1,721,562 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
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
Antenatal detection of arterio-arterial anastomoses by Doppler placental assessment in monochorionic twin pregnancies.
No full text
Role of ultrasound cervical length and vaginal infections in predicting spontaneous preterm delivery in twin pregnancies.
No full textObjective: To evaluate the role of short cervix at ultrasound exami- nation and vaginal infection in predicting spontaneous early preterm delivery in twin pregnancies.
Methods: Measurement of cervical length with ultrasound transvaginal (TV) probe was performed in 312 twin pregnan- cies between 19 and 25week’s gestation. Vaginal swabs at the same period were evaluated for all patients and the pres- ence of bacterial infection and/or trichomonas vaginalis was recorded. Patients with cervical length ≤ 20 mm and/or a diagnosis of vaginal infection were compared for preterm deliv- ery < 32 weeks with patients with normal cervical length and no signs of infections. Cerclage was performed in 20 patients with a cervical length ≤ 20 mm or prolapse of membranes < 25 weeks.
Results: Data for 8 cases delivered <32weeks for fetal and/or maternal indications were excluded, leaving 304 patients for the analysis. Cervical length ≤ 20 mm was found in 25 patients (8.2%) and a diagnosis of vaginal infection was made in 72 cases (23.7%).Spontaneous preterm delivery < 32 weeks occurred in 24 patients (7.8%). Five cases with cervical length ≤ 20 mm (20%) and 19 patients with longer cervix (6.8%) delivered spontaneously < 32 weeks (p = 0.019). When considering vaginal infection, spontaneous preterm delivery <32weeks occurred in 6 patients with positive test (8.3%) and in 18 with negative test (8.3%) (p = 0.87). Only one patient out of 7 with both short cervix and positive test for infection delivered < 32 weeks (p = 0.52).
Conclusions: Early spontaneous preterm delivery was significantly associated with short cervical length between 19 and 25 weeks’ gestation, while no correlation was found with a diagnosis of vaginal infection during pregnancy. In twin pregnancies spontaneous preterm delivery as well as shortening of the cervix have most likely different etiologies and cervical shortening is probably not related to infection
Antenatal detection of arterio-arterial anastomoses by Doppler placental assessment in monochorionic twin pregnancies.
No full textOBJECTIVES:
To evaluate the reproducibility of Doppler antenatal detection of arterio-arterial anastomoses (AAA) in monochorionic (MC) twin pregnancies.
METHODS:
Between October 2002 and February 2004, 21 MC diamniotic twin pregnancies and one dichorionic triamniotic triplet seen at the Twin Clinic at the University of Brescia were recruited. After routine ultrasonographic assessment, AAA were searched using Color or Power and spectral Doppler. The presence of AAA was confirmed postnatally by placental injection studies.
RESULTS:
Data of 19 patients were available for the analysis. AAA were detected in 12 cases (63%) antenatally and in 16 (84.2%) at injection study. Sensitivity and specificity of Doppler for detecting AAA were 75 and 100%, respectively. Detection rates increased at advanced gestations and with anterior/fundal placentae. The incidence of twin-twin transfusion syndrome was higher in the group with no AAA detected in vivo compared to the group with AAA found with Doppler (28.5 vs. 16.6%), but the difference was not statistically significant (p = 0.5).
CONCLUSION:
This study confirmed the feasibility of AAA Doppler detection in vivo in MC pregnancies
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