1,720,977 research outputs found
A cell line resource derived from honey bee (Apis mellifera) embryonic tissues
No full textA major hindrance to the study of honey bee pathogens or the effects of pesticides and nutritional deficiencies is the lack of controlled in vitro culture systems comprised of honey bee cells. Such systems are important to determine the impact of these stress factors on the developmental and cell biology of honey bees. We have developed a method incorporating established insect cell culture techniques that supports sustained growth of honey bee cells in vitro. We used honey bee eggs mid to late in their embryogenesis to establish primary cultures, as these eggs contain cells that are progressively dividing. Primary cultures were initiated in modified Leibovitz’s L15 medium and incubated at 32°C. Serial transfer of material from several primary cultures was maintained and has led to the isolation of young cell lines. A cell line (AmE-711) has been established that is composed mainly of fibroblast-type cells that form an adherent monolayer. Most cells in the line are diploid (2n = 32) and have the Apis mellifera karyotype as revealed by Giemsa stain. The partial sequence for the mitochondrial-encoded cytochrome c oxidase subunit I (Cox 1) gene in the cell line is identical to those from honey bee tissues and a consensus sequence for A. mellifera. The population doubling time is approximately 4 days. Importantly, the cell line is continuously subcultured every 10–14 days when split at a 1:3 ratio and is cryopreserved in liquid nitrogen. The cell culture system we have developed has potential application for studies aimed at honey bee development, genetics, pathogenesis, transgenesis, and toxicology.Goblirsch, Michael J.; Spivak, Marla S.; Kurtti, Timothy J.. (2013). A cell line resource derived from honey bee (Apis mellifera) embryonic tissues. Retrieved from the University Digital Conservancy, 10.1371/journal.pone.0069831
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
Experimental data associated with the study "The Ixodes scapularis symbiont Rickettsia buchneri inhibits growth of pathogenic Rickettsiaceae in tick cells: implications for vector competence"
No full textSpreadsheets containing raw data from fluorescent plate reader experiments detailed in the research paper.These experimental data are made available as part of the study "The Ixodes scapularis symbiont Rickettsia buchneri inhibits growth of pathogenic Rickettsiaceae in tick cells: implications for vector competence" published in Frontiers in Veterinary Science.
Abstract: The blacklegged tick Ixodes scapularis is a vector of pathogens of medical and veterinary importance in North America. Unlike other important human-biting Ixodes species however, this tick does not transmit pathogenic Rickettsia species, instead hosting a rickettsial endosymbiont, Rickettsia buchneri. A gene cluster encoding aminoglycoside antibiotic biosynthesis machinery has been identified in R. buchneri, which is not present in other rickettsiae, and therefore antibiotic production might represent a mechanism by which the endosymbiont is able to exclude pathogenic Rickettsia species from I. scapularis. This study identifies a second antibiotic cluster in R. buchneri with genes similar to polyketide/non-ribosomal peptide synthesis genes. Using cell culture experiments we provide evidence that infection of tick cells with R. buchneri, even at low rates, significantly reduces the ability of the pathogens Anaplasma phagocytophilum and R. parkeri to infect and replicate in cells, whereas the presence of low-pathogenic R. amblyommatis or the endosymbiotic R. peacockii in cells only partially reduced infection by R. parkeri. This research suggests a potential role of the endosymbiont in preventing other rickettsiae from colonizing I. scapularis and/or being transmitted transovarially. Whilst a link between the observed inhibition and antibiotic production is yet to be confirmed, this work contributes further to our understanding of rickettsial competition and how endosymbionts might alter vector competence by preventing colonization of the tick by pathogens.National Institutes of Health (grants R01 AI49424 and R01 AI081690 to UGM)University of Minnesota Agricultural Experiment StationCull, Benjamin; Burkhardt, Nicole Y; Wang, XinRu; Thorpe, Cody J; Oliver, Jonathan D; Kurtti, Timothy J; Munderloh, Ulrike G. (2021). Experimental data associated with the study "The Ixodes scapularis symbiont Rickettsia buchneri inhibits growth of pathogenic Rickettsiaceae in tick cells: implications for vector competence". Retrieved from the University Digital Conservancy, https://doi.org/10.13020/ZQXG-JF78
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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