1,721,003 research outputs found

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

    Green tea attenuates angiotensin II-induced cardiac hypertrophy in rats by modulating reactive oxygen species production and the Src/EGFR/Akt signalling pathway.

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    We previously documented a clear-cut antihypertensive effect of green teat extract (GTE), which was associated with correction of endothelial dysfunction and prevention of left ventricular hypertrophy in an angiotensin II (Ang II)-dependent model of hypertension, but the molecular mechanisms remain to be defined. As several effects of Ang II involve production of reactive oxygen species (ROS) and activation of 2nd messengers, such as mitogen-activated protein kinase (MAPK) and Akt, we investigated the effect of GTE on these signal transduction pathways in Ang II-treated rats. Rats were treated for 2 wk with Ang II infusion (700 mug.kg(-1).d(-1); n = 6, via osmotic minipumps), Ang II plus GTE (6 g/L) dissolved in the drinking water; n = 6), or vehicle (n = 6) to serve as controls. Blood pressure was monitored by telemetry throughout the study. The activation and expression of NAD(P)H oxidase subunits, protein kinase C isoforms, Src, epidermal growth factor receptor (EGFR), Akt, and MAPK were determined in the heart in vitro through immunoprecipitation and western blot analysis with specific antibodies. NAD(P)H oxidase enzymatic activity was measured by cytochrome c reduction assay. GTE blunted Ang II-induced blood pressure increase and cardiac hypertrophy. In Ang II-treated rats, GTE decreased the expression of the NAD(P)H oxidase subunit gp91(phox) and the translocation of Rac-1, as well as NAD(P)H oxidase enzymatic activity. Furthermore, it specifically reduced Ang II-induced Src, EGFR, and Akt phosphorylation. These results show that GTE blunts Ang II-induced cardiac hypertrophy specifically by regulating ROS production and the Src/EGFR/Akt signaling pathway activated by Ang II

    Variations on the Author

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    “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

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    We 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

    Effects of Mineralocorticoid and AT1 Receptor Antagonism on The Aldosterone-Renin Ratio In Primary Aldosteronism-the EMIRA Study

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    Abstract Context While current guidelines recommend the withdrawal of mineralocorticoid receptor antagonist (MRA) and renin-angiotensin system blockers for the screening and detection of primary aldosteronism (PA), this can worsen hypokalemia and control of high blood pressure (BP) values. Objective To investigate whether aldosterone/renin ratio (ARR) values were affected by the MRA canrenone and/or by canrenone plus olmesartan treatment in patients with PA. Design Within-patient study. Setting The European Society of Hypertension center of excellence at the University of Padua. Patients Consecutive patients with an unambiguous diagnosis of PA subtyped by adrenal vein sampling. Interventions Patients were treated for 1 month with canrenone (50–100 mg orally), and for an additional month with canrenone plus olmesartan (10–20 mg orally). Canrenone and olmesartan were up-titrated over the first 2 weeks until BP values and hypokalemia were controlled. Patients with unilateral PA were adrenalectomized; those with bilateral PA were treated medically. Main Outcome Measures BP, plasma levels of sodium and potassium, renin and aldosterone. Results Canrenone neither lowered plasma aldosterone nor increased renin; thus, the high ARR and true positive rate remained unaffected. Addition of the angiotensin type 1 receptor blocker raised renin and slightly lowered aldosterone, which reduced the ARR and increased the false negative rate. Conclusions At doses that effectively controlled serum potassium and BP values, canrenone did not preclude an accurate diagnosis in patients with PA. Addition of the angiotensin type 1 receptor blocker olmesartan slightly raised the false negative rate. Hence, MRA did not seem to endanger the accuracy of the diagnosis of P
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