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Yunrong Li Filippo Radicchi Claudio Castellano Javier Ruiz-Castillo 《Journal of Informetrics》2013,7(3):746-755
Wide differences in publication and citation practices make impossible the direct comparison of raw citation counts across scientific disciplines. Recent research has studied new and traditional normalization procedures aimed at suppressing as much as possible these disproportions in citation numbers among scientific domains. Using the recently introduced IDCP (Inequality due to Differences in Citation Practices) method, this paper rigorously tests the performance of six cited-side normalization procedures based on the Thomson Reuters classification system consisting of 172 sub-fields. We use six yearly datasets from 1980 to 2004, with widely varying citation windows from the publication year to May 2011. The main findings are the following three. Firstly, as observed in previous research, within each year the shapes of sub-field citation distributions are strikingly similar. This paves the way for several normalization procedures to perform reasonably well in reducing the effect on citation inequality of differences in citation practices. Secondly, independently of the year of publication and the length of the citation window, the effect of such differences represents about 13% of total citation inequality. Thirdly, a recently introduced two-parameter normalization scheme outperforms the other normalization procedures over the entire period, reducing citation disproportions to a level very close to the minimum achievable given the data and the classification system. However, the traditional procedure of using sub-field mean citations as normalization factors yields also good results. 相似文献
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Antonio Crisafulli Franco Melis Filippo Tocco Gianluigi Pittau Luigi Lorrai Tommaso Gori 《Journal of sports sciences》2013,31(12):1393-1401
Abstract Nitroglycerin induces the so-called second window of protection (SWOP), which alleviates myocardial damage and stunning after ischaemia/reperfusion. To determine whether myocardial performance during exercise is improved in the second window of protection, we studied the haemodynamic responses of 12 trained and 11 sedentary individuals during a sequence of maximal tests on a cycle ergometer. A baseline test (basal test) was followed by a second effort performed during the second window of protection (exercise-SWOP test). Haemodynamics was also evaluated after pharmacologically induced SWOP 48 h after transdermal administration of 10 mg of nitroglycerin (pharmacologically induced SWOP test). The exercise-SWOP and pharmacologically induced SWOP tests were separated by a 1-week washout period. Endothelial-dependent vasodilatation after nitroglycerin pre-treatment was also assessed in five sedentary individuals to determine whether nitrate donors could affect vascular function. We found that nitroglycerin pre-treatment did not induce any improvement in haemodynamics in either trained or sedentary individuals, since maximum values of workload, heart rate, stroke volume, cardiac output, myocardial contractility, and double product were similar between the exercise-SWOP and pharmacologically induced SWOP tests in both groups. Furthermore, nitroglycerin pre-treatment did not alter flow-mediated dilation during pharmacologically induced SWOP. Although nitroglycerin pre-treatment alleviates post-ischaemic myocardial stunning, our results suggest that it does not affect the myocardial performance of healthy individuals during exercise performed in the second window of protection, independently of the training status of the individuals. Moreover, nitroglycerin pre-treatment does not ameliorate endothelial function. 相似文献
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Antonio Serra Daniela Manno Emanuela Filippo Rosa Vitale Giuseppe Sarcinelli Lucio Calcagnile Gianluca Quarta Giuseppe Giovannelli Benedetto Bozzini Aldo Siciliano 《Journal of Cultural Heritage》2010,11(2):233-238
Out of the staters collection of the National Archaeological Museum of Taranto, during the full examination of about one hundred coins minted by the Greek colony of Taras between the V century BC and the III century BC, our attention has been devoted to a lead coin, which has been regarded for many years as a genuine silver coin. This artifact, entry number 13 in the inventory list for the Parabita hoard, has been studied with the combined use of surface and micro-analytical techniques (SEM, EDX, PIXE, XRD). The joint use of different analytical techniques allowed us to obtain information about the morphology, the structure and the chemical composition of the analysed coin, that revealed a lead core coated with a bi-layer of copper and silver. 相似文献
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The name ambiguity problem is especially challenging in the field of bibliographic digital libraries. The problem is amplified when names are collected from heterogeneous sources. This is the case in the Scholarometer system, which performs bibliometric analysis by cross-correlating author names in user queries with those retrieved from digital libraries. The uncontrolled nature of user-generated annotations is very valuable, but creates the need to detect ambiguous names. Our goal is to detect ambiguous names at query time by mining digital library annotation data, thereby decreasing noise in the bibliometric analysis. We explore three kinds of heuristic features based on citations, metadata, and crowdsourced topics in a supervised learning framework. The proposed approach achieves almost 80% accuracy. Finally, we compare the performance of ambiguous author detection in Scholarometer using Google Scholar against a baseline based on Microsoft Academic Search. 相似文献
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Filippo M. de Sanctis 《International Review of Education/Internationale Zeitschrift für Erziehungswissenschaft/Revue internationale l'éducation》1974,20(4):474-485
Sans résumé
Media and educational materials in the context of lifelong education
Lehrmittel Und -Materialien Im Rahmen Der Lifelong Education相似文献
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Crisafulli A Melis F Tocco F Pittau G Lorrai L Gori T Mancardi D Concu A Pagliaro P 《Journal of sports sciences》2007,25(12):1393-1401
Nitroglycerin induces the so-called second window of protection (SWOP), which alleviates myocardial damage and stunning after ischaemia/reperfusion. To determine whether myocardial performance during exercise is improved in the second window of protection, we studied the haemodynamic responses of 12 trained and 11 sedentary individuals during a sequence of maximal tests on a cycle ergometer. A baseline test (basal test) was followed by a second effort performed during the second window of protection (exercise-SWOP test). Haemodynamics was also evaluated after pharmacologically induced SWOP 48 h after transdermal administration of 10 mg of nitroglycerin (pharmacologically induced SWOP test). The exercise-SWOP and pharmacologically induced SWOP tests were separated by a 1-week washout period. Endothelial-dependent vasodilatation after nitroglycerin pre-treatment was also assessed in five sedentary individuals to determine whether nitrate donors could affect vascular function. We found that nitroglycerin pre-treatment did not induce any improvement in haemodynamics in either trained or sedentary individuals, since maximum values of workload, heart rate, stroke volume, cardiac output, myocardial contractility, and double product were similar between the exercise-SWOP and pharmacologically induced SWOP tests in both groups. Furthermore, nitroglycerin pre-treatment did not alter flow-mediated dilation during pharmacologically induced SWOP. Although nitroglycerin pre-treatment alleviates post-ischaemic myocardial stunning, our results suggest that it does not affect the myocardial performance of healthy individuals during exercise performed in the second window of protection, independently of the training status of the individuals. Moreover, nitroglycerin pre-treatment does not ameliorate endothelial function. 相似文献