1,721,090 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
Computer Assisted Detection in neuroimmagini FLAIR e DTI: individuazione, segmentazione automatica e volumetria dei gliomi cerebrali
No full textCOMPUTER ASSISTED DETECTION IN NEUROIMMAGINI FLAIR E DTI: INDIVIDUAZIONE, SEGMENTAZIONE AUTOMATICA E VOLUMETRIA DEI GLIOMI CEREBRALI
Marina Donativi (1,6), Antonella Castellano (2,6), Giorgio De Nunzio (1,6), Gabriella Pastore (3,6), Matteo Rucco (4,6), Antonella Iadanza (2), Marco Riva (5), Lorenzo Bello (5), Andrea Falini (2)
1. Dip. di Matematica e Fisica “Ennio De Giorgi”, Univ. del Salento, Lecce
2. U.O. Neuroradiologia, Ospedale San Raffaele e Univ. Vita-Salute, Milano
3. Istituto di Ricerche Cliniche Ecomedica, Centro di Radioterapia e IGRT, Empoli
4. Univ. di Camerino, School of Science and Technology, Computer Science Division, Camerino
5. U.O. Neurochirurgia, Ist. Clinico Humanitas, Univ. di Milano, Milano
6. Advanced Data Analysis in Medicine, http://adamgroup.it
FINALITA'. I sistemi automatici (CAD, Computer Assisted Detection) per la segmentazione e la volumetria dei gliomi cerebrali sono di grande interesse per la valutazione dell’estensione tumorale nella diagnosi, la pianificazione terapeutica e il follow-up: l’uso di un CAD può ridurre la soggettività della diagnosi, aumentandone l’accuratezza.
In questo studio le immagini FLAIR e DTI di pazienti con glioma cerebrale sono state elaborate tramite analisi statistica tessiturale 3D per caratterizzare la struttura del tessuto tumorale e sviluppare un tool di segmentazione supervisionata automatica (“GlioCAD”), che fornisca la misura volumetrica delle lesioni e una valutazione degli istogrammi dei livelli di grigio di regioni di interesse [1].
MATERIALI E METODI. 34 pazienti con gliomi di basso e alto grado sono stati sottoposti a RM a 3T con sequenze 3D-FLAIR assiali e DTI (single-shot EPI, b=1000 s/mm2, 32 direzioni). Dalle immagini DTI sono state ottenute le mappe FA, MD, p e q. In ogni mappa sono state segmentate manualmente le regioni patologiche e, a queste ed al tessuto sano controlaterale, è stata applicata l’analisi tessiturale per identificare le caratteristiche (feature) discriminanti. La dimensionalità dello spazio delle feature è stata ridotta tramite Linear Discriminant Analysis (LDA), permettendo la classificazione e la segmentazione automatica del tumore.
RISULTATI. Per ogni mappa sono state calcolate sensibilità, specificità e curve ROC, con ottimi risultati (0.90≤AUC≤0.97). Per la fruizione in remoto di GlioCAD è stato realizzato un plugin per OsiriX, che permette caricamento e visualizzazione delle immagini da segmentare, e l’invio al server sul quale risiede GlioCAD. Dopo un tempo di calcolo compatibile con la pratica clinica, le segmentazioni tornano al client e sono visualizzate insieme alle misure volumetriche e agli istogrammi.
CONCLUSIONI. GlioCAD si propone come nuovo strumento, basato sull’analisi statistica tessiturale, per la segmentazione automatica dei gliomi cerebrali, la volumetria, e l’analisi quantitativa degli istogrammi nelle regioni di interesse.
[1] G. De Nunzio, G. Pastore, M. Donativi, A. Castellano, A. Falini, A CAD system for cerebral gliomas based on texture features in DT-MR images, NIM A, doi:10.1016/j.nima.2010.12.086 (2011
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
Utilizzo del mappaggio sottocorticale intraoperatorio in associazione alla trattografia di risonanza magnetica per le fibre motorie e del linguaggio nella chirugia dei gliomi
No full textPreoperative DTI Fiber Tracking (DTI-FT) reconstruction of functional tracts combined with intraoperative subcortical mapping (ISM) is potentially useful to improve surgical procedures in gliomas located in eloquent areas. Aims of the study are: (1) to evaluate the modifications of fiber trajectory induced by the tumor; (2) to validate preoperative DTI-FT results with intraoperative identification of functional subcortical sites through direct subcortical stimulation; (3) to evaluate the impact of preoperative DTI-FT reconstructions in a neuronavigational setup combined with ISM technique on duration and modalities of surgical procedures, and on functional outcome of the patients. Data are available on 110 patients (90 low-grade and 20 high-grade gliomas). DTI-FT was acquired by a 3-TMR scanner with a single-shot EPI sequence (TR/TE 8986/80 ms, b=1000 s/mm) with gradients applied along 32 non-collinear directions. 3D Fast Field Echo (FFE) T1-weighted imaging (TR/TE 8/4 ms) was performed for anatomic guidance. The corticospinal tract (CST), superior longitudinal, inferior fronto-occipital and uncinatus fasciculi were reconstructed. Data were transferred to the neuronavigational system. Functional subcortical sites identified during ISM were correlated with fiber tracts depicted by DTI-FT. In high-grade gliomas, DTI-FT depicted tracts mostly at the tumor periphery; in low-grade gliomas, fibers were frequently located inside the tumor mass. There was a high correlation between DTI-FT and ISM (sensitivity for CST=95%, language tracts=97%). For a proper reconstruction of the tracts, it was necessary to use a low FA threshold of fiber tracking algorithm and to position additional regions of interest (ROIs). The combination of DTI-FT and ISM decreased the duration of surgery, patient fatigue, and intraoperative seizures. Combination of DTI-FT and ISM allows accurate identification of eloquent fiber tracts and enhances surgical performance and safety maintaining a high rate of functional preservation
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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
