1,721,040 research outputs found
Concentration and ROC Curves, Revisited
This work is aimed at illustrating the strict relationship between a general definition of concentration function appeared quite some time ago on this journal and a widely used measure of the diagnostic strength of a family of binary classifiers indexed by a threshold parameter, the so-called ROC curve. The ROC curve is a common work tool in Statistics, Machine Learning and Artificial Intelligence, appearing in many applications where a binary classification (diagnosis) procedure is of interest. Hence, it is worth remarking that diagnostic strength and concentration are two sides of the same coin: the higher the concentration of one probability measure with respect to another, the higher the diagnostic strength of the likelihood ratio classification rule
On the definition of a concentration function relevant to the ROC curve
This work provides a definition of concentration curve alternative to the one presented on this journal by Schechtman and Schechtman (Metron 77:171–178, 2019). Our definition clarifies, at the population level, the relationship between concentration and the omnipresent ROC curve in diagnostic and classification problems
Facial Nerve Neurophysiologic Assessment in Vestibular Schwannoma Removal with Transcanal Approach: A Pilot Clinical Study.
Background: The transcanal transpromontorial approach has been introduced to remove vestibular schwannomas. As with other techniques, preservation of the facial nerve (FN) is challenging. This pilot study described FN outcomes of patients preoperatively and postoperatively assessed with electromyography (EMG) and blink reflex (BR). Methods: Between September 2017 and December 2018, 10 patients (5 men; 5 women; mean age, 59.8 years; age range, 25-77 years) underwent removal of vestibular schwannoma via the transcanal transpromontorial approach. FN assessment using EMG/BR and clinical evaluation with the House-Brackmann (HB) grading scale was performed preoperatively and 2 months postoperatively. If facial impairment was present postoperatively, further analysis was performed 6 months after surgery. Results: All 10 patients had normal FN function on preoperative EMG/BR. After 2 months, 4 patients had normal FN function on EMG/BR, 4 patients showed a slight delay of FN responses, 1 patient had moderate dysfunction, and 1 patient had consistent damage. After 6 months, among the 6 patients with a pathologic neurophysiologic study, consistent EMG/BR improvement was shown, with complete recovery in 3 cases. At the last follow-up, 8 patients had HB grade I, 1 patient had HB grade II, and 1 patient had HB grade III in 1, showing progression toward healing in 9 of 10 cases. Conclusions: The transcanal transpromontorial approach is an effective procedure for vestibular schwannoma removal. EMG/BR represents an objective evaluation method to verify FN recovery after surgery and confirms the low impact of this surgical procedure on the FN
Going Beyond Counting First Authors in Author Co-citation Analysis
The 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
“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
We 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
Maxillary Sinusitis as a Complication of Zygomatic Implants Placement: A Narrative Review
Aims: The aim of this review is to consider maxillary sinusitis as a complication of zygomatic implants placements. Maxillary sinusitis a common complication but in the literature there are no reviews that focus only on this condition and its possible treatment. This review was carried out with to highlight the main findings of the literature on this topic and to improve knowledge in this field. Methods: The search strategy resulted in 155 papers. After selection of the inclusion criteria only 11 papers were examined. From the papers these, 12.3% patients presented maxillary sinusitis but only four studies evaluated sinusitis (both clinical and radiological evaluation). The most common treatment used by the authors were antibiotics alone or combined with functional endoscopic sinus surgery (FESS). Results: The literature shows an absence of precise and shared guidelines diagnosis and post-operative follow-up, and of the treatment of maxillary sinusitis following zygomatic implantology. It has not been determined if the surgical placement of ZIs is better than the other techniques for treatment of the onset of maxillary sinusitis in the post-operative period. Conclusion: To date there are no shared protocols for maxillary sinusitis treatment. In our experience, and according to the literature in the presence of risk factors such as age, comorbidities, smoking, nasal septal deviation or other anatomical variants, we suggested that FESS is performed at the same time as placement of zygomatic implants
Timing of treatment and the concept of urgency in orthodontics. Guidelines and review of the literature
Objectives. The objective of the study is to define the optimal timing of "urgent" orthodontic treatment of malocclusions. Materials and methods. We conducted a systematic review of the literature that contained quantitative and qualitative data on the timing of orthodontic treatment of various types of malocclusions. Our analysis centered on articles indexed in the Medline database that had been published from 1970 through November 2010, including review articles, meta-analyses, and randomized and controlled clinical trials (RCT and CCT). Results and conclusions. Our analysis of the literature indicates that there are "urgent" orthodontic problems that require prompt treatment, even if the permanent teeth have not erupted. These cases include crossbites, skeletal class III malocclusion, certain behavioral anomalies, the presence of obstacles to eruption or supernumerary teeth, and early tooth shedding. In these cases, early treatment often prevents the later development of severe, frequently skeletal malocclusions. © 2011 Elsevier Srl
Dispelling the Myths Behind First-author Citation Counts
We 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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