1,720,964 research outputs found
L'ortopantomografia digitale nei pazienti portatori di sistemi di fissazione interna rigida maxillo-facciale
No full textIntroduction. Digital techniques have found promising applications in dental radiology in the recent past, namely with radiovisiography and digital panoramic radiography. These images present some features making them particularly interesting for alveolar bone studies. Material and methods. Digital panoramic radiography with light-emitting phosphors was performed on 16 patients during postoperative follow-up. The patients were previously submitted to multiple maxillofacial osteosynthesis with rigid internal fixation devices (32 miniplates, 12 microplates, 14 screws). Digital images were always observed and printed with analogic-like and Xeroradiographic-like post-processing. Results. Digital panoramic radiographs yielded clear and effective images of the maxillary and mandibular arches and of surgical osteosynthesis, as demonstrated by a retrospective evaluation performed by three independent observers on a blind basis (score 3: 60.42%), with no major interobserver differences (p =.7286). Xeroradiographic-like images were the most effective in depicting bone structures and osteosynthesis materials, thanks to their better detailing and typically lower overall contrast. Among the drawbacks of the digital technique, reduced cassette size may prevent the full view of the mandibular arch from the symphysis to both condylar regions. The edge effect, which is typical of Xeroradiographic images, may mask useful details within the trabecular bone close to metal implants. This effect was present in some of our cases, but it was seldom disturbing according to our retrospective evaluation (score 3: 53.40%), with good interobserver agreement (p = .1117). Conclusion. Digital panoramic radiography proves to be a useful tool to study metal implants after maxillofacial surgery as well as alveolar bone structure. The digital technique markedly reduces the radiation dose to the patient, which is very important for an X-ray examination that must be repeated several times, often in young subjects
Valutazione ecografica dei nuclei di ossificazione del polso e del picco di crescita puberale
No full textHigh-resolution ultrasound (US) of the hand and wrist was compared with radiography in 26 young patients (mean age: 11.4 years) to be submitted to orthodontic therapy. US scans were targeted on the ossification centers critical for the growth spurt, namely the pisiform and adductor sesamoid bones of the metacarpophalangeal joint of the thumb and the cartilage of the distal phalanx of the third finger. All images were retrospectively reviewed on a double-blind basis by two independent observers who gave a conspicuity score to each structure of interest. All the scores were submitted to statistical analysis with the Wilcoxon test. US images clearly demonstrated the initial appearance of the ossification centers of the pisiform and sesamoid bones. These structures appeared as hyperechoic spots causing marked acoustic shadowing. The persistence of the phalangeal cartilage was depicted as a thin rim interrupting the hyperechoic cortical profile of the bone. US results were statistically equivalent to radiographic findings in the pisiform [p (op1) = .3105; p (op2) = .8886] and sesamoid bones of the thumb [p (op1) = .1386; p (op2) = .354]. A statistically significant difference between the two techniques was found in the third finger cartilage (p (op1) = .0277; p (op2) = .0759) because its profile was poorly depicted on some US images. To conclude, wrist US is proposed as a simple and valuable radiation-free support examination for the follow-up of skeletal maturation in adolescents to be submitted to orthodontic therapy
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
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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