1,721,069 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
IMMEDIATE LOADING OF 3 MM-DIAMETER IMPLANTS AS AN ALTERNATIVE TO HORIZONTAL BONE AUGMENTATION FOR PLACING NORMAL DIAMETER IMPLANTS: FOUR-MONTH POST-LOADING RESULTS FROM A MULTICENTRE RANDOMISED CONTROLLED TRIAL
No full textPURPOSE. To evaluate the effectiveness of immediately loaded 3 mm-diameter implants in alternative to horizontal bone augmentation procedures to allow placement of implants with a conventional diameter of 4 mm. MATERIALS AND METHODS. Forty-five partially edentulous patients with a bone width of between 4 and 5 mm 3 mm below the crest in areas requiring one to three adjacent implants were randomised, according to a parallel-group design, to receive one to three 3.0 mm-wide implants to be loaded immediately (23 patients) or horizontal crest augmentation with a granular bone substitute covered with a bone lamina for placing, after 6 months of healing, one to three implants at least 4 mm wide (22 patients) at two centres. Implants at augmented sites were left to heal unloaded for 4 months. Four mm-diameter implants were restored using provisional screw-retained reinforced acrylic prostheses, replaced after 4 months by definitive prostheses. Three mm-diameter implants were loaded immediately (if the insertion torque was ≥ 35 Ncm) or after 4 months with definitive metal-composite prostheses. Patients were followed-up to 4-month post-loading. Outcome measures were: prosthesis and implant failures, any complication, peri-implant marginal bone level changes, and patient satisfaction. RESULTS. No patient dropped out. In three patients, five 3 mm-diameter implants could not be inserted with a torque of 35 Ncm, so were submerged unloaded for 4 months. Two implants failed in two patients from the augmented group (P [Fisher’s exact probability test] = 0.2333; difference in proportion =-0.09; CI 95%-0.24 to 0.07) and neither patient was fitted with a definitive prosthesis. Three patients with small diameter implants were affected by three complications versus nine augmented patients with 10 complications, the difference being statistically significant (P [chi-square test] = 0.0346; difference in proportion =-0.28; CI 95%-0.50 to-0.01). Patients with 3 mm-diameter implants lost on average 0.09 mm of peri-implant bone at 4 months, while augmented patients lost 0.26 mm, a statistically significant difference (mean difference = 0.17 mm, 95% CI 0.02 to 0.31, P = 0.0235). All patients were fully satisfied with both function and aesthetics, with two exceptions: one patient from the 3-mm group was only partially satisfied with both aesthetics and function, and one patient from the augmentation group was only partially satisfied with the aesthetics. However, all patients would undergo the same procedure again. CONCLUSIONS. Four months after loading, patients treated using 3 mm-wide implants displayed better results than those horizontally augmented to receive 4 mm-wide im-plants. Three mm-wide implants might therefore be a preferable choice with respect to bone horizontal bone augmentation, the treatment being less invasive, faster, cheaper, and associated with less morbidity; however, 5-to 10-year post-loading data will be necessary before reliable recommendations can be made. CONFLICT OF INTEREST STATEMENT. Global D (Brignais, France) partially supported this trial and donated the implants and prosthetic components. OsteoBiol (Tecnoss, Giaveno, Italy) donated the biomaterials used for bone augmentation. However, the data property belonged to the authors and neither Global D nor OsteoBiol interfered in any way with the conduct of the trial or the publication of the results
ENDODONTIC RETREATMENT OF TEETH WITH UNCERTAIN ENDODONTIC PROGNOSIS VERSUS DENTAL IMPLANTS: 5-YEAR RESULTS FROM A RANDOMISED CONTROLLED TRIAL
Full text linkPURPOSE. To ascertain whether it is better to endodontically retreat a previously endo-dontically treated tooth with periapical pathology and/or symptoms and an uncertain prognosis, or to replace the tooth with a single implant-supported crown. MATERIALS AND METHODS. Twenty patients requiring treatment of a previously endodon-tically treated tooth with periapical pathology and/or symptoms of endodontic origin and an uncertain prognosis, as judged by the recruiting investigator, were randomly allocated to endodontic retreatment (endo group; 10 patients) or tooth extraction and replacement with an implant-supported crown (implant group; 10 patients) according to a paral-lel-group design at a single centre. Patients were followed up to 5 years after treatment completion. Outcome measures were: procedure failure; complications; marginal bone level changes at both teeth and implants; radiographic endodontic success (teeth only); number of patient visits and days to complete treatment; chair..
