1,720,965 research outputs found
Transvaginal ultrasonography in the diagnosis of vesico-peritoneal fistula due to deep infiltrating endometriosis as a cause of uroperitoneum
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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
Three-dimensional ultrasonography in the diagnosis of deep endometriosis
No full textSTUDY QUESTION:
In the use of 'tenderness-guided' transvaginal ultrasound, is the diagnostic accuracy of three-dimensional (3D) ultrasonography better than two-dimensional (2D) ultrasonography in the identification of deep endometriosis?
SUMMARY ANSWER:
Three-dimensional ultrasonography has a significantly higher diagnostic accuracy in the diagnosis of posterior locations of deep endometriosis without intestinal involvement, such as the uterosacral ligaments, vaginal and rectovaginal endometriosis.
WHAT IS KNOWN ALREADY:
The only previous study of the diagnosis of posterior compartment endometriosis reported an poor sensitivity of 3D ultrasonography for uterosacral and sigmoid colon involvement.
STUDY DESIGN, SIZE, DURATION:
This diagnostic test study included 202 patients scheduled for surgery because of clinical suspicion of deep pelvic endometriosis and was carried out between January 2009 and September 2012.
PARTICIPANTS/MATERIALS, SETTING, METHODS:
Modified transvaginal ultrasonography was performed on all of the women by a single examiner. Two locations of deep endometriosis were considered: intestinal involvement and other posterior lesions (including vaginal location, rectovaginal septum and uterosacral ligaments). Once the 2D ultrasonography had been performed, the 3D acquisition was performed and the obtained volume was stored. To avoid the risk of recall bias, the same operator evaluated the 3D volumes 6 months after the last examination using virtual navigation to provide a presumptive diagnosis of the presence and localization of deep endometriosis. In addition, to evaluate the reproducibility of 3D, two operators with different levels of expertise performed a retrospective review of 3D volumes from a random sample of 35 patients, twice, 1 week apart to also assess intraobserver agreement. The diagnostic performance of both tests was expressed as area under the receiver-operating characteristics curve (AUC), sensitivity, specificity, positive and negative predictive values, positive (LR+) and negative (LR-) likelihood ratios, with their respective 95% confidence interval (CI). Reproducibility was evaluated using kappa statistics.
MAIN RESULTS AND THE ROLE OF CHANCE:
Surgery revealed deep endometriosis in 129 patients. The AUCs for endometriosis of intestinal location were similar for both ultrasound techniques. The AUCs for endometriosis of other posterior locations were significantly different (0.891, 95% CI 0.839-0.943 for 3D versus 0.789, 95% CI 0.720-0.858 for 2D; P = 0.0193). For the intestinal involvement, the specificity, sensitivity, positive and negative predictive value, and LR+ and LR- were 93% (89-95%), 95% (88-98%), 89% (83-92%), 97% (93-99%), 13, and 0.06, respectively, for 2D ultrasound and 97% (93-99%), 91% (84-94%), 95% (88-98%), 95% (91-96%), 25, and 0.09, respectively, for 3D ultrasound. For other posterior locations, the specificity, sensitivity, positive and negative predictive value, and LR+ and LR- were 88% (82-93%), 71% (64-77%), 83% (75-90%), 79% (74-83%), 6.10, 0.32, respectively, for 2D ultrasound and 94% (89-97%), 87% (81-91%), 92% (86-96%), 90% (85-93%), 14.0, 0.14, respectively, for 3D ultrasound. Intraobserver agreement was substantial for both examiners (kappa 0.8754, for operator A and 0.7087, for operator B, respectively). Interobserver agreement was also substantial.
LIMITATIONS, REASONS FOR CAUTION:
The disadvantages of 3D ultrasound to be considered are the necessity of newer ultrasonographic equipment and that fewer sonographers completely know the 3D technique. There are also some limitations within this study. First, an expert examiner performed the real-time ultrasound and 3D volume acquisitions. Second, the same operator also performed the 3D evaluations but at least 6 months after the last acquisition to avoid a possible recall bias.
WIDER IMPLICATIONS OF THE FINDINGS:
The diagnostic performance obtained in the present study is superior to the accuracy reported in other studies of 3D ultrasonography, but not superior to all other published articles of 2D ultrasonography. The reported high diagnostic accuracy of 3D ultrasound could be widely generalizable because good reproducibility was demonstrated even with an operator with less expertise.
STUDY FUNDING/COMPETING INTEREST(S):
This study was supported in part by the Regione Autonoma della Sardegna (project code CPR-24750)
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
Assessing the reproducibility of the IOTA simple ultrasound rules for classifying adnexal masses as benign or malignant using stored 3D volumes
No full textOBJECTIVE:
To analyze the reproducibility of the IOTA simple ultrasound rules for classifying adnexal masses as benign or malignant among examiners with different level of expertise using stored 3D volumes of adnexal masses.
STUDY DESIGN:
Five examiners, with different levels of experience and blinded to each other, evaluated 100 stored 3D volumes from adnexal masses and looked for the presence or absence of malignant or benign features according to the IOTA definitions. Multiplanar view and virtual navigation were used. All examiners had to assess the 3D volume of each adnexal mass and classify it as benign or malignant. To analyze intra-observer agreement each examiner performed the assessment twice with a two-week interval between the first and second assessments. To analyze the inter-observer agreement, the second assessment from each examiner was used. Reproducibility was assessed calculating the weighted Kappa index.
RESULTS:
Intra-observer reproducibility was moderate or good for all observers (Kappa index ranging from 0.59 to 0.74). Inter-observer reproducibility was moderate to good (Kappa index range: 0.46-0.67).
CONCLUSIONS:
The simple rules are reasonably reproducible among observers with different level of expertise when assessed in stored 3D volumes
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
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