1,721,020 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
Crosstalk Between Mesenchymal Stem/Stromal Cells and Host Immune Cells as a Critical Mechanism of Immunomodulation in Severe Viral Lung Infection and Sepsis
No full textSepsis is characterized by a systemic dysregulated immune response to severe infection. Research has shown that mesenchymal stromal/stem cells (MSCs) exert immunemodulatory functions in vitro and therapeutic benefits in various animal models of severe immune diseases. These promising results have driven the translation of MSCs as cellular therapy into clinical settings. The host sepsis environment, including the pathogens and the host immune response (cells and soluble factors), may play a crucial role in modifying the therapeutic ePicacy of infused MSCs. Here, we aim to investigate the interplay between MSCs and the host microenvironment in three disease contexts: 1) severe SARS-CoV-2 infection (COVID-19), 2) acute lung injury (ALI) induced by H1N1 influenza A virus (IAV) infection and 3) human sepsis caused by heterogenous organisms. First, we hypothesized that, in severe COVID-19, priming MSCs with a viral mimic would improve their abilities to rebalance the dysregulated immune responses. Transcriptome analysis of Poly(I:C)-primed MSCs (pIC-MSCs) revealed upregulation of pathways involved in antiviral and immunomodulatory responses. Together with increased expression of antiviral proteins, these changes translated into greater MSC ePector functions in regulating monocytes and granulocytes, while enhancing their ability to block SARS-CoV-2 pseudovirus entry into epithelial cells. Importantly, the addition of pIC-MSCs to COVID-19 patient whole blood significantly reduced inflammatory neutrophil populations, increased the proportion of M2 monocytes and enhanced their phagocytic function.
In the second study, deep immune profiling was performed on airway and circulating immune cells to examine the ePect of immunomodulation and therapeutic outcomes of MSCs therapy in mice with H1N1-induced ALI. Immune cell populations and phenotypic shifts were mapped in whole blood by mass cytometry, showing altered immune responses in animals receiving MSCs vs vehicle treatment. Compared to sham animals, IAV infection induced a significant increase in BAL total cell counts. MSC administration significantly decreased BAL total cell counts and altered immune infiltrations in IAV-infected mice.
Phenotypic immune cell profiling of blood and BAL revealed a significant increase in the monocyte population with M2 phenotype in MSCs-treated animals. However, MSCs treatment did not improve survival of infected mice or reduce viral titres in the lungs of infected mice. Further investigation revealed that MSCs were highly susceptible to H1N1 IAV infection, leading to increased cell death and potentially reduced their ePicacy. Lastly, ex vivo human and in vivo animal models were utilized to investigate neutrophil and monocyte modulation by MSCs in sepsis. Results showed phenotypic and functional improvements of myeloid cells after coculture with MSCs. Interestingly, transcriptomic and cytokine analyses revealed adaptive reprograming of MSCs in response to the sepsis milieu. This activation of caspase-1 pathway of MSCs was subsequently confirmed as an essential molecular mechanism for the immunomodulatory ePects of MSCs on dysfunctional neutrophils and monocytes. Caspase-1 activation in MSCs enhanced their therapeutic benefits in treating sepsis in vivo.
Overall, my work suggests that the function and ePicacy of MSCs vary depending on types of infection induced by diPerent pathogens and the host immune microenvironment. These findings highlight the importance of understanding the adaptive responses of MSCs to the host environment in order to better tailor MSC-based therapy for severe viral and 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
Extracellular Vesicles Derived from Mesenchymal Stromal Cells : A Multidisciplinary Analysis of Methodology, Efficacy and Biodistribution in Lung Disease
No full textAcute respiratory distress syndrome (ARDS) is a devastating critical illness that holds the highest cost of any acute care condition in Canada. In ARDS, a localized inflammatory response caused by lung infection or injury leads to vascular damage and migration of inflammatory cells into the airways resulting in impaired gas exchange and respiratory failure. Despite decades of research, there are no curative therapies for this daunting acute lung condition. Animal studies have demonstrated a potential for mesenchymal stromal cells (MSCs) to reduce inflammation, promote tissue regeneration and improve survival in acute lung injury (ALI, the preclinical correlate of ARDS). In particular, a growing body of evidence suggests that MSCs elicit their protective effects in large part by secretion of small membrane-bound particles known as "extracellular vesicles". These vesicles carry biologically active cargo that modulate critical cell processes including programmed cell death, proliferation and inflammation. Hence, MSC-derived extracellular vesicles (MSC-EVs) may have advantages as a safer off-the-shelf, cell-free immune modulatory therapy. However, the optimal approach for isolating and administering MSC-EVs have yet to be established within this new field of regenerative medicine. The aims of this project were to: (1) evaluate the current preclinical evidence on methodology and efficacy of MSC-EVs, (2) determine the effectiveness of MSC-EVs for ALI and other pulmonary diseases in animal models, and (3) explore the kinetics and biodistribution of MSC-EVs during healthy and disease state as a prerequisite to designing optimal therapeutic strategies. By combining both clinical meta-research methodology and basic science techniques, I hoped to create a comprehensive evidence map of mechanistic insights and the therapeutic benefits of MSC-EVs.
Importantly, ARDS is recognized as the main cause of mortality for patients with COVID-19. In response to the SARS-CoV2 pandemic and restrictions placed on routine, non-COVID related lab work, an additional objective for my PhD focused on developing a novel, more accessible mouse model of COVD-19 associated ARDS. A SARS-CoV2 "pseudovirus" was created to enable its use in a less stringent Containment Level 2 lab setting. Dose-escalation experiments in mice helped determine the optimal dose that produces clinically-relevant COVID-19 ARDS pathology. Moreover, the specificity of our pseudovirus to human ACE2 receptors was tested using preclinical models. If successful, this model will allow researchers worldwide to study key mechanisms in COVID-19 pathophysiology and investigate novel vaccines or therapies to combat this global pandemic
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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