1,720,977 research outputs found

    Going Beyond Counting First Authors in Author Co-citation Analysis

    Get PDF
    The 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 PDF
    We 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

    Characterization of Susceptibility Artifacts in MR-thermometry PRFS-based during Laser Interstitial Thermal Therapy

    Get PDF
    Magnetic Resonance Thermometry (MRT) is demonstrating huge abilities to guide laser interstitial thermal therapy (LITT) in several organs, such as the brain. Among the methods to perform MRT, Proton Resonance Frequency (PRF) shift holds significant benefits, like tissue independence. Despite its potential, PRF shift-based MRT holds significant challenges affecting the accuracy of reconstructed temperature maps. In particular, susceptibility artifacts due to gas-bubble formation are an important source of error in temperature maps in MRT-guided LITT. This work presents the characterization of the susceptibility artifacts in MRT-guided LITT and the measurement of its size. LITT was performed in gelatin-based phantoms, at 5 W, 2 W, 1 W, and 0.5 W under MRI guidance with a 1.5 T clinical MRI scanner. Temperature images were obtained with a 3D EPI (Echo planar imaging) prototype sequence. Areas of temperature errors were defined as zones of negative temperature variation <-2 degrees C. Moreover, we have analyzed the artifact shape in sagittal, axial and coronal planes. The analysis demonstrates a double-lobe shape for the susceptibility artifact mainly distributed in the sagittal plane. Also, the higher laser power caused a bigger artifact area. Temperature errors of similar to 80 degrees C proved the necessity to avoid susceptibility artifact generation during MRT-guided LITT. The analysis of the influence of the laser power on the artifact has suggested that using low laser power (0.5 W) helps avoid this measurement error

    Dispelling the Myths Behind First-author Citation Counts

    Get PDF
    We 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

    Author Index

    No full text
    Nao informado

    Rubber transcystic drainage reduces the post-removal biliary complications in liver transplantation: a matched case-control study

    No full text
    Bile duct (BD) complications continue to be the "Achilles' heel" of liver transplantation, and the utilization of bile duct drainage is still on debate. We describe the results of a less invasive rubber trancystic biliary drainage (TBD) compared to a standard silicone T-tube (TT). The transplanted patients (n = 248), over a period of 5 years with a TBD (n = 20), were matched 1:2 with control patients with a TT (n = 40). Primary end points were the overall incidence of BD complications and graft and patient survival. Secondary end points included the complications after the drainage removal. Although the bile duct leakage rates were not significantly different between both groups, the TT group had a significantly higher rate of overall 1-year BD stenosis (40 versus 10 %) (p = 0.036). Three-year patient/graft survival rates were 83.2/80.1 and 84.4/84.4 % for the TT and TBD groups, respectively. The postoperative BD complications, after drainage removal (peritonitis and stenosis), were significantly reduced (p = 0.011) with the use of a TBD. The use of rubber TBD in liver transplant recipients does not increase the number of BD complications compared to the T-tube. Furthermore, less BD anastomotic stenosis and post-removal complications were observed in the TBD group compared to the TT group

    Hepatic artery complications following liver transplantation. Does preoperative chemoembolization impact the postoperative course?

    No full text
    BackgroundTransarterial chemoembolization (TACE) in patients with hepatocellular carcinoma (HCC) may cause damage to the hepatic artery (HA) and impact the postoperative course of the liver transplantation (LT). We aim to describe the relationship between preoperative TACE and the occurrence of histological and radiological hepatic artery complications (HAC). MethodsAll cirrhotic patients with HCC undergoing LT between January 2009 and October 2012 were included and divided in two groups: TACE (group 1) and No TACE (group 2). HA histological complications were reviewed and compared. ResultsSixty-seven patients were reviewed, 32 in group 1 and 35 in group 2. Both groups were similar in gender, age, cirrhosis origin, and American Society of Anesthesiology (ASA) score. After a mean follow-up of 17months, 10 radiological HAC occurred: seven in group 1 and three in group 2 (p=0.02). There was one thrombosis in each group: six non-thrombotic complications in group 1 and two in group 2. Histological screening showed 12 HA injuries in group 1 (three HA wall edemas, five fibrosis, one edema+fibrosis, one hemorragic necrosis+thrombosis, two thrombosis) and three in group 2 (two HA wall edemas, one fibrosis) (p=0.01). All these injuries were found at the proper HA and at the right/left HA bifurcation level. ConclusionsDespite the limits of our study, we found a higher incidence of radiological and histological injury in patients underwent TACE

    koamabayili/VECTRON-author-checklist: VECTRON author checklist

    No full text
    We 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
    corecore