1,720,979 research outputs found
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
Age-stratified patterns in clinical presentation, treatment and outcomes in acute pericarditis: a retrospective cohort study
No full textBackground: There are limited data on acute pericarditis according to different age groups. The aim of this study is to investigate the role of age-related features in clinical characteristics, management, and outcomes of acute pericarditis, with a focus on the geriatric population. Methods: Patients with a first episode of acute pericarditis were consecutively enrolled between January 2014 and June 2022, and divided into four groups according to age (G1: 18-35 years; G2: 35-55 years; G3: 55-75 years; G4: >75 years). Clinical characteristics and medical therapy were recorded at baseline, and during follow-up. Results: A total of 471 patients (median age 56.3 (IQR 33-73) years, 32.3% women) were included. Younger age (G1-G2-G3) was associated with a higher frequency of chest pain, pericardial rubs (p<0001), ECG changes (p=0.002) and were more commonly treated with colchicine (p<0.001), and non-steroidal anti-inflammatory drugs (p=0.006). Older patients (G4) depicted more commonly dyspnoea, pericardial/pleural effusion (p=0.007) and were more often treated with corticosteroids (p=0.037). A secondary cause of pericarditis was detected in 128/471 (27.2%) patients. Older patients were more commonly hospitalised and had a complicated course with new-onset atrial fibrillation (p<0.001) and cardiac tamponade (p=0.005), compared with younger patients, who presented more recurrences (respectively G1: 43.0%, G2: 34.7%, G3: 28.2% and G4: 16.2%; p<0.001). After multivariable analysis, younger age remained the strongest independent predictor for recurrences (HR 3.23, 95% CI 1.81 to 5.58, p<0.001). Conclusion: Older age is associated with less recurrences of pericarditis, but more severe complications with need for hospitalisation
Clinical presentation and long-term follow-up of perimyocarditis.
No full textBACKGROUND: The natural history of perimyocarditis (PMY) is not yet completely known. We aimed to analyse the clinical laboratory data of PMY at diagnosis and during follow-up, in order to assess the natural history and prognostic stratification of the disease (including different aetiology). METHODS: We enrolled 62 consecutive patients (men 79%, aged 38 ± 18 years) with PMY (84% idiopathic, 8% autoimmune, 8% infective) from August 2002 to July 2010. The diagnosis has been made according to clinical and laboratory data (significant increase of troponin I in all patients). After at least 1 year (mean follow-up: 1635 ± 298 days), 59 patients (95%) had available data. RESULTS: Chest pain was present in 59 patients (95%), flu-like syndrome in 36 (58%) and pericardial rubs in 15 (24%). None of the patients showed heart failure at presentation. At admission, eight patients (13%) presented mild-moderate left ventricular systolic dysfunction, 13 (22%) showed wall motion abnormalities, and 10 (17%) showed mild pericardial effusion. At 1 year no patients died, developed heart failure or showed abnormal echocardiogram. NSAIDs were the first choice therapy in 61 (98%) patients with clinical resolution in 58 (95%) of them. Seven patients (12%) experienced intermittent recurrences without development of constrictive pericarditis or heart failure. CONCLUSION: This study underlines the benign mid- to long-term outcome of PMY regardless of clinical laboratory characteristics at presentation, different aetiology and possibility of relapses; minimizing the role of endomyocardial biopsy in these specific patients
HIGH ASPECT RATIO WING WITH CURVED PLANFORM: CFD AND FE ANALYSES
No full textModern configurations of aircraft deal with a high performance design of lifting systems especially oriented to reduction of weight, aerodynamic drag and fuel consumption. The paper shows preliminary results of aerodynamic and structural analyses of a high aspect ratio wing with curved planform, carried out at the Department of Aerospace Engineering of the University of Pisa. In transonic flight condition (high subsonic), for curved planform wing, the wave drag effects are significantly reduced. A numerical comparison, carried out using the FLUENT® code, between curved and traditional swept wing, both designed with the same supercritical airfoil, shows a drag coefficient reduction of 4% and more for asymptotic Mach numbers greater than 0.85. The B787 aircraft’s wing planform has been assumed as reference geometry to carry out the numerical analyses. The curved planform configuration also improves the aeroelastic behaviour of the wing: some preliminary results obtained using the NASTRAN® code are summarized in the paper
New Developments in the Management of Recurrent Pericarditis
No full textRecurrent pericarditis is a common and troublesome complication that affects 15%-30% of patients with a previous episode of pericarditis. However, the pathogenesis of these recurrences is not well understood, and most cases remain idiopathic. Recent advances in medical therapy, including the use of colchicine and anti-interleukin-1 agents like anakinra and rilonacept, have suggested an autoinflammatory rather than an autoimmune mechanism for recurrences with an inflammatory phenotype. As a result, a more personalized approach to treatment is now recommended. Patients with an inflammatory phenotype (fever and elevated C-reactive protein level) should receive colchicine and anti-interleukin-1 agents as first-line therapy, whereas those without systemic inflammation should receive low to moderate doses of corticosteroids (eg, prednisone 0.2-0.5 mg/kg/d as an initial dose) and consider azathioprine and intravenous human immunoglobulins in the case of corticosteroid failure. Tapering of corticosteroids should be slow after achieving clinical remission. In this article, we review the new developments in the management of recurrent pericarditis
CURVED PLANFORM WINGS WITH A HIGH ASPECT RATIO FOR AIRCRAFTS OPERATING IN THE TRANSONIC REGIME
Full text linkThe present invention concerns an innovative
wing (1) specific for an aircraft operating in the
transonic regime and comprising:
- A root section ;
- A tip section and;
- A leading edge for connecting the root section to the tip section.
In accordance with the invention, the curved leading edge is configured according to a line by
which locally the angle (Λ) formed by the forwarding direction of the wing and the perpendicular to the
tangent of the leading edge increases progressively from the root section to the tip section of the wing.
In such a way, the speed component (Vu) of the asymptotic flow orthogonal to the leading edge decreases
progressively from the root section to the tip section, thus reducing the local Mach number progressively
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