1,720,958 research outputs found
“Pharmacological Targeting of Glutamine Synthetase Skews Macrophages Toward An Inflammatory Phenotype and Inhibits Metastasis”
No full textPharmacological Targeting of Glutamine Synthetase Skews Macrophages Toward An Inflammatory Phenotype and Inhibits Metastasi
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
BLOCKADE OF GLUTAMINE SYNTHETASE SKEWS MACROPHAGES TOWARDS AN M1-LIKE PHENOTYPE AND INHIBITS TUMOR METASTASIS
No full textGlutamine-synthetase (GS), the glutamine-synthesizing enzyme from glutamate, controls
important events including the release of inflammatory mediators, mTOR activation and
autophagy. However, its role in macrophages remains elusive. Here we report that pharmacologic
inhibition of GS skews M2-polarized macrophages toward the M1-like phenotype, characterized
by reduced intracellular glutamine and increased succinate with enhanced glucose flux through
glycolysis and pyruvate carboxylase, and consequent HIF1α activation. These metabolic changes
and HIF1α accumulation in GS-inhibited macrophages promote M1 markers expression,
accompanied by the ability to boost T-cell proliferation and migration, and to impair endothelial
cell branching or cancer cell motility. Genetic deletion of macrophagic GS in tumor-bearing mice
promotes tumor vessel pruning, vascular normalization and accumulation of cytotoxic T-cells,
leading to metastasis inhibition. These data identify GS activity as mediator of the proangiogenic,
immunosuppressive and prometastatic function of M2-like macrophages and highlight the
possibility to target this enzyme in the treatment of cancer metastasis
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
Metabolomic identification of substrates for monoamine oxidases in hearts subjected to oxidative stress.
No full textOxidative stress plays a key role in cardiac diseases, although the sources of reactive oxygen species (ROS) have not been defined conclusively. Recent studies demonstrated that the mitochondrial enzymes monoamine oxidases (MAO) are a major source of ROS in reperfusion injury and decompensated hypertrophy. The present study characterized the molecular mechanisms responsible for the increased activity of MAO. Based upon available information, the activity of these enzymes depends mostly on substrate availability. Therefore, we aimed at identifying the major substrates of MAO in hearts undergoing oxidative stress. Mass spectrometry was used to identify and quantitate potential substrates by comparing their contents in the absence and the presence of MAO inhibition.
METHODS AND RESULTS:
Firstly, we applied a metabolomic profiling method to investigate changes in amine contents in isolated mouse hearts, by means of a LC-MS/MS approach in the precursor ion scanning mode. Maximal oxidative stress was induced by perfusing isolated mouse hearts with 1 mM hydrogen peroxide for 15 min. Addition of 0.5 mM pargyline to the perfusion buffer 10 min before hydrogen peroxide resulted in a significant increased content of the typical MAO substrates serotonin and epinephrine, along with histamine and its product N1-methyl histamine. N1-methyl histamine was found to be the more aboundant metabolite and its content displayed a 180% increase in pargyline-treated hearts, as compared to the untreated ones. The accumulation of MAO substrates upon pargyline treatment correlated with a reduced MAO-dependent production of hydrogen peroxide. In fact we observed a decreased extent of (i) oxidation of myofibrillar proteins, as detected by disulfide bond formation in tropomyosin (Western blot under non reducing conditions), and (ii) ROS levels in tissue, as detected by dihydroethidine (DHE) staining. Surprisingly, these findings imply that the profound injury induced by H2O2 administration is not due to a direct action. Indeed, H2O2 perfusion appears to trigger an amplification pathway whereby the increase in MAO activity due to a larger substrate availability is the end-effector of the initial oxidative stress.
CONCLUSIONS:
This study provides the first information on endogenous substrates of MAO becoming available under conditions of oxidative stress that is then amplified by the increased MAO activity. The identification of histamine and N1-methyl histamine, that are involved in neurotransmission and immune response, suggests a significant trafficking of MAO substrates between myocytes and non-myocyte cells in the heart
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