1,721,042 research outputs found
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
Dual-specificity phosphatase 6 deficiency protects against intimal hyperplasia after arterial injury
No full text[[abstract]]Dysregulation of MAPK activation cascades has been implicated in various diseases. Dual-specificity phosphatases (DUSPs) are a subfamily of protein tyrosine phosphatases that dephosphorylate MAPKs and modulate critical signaling pathways. Studies have shown that DUSP6 plays an important role in the heart and diet-induced obesity. However, the role of DUSP6 in vascular disease is largely unclear. Our goal is to investigate whether DUSP6 has a role in occlusive vascular disease. To this end, we used a neointima formation model by denuding endothelium of mouse femoral arteries with a guide wire. We showed that DUSP6 was expressed at very low levels in the normal uninjured mouse arteries; however, DUSP6 expression was increased in the arterial wall of injured blood vessels, suggesting a potential role of DUSP6 in vascular disease. Compared with wild-type mice, DUSP6 deficiency reduced neointima formation 4 weeks after arterial injury in mice. BrdU incorporation assays revealed that lack of DUSP6 resulted in decreased smooth muscle cell (SMC) proliferation in the neointima and media 2 weeks after injury, indicating DUSP6 may promote SMC proliferation in response to injury. Indeed, overexpressing DUSP6 in primary SMCs increased cellular proliferation, similar to that exerted by inflammatory cytokine IL-1β while knocking down DUSP6 expression with siRNA abrogated IL-1β-induced SMC proliferation. Pathway analysis showed that IL-1β-induced ERK1/2 activation preceded DUSP6 induction in SMCs. Intriguingly, ERK1/2 inhibitor U0126 abolished IL-1β-mediated ERK1/2 activation, DUSP6 induction, and SMC proliferation. Taken together, our results indicate that DUSP6 induction promotes vascular remodeling under pathological conditions. DUSP6 might be a therapeutic target for preventing/treating occlusive vascular disease
Heme oxygenase-1 deficiency promotes embryonic stem cell differentiation
No full text[[abstract]]Pluripotent embryonic stem cells (ESCs) are promising donor sources in cell therapies for various diseases. Many signals including cytokines, growth factors, and oxidative stress influence ESC survival and differentiation. The stress response protein heme oxygenase-1 (HO-1) has been shown to protect tissues from injury via its antioxidative and anti-inflammatory functions. Given that ESCs are highly proficient in antioxidant defense, we hypothesized that HO-1 might contribute to ESCs' antioxidant defense and differentiation. To test this hypothesis, we isolated HO-1-deficient (HO-1–/–) ESCs from mouse blastocysts. As with D3 wild type ESCs, HO-1–/– ESCs exhibit high levels of pluripotent markers Oct3/4 and SSEA-1, strong alkaline phosphatase activity, and low levels of reactive oxygen species (ROS). Since elevated levels of ROS can initiate differentiation, we used an embryoid body (EB) model and harvested EBs at day 3, 5, and 7 to first examine ROS levels. ROS levels increased during ESC differentiation, reaching maximum levels at day 5. However, HO-1 deficiency enhanced ROS levels at day 3. We next examined differentiation marker gene expression by quantitative RT-PCR. The endoderm marker GATA6 increased during the course of differentiation; interestingly, HO-1 deficiency enhanced GATA6 levels by 9-fold at day 3. Furthermore, the mesoderm marker Brachyury was 50-fold higher than D3 at day 3. However, no difference was observed in ectoderm marker FGF5 between D3 and HO-1–/– ESCs at day 3. Collectively, these results suggest that HO-1 might modulate ESC differentiation, particularly endoderm and mesoderm, via regulating cellular ROS levels
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
Heme oxygenase-1 (HO-1) inhibits post myocardial infarction remodeling and restores ventricular function
Get PDFWe reported previously that predelivery of the anti-oxidant gene heme oxygenase-1 (HO-1) to the heart by adeno associated virus (AAV) markedly reduces injury after acute myocardial infarction (MI). However, the effect of HO-1 gene delivery on postinfarction recovery has not been investigated. In the current study, we assessed the effect of HO-1 gene delivery on post-MI left ventricle (LV) remodeling and function using echocardiographic imaging and histomorphometric approaches. Two groups of Sprague-Dawley rats were injected with 4 x 10(11) particles of AAV-LacZ (control) or AAV-hHO-1 in the LV wall. Eight wk after gene transfer, the animals were subjected to 30 min of ischemia by ligation of left anterior descending artery (LAD) followed by reperfusion. Echocardiographic measurements were obtained in a blinded fashion prior and at 1.5 and 3 months after I/R. Ejection fraction (EF) was reduced by 13% and 40% in the HO-1 and LacZ groups, respectively at 1.5 months after MI. Three months after MI, EF recovered fully in the HO-1, but only partially in the LacZ-treated animals. Post-MI LV dimensions were markedly increased and the anterior wall was markedly thinned in the LacZ-treated animals compared with the HO-1-treated animals. Significant myocardial scarring and fibrosis were observed in the LacZ-group in association with elevated levels of interstitial collagen I and III and MMP-2 activity. Post-MI myofibroblast accumulation was reduced in the HO-1-treated animals, and retroviral overexpression of HO-1 reduced proliferation of isolated cardiac fibroblasts. Our data indicate that rAAV-HO-1 gene transfer markedly reduces fibrosis and ventricular remodeling and restores LV function and chamber dimensions after myocardial infarction
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
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