1,720,957 research outputs found
Investigation of Triose Phosphate Isomerase dysfunction and Redox Stress in a Drosophila Melanogaster model of Neurodegenerative Disease
Get PDFNeurodegenerative diseases have been extensively associated with increased redox stress, often this is linked to aberrant production of reactive species such as advanced glycation end products (AGEs). AGEs, and smaller reactive species like nitric oxide (NO), have been shown to increase redox stress, promoting protein and DNA modification, often via post translational modifications such as 3-Nitrotyrosination. Triose phosphate isomerase (TPI) is one protein that has been shown to undergo such modifications. TPI is an important, but non-essential, glycolytic enzyme whose main role is in the conversion of dihydroxyacetone phosphate (DHAP) to glyceraldyhyde-3-phosphate (G3P). This is an important conversion as it controls levels of methylglyoxal (MGO) which when increased significantly has also been directly linked to increased redox stress, protein modification, and DNA modification via AGE production. Thus, TPI dysfunction has been reported to lead to increased redox stress, enhancing glycation signalling, neuroinflammation, and neurodegeneration, and to be sensitive to redox stress itself, containing multiple sites for 3-nitrotyrosination. The resulting physiological mechanisms of TPI dysfunction are not yet well understood. TPI dysfunction has in turn been linked to various neurodegenerative disorders, including Alzheimer’s disease. Glyoxalase (Glo) is another key enzyme which provides an innate protective mechanism against MGO build up. This work aims to use Drosophila melanogaster to identify impacts of altered TPI on neuronal physiology linking aberrant TPI function and redox stress to synaptic deficits at the glutamatergic Drosophila neuromuscular junction (NMJ). A Drosophila mutant expressing reduced Glo activity is also reported to further investigate this metabolic pathway, and subsequent connection to neurodegeneration. Electrophysiology and immunohistochemistry, among other techniques, are utilised to investigate this pathology.
This work suggests that the phenotype arising from dysfunctional TPI is in part due to altered vesicle dynamics, possibly in vesicle pool organisation of the presynaptic neuron or endo/exocytosis, thus expanding our knowledge of the resultant mechanisms of TPI dysfunction. The data presented here implies that there are various mechanisms of dysfunction, likely to be via exacerbated redox stress, and compensatory mechanisms, suggested to be primarily via altered vesicle dynamics, leading to distinct pathologies with different mutations of the TPI protein. Impaired TPI and Glo activity are suggested to enhance protein glycation, redox stress, and post translational modifications, implying a possible route of pathology and presenting a potential target for therapies
Investigation of Triose Phosphate Isomerase dysfunction and Redox Stress in a Drosophila Melanogaster model of Neurodegenerative Disease
Get PDFNeurodegenerative diseases have been extensively associated with increased redox stress, often this is linked to aberrant production of reactive species such as advanced glycation end products (AGEs). AGEs, and smaller reactive species like nitric oxide (NO), have been shown to increase redox stress, promoting protein and DNA modification, often via post translational modifications such as 3-Nitrotyrosination. Triose phosphate isomerase (TPI) is one protein that has been shown to undergo such modifications. TPI is an important, but non-essential, glycolytic enzyme whose main role is in the conversion of dihydroxyacetone phosphate (DHAP) to glyceraldyhyde-3-phosphate (G3P). This is an important conversion as it controls levels of methylglyoxal (MGO) which when increased significantly has also been directly linked to increased redox stress, protein modification, and DNA modification via AGE production. Thus, TPI dysfunction has been reported to lead to increased redox stress, enhancing glycation signalling, neuroinflammation, and neurodegeneration, and to be sensitive to redox stress itself, containing multiple sites for 3-nitrotyrosination. The resulting physiological mechanisms of TPI dysfunction are not yet well understood. TPI dysfunction has in turn been linked to various neurodegenerative disorders, including Alzheimer’s disease. Glyoxalase (Glo) is another key enzyme which provides an innate protective mechanism against MGO build up. This work aims to use Drosophila melanogaster to identify impacts of altered TPI on neuronal physiology linking aberrant TPI function and redox stress to synaptic deficits at the glutamatergic Drosophila neuromuscular junction (NMJ). A Drosophila mutant expressing reduced Glo activity is also reported to further investigate this metabolic pathway, and subsequent connection to neurodegeneration. Electrophysiology and immunohistochemistry, among other techniques, are utilised to investigate this pathology.
This work suggests that the phenotype arising from dysfunctional TPI is in part due to altered vesicle dynamics, possibly in vesicle pool organisation of the presynaptic neuron or endo/exocytosis, thus expanding our knowledge of the resultant mechanisms of TPI dysfunction. The data presented here implies that there are various mechanisms of dysfunction, likely to be via exacerbated redox stress, and compensatory mechanisms, suggested to be primarily via altered vesicle dynamics, leading to distinct pathologies with different mutations of the TPI protein. Impaired TPI and Glo activity are suggested to enhance protein glycation, redox stress, and post translational modifications, implying a possible route of pathology and presenting a potential target for therapies
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
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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