1,720,968 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
Antibodies against hepatitis C virus in hemodialysis patients in the central Italian region of Umbria: evaluation of some risk factors.
No full textThe epidemiology of non-A, non-B hepatitis (NANBH) is still incomplete. To define the prevalence of antibodies against the main causative agent of NANBH, the hepatitis C virus (HCV) and the role of some risk factors, we tested sera from 269 patients on chronic dialysis at the hemodialysis units in our region in central Italy. We utilized the recently developed serological assay. Twenty-nine hemodialysis patients (13.3%) and 3 peritoneal dialysis patients (4.8%) were anti-HCV positive. Of these, 13 (40.6%) had antibodies to hepatitis B core antigen (anti-HBc) indicating prior hepatitis B infection. The anti-HCV seropositive patients had been on dialysis longer than the seronegative ones; they had received more transfusions than the others but without a significant difference. The prevalence rate of anti-HCV was statistically significantly higher among hemodialysis patients utilizing the same dialysis equipment for the previous 12 months
Relations between intima-media thickness, the vascular resistence index, homocysteine, cysteine and sulphate levels in patients with varying degrees of kidney impairment
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
Inflammation, infection and cardiovascular events in chronic hemodialysis patients: a prospective study.
No full textBACKGROUND:
Cardiovascular (CV) disease is the leading cause of morbidity and mortality in chronic hemodialysis (HD) patients. Inflammation is a potent risk factor for CV disease in the general population. Recent evidence suggests infection, particularly with agents such as Chlamydia pneumoniae (C.pneumoniae) and Helicobacter pylori (H.pylori), as a source of sustained inflammation. Our study tested the hypothesis that C-reactive protein (CRP) and positive serology for antibodies to C.pneumoniae and H.pylori can be associated with the occurrence of new CV events in chronic HD patients.
METHODS:
We evaluated 76 chronic HD patients (33 women and 43 men, aged 60.5+/-17.3 years) by measuring baseline CRP levels as well as the titres of antibodies (IgG and IgA) to C.pneumoniae and(IgG) to H.pylori. In addition, risk factors such as hypertension, smoking, diabetes, cholesterol levels and albumin were assessed at baseline. The incidence of new CV events (myocardial infarction and ischemic stroke) was recorded during a 36-month follow-up period. The effect of prognostic factors was evaluated by logistic regression analysis.
RESULTS:
The incidence of CV events was significantly higher in patients seropositive for C.pneumoniae antibodies than in those seronegative (16.1 vs. 4.3 events/100 patient-years, p=0.017, risk ratio 3.76), whereas it did not differ for H.pylori (12.2 vs. 11.7 events/100 patient-years,p=0.91, risk ratio 1.04). Logistic regression analysis showed C.pneumoniae seropositivity (odds ratio 10.11, p=0.04) and CRP levels (odds ratio 1.78, p=0.03) to be independent predictors of the occurrence of CV events.
CONCLUSIONS:
CRP levels and C.pneumoniae antibodies, but not H.pylori antibodies, were predictors of CV morbidity in the chronic HD patients studied
Fattori infiammatori, infettivi ed eventi cardiovascolari in pazienti sottoposti ad emodialisi
No full textAppropriate 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
Hyperhomocysteinemia:only an aspect of the more complex thiol metabolic alteration in haemodialysis patients
No full textDispelling 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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