1,720,965 research outputs found
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
Role of Doppler velocimetry of uterine arteries and ambulatory blood pressure monitoring in detecting pregnancies at risk for preeclampsia
No full textAIM:
The aim of this study is to evaluate the performance of ambulatory blood pressure monitoring (ABPM) in association with Doppler velocimetry of uterine arteries in the detection of preeclampsia (PE).
METHODS:
In a prospective study, 22 patients at risk for the development of PE have been en-rolled: 17 were nulliparous women with increased resistances in uterine arteries at 24 weeks and 5 had an obstetric history of PE. All patients were tested with ABPM and uterine arteries Doppler velocimetry. A resistance index (RI) higher than 0.62 for the Doppler velocimetry and a diastolic midline estimating statistic of rhythm (MESOR) higher than 68 for the ABPM were considered abnormal. Patients were followed longitudinally until delivery. The occurrence of PE and low birth weight were considered as gestational outcomes endpoints.
RESULTS:
Overall, the mean gestational age at delivery was 36.3+/-3.4 weeks (range 29.4-41). Six out of 22 (27.2%) patients developed PE; 4 out of 22 (18%) newborns were small for gestational age (SGA) <5 degrees percentile. In the prediction of PE, ABPM in association with Doppler velocimetry showed a positive predictive value (PPV) of 42% and a negative predictive value (NPV) of 90%, for the development of low birth weight the PPV was 33% and the NPV 100%.
CONCLUSION:
This study shows that ABPM in association with Doppler velocimetry evaluation is a useful test to detect patients at high risk for the development of PE
Effect of betamethasone on computerized cardiotocographic parameters in preterm growth-restricted fetuses with and without cerebral vasodilation.
No full textOBJECTIVE:
To verify the effects of maternal corticosteroid administration on fetal behavior and heart rate variation using computerized cardiotocography (cCTG) in a selected group of growth retarded fetuses.
STUDY DESIGN:
Fifty singleton pregnancies complicated by fetal growth restriction were enrolled in the study before 34 weeks of gestation. All of them received two intramuscular injections of 12 mg of betamethasone 24 h apart. Fetal heart rate was recorded by cCTG before the first injection, and every 24 h for the 3 days following the end of the treatment. After Doppler evaluation of cerebral circulation, fetuses were divided into a group with and a group without signs of cerebral vasodilation. Basal heart rate, short- and long-term variation, percentage of time spent in high variability, fetal movements and percentage of small accelerations were evaluated.
RESULTS:
Basal fetal heart rate did not show significant changes. Short-term variation and percentage of time spent in high variability significantly decreased in fetuses with but not in fetuses without vasodilation. Long-term variation and fetal movements significantly decreased in both groups.
CONCLUSIONS:
Maternal administration of betamethasone in growth-retarded fetuses with cerebral vasodilation is associated with significant but transitory modifications of fetal heart rate variation
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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