1,721,042 research outputs found
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe 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
Full text link“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
Full text linkWe 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
Role of osteopontin in dendritic cell shaping of immune responses
Full text linkOsteopontin (OPN) is a pleiotropic cytokine produced both by immune and non-immune cells and active on different cellular targets. OPN production has been associated with several pathological conditions, including autoimmune diseases (e.g. lupus, multiple sclerosis and rheumatoid arthritis) and cancer. Emerging evidence suggests that the role of OPN has been underestimated, as it seems to be working at multiple levels of immune regulation, such as the shaping of T cell effector responses, the regulation of the tumor microenvironment, and the functional interaction with mesenchymal stromal cells. In this context, dendritic cells (DCs) play a crucial role being both an important source and a cellular target for OPN action. DC family is composed by several cell subsets endowed with specific immune functions. OPN exerts its biological functions through multiple receptors and is produced in different intracellular and secreted forms. OPN production by DC subsets is emerging as a crucial mechanism of regulation in normal and pathological conditions and starts to be exploited as a therapeutic target. This review will focus on the role of DC-derived OPN in shaping immune response and on the complex role of this cytokines in the regulation in immune response
TLR4-mediated signalling potentiates the expression of IFNβ mRNA in human phagocytes transfected with plasmid DNA.
No full textThe detection of intracellular DNA of bacterial or viral origin is critical to induce a proper innate immune response to pathogens, which often includes the production of type I interferons. However, knowledge of how intracellular DNA is sensed, particularly in human immune cells, is still limited. This being said, we have optimized an electroporation method to efficiently transfect plasmid DNA into neutrophils and monocytes (including a plasmid carrying PKCε, since neutrophils do not express it). By doing so, we could observe a significant IFNβ mRNA expression - in the absence of LPS-stimulation - not only in PKCε-overexpressing neutrophils but also in cells transfected with a series of empty plasmids: LPS, however, further upregulated IFNβ mRNA in plasmid-transfected neutrophils, regardless of PKCε-overexpression. Notably, the same findings were observed also in autologous monocytes, which however constitutively display a functional PKCε. Consistent with the previous observations, immunoblotting and coimmunoprecipitation studies not only revealed that both monocytes and neutrophils constitutively express various cytosolic DNA sensors, including IFI16, LRRFIP1 and DDX41, but also identified IFI16 as the intracellular receptor recognizing transfected DNA. Furthermore, chromatin immunoprecipitation assays, targeting the IFNβ promoter, revealed that IFNβ mRNA induction occurred through the cooperative action of IRF3 activated by transfected DNA, and NF-κB activated by LPS. Taken together, data indicate that human monocytes and neutrophils recognize and respond to microbial cytosolic DNA, in terms of IFNβ induction, via IFI16 involvement. Data also uncover that, in DNAtransfected monocytes and neutrophils, LPS further upregulates the IFNβ transcription by specifically activating NF-κB
LE/shmania major. Infection of human monocytes selectively induces production of chemokines
No full textLeishmania are obligate intracellular parasites of monocytes, that may cause systemic disease or skin manifestations in humans. Leishmanial lesions are constituted of infected cells surrounded by macrophages interspersed with lymphocytes and polymorphonuclear cells (PMN). Since leukocyte infiltration is a common event of any inflammatory response, and monocytes are a major source of cytokines with chemotactic properties for PMN (IL-8) and for monocytes (MCAF), we asked whether L major might induce monocytes production of chemokines. Human monocytes were infected with L major ; supematants, that were collected after 18 hours of incubation, had chemotactic properties for monocytes as well as for PMN. Anti-MCAF Ig neutralized up to 52% of the monocyte chemotactic activity while anti-IL-8 neutralized up to 73% of the PMN chemotactic activity. Then we investigated whether chemokines expression by Le/shmama-infected-monocytes were accompanied with production of proinflammatory cytokines. TNF-o and IL-1II were detected at concentrations about 20 times lower than IL-8 in supematants derived from J.e/sftmama-infected monocytes while LPS was effective to the same extent to induce TNF-a, IL-1S and IL-8 secretion. These results suggest that L. major might induce a selective activation of monocytes for chemokines production to determine the recruitment of host cells permissive to the parasite
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
- …
