1,720,974 research outputs found
Sviluppo di un protocollo nell'analisi morfologica e funzionale dei tessuti periorali mediante l'uso di nuove tecnologie
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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
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
Three-dimensional analysis of hard palate in Down syndrome subjects
No full textAim: Down syndrome (DS) is the most frequent chromosomal aberration in man, with a prevalence of about 40,000 affected people in Italy, resulting from complete or partial trisomy of chromosome 21. Several peculiar maxillofacial features have been described in DS subjects, but quantitative assessments of hard tissue palatal features in subjects are still scanty (1) and no data concerning Italian DS people do exist. The purpose of the study was to collect data on palatal size and shape in DS subjects focusing on the major determinants of the hard palate modifications, whether only the Down syndrome or some other variables. Both the dental formula and the ethnicity were thus considered.
Materials and Methods: Hard tissue palatal shape and dimensions in 41 Italian DS subjects (29 men, 12 women) were analyzed and compared to normal reference data (15 men, 13 women). Palatal landmarks were digitized with a 3D computerised electromagnetic instrument and their coordinates were used to construct a mathematical equation of palatal shape, independent of dimensions (2, 3). Palatal length, slope, width, maximum palatal height in both sagittal and frontal plane were measured and two percentage ratios (maximum height to width and width to length) were obtained.
Results: All average dimensions were reduced in DS subjects without any significant sex difference except for palatal height in the sagittal plane (larger in males). The height to width ratio increased in Down syndrome individuals, while width to length ratio was similar. In the sagittal plane the curves of DS and normal subjects within each sex were nearly superimposable; in the frontal plane Down individuals showed a higher palate than healthy subjects, particularly females. To assess the influence of posterior teeth on palatal morphology, DS males were then divided in two groups (eight totally edentulous and 21 partially dentate) and compared to normal subjects by analysis of variance. Global F values were significant for all variables. Partial comparisons showed significant smaller measures in edentulous versus dentate DS males (not width) and versus normal subjects (not slope). All parameters but slope and height in the frontal plane were larger in reference than in partially dentate DS males. Shape modifications were larger in edentulous subjects with a flattening of palatal curves; all ratios were significantly reduced.
Conclusions: Trisomy of chromosome 21 seems to alter the normal palatal size and shape in Italian subjects, although further analyses may involve a larger group. Quantitative data on palatal features could be useful for clinicians when planning dental rehabilitation of DS patients, providing a reference to construct suitable prosthetic devices with improved oral health and dental care
Three-dimensional computerized anthropometry of the nose: landmark representation compared to surface analysis
No full textOBJECTIVE: To compare three-dimensional nasal measurements directly made on subjects to those made on plaster casts and nasal dimensions obtained with a surface based-approach to values obtained with a landmark representation. METHODS: Soft-tissue nasal landmarks were directly digitized on 20 healthy adults. Stone casts of their noses were digitized and mathematically reconstructed using NURBS (Non Uniform Rational B-Splines) curves. Linear distances, angles, volumes and surface areas were computed using facial landmarks and NURBS-reconstructed models (surface based-approach). RESULTS: Measurements on the stone casts were somewhat smaller than values obtained directly from subjects (differences between -0.05 and -1.58 mm). Dahlberg's statistic ranged between 0.73 and 1.47 mm. Significant (p<0.05) t values were found for 4 of 15 measurements. The surface-based approach gave values 3.5 (volumes) and 2.1 (surface area) times larger than those computed with the landmark-based method. The two values were significantly related (volume, r=0.881; surface, r=0.924; p<0.001), the resulting equations well estimated actual values (mean difference, volume -0.01 mm3, SD 1.47, area 0.05 cm2, SD 1.44); limits of agreement between -2.89 and 2.87 mm3 (volume); -2.88 and 2.78 cm2 (area). CONCLUSIONS: Considering the characteristics of the two methods, and for practical purposes, nasal distances and angles obtained on plaster models were comparable to digital data obtained directly from subjects. Surface areas and volumes were best obtained using a surface-based approach, but could be estimated using data provided by the landmark representation
Three-dimensional anthropometry of the nose : landmark representation vs. surface analysis
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