1,720,959 research outputs found
Investigating the impact of atrial fibrillation on the vascular onset of glaucoma via multiscale cardiovascular modeling
Full text linkBackground and objective: Atrial fibrillation (AF) is the most common tachyarrhythmia, exhibiting faster and irregular beating. Although there is growing evidence of the impact of AF on the cerebral hemodynamics, ocular hemodynamic alterations induced by AF are still poorly investigated to date. The objective of this study is to computationally inquire into the role of AF on the ocular hemodynamics as one of the possible vascular triggers of glaucoma, which is the leading cause of blindness due to the damage of the optic nerve. Methods: A validated 0D–1D multiscale cardiovascular model is exploited to compute the hemodynamic response of AF against sinus rhythm (SR), by simulating 2000 beats for each condition. To mimic AF rhythm, its main features are accounted for: (i) accelerated, variable and uncorrelated beating; (ii) absence of atrial kick; (iii) ventricular systolic dysfunction. Results: We focused on intraocular pressure (IOP), ocular perfusion pressure (OPP), and translaminar pressure (TLP). Apart from a modest OPP decrease, beat-averaged values of IOP and TLP barely vary in AF with respect to SR. Instead, during AF a significant reduction and dispersion of pulsatile values (i.e., maximum minus minimum values reached in a beat), as well as wave amplitude damping, is observed for IOP, OPP and TLP. The marked variability of pulsatile values, which are hardly measured due to clinical difficulties, can induce transient hypoperfusions and hypo-pulsatility events (for OPP) as well as hypertensive episodes (for TLP). Conclusions: Awaiting necessary clinical data which are to date lacking, the present study can enrich – through hemodynamic-driven hints in the AF framework – the vascular theory, which associates reduced ocular perfusion (by means of decreased OPP and increased TLP) to an augmented risk of glaucoma. In this context, present modeling findings suggest a possible mechanistic link between AF-induced hemodynamic alterations and the increased risk of glaucoma development
Digital Nudging and Cookie Rejection: An Experiment
No full textWhen browsing the Internet, web users tend to accept all cookies even though this may threaten their online security. We apply a salience nudge and a framing nudge to the design of a cookie banner and test their individual and combined effectiveness in fostering rejection of unnecessary cookies in an online experiment (N = 358). The salience nudge makes the rejection button more visible, and the framing nudge phrases button labels as negations. Compared to the control with no nudges, which elicited a rejection rate of 27%, the salience nudge increased rejection rate by 7 percentage points (but p = 0.305), the framing nudge by 18pp (p = 0.009), and the combination of the two by 53pp (p < 0.0001). We also find that, when users are offered a customization option rather than the rejection button, only 3% of them select the option and reject non-necessary cookies. Finally, we explore how cookie rejection is related to the time users spend making the decision and to their personality traits. Our findings suggest that cookie rejection can indeed be fostered by an appropriate design of cookie banners and that legislation for protecting the online security of users should introduce specific design guidelines
A Review of Nudges: Definitions, Justifications, Effectiveness
Full text linkIn 2008, the behavioral economist Richard Thaler and the legal scholar Cass Sunstein published a book in which they advocated a novel approach to public policy based on the notion of a ‘nudge’. Roughly speaking, a nudge is an intervention in the decisional context that steers people’s decisions by acting on their cognitive biases. The notion of a nudge generated an intense debate across different disciplines and proved popular with many policy makers around the world. The present paper reviews the debate and research on nudges by focusing on three main dimensions: (1) the exact definition of nudges; (2) the justification of nudge policies, with a focus on ‘libertarian paternalism’; and (3) the effectiveness of nudges, both over time and in comparison with standard policies
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
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