1,720,994 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
Successful resection of an epicardial cyst
No full textCases of pericardial cyst have been reported by many authors, but the incidence of epicardial cyst originating directly from the epicardium in the pericardial cavity is extremely rare. A case of successful resection of epicardial cyst fortuitously discovered and diagnosed during cardiac operation is presented
Cardiac myxoma : 15 years of surgical experience
No full textBACKGROUND: Among cardiac tumors myxoma is the most common benign neoplasm. The aim of this study was to review our Institution's 15-year experience with intracardiac myxoma.
METHODS: From 1985 through 2001, 38 patients (22 males, 16 females, mean age 57.06 +/- 11.1, range 32-74 years) underwent surgical resection of a cardiac myxoma at our Institution. The tumor was located in the left atrium in 29 patients (76.3%), in the right atrium in 8 patients (21%), and in the right ventricle in 1 patient (2.6%). The duration of symptoms prior to surgery ranged from 2 to 30 days. None of the patients had a familial myxoma. The surgical approach comprised complete wide excision in all patients. The incidence of delayed death, thromboembolic complications, valve degeneration, recurrence and reoperation were reviewed and the Kaplan-Meier survival curve was elaborated.
RESULTS: There were no perioperative deaths. Three patients (7.9%) developed postoperative neurological sequelae: transient ischemic attacks in 2 patients (5.2%) and a stroke with persistent neurological deficit in 1 patient (2.6%). One patient (2.6%) required pacemaker implantation for complete atrioventricular block. An inferior myocardial infarction occurred in 1 patient (2.6%). During the follow-up, complete in 89.4% of the patients (34 out of 38 patients, mean 96.8 +/- 68.4 months, range 1-218 months), there were 2 (5.8%) non-cardiac related deaths. All the patients underwent clinical examination and echocardiography at regular intervals (1 year): no neurological event was observed during the follow-up and 29 patients (90.6%) are in NYHA functional class I. At 15 years the event-free rate is 85.2%. At 15 years the actuarial survival for the whole group is 92%.
CONCLUSIONS: At present, the diagnosis of myxoma is easy to make and two-dimensional echocardiography plays a major role in this field. Surgery is the gold standard treatment and the clinical long-term results are excellent
Il mixoma cardiaco: risultati chirurgici e follow-up clinico a 15 anni
No full textBackground. Among cardiac tumors myxoma is the most common benign neoplasm. The aim of
this study was to review our Institution’s 15-year experience with intracardiac myxoma.
Methods. From 1985 through 2001, 38 patients (22 males, 16 females, mean age 57.06 ± 11.1, range
32-74 years) underwent surgical resection of a cardiac myxoma at our Institution. The tumor was located
in the left atrium in 29 patients (76.3%), in the right atrium in 8 patients (21%), and in the right
ventricle in 1 patient (2.6%). The duration of symptoms prior to surgery ranged from 2 to 30 days.
None of the patients had a familial myxoma. The surgical approach comprised complete wide excision
in all patients. The incidence of delayed death, thromboembolic complications, valve degeneration, recurrence
and reoperation were reviewed and the Kaplan-Meier survival curve was elaborated.
Results. There were no perioperative deaths. Three patients (7.9%) developed postoperative neurological
sequelae: transient ischemic attacks in 2 patients (5.2%) and a stroke with persistent neurological
deficit in 1 patient (2.6%). One patient (2.6%) required pacemaker implantation for complete
atrioventricular block. An inferior myocardial infarction occurred in 1 patient (2.6%). During
the follow-up, complete in 89.4% of the patients (34 out of 38 patients, mean 96.8 ± 68.4 months, range
1-218 months), there were 2 (5.8%) non-cardiac related deaths. All the patients underwent clinical examination
and echocardiography at regular intervals (1 year): no neurological event was observed
during the follow-up and 29 patients (90.6%) are in NYHA functional class I. At 15 years the eventfree
rate is 85.2%. At 15 years the actuarial survival for the whole group is 92%.
Conclusions. At present, the diagnosis of myxoma is easy to make and two-dimensional echocardiography
plays a major role in this field. Surgery is the gold standard treatment and the clinical longterm
results are excellent
Aortic valve stenosis in the elderly: when to intervene? Opinion of the surgeon cardiologist
No full text[Right pleural effusion in aortic dissecting aneurysm]
No full textRight hemorrhagic pleural effusion may be a presenting sign of thoracic aortic dissecting aneurysm. We describe 2 cases of massive right hemorrhagic pleural effusion and dissection of the descending aorta (type B) detected at tomographic scan. Transesophageal echocardiography ruled out a retrograde dissection of the ascending aorta. Right hemorrhagic pleural effusion is an unusual clinical presentation in thoracic aorta dissection and, up to now, the underling pathophysiology of this sign has not been defined yet
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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