1,720,990 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
The Dynamic Role of Pulmonary Neutrophils in the Fungal Clearance and Immunopathology During Systemic Candidiasis in vivo
No full textNeutrophils are key players in the host immune response against systemic infection with C. albicans, which is the fourth most common bloodstream infection in North America. Using intravital microscopy, we investigated the role of marginated pulmonary neutrophils in the host defense against disseminated C. albicans. We found that this unique population of neutrophils rapidly clears the fungus that sequesters to the pulmonary vasculature in a C5a-dependent fashion. This uptake of C. albicans by the neutrophils then leads to the formation of dense, motile clusters in the vasculature via LTB4 amplification. The formation and persistence of the neutrophil vascular clusters are independent of beta-2 integrins, platelets, and NETs. Although complement-mediated uptake of the fungus is required for the host survival, subsequent neutrophil cluster formation contributes to disease pathology. Therefore, we see that the rapid neutrophilic response in the lung against disseminated candidiasis is a dynamic, double-edged process
Investigating Pulmonary Immune Responses that Detect and Counteract Gram-negative Bacterial Infections
No full textInfections of the lungs can cause tremendous tissue damage which often leads to pathogens spreading into the bloodstream. In the airways, Gram-negative bacteria produce biofilms through exopolysaccharide (EPS) that provides microbial protection; however, the impact of EPS on detection remains uncertain. Using genome-engineered P. aeruginosa strains, we compared EPS-producers versus non-producers and a virulent E. coli pneumonia model in mice to better understand detection. EPS-negative P. aeruginosa and virulent E. coli infection caused severe sickness mediated by TRPV1+ TLR4+ sensory neuron detection of the exposed lipopolysaccharide (LPS). Stimulation of lung nociceptors induced acute stress responses in the paraventricular hypothalamic nuclei by activating corticotropin-releasing hormone neurons responsible for sickness behavior and hypothermia. Once bacteria enter the bloodstream, an immune paradox occurs where host responses counteract the invading pathogen but also contribute to devastating organ damage and death. During E. coli bacteremia, we observed in vivo pulmonary neutrophil and platelet interactions that resulted in immunothrombosis. Intravital microscopy and novel single cell behavioral analysis revealed that cathelicidin initiated neutrophil swarming and clustering, which preceded LTB4 dependent immunothrombosis. These immunothrombi trapped bacteria and promoted platelet dependent microbial resistance but also caused lethal vascular occlusions. Cathelicidin deficiency impaired this host defence mechanism leading to bacterial overgrowth that resulted in delayed sepsis mortality. Altogether, this thesis uncovers how Gram-negative bacteria evade neuronal detection, how the host counteracts them in the bloodstream, and how these insights may guide strategies to enhance host defence while reducing pathology
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
Neutrophil- and B cell-mediated host defense against viral and fungal respiratory infections
No full textInfections of the lung continue to be a worldwide annual problem affecting millions of people. Fighting acute respiratory infections requires rapid and collaborative responses involving diverse immune cells. An interesting and unexplained clinical problem that sparked this thesis was the clinical observation that influenza A, a common respiratory virus, increases susceptibility to secondary infections with environmental fungi such as Aspergillus fumigatus (Af). By establishing a mouse model of viral-fungal co-infection and using clinical human samples, I discovered an essential collaboration between an underappreciated innate B lymphocyte, called B1a, which produced natural antibodies against Af, which tagged the fungi for elimination by neutrophils. Following influenza A infections, B1a cells died of apoptosis leading to diminished natural anti-Af antibodies and negating the ability of neutrophils to target and eliminate Af. Disruption of this axis explained susceptibility in viral- and steroid-associated infections. Delving deeper into the requirements of immune cell resistance to influenza and Af as individual infections, I discovered unique roles for neutrophils during influenza and innate B cells in aspergillosis. While there is ample research investigating neutrophils and their roles during infections with extracellular pathogens, it remained unclear how the neutrophil pool is affected following viral infections and subsequent functional outcomes. Additionally, it has been recently proposed that an interferon-responsive neutrophil state with unknown functions emerges following viral infections. In isolated viral infection, I found neutrophils adapt to an anti-viral phenotype which is spatially regulated, requires type I interferon licensing and sympathetic drive. On the other hand, using a genetically engineered mouse, we studied the specific roles of innate B1a cells during Aspergillus infection and found that this rare antibody producing cells was essential for host resistance against isolated Af infection. Moreover, I discovered key molecular requirements of the B1a cells that allow them to traffic and recruit properly in the lung, and I discovered that these cells can be amplified to improve host defense against Af. Altogether, this body of work uncovers neutrophils’ effects following isolated viral infection and during co-infection and demonstrates the tight interconnectedness between neutrophils and B lymphocytes which are critical for anti-fungal immunity
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
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