1,721,028 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
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
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
Elucidating the Role of Antigen-presenting Cells in the Immunopathogenesis of the Porcine Reproductive and Respiratory Syndrome Virus
Full text linkThe porcine reproductive and respiratory syndrome virus (PRRSV) is a positive sense single-stranded RNA virus of the arteriviridae family and is one of the most economically devastating pathogens in the swine industry today. The PRRSV was discovered in the early 1990s in Europe and the United States, with strains being divided into Type 1 and Type 2 genotypes, respectively. Disease outcomes range from being asymptomatic to upwards of 100% mortality in herds, being attributable to the pathogenicity of the PRRSV strain, to co-infections with opportunistic pathogens, and to the age and breed of the pig. Animals subject to infection with PRRSV exhibit an array of clinical symptoms, including but not limited to, respiratory difficulty and pneumonia, weight loss, immune suppression leading to secondary bacterial infections, and spontaneous abortions/fetal mummification, from which the majority of the economic losses stem. Immunization with modified live vaccines are the most popular intervention to control disease, and although they are effective in improving health status of animals, the currently distributed vaccines pose a risk of reversion to virulence and afford limited cross protection amongst circulating strains of the virus. Thus, there is a high demand for a safe and effective vaccine.
The goal of this study was to investigate the role of specific antigen-presenting cell (APC) subsets during the pathogenesis of PRRSV and to further understand the progression to T cell immunity in response to PRRSV. To accomplish this, we chose to investigate the susceptibility of bone marrow-derived dendritic cells (BMDCs), monocyte-derived dendritic cells (MoDCs), and monocyte-derived macrophages (MoMΦs). After successfully differentiating and characterizing BMDCs from hematopoietic stem cells isolated from the sternum of animals, we demonstrated that PRRSV infection is restricted only to APCs that express CD163. Furthermore, we showed that PRRSV replicates more quickly in MoMΦ cell cultures than in CD163+ BMDC cultures and potentially in MoDCs. We continued to investigate PRRSV infection of APCs and discovered that in non-infected MoDCs, the cellular protein gamma actin 1 associates closely with MHCII. When MoDCs were infected with PRRSV, gamma actin 1 was no longer associated with MHCII. We hypothesize that PRRSV could be manipulating the actin cytoskeleton, potentially interfering with MHCII peptide presentation.
Ultimately, we were interested in the interaction of APCs with T cells. In order to study this interaction, we developed an assay utilizing a mixed leukocyte reaction (MLR). Our hypothesis was confirmed in the MLR that showed M1 MoMΦs (IFN-γ stimulated) are more potent inducers of cytotoxic lymphocyte (CTLs) and CD4α+ T cell proliferation than M2 MoMΦs (IL-4 stimulated) or M0 MoMΦs (non-stimulated). In addition, our results indicated that gamma delta (γδ) T cells did not participate in the MLR. Next we proceeded with an animal trial investigating the interaction of APCs with T cells in a PRRSV-antigen specific manner.
The objective of the trial was to investigate the progression to T cell immunity during a PRRSV infection. We used a commercial swine-influenza vaccine as a positive control antigen, and as a comparative measure for the T cell immune response to PRRSV. Our results indicated that PRRSV infection of APCs does not interfere with the ability of APCs to promote T cell proliferation. We detected IFN-γ secreting cells in PBMCs two weeks post infection, and T cell proliferation was evident in all lymphoproliferative cell cultures two weeks post infection. A comparison between MoMΦ-T cell co-cultures and MoDC-T cell co-cultures indicated that MoDCs may be more potent stimulators of central memory Th cell proliferation. Lastly, PRRSV infected animals showed a higher capacity to promote the proliferation of T cells specific for swine-influenza A virus, potentially signifying that the general monocyte population from PRRSV infected animals acquired an activated state as a result of the infection.
Overall, the work in this thesis allowed us to formulate a theory regarding the dysregulated immune response to PRRSV. A characteristic adaptive immune response to PRRSV includes the early appearance of non-neutralizing antibodies (within a week), a delayed induction of T cell immunity (2-3 weeks post infection), with neutralizing antibodies becoming detectable roughly 4 weeks post infection, correlating to the resolution of illness. We believe that specific subsets of DCs are responsible for the induction of T cell immunity, and the rarity of this DC population(s) causes a delay in the induction of the T cell immune response. Furthermore, the delayed induction of T cell immunity would affect the humoral immune response. In the absence of CD4+ follicular T helper cells, B cells would not be able to undergo proper somatic hypermutation and the result would be a state of hypergammaglobulinemia, similar to what is observed early during a PRRSV infection with non-neutralizing antibodies and auto-antibodies. The results herein support our theory, and contribute to the general knowledge surrounding the immunopathogenesis of PRRSV. Future work investigating the mechanisms by which PRRSV hinders the progression to adaptive immunity could prove to be fundamental in the development of a novel vaccine
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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