1,720,991 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
Implant surface roughness alterations induced by different prophylactic procedures: an in vitro study
No full textAIM:
To evaluate surface roughness alterations at the smooth neck of dental implants after the use of eight different prophylactic procedures.
MATERIALS AND METHODS:
50 tissue level implants (Institut Straumann AG, Basel, Switzerland) were used for the present investigation. The smooth collar of each implant was divided into two segments, each treated with one of eight cleaning procedures: use of a rubber cup (RCZ) or a brush (BZ) combined with an abrasive paste containing zirconium or a paste derived from perlite (RCP, BP); use of 2 composite resin burs reinforced by zirconium glass fibers (F1, F2); and use of an air-polishing system with glycine powder and two power settings (AP1, AP2). The qualitative alterations were recorded by means of a laser profilometer and the mean roughness (Ra ) and mean roughness profile depth (Rz ) were reported. Twenty untreated surfaces were used as controls.
RESULTS:
The implant collars treated with RCZ (Ra = 0.33 μm, Rz = 2.43 μm) or BZ (Ra = 0.30 μm, Rz = 3.70 μm) yielded the highest roughness values, followed by the surfaces treated with RCP (Ra = 0.28 μm, Rz = 2.02 μm), with BP (Ra = 0.25 μm, Rz = 2.16 μm) and by the use of F1 (Ra = 0.27 μm, Rz = 2.22 μm) and F2 (Ra = 0.27 μm, Rz = 2.04 μm). The lowest roughness values were observed in the AP1 (Ra = 0.23 μm, Rz = 1.60 μm) and AP2 (Ra = 0.16 μm, Rz = 1.06 μm) group, respectively. Implant collars treated with AP2 yielded statistically significantly lower (P = 0.01) Rz values compared with untreated surfaces.
CONCLUSION:
All tested procedures did not increase implant surface roughness significantly. Treatment with an air-powder abrasive system at high-pressure setting resulted in a smoothening of the implant collar surface
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
Findings of a Four-Year Randomized Controlled Clinical Trial Comparing Two-Piece and One-Piece Zirconia Abutments Supporting Single Prosthetic Restorations in Maxillary Anterior Region.
No full textPURPOSE: To evaluate whether 4.0 x 4.0 mm dental implants could be an alternative to implants at least 8.5 mm long, which were placed in posterior jaws, in the presence of adequate bone volumes.
MATERIALS AND METHODS:
One hundred and fifty patients with posterior (premolar and molar areas) jaws having at least 12.5 mm bone height above the mandibular canal or 11.5 mm below the maxillary sinus, were randomised according to a parallel group design, in order to receive one to three 4.0 mm-long implants or one to three implants which were at least 8.5 mm-long, at three centres. All implants had a diameter of 4.0 mm. Implants were loaded after 4 months with definitive screw-retained prostheses. Patients were followed up to 1-year post-loading and outcome measures were prosthesis and implant failures, any complications and peri-implant marginal bone level changes.
RESULTS:
Seventy-five patients were randomly allocated to each group. One patient dropped out after the 4-month post-loading evaluation from the long implant group. Up to 1-year post-loading, 3 patients lost one 4.0 mm-long implant each in comparison to 2 patients who lost one long implant each (difference in proportion = 0.013; 95% CI: -0.058 to 0.087; P = 0.506). All failures occurred before loading, the failed implants were replaced and the delivery of two prostheses in each group was delayed for several months (difference in proportion = 0.0004; 95% CI: -0.068 to 0.069; P = 0.685). Three short implant patients experienced three complications versus 2 long implant patients (difference in proportion = 0.013; 95% CI: -0.058 to 0.087; P = 0.506). There were no statistically significant differences in prosthesis failures, implant failures and complications. Patients with short implants lost on average 0.53 mm of peri-implant bone and patients with longer implants lost 0.57 mm. There were no statistically significant differences in bone level changes up to 1 year between short and long implants (mean difference = 0.038 mm; 95% CI: -0.068 to 0.138; P = 0.198).
CONCLUSIONS:
One year after loading 4.0 mm-long implants achieved similar results as 8.5 mm-long or longer implants in posterior jaws, however 5- to 10-year post-loading data are necessary before reliable recommendations can be made
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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