1,720,993 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
Role of sirtuins, calorie restriction and physical activity in aging.
No full textRecently it has been discovered that Sirtuins represent pivotal regulators of lifespan. Caloric restriction (CR) enhances longevity from yeast to mammals. Whereas the relationship between Sirt-1 and CR is clear, the molecular mechanisms by which Sir2 increases longevity are still unknown. In mammals, CR induces physiological and behavioral changes, and many studies have shown that CR decreases production of reactive oxygen species production thus minimizing oxidative damage, leading to the hypothesis that CR by reducing oxidative stress extends the lifespan by counteraction of aging. In fact, the pathophysiology of aging and age-related diseases involves oxidative stress as an early stage in its development. Recently we found that in aged rats the SIRT1 activity was decreased in heart and adipose tissue, showing as aging is characterized in vivo by a reduced efficiency of this key-regulator of longevity. Whereas several studies have reported that increased physical activity can improve mean life span presumably by reducing mortality risk from many age-related diseases, exercise and longevity studies have failed to document an exercise effect on maximum life span. However, in aged rats a moderate prolonged exercise training is able to induce increase in SIRT1 activity, suggesting that this tool could counteract age-related dysfunctions
Heart Rate Variability in Noltisalis Database: Twenty-Four-Hour Fractal Dimension Analysis
No full textNonlinear analysis of HRV has recently been recognized to provide valuable information in the
prognostic classification of cardiac patients. Among the numerous non-linear parameters related to the fractal
behaviour of the HRV signal, two classes have gained wide interest in the last years: that based on the 1/flike
relationship, starting from the spectral power, and that based on fractal features. We present results
obtained from the analysis of 50 heart rate variability series which have been extracted from Holter
recordings in the 24-hours in normal subjects and pathological patients. Data have been collected inside a
multicentric research program, which aimed at the nonlinear analysis of heart rate variability series.
Differently from methods usually used in literature to evaluate the fractal dimension, the parameter used in
this work has been extracted directly from the HRV sequences in the time domain, by means of the Higuchi's
algorithm. Results show that this fractal dimension can be used to separate normal subjects from patients
suffering from cardiovascular diseases and to evaluate the presence of circadianity in the HRV over the
whole twenty four hours
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
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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