1,720,980 research outputs found
Automated On-line Data Analysis During Electrophysiological Studies in Humans
No full textWe have developed a microprocessor-based system which analyses on-line four channels of data: two endocavitary electrograms, a surface ECG and a pacemaker stimulus. The system detects the stimulus as well as atrial, His and ventricular waves and measures the time-intervals between them in real-time. Preliminary measurements have been made on 31 patients chosen at random and include different conditions like sinus rhythm, acute drug tests and programmed atrial pacing. Comparison between computer-determined and manual-determined intervals gives correlation coefficients always greater than 0.85
Electrophysiological effects of flecainide in atrial flutter. Acute test evaluation by on-line data analysis.
No full textIntravenous Flecainide in atrial flutter. Acute test evaluation by on-line data analysis
No full textEffects of Pharmacological Agents in the Study of Atrial Flutter Mechanism
No full textAlterations in physiologic properties induced by pharmacologic agents may provide useful data to clarify the mechanism of atrial flutter (AF) inman. In 15 pts, all with common type of AF, we performed one or more drug tests using: 1) Verapamil (V), to abolish abnormal automaticity like triggered activity; 2) Edrophonium chloride (EC), a cholinergic compound to shorten atrial refractoriness; 3) propaphenon (P), which has been shown to prolong atrial conductionand refractoriness. V, 0.10 mg/Kg i.v. in 5 pts (average AF cycle length 248 msec ± 11) and EC, 0.15 mg/Kg i.v. in 6 pts (average cycle length 246 msec ± 14), neither terminated AF nor changed AF cycle length significantly. P, 1.5 mg/Kg i.v. in 8 pts (average AF Cycle length 236 ms ± 25), always increased AF cycle length (average increase 62 msec, that is 26.2% of the base cycle).Thespite the complexity of drug action inman, these results are in favor of a reeentry circuit as electrogenetic mechanism of common AF
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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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