1,720,983 research outputs found
Single cardiac vagal fiber activity, acute myocardial ischemia, and risk for sudden death.
No full textThe experience of Patrimonio Ca’ Granda Foundation: social report and environmental impacts
No full textAutonomic control of heart rate: pharmacological and nonpharmacological modulation.
No full textThe evidence of the predictive value of autonomic markers has generated a growing interest for interventions able to influence autonomic control of heart rate. The hypothesis is that an increase in cardiac vagal activity as detected by an increase in heart rate variability (HRV) or baroreflex sensitivity (BRS) may be beneficial in the ischemic heart. Numerous experimental data support the hypothesis that augmenting vagal activity might be protective against lethal ischemic arrhythmias. Among them is the evidence that ventricular fibrillation during acute myocardial ischemia may be largely prevented by electrical stimulation of the right cervical vagus or by pharmacological stimulation of cholinergic receptors with oxotremorine. There is an inherent danger in the so far unwarranted assumption that modification of HRV or BRS translates directly in cardiac protection. This may or may not be the case. It should be remembered that the true target is the improvement in cardiac electrical stability and that BRS or HRV are just markers of autonomic activity. Low dose scopolamine increases HRV in patients with a prior myocardial infarction. This observation, combined with the evidence that elevated cardiac vagal activity during acute myocardial ischemia is antifibrillatory, has generated the hypothesis that scopolamine might be protective after MI. We tested low dose scopolamine in a clinically relevant experimental preparation for sudden death in which other vagomimetic interventions are effective and found that this intervention does indeed increase cardiac vagal markers but has minimal antifibrillatory effects. This is in contrast to exercise training that in the same experimental model had a marked effect on both BRS and HRV and at the same time provided strong protection from ischemic ventricular fibrillation. Thus, based on the current knowledge it seems appropriate to call for caution before attributing excessive importance to changes in "markers" of vagal activity in the absence of clearcut evidence for a causal relation with an antifibrillatory effect
Project quality verification tool efficacy|L'efficacia dello strumento di verifica per la qualità dei progetti
No full textThis essay develops a critical reflection on the effectiveness of design verification procedures and tools with regard to the actual improvement of the quality of public works projects. After a regulatory and lexical examination, the main criticalities that characterise the validation process between the design and construction of public works in the Italian context are examined in depth. The effectiveness of the current inspection process is empirically evaluated by analysing a database of an accredited inspection organisation, identifying prospects of innovation and criteria for adaptation to the contemporary context of project production
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
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