1,720,957 research outputs found
Ultrasonografia ossea quantitativa (QUS) falangea e densitometria ossea a doppio raggio-X (DXA) lombare in pazienti pediatrici affetti da osteogenesi imperfetta
No full textScopo
Obiettivo dello studio è stato quello di comparare, in pazienti pediatrici affetti da osteogenesi imperfetta, parametri di ultrasonografia ossea quantitativa (QUS, Quantitative Ultrasound) misurati a livello delle falangi della mano, con la densità minerale ossea (BMD, Bone Mineral Density) ottenuta tramite DXA (Dual-Energy X-Ray Absorptiometry) della colonna lombare.
Materiali e Metodi
In 87 pazienti, affetti da osteogenesi imperfetta, di età compresa fra 3 e 18 anni sono stati rilevati i parametri ultrasonografici AD-SoS (Amplitude Dependent Speed of Sound), BTT (Bone Transmission Time), NP (Number of Peaks), UBPI (Ultrasound Bone Profile Index) e il parametro BMD fornito dalla DXA lombare.
Mediante analisi della regressione lineare è stata verificata la correlazione fra parametri QUS e BMD. L’analisi Receiver Operating Characteristic (ROC) è stata utilizzata per determinare la capacità discriminante dei parametri QUS e DXA rispetto al rischio di frattura, espresso come tasso di fratture per anno.
Risultati
Le correlazioni fra BMD e AD-SoS (r = 0,66), BMD e BTT (r = 0,68), BMD e NP (r = 0,64), erano statisticamente significative (p<0,01).
Rispetto al rischio di frattura, AD-SoS e BMD hanno mostrato una capacità discriminante moderatamente accurata, praticamente sovrapponibile (rispettivamente AUC= 0,851 e AUC= 0,834) e le due metodiche non hanno evidenziato nessuna differenza statisticamente significativa.
Conclusione
Pur necessitando di ulteriori approfondimenti, confrontata alla DXA, la QUS ha mostrato capacità diagnostiche non inferiori a quelle radiologiche.
La QUS può pertanto integrare la DXA nello studio di pazienti pediatrici affetti da osteogenesi imperfetta
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
New 3D cone beam CT imaging parameters to assist the dentist in treating patients with Osteogenesis Imperfecta
Get PDF(1) Background: The aim of the work is to identify some imaging parameters in osteogenesis imperfecta to assist the dentist in the diagnosis, planning, and orthodontic treatment of Osteogenesis Imperfecta (OI) using 3D cone beam Computed Tomography (CBCT) and the Double Energy X-ray Absorptiometry (DEXA) technique. (2) Methods: 14 patients (9 males and 5 females; aged mean ± SD 15 ± 1.5) with a clinical-radiological diagnosis of OI were analyzed and divided into mild and moderate to severe forms. The patients’ samples were compared with a control group of 14 patients (8 males and 6 females; aged mean ± SD 15 ± 1.7), free from osteoporotic pathologies. (3) Results: The statistical analysis allowed us to collect four datasets: in the first dataset (C1 sick population vs. C1 healthy population), the t-test showed a p-value < 0.0001; in the second dataset (C2 sick population vs. C2 healthy population), the t-test showed a p-value < 0.0001; in the third dataset (parameter X of the sick population vs. parameter X of the healthy population), the t-test showed a p-value < 0.0001; in the fourth dataset the bone mineralometry (BMD) value detected by the DEXA technique compared to the C2 value of the OI affected population only) the Welch–Satterthwaite test showed a p-value < 0.0001. (4) Conclusions: The research has produced specific imaging parameters that assist the dentist in making diagnostic decisions in OI patients. This study shows that patients with OI have a characteristic chin-bearing symphysis, thinned, and narrowed towards the center, configuring it with a constant “hourglass” appearance, not reported so far in the literature by any author
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
- …
