1,720,990 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
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
A modified fast-track program for pancreatic surgery: A prospective single-center experience
No full textOBJECTIVE:
The objective of this study is to evaluate the impact of a fast-track protocol in a high-volume center for patients with pancreatic disorders.
BACKGROUND:
The concept of fast-track surgery allowing accelerated postoperative recovery is accepted in colorectal surgery, but efficacy data are only preliminary for patients undergoing major pancreatic surgery. We aimed to evaluate the impact of a modified fast-track protocol in a high-volume center for patients with pancreatic disorders.
METHODS:
Between February 2005 and January 2010, 145 subjects had resective pancreatic surgery and were enrolled in the program. Essential features of the program were no preanaesthetic medication, upper and lower air-warming device, avoidance of excessive i.v. fluids perioperatively, effective control of pain, early reinstitution of oral feeding, and immediate mobilization and restoration of bowel function following surgery. Outcome measures were postoperative complications such as pancreatic fistula, delayed gastric emptying, biliary leak, intra-abdominal abscess, post-pancreatectomy hemorrhage, acute pancreatitis, wound infection, 30-day mortality, postoperative hospital stay, and readmission rates.
RESULTS:
On average, patients were discharged on postoperative day 10 (range 6-69), with a 30-day readmission rate of 6.2%. Percentage of patients with at least one complication was 38.6%. Pancreatic anastomotic leakage occurred in seven of 101 pancreatico-jejunostomies, and biliary leak in three of 109 biliary jejunostomies. Postoperative hemorrhage occurred in ten (6.9%) patients and wound infection in nine (6.2%) cases. In-hospital mortality was 2.7%. Fast-track parameters, such as normal food and first stool, correlated significantly with early discharge (<0.05). At multivariate analysis, lack of jaundice, and resumption of normal diet by the 5th postoperative day were independent factors of early discharge.
CONCLUSION:
Fast-track programs are feasible, easy, and also applicable for patients undergoing a major surgery such as pancreatic resection
Influence of preoperative biliary drainage on surgical outcome after pancreaticoduodenectomy: Single centre experience
No full textPURPOSE:
Controversy prevails on the impact of preoperative biliary drainage (PBD) on postoperative complications and clinical outcome of pancreatic cancer. We determined whether PBD is associated with increased morbidity and mortality rates after pancreaticoduodenectomy.
METHODS:
A total of 131 consecutive patients who underwent pancreaticoduodenectomy (93 jaundiced, 38 with no jaundice) were included in this study. Overall, 57 % of jaundiced patients underwent PBD, while 43 % were not drained. The impact of PBD on postoperative morbidity and mortality was evaluated by means of logistic regression analysis. The Kaplan-Meier method was applied to determine the effect of PBD on survival of patients with malignant lesions.
RESULTS:
Mortality and morbidity rate was 3 % and 54.6 %, respectively. PBD was demonstrated to be the unique predictor of complications (odds ration [OR] = 10.18; 95 % confidence interval [CI], 3.65-28.39, p < 0.001). The jaundiced patients who were drained exhibited high frequencies of wound infection (p < 0.001), post-pancreatectomy haemorrhage (p = 0.0185) and hyperglycaemia (p < 0.001). In addition, an increased frequency of pancreatic fistula emerged among drained patients compared to those who were not drained (p = 0.036). PBD did not affect survival of patient with malignant lesions
Continuous infusion versus bolus administration of steroids in severe attacks of ulcerative colitis: A randomized, double-blind trial
No full textBACKGROUND: In patients with severe attacks of ulcerative colitis (UC), IV steroids represent the first-line treatment, leading to clinical improvement in approximately 50-60% of patients. AIM: The aim of this study was to prospectively compare the efficacy and safety of different modalities of steroid administration, and to evaluate predictors of failure to therapy. MATERIALS AND METHODS: In a single-center, double-blind trial, consecutive patients with a severe attack of UC received 1 mg/kg/day of 6-methyl-prednisolone administered randomly by either a bolus injection (group A) or continuous infusion (group B). RESULTS: Sixty-six patients were enrolled (35 men, mean age 38 ± 15, range 18-75 yr), 15 of them at their first attack of UC; in the remaining cases, the mean duration of disease was 4.5 ± 5 yr. At inclusion, forty patients (60%) had pancolitis and the remainder had left-sided colitis. Overall, thirty-three patients (50%) underwent clinical remission after 7 days of treatment: 16 of 32 in group A and 17 of 34 in group B. Thirty-one patients eventually underwent total colectomy (12 in group A and 9 in group B), which was carried out by the first month in 10 patients (5 in each group). Twenty-eight patients (15 in group A and 13 in group B) experienced steroid-related adverse reactions. All differences between groups were not statistically significant. Previous use of steroids (OR 13.6, CI 2-86) and active smoking (OR 11.6, CI 1.4-107) were independent predictors of nonresponse. CONCLUSIONS: In severe attacks of UC, methyl-prednisolone given as a continuous infusion was no better than bolus administration in terms of efficacy and safety. © 2007 by Am. Coll. of Gastroenterology
