1,720,987 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
Coverage of visible intercostal and lumbar segmental arteries can predict the volume of cerebrospinal fluid drainage in elective endovascular repair of descending thoracic and thoracoabdominal aortic disease: A pilot study
No full textOBJECTIVES Our goal was to identify anatomical and physiological factors that could predict the amount of cerebrospinal fluid (CSF) drainage in patients undergoing elective endovascular repair of descending thoracic and thoracoabdominal aortic disease. METHODS All consecutive elective endovascular procedures performed for descending thoracic or thoracoabdominal aortic disease between January 2015 and December 2017 were included in the study. Routine use of CSF drainage was established in all patients. The goal of drainage was to reach a spinal fluid pressure of 10-12 mmHg by draining in 5-15-ml aliquots. The number of visible intercostal and lumbar segmental arteries (SAs) was evaluated before and after endovascular repair. The covering ratio of SAs was calculated as covered preoperative SAs/total preoperative SAs. RESULTS Twenty-four consecutive patients were included in the final analysis. The indication for the intervention was a descending thoracic aneurysm in 13 cases, a thoracoabdominal aneurysm in 4 cases and a chronic type B dissection in 7 cases. The procedure performed was thoracic endovascular aortic repair in 20 cases and fenestrated endovascular aneurysm repair in 4 cases. None of the patients developed spinal cord ischaemia. The mean volume of CSF drained was 46 ml. The mean length of aortic coverage was 231 mm. The mean number of total preoperative SAs and of covered preoperative SAs was, respectively, 22 and 9. The volume of CSF drained was significantly correlated with all these variables (length of aortic coverage, total visible SAs and covered SAs), but the most powerful correlation was individuated with the covering ratio of SAs. CONCLUSIONS Our findings suggest that the percentage of intercostal and lumbar SAs covered by placement of a stent graft can predict the volume of CSF drained in patients undergoing elective endovascular repair of descending thoracic and thoracoabdominal aortic disease
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
Predicting a prolonged air leak after video assisted thoracic surgery, is it really possible?
No full textValidation of predictive risk models for prolonged air leak (PAL) is essential to
understand if they can help to reduce its incidence and complications. This
study aimed to evaluate both the clinical and statistical performances of 4
existing models. We selected 4 predictive PAL risk models based on their
scientific relevance. We referred to these models as Chicago, Bordeaux,
Leeds and Pittsburgh model, respectively, according to the affiliation place
of the first author. These predicting risk models were retrospectively applied
to patients recorded on the second edition of the Italian Video-Assisted
Thoracoscopic Surgery Group registry. Predictions for each patient were
calculated based on the logistic regression coefficient values provided in the
original manuscripts. All models were tested for their overall performance,
discrimination, and calibration. We recalibrated the original models with the
re-estimation of the model intercept and slope. We used curve decision
analysis to describe and compare the clinical effects of the studied risk mod
els.
Better statistical metrics characterize the models developed on larger
populations (Chicago and Bordeaux models). However, no model has a valid
benefit for threshold probability greater than 0.30. The Net benefit of the
most performing model (Bordeaux model) at the threshold probability of
0.11 is 23 of 1000 patients, burdened by 333 false positive cases. One of
1000 is the Net benefit at the threshold probability of 0.3. The use of PAL
scores based on preoperative predictive factors cannot be currently used in
a clinical setting because of a high false positive rate and low positive pre
dictive valu
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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