or rules by which parasites establish and persist in free-living species is a rapidly expanding area of interest for both parasitologists and ecologists. Though host-parasite interactions are fairly well understood at the population level, little is known about parasitism at the community level, nor why some free-living species harbor many parasite taxa while others are seemingly resistant to parasite establishment. The purpose of this dissertation was to explore several species and community attributes that could be important to parasite establishment and persistence in both a marine saltmarsh (Tuckerton, NJ) and a freshwater riverine system (Raritan River, NJ). This study specifically emphasized feeding interactions, abundance and spatial distributions of free-living species and their respective helminth parasites. In Tuckerton saltmarsh, I observed a strong spatial patterning in trematode infections of the mudsnail, Ilyanassa obsoleta, and this pattern is strongly correlated with habitat type and host quality. At the community level (along with data from four previously published systems), trophically transmitted parasites were found to utilize asymmetric predator-prey interactions, in which predator hosts have many prey items and prey hosts have relatively few predators. In a pristine site along the Raritan River high resolution abundance data revealed that predator-prey interactions are spatially constrained by habitat and that this pattern was even stronger for host-host and parasite-host interactions. Finally, I found a decrease in efficiency of biomass transfer up trophic levels across a perturbation gradient in this river system. This pattern correlated with losses in both free-living and parasite diversity. However, the relationship between these factors and human impact was not linear, suggesting a threshold at which community structure becomes less invasible by parasites. Collectively, this study suggests that spatial context, in combination with community structure, can greatly affect parasite establishment and persistence and can be used to explain or predict which free-living species are more hospitable hosts.Ph. D.Includes bibliographical referencesby Wayne David Rossite
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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