1,720,983 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
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
Salmonella Enterica serovar Typhimurium induces rapid migration of dendritic cells into the gut lumen
No full textDendritic cells (DC)s are key elements for the immune responses and can operate as antigen sampling cells. We report now that they can also migrate into the gut lumen upon bacterial challenge. Isolated intestinal loops in BALB/c mice, C57/BL6 and C57/BL6 MyD88 knock out (KO) mice were infected with non invasive GFP-labelled S. Typhimurium strain SL1344 (?SPI1, rpsM-gfp), a derivative of the same strain lacking SPI1 and both fliC and fljB flagellin encoding genes, E. coli DH5a (/pZEP16, rpsM-gfp), or PBS. After three hours, luminal content was harvested, washed and DCs were separated. FACS was carried out to characterize and enumerate the recovered cells. Confocal microscopy (CM) and TEM were also performed.
Approximately 7 x 104 cells were present in loops treated with flagellated S. typhimurium SL1344, but not in loops belonging to the C57/BL6 MyD88 KO mice. Phenotypic analysis showed the presence of CD11c+, CX3CR1+, MHCII+, CD8a– and CD11b– cells associated with Salmonella. CM confirmed the increase of CD11c+ DCs in the gut lamina propria. TEM and CM showed bacteria associated with luminal DCs. These data show that Salmonella induces flagellin- and Toll-like receptor-dependent DC migration into the gut lume
Salmonella Enterica serovar Typhimurium induces rapid migration of dendritic cells into the gut lumen
No full textDendritic cells (DC)s are key elements for the immune responses and can operate as antigen sampling cells. We report now that they can also migrate into the gut lumen upon bacterial challenge. Isolated intestinal loops in BALB/c mice, C57/BL6 and C57/BL6 MyD88 knock out (KO) mice were infected with non invasive GFP-labelled S. Typhimurium strain SL1344 (?SPI1, rpsM-gfp), a derivative of the same strain lacking SPI1 and both fliC and fljB flagellin encoding genes, E. coli DH5a (/pZEP16, rpsM-gfp), or PBS. After three hours, luminal content was harvested, washed and DCs were separated. FACS was carried out to characterize and enumerate the recovered cells. Confocal microscopy (CM) and TEM were also performed.
Approximately 7 x 104 cells were present in loops treated with flagellated S. typhimurium SL1344, but not in loops belonging to the C57/BL6 MyD88 KO mice. Phenotypic analysis showed the presence of CD11c+, CX3CR1+, MHCII+, CD8a– and CD11b– cells associated with Salmonella. CM confirmed the increase of CD11c+ DCs in the gut lamina propria. TEM and CM showed bacteria associated with luminal DCs. These data show that Salmonella induces flagellin- and Toll-like receptor-dependent DC migration into the gut lume
Oral delivery of Lactobacillus casei Shirota modifies allergen-induced immune responses in allergic rhinitis
No full textBackground Changes in the composition of the gut microbiota have been implicated in the pathogenesis of allergic disorders, suggesting beneficial interactions between the intestinal immune system and specific bacterial strains. Lactobacilli are naturally present within the complex gastrointestinal microbiota of humans and they are currently present in many probiotic supplements.
Objective We sought to investigate the role that Lactobacillus casei Shirota (LcS) may play in modulating seasonal allergic rhinitis (SAR).
Methods The study format was double-blinded, placebo-controlled with 10 SAR sufferers in each group. We have documented and compared changes in immune status arising through the daily ingestion of a milk drink with or without live LcS, over a period of 5 months. Pre-, peak- and post-grass pollen season blood samples were collected for determination of plasma total IgE and grass pollen-specific IgG and IgE levels by an enzyme immunoassay. At the same time, cytokine levels were determined by flow cytometric bead array technology following culture of peripheral blood mononuclear cells for 6 days in the presence or absence of specific grass pollen antigens.
Results Volunteers treated with LcS showed a significant reduction in levels of antigen-induced IL-5, IL-6 and IFN-gamma production compared with volunteers supplemented with placebo. Meanwhile, levels of specific IgG increased and IgE decreased in the probiotic group.
Conclusion Changes in antigen-induced production of cytokines were observed in patients treated with probiotics. These data show that probiotic supplementation modulates immune responses in allergic rhinitis and may have the potential to alleviate the severity of symptoms
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