1,720,968 research outputs found
Cardiovascular MRI assessment of pectus excavatum in pediatric patients and postoperative simulation using vacuum bell
No full textBackground: The sternal lift by Vacuum Bell (VB) is effective, as largely demonstrated by its intraoperative use during surgical procedure to elevate the sternum during the Nuss procedure routinely. Indeed, the thoracic remodelling during VB application is comparable to post-surgical scenario, and suitable to compare cardiovascular parameters of the two different thoracic configurations immediately. Objective: We would quantify and correlate preoperative parameters which determine the severity of the pectus excavatum (PE), and the cardiovascular effects at the baseline. Than we would assess the cardiovascular changes during VB positioning, mimicking the immediate, temporary effect of Pectus-correction. Materials and Methods: We included 26 consecutive patients (mean age is 13,3 +/- 2,2 years) symptomatic and non, with a previous clinical diagnosis of PE. CMR was performed before and during application of VB, using the same imaging protocol. In both conditions, we measured thoracic indexes, and cardiac function as well as flow through main vessels. Results: Mean expiratory Haller Index (HI) was 5,4 (+/-1,4 SD; normal <3). During VB application, all patients showed improvement in the main morphologic parameters of the thorax (mean expiratory HI = 4,7 (+/-1,6 SD, delta -13%, P = 0,01). During VB application, a minimal but not significant increase of Right Ventricle End Diastolic Volume (RVEDVi) (delta +4,6%, P = 0,12), and Right Ventricle Ejection Fraction (RVEF) (delta +1,2%, P = 0,2) was observed. Conclusion: In adolescents affected by PE, cardiacMRI (CMR) demonstrates normal values of biventricular volume and systolic function. During VB application, beside significative improvements in chest wall anatomy, CMR shows a minimal positive variation in right ventricle volume and function. A minority of patients showed some degree of diastolic dysfunction at baseline, unchanged after VB application, with possible correlation between valve inflow and sternal impingement
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
Seismic risk assessment for masonry buildings typologies from L’Aquila 2009 earthquake damage data
No full textIn this study a seismic risk analysis of masonry buildings based on damage data of L’Aquila 2009 earthquake is presented. Typological loss curves and Expected Annualized Losses (EAL) values are presented, starting from the data collected into AeDES forms available in the Da.D.O. database. A completion is proposed for improving the sample statistical significance, and correctly including undamaged and not surveyed buildings that suffered low shaking values. Finally, the loss curves proposed permits to economically assess the effectiveness of some local and very frequent interventions (such as chains/ring beams), and their consequent impact in seismic risk mitigation
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
Attenuation of induced-bronchoconstriction in healthy subjects: effects of breathing depth
No full textFragility Curves and Economic Loss Assessment of RC Buildings after L’Aquila 2009 Earthquake
No full textA buildings stock of 12,016 Reinforced Concrete (RC) buildings is investigated to propose vulnerability, fragility, and loss curves, as well as an Expected Annual Loss (EAL) assessment. The buildings data are collected within Da.D.O. database, considering the observed damage due to L’Aquila earthquake (2009). The adopted methodology allows us to add undamaged and not-surveyed buildings, not included within the database, by considering the typological distribution of two different reference municipalities. The obtained results highlight that the completed database allows a more reliable seismic risk assessment, even if resulting EAL is poorly influenced by reference municipality assumed for undamaged buildings estimation
Attenuation of induced bronchoconstriction in healthy subjects: effects of breathing depth.
No full textThe effects of breathing depth in attenuating induced bronchoconstriction were studied in 12 healthy subjects. On four separate, randomized occasions, the depth of a series of five breaths taken soon (approximately 1 min) after methacholine (MCh) inhalation was varied from spontaneous tidal volume to lung volumes terminating at approximately 80, approximately 90, and 100% of total lung capacity (TLC). Partial forced expiratory flow at 40% of control forced vital capacity (V(part)) and residual volume (RV) were measured at control and again at 2, 7, and 11 min after MCh. The decrease in V(part) and the increase in RV were significantly less when the depth of the five-breath series was progressively increased (P < 0.001), with a linear relationship. The attenuating effects of deep breaths of any amplitude were significantly greater on RV than V(part) (P < 0.01) and lasted as long as 11 min, despite a slight decrease with time when the end-inspiratory lung volume was 100% of TLC. In conclusion, in healthy subjects exposed to MCh, a series of breaths of different depth up to TLC caused a progressive and sustained attenuation of bronchoconstriction. The effects of the depth of the five-breath series were more evident on the RV than on V(part), likely due to the different mechanisms that regulate airway closure and expiratory flow limitation
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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