1,721,052 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
Epigenetic signatures of p66Shc promoter contribute to persistent endothelial dysfunction in type 2 diabetics with optimal glycemic control
No full textIntroduction: optimal glycemic control (OGC) has failed to improve cardiovascular outcomes in patients with diabetes. We have recently reported that epigenetic regulation of the mitochondrial adaptor p66Shc, critically involved in oxidative stress, accounts for persistent endothelial dysfunction in diabetic mice with OGC.
Hypothesis: we investigate whether epigenetic changes of p66Shc contribute to residual oxidative stress and vascular disease in patients with type 2 diabetes (T2DM).
Methods: 7 patients with newly-diagnosed T2DM and 7 age-matched controls were studied (age 46±3 vs. 42±7 years, p=NS). After the enrolment, T2DM patients were assigned to OGC for 6 months. Glycated haemoglobin (HbA1c) and continuous blood glucose monitoring (CGM) were used as markers of glycemic control. At baseline and follow-up, patients underwent flow-mediated vasodilation (FMD) of the brachial artery. Urinary levels of 8-isoprostaglandinF2α (8-isoPGF2α) were measured as a marker of oxidative stress. p66Shc mRNA expression was assessed from peripheral blood monocytes (PBM). Chromatin immunoprecipitation (ChIP) and real time PCR were performed to investigate histone acetylation and DNA methylation of p66Shc promoter, respectively.
Results: Hb1Ac (9.4±2 vs. 6.9±1%, p<0.01) and CGM (235±25 vs. 131±28 mg/dl, p<0.05) confirmed OGC in T2DM patients. As compared with controls. T2DM patients showed blunted FMD (6.8±1.9 vs. 8.6±1.4 %, p<0.05), increased urinary 8-isoPGF2α levels (295±100 vs. 33±9 pg/mL, p<0.05) and p66Shc gene upregulation (0.18±0.06 vs.0.05±0.03 AU, p<0.05). However, OGC did not rescue endothelial function (FMD 6.9±1.7 vs. 6.8±1.9%, p=NS), oxidative stress (295±100 vs. 292±85 pg/ml, p=NS) and p66Shc upregulation (0.18±0.06 vs.0.22±0.1, AU, p=NS). T2DM patients showed lysine 14 acetylation of histone 3 binding p66Shc promoter and hypomethylation of CpG dinucleotides, two critical epigenetic markers favouring p66Shc overexpression. Interestingly, these epigenetic changes remained despite OGC and correlated with persistent endothelial dysfunction and oxidative stress.
Conclusions: Epigenetic regulation of p66Shc gene may contribute to the residual burden of vascular disease in T2DM individuals with OGC
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
Targeting Prolyl-isomerase-1 protects against hyperglycemia-induced endothelial dysfunction and vascular inflammation: alterations in patients with type 2 diabetes
No full textIntroduction: Prolyl-isomerase-1 (Pin1) regulates function of protein substrates through isomerization of peptide bonds that link phosphoserine or phosphothreonine to proline. Recent studies showed that Pin1 favours cancerogenesis through reactive oxygen species (ROS) production and inflammation. Whether Pin1 partecipates to vascular disease is unknown.
Hypothesis: This study investigates the role of Pin1 in diabetes-related vascular dysfunction.
Methods: Human aortic endothelial cells (HAECs) were exposed to normal (NG, 5mmol/L) or high glucose concentrations (HG, 25 mmol/L) in the presence or in the absence of Pin1 pharmacological inhibitor Juglone or siRNA-mediated knockdown. Diabetes was induced by streptozotocin in C57/B6 mice and animals treated with Pin1 siRNA i.v or Juglone i.p for 30 days. Endothelial function was assessed by dose-response curve with acetylcoline (10-9-10-6 mol/L). Mitochondrial ROS were measured by ESR spectroscopy. Pin1 gene expression was assessed in peripheral blood monocytes (PBM) of 37 patients with type 2 diabetes (T2DM) and 20 age-matched controls and correlated with flow-mediated vasodilation (FMD) of the brachial artery, urinary oxidative marker 8-isoprostaglandinF2α (8-isoPGF2α) and plasma adhesion molecules VCAM-1, ICAM-1 and MCP-1.
Results: Pin1 expression increased in HAECs exposed to HG (289±22% vs. NG, p<0.01) and aortas of diabetic mice (216±32% vs. controls, p<0.05). Immunoprecipitation showed that Pin1 recognizes phosphoserine motifs of the pro-oxidant mitochondrial adaptor p66Shc and NF-kB p65. Interestingly, Juglone or Pin1siRNA prevented p66Shc-induced ROS production and suppressed NF-kB-dependent upregulation of adhesion molecules. In diabetic mice, silencing of Pin1 or Juglone prevented endothelial dysfunction, ROS production and vascular inflammation. Of note, Pin1 mRNA was significantly upregulated in PBM of T2DM patients as compared with controls (370±97 vs. 25±28,p<0.01) and correlated with FMD (r=-0.33, p<0.01), urinary 8-isoPGF2α (r=0.46, p<0.05), VCAM-1 (r=0.58, p<0.05) and ICAM-1 (r=0.55, p<0.05).
Conclusions: Pin1 may critically participate to vascular disease in T2DM patients
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