1,720,994 research outputs found

    Going Beyond Counting First Authors in Author Co-citation Analysis

    Full text link
    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

    Prevalence, Clinical Features, and Acute Course of Atypical Myocardial Infarction

    No full text
    Ninety-four consecutive patients (60 men and 34 women; mean age 68.5 ± 11.5 years) with acute myocardial infarction (MI) were investigated ret rospectively, in order to evaluate the prevalence, clinical features, and short- term course of the atypical forms (symptoms other than chest pain). An atypical MI was found in 30 patients, with a prevalence of 32% (95% confidence limits 27-36%). It was most prevalent in women above sixty-five years old (P < 0.05). Abdominal pain, paroxysmal dyspnea, and pulmonary edema were the most frequent symptoms (33%, 17%, 13%, respectively). No differences were ob served between typical and atypical MI in regard to risk factors (hypercholes terolemia, arterial hypertension, diabetes mellitus, cigarette smoking) and history of MI, cerebrovascular disease, peripheral vascular disease, or chronic lung disease. Significantly fewer patients with atypical MI had a history of an gina pectoris (P < 0.05). No differences were observed in regard to previous medication, except for antiarrhythmic drugs, more often used by atypical pa tients (P < 0.05). Location and severity of MI (as judged by ECG and peak levels of creatine kinase in the serum) were similar in both subgroups, as were the complications (34% typical and 50% atypical) and death rate (12.5% and 16.7%, respectively). In conclusion, atypical MI is not less severe than typical. This emphasizes the need for a high suspicion index in many different clinical settings, but particu larly (although not exclusively) in elderly females, in the presence of abdominal pain or otherwise unexplained paroxysmal dyspnea. © 1994, Sage Publications. All rights reserved

    The characteristics of the thrombi of the lower limbs, as detected by ultrasonic scanning, do not predict pulmonary embolism

    No full text
    Objective: To evaluate whether pulmonary embolism (PE), as detected by perfusion lung scan, could be predicted by the ultrasonic (US) characteristics of the thrombi in patients with deep venous thrombosis (DVT) of the lower limbs.Patients: Ninety-three consecutive patients with DVT and no symptoms of lung involvement (52 men, 41 women; mean age, 67+/-17 years).Measurements and results: The degree of thrombotic involvement of the lower limbs was assessed using a US score system ranging from 1 (indicating a subsegmental, nonocclusive thrombus) to 16 (massive, occlusive). According to the echographic and color-Doppler features, the thrombi were classified in terms of echoreflectivity, adhesiveness to the vein wall, and organization. The diagnosis of PE (PIOPED criteria) was highly probable in 46% of the patients, intermediate in 15%, low In 8%, and very low/normal in 31%, No correlations were found between the lung scan findings on one side and the venous scoring system or the US features of the thrombi on the other side.Conclusions: While confirming that the prevalence of PE in patients with DVT is elevated, we failed to define a subgroup of patients at higher risk, Our data imply that lung scan should be used extensively for the detection of silent PE and that anticoagulation should not be graded on US findings

    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 link
    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

    Dispelling the Myths Behind First-author Citation Counts

    Full text link
    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
    corecore