1,720,965 research outputs found
The Effect of Chronic Psychological Stress on the Cutaneous Immune Response in the Development of a Contact Hypersensitivity Reaction
No full textIncreasing evidence demonstrates that psychological stress can have an impact on the cutaneous immune response. While there have been many studies examining the impact of acute stress on an allergic contact dermatitis model, there are few studies concerning the impact of chronic psychological stress. Furthermore, the mechanism of the impact of chronic stress on contact hypersensitivity remains to be fully explored. Here we show that chronic restraint stress induces activation of the hypothalamus-pituitary-adrenal axis and delays weight gain in female BALB/c mice. In addition, we observed that chronic psychological stress reduces the cutaneous immune response in a contact hypersensitivity reaction. This suppression was not observed 30 days after stress cessation, suggesting the impact of chronic stress is a transient occurrence. Additionally, chronic stress does not influence T cell proliferation, activation, or sensitivity to glucocorticoids. In response to contact hypersensitivity, chronic stress induces a decrease in overall circulating white blood cells, lymphocytes, and monocytes. This correlated to decreased dermal infiltrate and increased percentages of CD4+ and CD8+ T cells in auricular lymph nodes. In addition, decreased amounts of local IFN-γ were observed in inflamed ear tissue of chronically stressed mice. Overall, the results suggest that chronic psychological stress reduces contact hypersensitivity reactions in a relatively transient manner and disrupts local immune cell trafficking resulting in reduced IFN-γ production
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
Extracellular Superoxide Dismutase Indirectly Enhances the Release of Immature Neutrophils from the Murine Bone Marrow
Get PDFExtracellular superoxide dismutase (ecSOD) regulates extracellular concentrations of reactive oxygen species (ROS) to protect tissues during infection and inflammation. Using ecSOD HI, ecSOD WT, and ecSOD KO mice, we have previously shown that ecSOD activity enhances neutrophil recruitment to the liver, yet inhibits the innate immune response against Listeria monocytogenes leading to increased host susceptibility. Using adoptive transfer experiments, we observed that ecSOD activity does not affect neutrophil recruitment or function in a cell-intrinsic manner. Additionally, we noted that ecSOD activity results in decreased retention of immature neutrophils in the bone marrow without altering granulopoiesis. Furthermore, we determined that ecSOD activity protects the extracellular matrix (ECM) and increases concentrations of neutrophil-attracting chemokines leading to an increase in immature neutrophils in the liver.
Since ecSOD can be produced by cells from the hematopoietic lineage as well as non-hematopoietic cells, we used bone marrow chimeric mice to investigate the relative contribution of ecSOD produced by cells from each lineage. Ultimately, it was determined that ecSOD from both hematopoietic and non-hematopoietic cells contributes to the overall phenotype observed in ecSOD congenic mice. Collectively, our data suggest that ecSOD activity inhibits degradation of the ECM and promotes egress of immature neutrophils out of the bone marrow and into the liver where they provide inadequate protection against L. monocytogenes. These studies highlight the potential therapeutic value of ecSOD inhibitors to enhance immune responses during bacterial infections
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
Effect of CD44 Expression on T Cell Acute Lymphocytic Leukemia
Get PDFCD44 is a cell surface glycoprotein that serves as a multifunctional receptor aiding in trafficking and adhesion of immune cells. CD44 also serves as a recruitment platform for signaling molecules and has been shown to regulate proliferation. In several types of leukemia the presence or absence of CD44 expression is associated with different clinical outcomes, with patients who have increased expression of CD44 exhibiting a stronger response to conventional chemo- and radiotherapy. By using Jurkat T cells, which do not express CD44, to determine the effects of CD44 expression in a model Acute Lymphocytic Leukemia cell line, we have outlined two major areas of study. Firstly, upon expression of CD44, Jurkat T cells proliferate slowly compared to the control cells. This decrease in proliferation is coupled to an arrest in the cell cycle during the transition from the G1 phase into S phase. The dysregulation of the cell cycle induced by CD44 also leads to the induction of aneuploidy. CD44 expressing Jurkat T cells have reduced mRNA expression for several key regulators of chromosome separation and the mitotic spindle complex. This finding, coupled with decreased EGR-1 expression, which controls the cyclins responsible for transition from G1 into S phase, leads to an unstable cell phenotype which proliferates slowly and accumulates extra chromosomes in daughter cells. The second area of study focuses on the mechanism by which CD44 expression at the cell surface results in the observed decreases in proliferation, Akt activation, and EGR-1 expression. We observed that CD44 expressing Jurkat cells show four to five times higher calcium influx when at rest compared to the vector control cells. This influx in calcium is due to CD44 expression activating a cell surface inducible calcium release activated calcium channel. The excess calcium activates calcium-activated phosphatases and kinases, disrupting EGR-1 expression and inducing a hypophosphorylation of Akt. Together, these findings indicate that CD44 expression can regulate cell proliferation and signal transduction pathways in addition to its role in adhesion. Thus, our data provide a further understanding of how CD44 expression modifies leukemic cells into cells that are favorable for therapeutic intervention
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