1,720,980 research outputs found
[Groups with volunteers cardiac surgery patients: experience in a cardiovascular rehabilitation department].
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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
Multifractal multiscale dfa of cardiovascular time series: Differences in complex dynamics of systolic blood pressure, diastolic blood pressure and heart rate
No full textThe heart-rate fractal dynamics can be assessed by Detrended Fluctuation Analysis (DFA), originally proposed for estimating a short-term coefficient, α1(for scales nâ¤12 beats), and a long-term coefficient α2(for longer scales). Successively, DFA was extended to provide a multiscale α, i.e. a continuous function of n, α(n); or a multifractal α, i.e. a function of the order q of the fluctuations moment, α(q). Very recently, a multifractal-multiscale DFA was proposed for evaluating multifractality at different scales separately. Aim of this work is to describe the multifractal multiscale dynamics of three cardiovascular signals often recorded beat by beat in physiological and clinical settings: systolic blood pressure (SBP), diastolic blood pressure (DBP) and pulse interval (PI, inverse of the heart rate). We recorded SBP, DBP and PI for at least 90â2 in 65 healthy volunteers at rest, and adapted the previously proposed multifractal multiscale DFA to estimate α as function of the temporal scale, Ï, between 15 and 450 s, and of the order q, between -5 and 5. We report, for the first time: 1) substantial differences among α(q,Ï) surfaces of PI, SBP and DBP; 2) a strong dependency of the degree of multifractality on the temporal scale
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
Hemodynamic and Autonomic Response to Different Salt Intakes in Normotensive Individuals
Full text linkBackground: Even if sodium sensitivity represents a risk factor at any blood pressure (BP) level, limited evidence is available that it may influence cardiovascular control in normotensives, particularly in white individuals. Therefore, the aim of the study was to investigate whether sodium sensitivity alters hemodynamic or autonomic responses to salt in normotensives. Methods and Results: We evaluated the Sodium-Sensitivity Index (SS-Index) in 71 white normotensives after 5 days of high- and low-sodium diets. We measured BP continuously at the end of each period, estimating hemodynamic indices from BP waveform analysis, and autonomic indices from heart rate (HR) and BP variability. According to the SS-Index distribution, we defined 1 sodium-sensitive group (SS, with SS-Index >15 mm Hg/[mmol·day]), 1 sodium-resistant group, (unresponsive to sodium load with -15≤ SS-Index ≤+15), and 1 inverse sodium-sensitive group, responsive to sodium by decreasing BP, with SS-Index <-15). We compared the effects of the diets among groups, and correlated autonomic/hemodynamic indices with the SS-Index. After sodium loading, a significant decrease in systemic peripheral resistances, HR, spectral indices of BP modulation, and a significant increase of indices of HR vagal modulation were found in the inverse sodium-sensitive group but not in SS normotensives. Moreover, the highest SS-Indices were associated with the lesser vagal HR decelerations. Conclusions: Our data suggest that salt sensitivity in white normotensive individuals is associated with impaired vasodilation and altered autonomic response to dietary salt. Such dysfunction may critically contribute to induce a BP response to dietary salt
A cautious view of the relationship between ambulatory blood pressure monitoring data and salt-sensitivity of blood pressure.
No full textAppropriate 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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