1,720,979 research outputs found
18 F-Fluorodeoxyglucose Positron Emission Tomography-Magnetic Resonance Monitoring of Brain Metabolic Changes in a Case of Arteriovenous Malformation–Related Steal Phenomenon Symptoms
No full textAccuracy of deep learning to differentiate the histopathological grading of meningiomas on MR images: a preliminary study
Full text linkBackground: Grading of meningiomas is important in the choice of the most effective treatment for each patient.
Purpose: To determine the diagnostic accuracy of a deep convolutional neural network (DCNN) in the differentiation of
the histopathological grading of meningiomas from MR images.
Study Type: Retrospective.
Population: In all, 117 meningioma-affected patients, 79 World Health Organization [WHO] Grade I, 32 WHO Grade II,
and 6 WHO Grade III.
Field Strength/Sequence: 1.5 T, 3.0 T postcontrast enhanced T1 W (PCT1W), apparent diffusion coefficient (ADC) maps
(b values of 0, 500, and 1000 s/mm2).
Assessment: WHO Grade II and WHO Grade III meningiomas were considered a single category. The diagnostic accuracy
of the pretrained Inception-V3 and AlexNet DCNNs was tested on ADC maps and PCT1W images separately. Receiver
operating characteristic curves (ROC) and area under the curve (AUC) were used to asses DCNN performance.
Statistical Test: Leave-one-out cross-validation.
Results: The application of the Inception-V3 DCNN on ADC maps provided the best diagnostic accuracy results, with an
AUC of 0.94 (95% confidence interval [CI], 0.88–0.98). Remarkably, only 1/38 WHO Grade II–III and 7/79 WHO Grade I
lesions were misclassified by this model. The application of AlexNet on ADC maps had a low discriminating accuracy, with
an AUC of 0.68 (95% CI, 0.59–0.76) and a high misclassification rate on both WHO Grade I and WHO Grade II–III cases.
The discriminating accuracy of both DCNNs on postcontrast T1W images was low, with Inception-V3 displaying an AUC of
0.68 (95% CI, 0.59–0.76) and AlexNet displaying an AUC of 0.55 (95% CI, 0.45–0.64).
Data Conclusion: DCNNs can accurately discriminate between benign and atypical/anaplastic meningiomas from ADC
maps but not from PCT1W images.
Level of evidence: 2
Technical Efficacy: Stage
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
CSF-venous leak responsible for spontaneous intracranial hypotension treated by endovascular venous route: First cases in Italy
No full textSpontaneous intracranial hypotension (SIH) is due to a leakage of CSF lowering the pressure of subarachnoid space, mostly caused by a dural breach or discogenic microspur. Clinical and MRI are usually typical enough to allow diagnosis, while finding the location of the dural breach is challenging. Since some years, CSF venous fistulas have been described as the cause of SIH, and a specific diagnostic and therapeutic path has been proposed. Here we report the first two successfully treated patients in Italy. Both had chronic and non specific symptoms, with severe reduction of quality of life; clinical symptoms improved after endovascular occlusion of the responsible vein
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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