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
On the role of keratinised mucosa at dental implants: A 5-year prospective single-cohort study
No full textPurpose: The purpose of this study was to evaluate the role of keratinised mucosa on the longterm success of dental implants. Materials and methods: Thirty-two edentulous patients had one of their dental arches rehabilitated with a provisional screw-retained resin reinforced cross-arch fixed prosthesis supported by four immediately loaded implants. The two central straight implants were randomly allocated in two equal groups, according to a parallel-group design, to receive or not intermediate abutments (Multi -Unit Abutment, MUA). However, for the purpose of the present publication, the study was considered as a prospective single cohort study. To be immediately loaded, implants had to be inserted with a minimum torque of 30 Ncm, which was achieved by all implants. Provisional prostheses were delivered within 24 hours and were replaced, after 4 months, by definitive screwretained metal-ceramic prostheses. Patients were followed up to 5 years after loading. Prostheses were removed every 8 months to facilitate professionally delivered maintenance. Outcome measures were prosthesis and implant failures, complications, peri-implant marginal bone level (MBL) changes, bleeding on probing (BoP) and keratinised mucosa height (KMH). The absence of vestibular or lingual keratinised mucosa was put in relation with peri-implant bone loss and BoP. Results: Five-years after loading two patients dropped out and no implant or prosthetic failure occurred. Four patients were affected by prosthetic complications. At delivery of definitive prostheses, 32 (25%) implants had at least one vestibular or lingual site with no KMH and 96 (75%) implants had both sites with some KMH. Multi-level models did not show any statistically significant association between KMH at the time of delivery of the definitive prosthesis and changes in MBL and BoP at 5 years (estimate = 0.02; 95% CI: -0.02 to 0.05; P = 0.3393; and 1.02; 95% CI: 0.79 to 1.33; P = 0.8695, respectively). When KMH was analysed as dichotomous variable, implants with presence of KMH at delivery of definitive prosthesis at both vestibular and lingual aspects showed a trend of less BoP (estimate = -0.8; 95% CI: -1.69 to 0.08; P = 0.0741) but a statistically significant greater MBL loss compared to implants where KMH was only present at one site (estimate = 0.18; 95% CI: -0.1 to 0.3; P = 0.0041). Conclusions: The 5-year after loading outcome of immediately loaded screw-retained cross-arch prostheses supported by four implants is excellent in both the maxilla and mandible. Although the height of the keratinised mucosa did not seem to alter the clinical outcomes, its presence both at vestibular and lingual sites was associated with an increased marginal bone loss when compared to implants having at least one side without keratinised mucosa
IMMEDIATE, EARLY (6 WEEKS) AND DELAYED (4 MONTHS) SINGLE POST-EXTRACTIVE IMPLANTS: 3-YEAR POST-LOADING DATA FROM A RANDOMISED CONTROLLED TRIAL
No full textPURPOSE. To compare the clinical outcome of single implants placed immediately after tooth extraction with those placed 6 weeks after tooth extraction (early placement), and those placed 4 months after extraction and socket healing (delayed placement). MATERIALS AND METHODS. Two hundred and ten patients requiring one single im-plant-supported crown to replace a tooth to be extracted were randomised into 3 groups of 70 patients each to receive immediate, early (at 6 weeks), or delayed (after 4 months of healing) post-extraction implants, according to a parallel-group design. When needed, patients from the immediate and early groups had bone substitute grafts in the extraction socket, covered with a resorbable membrane, at implant placement. Sockets randomised to delayed implants were grafted in the same manner if poorly preserved, or in the “aesthetic” areas (from second upper premolar to second upper premolar). Implants inserted with at least 25 Ncm torque were left to heal unloaded for 4 months, whereas those inserted with less than 25 Ncm were left to heal unloaded for 6 months. Temporary crowns were delivered, and were to be replaced by definitive ones after 4 months. Outcome measures were crown and implant failures; complications; peri-im-plant marginal bone level changes; aesthetics, as assessed using the pink aesthetic score (PES); and patient satisfaction, recorded by blinded assessors. Patients were fol-lowed-up for 3 years post-loading. RESULTS. Three years after loading, drop-outs were: five (7.1%) patients from the imme-diate, nine (12.9%) from the early, and eight (11.4%) from the delayed group. Five implants (9.2%) failed in the immediate, four (6.6%) in the early, and one (1.6%) in the delayed group (P [Freeman-Halton] = 0.282). Apart from the crowns that failed due to implant losses, no other definitive crown had to be remade. Complications affected eleven patients from the immediate group, 12 from the early, and eight from the delayed group (P [chi-square test] = 0.596). Mean peri-implant marginal bone loss after 3 years was-0.33 ± 0.22 mm at immediate,-0.43 ± 0.26 mm at early, and-0.49 ± 0.30 at delayed implants; (P [Kruskal Wallis test] <0.001); there were significant pairwise differences between immediate and early (0.10 mm; CI 95%-0.02; 0.22; P [Dunn-Bonferroni post-hoc] = 0.0391) and immediate and delayed implants (0.16 mm; CI 95% 0.04; 0.27; P [Dunn-Bonferroni post-hoc] = 0.0004), but no difference between early and delayed implants (0.06 ± 0.05 mm; CI 95%-0.06; 0.18; P [Dunn-Bonferroni post-hoc] = 0.6015). Three years after loading, the mean overall PES were 12.25, 11.98 and 11.17 in the immediate, early and delayed groups, respectively (P [Kru-skal Wallis test] <0.001); there were significant pairwise differences between immediate and delayed (1.08 ± 0.27 mm; CI 95% 0.45; 1.72; P [Dunn-Bonferroni post-hoc] = 0.0006), and early and delayed implants (0.81 ± 0.27 mm; CI 95% 0.17; 1.46; P [Dunn-Bonferroni post-hoc] = 0.0099), but no difference between immediate and early implants (0.27 ± 0.27 mm; CI 95%-0.37; 0.90; P [Dunn-Bonferroni post-hoc] = 1.0000). There were no significant diffe-rences in patient satisfaction regarding function (P = 0.353) or aesthetics (P=0.531), and all patients would undergo the same procedure again. CONCLUSIONS. No statistically significant differences in failure, complications or patient satisfaction were observed when placing single implants immediately, 6 weeks or four months after tooth extraction, even though failures were more frequent in immediate and early implants. Bone loss was significantly smaller at immediate implants, and aesthetic evaluation scores were higher for immediate and early implants
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
- …
