1,720,974 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
The role of Arl17 in healthy and influenza A virus infected cells
Full text linkInfluenza A virus (IAV) is an important human pathogen that causes epidemic and pandemic events of flu. The study of the viral life cycle and its interactions with the infected host is crucial for the development of novel therapeutic strategies. IAV has an eight-part segmented RNA genome organized in viral ribonucleoprotein complexes (vRNP), which are replicated in the nucleus of the cell. De novo synthesized vRNPs need to leave the nucleus to reach the cytosol for viral assembly, budding and release. Several pathways have been implicated in nuclear export of vRNPs, including CRM1, apoptosis activation and extracellular signal-regulated kinase 1 and 2 (ERK1/2) signaling cascade.
Mitochondria are crucial organelles for the maintenance of cellular homeostasis, since they are responsible for the regulation of metabolism, apoptosis, calcium homeostasis and innate immunity. Their functions are tightly regulated by dynamic changes in mitochondrial morphology. Given their importance, many viruses modulate mitochondria to promote cellular environments favoring their proliferation. IAV has been shown to fragment mitochondria to decrease the antiviral immune response. Our lab identified a candidate modulator of mitochondrial morphology and IAV infection: the host GTPase Arl17. Our work demonstrated that depletion of Arl17 leads to a reduction in viral titers and promotes mitochondrial fragmentation, regardless of infection. Interestingly, this phenotype was not accompanied by alterations in IFNβ1 expression and mitochondrial unfolded protein response activation (UPRmt). However, ATP levels were significantly reduced in the absence of Arl17. Additionally, we showed that Arl17 is required for regular vRNP nuclear export. In its absence, we observed a delay in vRNPs nuclear export that was CRM1- and ERK1/2-independent. Therefore, influence of Arl17 on the induction of apoptosis should be further investigated as its inhibition could explain vRNPs nuclear export delay and it could be the element that links mitochondria and vRNPs nuclear export
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
Influenza A virus modulation of mitochondria dynamics
No full textDissertação de Mestrado em Investigação Biomédica, apresentada à Faculdade de Medicina da Universidade de CoimbraMitochondria were originally described as the power house of the cell, but their importance expanded as their role in controlling several death processes was discovered. Recently, this organelle also emerged as the central player in a number of cellular innate immune responses, in particular interferon (IFN) responses, which constitute the first line of defence against intracellular pathogens. Mitochondria thus operate in response to cellular insults, ultimately deciding its fate. Interestingly, all mitochondria functions are intimately related to dynamic changes in their morphology and distribution. Morphological changes operate by fusion and fission events that are regulated by dynamin-like large GTPases, some of them already existing within the mitochondria (mitofusins) whilst others requiring active recruitment (dynamin-related protein 1, Drp1). The emerging view is that trafficking of cytoplasmic Drp1 to the mitochondria is a crucial regulatory step in mitochondrial responses. It has been demonstrated that many viruses interfere with mitochondria dynamics to favour infection at specific steps.
Influenza A virus (IAV) is an important human pathogen responsible for acute respiratory disease, which provokes yearly epidemics and occasional pandemics. Pathogenicity of infection has been associated with the ability to modulate immune responses. One report suggested that IAV decreases innate immunity activation by inducing mitochondria fragmentation. However, the knowledge on the mitochondria-IAV interplay remains largely unexplored. This thesis aims to study the effects of IAV infection in mitochondria dynamics, by elucidating the changes in mitochondria morphology during infection and determining the host and viral factors involved. The ultimate goal is to understand the mechanisms by which the IAV modulates mitochondria dynamics and elucidate the functional relevance of this process. Our results indicate that infection leads to mitochondria fragmentation of two types: complete fragmentation and fragmented mitochondria localised at the periphery. We further assessed that at least three viral components modulate mitochondria shape, the viral proteins NS1, PB1-F2 (and/or PB1-N40) and vRNPs. In addition we have tested the role of two host GTPases in the process: Drp1 and Arl17. Our results strongly suggest that Drp1 is implicated in mitochondria fragmentation during IAV infection whilst Arl17, although essential for infection, might operate at the level of mitochondria quality control.A mitocondria foi inicialmente identificada e descrita pelas suas funções no metabolismo celular e pelo seu papel na produção de grandes quantidades de energia na forma de ATP. A relevância deste organelo aumentou à medida que se descobriu que a mitocondria desempenha um papel fundamental em diversos processos de morte celular e, mais recentemente, em vários mecanismos de resposta imune inata da célula, particularmente, na activação de interferão que constitui a primeira linha de defesa contra agentes patogénicos intracelulares. A mitocondria adapta as suas funcionalidades em resposta a um estimulo celular e, em última análise, decide o destino da célula. Todas as funções mitocondriais estão relacionadas com alterações dinâmicas na sua morfologia e distribuição celular. A morfologia mitocondrial é alterada por processos de fissão e fusão que são reguladaos por GTPases, algumas, como as mitofusinas, estão presentes na mitocondria e outras, como a Drp1, necessitam de ser recrutadas para o organelo. A Drp1 é uma proteína citoplasmática e o seu recrutamento para a mitocondria é visto como um passo regulador das respostas e funções mitocondriais. A literatura descreve a forma como diversos vírus alteram a dinâmica mitocondrial de modo a favorecer a progressão da infecção.
O vírus influenza A (IAV) é um importante agente patogénico em humanos e é responsável por epidemias sazonais e pandemias ocasionais. A patogenicidade da infecção está directamente relacionada com a capacidade do vírus modular a resposta imune da célula e uma das formas de o fazer é induzindo a fragmentação da mitocondria de modo a diminuir a activação da resposta imune inata. No caso do IAV, há ainda muito por explicar em relação à interacção entre a mitocondria e o vírus. Por isso mesmo, os objectivos desta tese são o estudo dos efeitos da infeção pelo IAV na dinâmica mitocondrial, identificando alterações morfológicas da mitocondria e determinando se as alterações observadas são provocadas pelo vírus ou, pelo contrário, pela resposta da célula à infecção. O objectivo último deste estudo é perceber os mecanismos que o IAV utiliza para modular a dinâmica mitocondrial e elucidar qual a função deste processo. Os nossos resultados indicam que a infecção pelo IAV leva a um aumento da segmentação mitocondrial que pode ser uma fragmentação completa do organelo ou uma fragmentação localizada na periferia da célula. A nossa análise indica que pelo menos três componentes virais modulam a morfologia mitocondrial: as proténas virais NS1 e PB1-F2 e/ou complexos virais denominados ribonucleoproteínas. Este estudo também envolveu a análise do papel de duas GTPases celulares na modulação da mitocondria durante a infeção: a Drp1 e a Arl17. Os nossos resultados sugerem que a Drp1 está implicada na fragmentação da mitocondria enquanto a Arl17 parece estar a actuar a nível do controlo da qualidade da mitocondria, não deixando, contudo, de ser essencial para a infeção
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
- …
