1,720,979 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
Medical or Surgical Management of GERD Patients with Barrett's Esophagus: The LOTUS Trial 3-Year Experience.
No full textINTRODUCTION: The long-term management of gastroesophageal reflux in patients with Barrett's esophagus (BE) is not well supported by an evidence-based consensus. We compare treatment outcome in patients with and without BE submitted to standardized laparoscopic antireflux surgery (LARS) or esomeprazole treatment.
METHODS: In the Long-Term Usage of Acid Suppression Versus Antireflux Surgery trial (a European multicenter randomized study), LARS was compared with dose-adjusted esomeprazole (20-40 mg daily). Operative difficulty, complications, symptom outcomes [Gastrointestinal Symptom Rating Scale (GSRS) and Quality of Life in Reflux and Dyspepsia (QOLRAD)], and treatment failure at 3 years and pH testing (after 6 months) are reported.
RESULTS: Of 554 patients with gastroesophageal reflux disease, 60 had BE-28 randomized to esomeprazole and 32 to LARS. Very few BE patients on either treatment strategy (four of 60) experienced treatment failure during the 3-year follow-up. Esophageal pH in BE patients was significantly better controlled after surgical treatment than after esomeprazole (p = 0.002), although mean GSRS and QOLRAD scores were similar for the two therapies at baseline and at 3 years. Although operative difficulty was slightly greater in patients with BE than those without, there was no difference in postoperative complications or level of symptomatic reflux control.
CONCLUSION: In a well-controlled surgical environment, the success of LARS is similar in patients with or without BE and matches optimized medical therapy
Standardization of surgical technique in antireflux surgery: the LOTUS Trial experience
No full textBackground: To date, it has been difficult to compare medical therapy for gastroesophageal reflux disease with that of surgical management from a scientific viewpoint, mainly because of the lack of standardization of the operative technique. This study was designed to identify a methodology for standardization of surgical technique and to measure the effectiveness of this standardization.
Methods: Surgeons contributing to a major international multicenter trial comparing optimum medical therapy with surgical therapy for treatment of gastroesophageal reflux attempted to optimize their surgical techniques so that a realistic comparison could be made that may aid clinical decision-making. The surgeons met, shared their techniques using video, and produced a standardized set of criteria for the surgical centers and a common operative technique. Data collection methods ensured accuracy of the records of the procedure applied and the data were analyzed for consistency with set surgical standards.
Results: There was a high degree of conformity (>95%) between the recommended method of performing a Nissen fundoplication as defined in the trial protocol, and variations were restricted to isolated individuals. The operations were completed without mortality, few conversions, and with very low postoperative morbidity.
Conclusions: This study has shown that, contrary to commonly held belief, surgeons are able to standardize their work for the purposes of measuring the outcome of an operative procedure within the context of a randomized, controlled trial
Consequences of Acid Suppression With Esomeprazole and Laparoscopic Antireflux Surgery on Esophageal Squamous Epithelium Morphology: Lessons From the Lotus Study.
No full textVariations 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
Long-term effect on symptoms and quality of life of maintenance therapy with esomeprazole 20 mg daily: a post hoc analysis of the LOTUS trial.
No full textOBJECTIVE: To assess the long-term effect on symptoms and quality of life of esomeprazole 20 mg once daily, a recommended dose for maintenance therapy of gastroesophageal reflux disease (GERD).
RESEARCH DESIGN AND METHODS: This is a post hoc analysis of 5 year data from patients in the LOTUS trial (ClinicalTrials.gov identifier: NCT00251927) who were randomized to esomeprazole 20 mg once daily. All participants had chronic, symptomatic GERD responsive to treatment. Gastrointestinal symptoms were assessed by physicians and by using patient-reported outcome instruments. Investigations included gastrointestinal endoscopy (with biopsy sampling), 24 hour esophageal pH monitoring and laboratory measurements.
RESULTS: In total, 157 of 256 patients randomized to esomeprazole 20 mg once daily remained on this dose until the end of follow-up or study discontinuation, whereas 99 patients had their dose increased because of inadequate symptom control (of these, 29 subsequently returned to the allocated dose). On logistic regression, a long objectively defined GERD history, smoking, female sex, absence of Helicobacter pylori infection and high supine baseline acid reflux into the esophagus were associated with an increased likelihood of requiring dose escalation to esomeprazole 40 mg daily (all p < 0.05). Symptoms were fairly stable and quality of life was normal throughout follow-up in patients remaining on esomeprazole 20 mg once daily, with no more than mild symptom severity, and mean (standard deviation) percentage time with intraesophageal pH <4 was reduced from 10.7 (10.7) pre-randomization to 6.3 (10.2) at 6 months and 4.9 (7.3) at 5 years. The number of serious adverse events was low (0.079 per patient per year).
LIMITATIONS: Post hoc analysis with no control group.
CONCLUSIONS: Esomeprazole at a maintenance dose of 20 mg once daily offers effective long-term treatment for chronic GERD in patients initially responsive to the medication, with durable symptom control and sustained reductions in intraesophageal acid exposure
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
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