Analysis of candidate genes on chromosomes 5q and 19p in celiac disease
No full textBACKGROUND AND AIM: Celiac disease (CD) is a multifactorial disease with involvement of both environmental and genetic susceptibility factors. The HLA-DQ loci account for <40% of CD heritability, but linkage studies have delineated other loci at the 5q31g-33 (CELIAC2), and 19p13 regions (CELIAC4), similarly as in inflammatory bowel diseases. However, data in association studies are contradictory. To evaluate whether single nucleotide polymorphisms (SNPs) tagging the MYO9B susceptibility haplotype and the IBD5 locus (5q31-33) are involved in CD predisposition, we performed case-control and family-based analyses. Additionally, any possible correlation with the HLA-DQ status was investigated. Finally, our data were pooled with the results of other studies by a meta-analysis. PATIENTS AND METHODS: In all, 337 unrelated patients with CD, 424 parents (212 sets), and 452 healthy individuals were genotyped for the IGR2198a_1, rs12521868, rs1050152, and rs2631367 SNPs (IBD5 locus) and the rs962917, rs2305764, and rs1545620 SNPs of the MYO9B gene by the restriction enzyme method and the TaqMan system ABI PRISM 7700, respectively. RESULTS: In comparison with healthy control individuals, the allele, genotype, and haplotype frequencies of all investigated SNPs were not different in the CD patients, nor was any correlation observed with the HLA-DQ status or clinical presentation. The transmission disequilibrium test did not show a transmission distortion. Five other studies were available for meta-analysis on MYO9B variants; by pooling of data, no significant association was demonstrated by the random effect model. A significant heterogeneity (P < 0.002) among the studies was present, mainly explained by a single study in the Dutch population. CONCLUSIONS: Our results and those of the meta-analysis (>2000 CD patients and 4000 control individuals) question the role of MYO9B at the CELIAC4 locus as a disease-causing gene. Moreover, none of the investigated SNPs explain the linkage at the CELIAC2 locus. © 2007 by European Society for Pediatric Gastroenterology, Hepatology, and Nutrition and North American Society for Pediatric Gastroenterology, Hepatology, and Nutrition
Evaluating the role of the genetic variations of PTPN22, NFkB1 and FcGRIIIA genes in inflammatory bowel disease: A meta-analysis
No full textBackground: We tested several polymorphisms of genes involved in the mucosal immune system in a population of inflammatory bowel disease (IBD) patients to investigate their possible implication in disease predisposition. Methods: Polymorphisms of 3 candidate genes (PTPN22, NFkB1, and FcGRIIIA) were investigated in 649 IBD patients (343 with Crohn's disease [CD] and 306 with ulcerative colitis [UC]), 176 unaffected relatives, and 256 healthy controls. Allele and genotype frequencies were correlated with clinical characteristics and major variants of the CARD 15 gene. Our findings were pooled in a meta-analysis with the available studies in the literature. Results: No significant difference for the PTPN22 and NFkB1 variants was found. In contrast, allele and genotype frequencies of the G559T allele of the FcGRIIIA gene were significantly different in CD patients compared to controls (allele T 12% versus 8%, odds ratio [OR] = 1.58, 95% confidence interval [CI] 1.06-2.35; GT genotype 23% versus 16%, OR = 1.64, 95% CI = 1.08-2.5). However, no significant overtransmission of the T allele was confirmed at the family-based analysis. For all genes, neither an interaction with CARD15 gene, nor a significant difference at genotype/phenotype analysis was demonstrated, included response to medical therapy. Conclusions: Although involved in autoimmune diseases, the PTPN22 and NFkB1 genes do not seem involved in the IBD predisposition, also according to meta-analysis results. The association with the G559T polymorphism of the FcGRIIIA gene in CD patients deserves further investigation. Copyright © 2007 Crohn's & Colitis Foundation of America, Inc
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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