1,720,974 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
Cytomegalovirus-associated stage 4S neuroblastoma relapsed stage 4.
No full textNeuroblastoma is one of the most frequent solid tumors in childhood, rarely recurrent after five years from diagnosis. Cytomegalovirus (CMV), a major pathogen causing congenital birth defects and severe opportunistic diseases, has been shown to have teratogenic, immunodepressive and oncogenic properties. The case of a girl with stage 4S neuroblastoma diagnosed at three months and relapsed as stage 4 five years later is reported. In both circumstances, active CMV infection was revealed by positive CMV-specific IgM and IgA antibodies, CMV-DNAemia and CMV culture. At three months, the patient presented with subcutaneous nodules, hepatosplenomegaly and increased aminotransferase levels, and the opsolonus-myoclonus syndrome. Mental retardation developed later on. At 5 years, relapsed neuroblastoma was preceded by a mononucleosis-like syndrome concomitant with active CMV infection and decreased levels of immune cells and natural killer activity. Clinical, virologic, and immunologic findings suggest an immune-mediated pathogenic role for CMV in this tumo
Enterovirus in dilated cardiomyopathic hearts: molecular evidence using PCR and nucleotide sequencing of the amplified product
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Prevalence and subtypes distribution of BK virus in healthy people and immunocompromised patients detected by PCR-restriction enzyme analysis.
No full textBACKGROUND: Four antigenic subtypes of BK virus (BKV) have recently been characterised by both genomic subtyping and serological reactivity.
OBJECTIVES: To study the prevalence and distribution of subtypes of BKV in different groups of patients.
STUDY DESIGN: Urine specimens were collected from 33 bone marrow transplant (BMT) recipients, from 101 HIV-infected patients, from 15 children aged 2-5 and from 40 pregnant women were tested for BKV DNA by polymerase chain reaction (PCR) and subtyped using a PCR-sequencing (PCR-S) and a modified PCR-restriction enzyme analysis (PCR-RE) methods.
RESULTS: BKV DNA was detected in 12/18 (67%) of BMT patients with haematuria and 5/15 (33%) without. Overall BKV DNA was detected in 45% of HIV-infected patients, the prevalence of BKV DNA increased with greater immunosuppression as defined by CD4 cell counts. BKV DNA was detected in urine samples from 27% of children and 47% of pregnant women. Four stable BKV subtypes were detected in these patient groups. Dual infections with more than one subtype were identified in urine samples from HIV-infected patients, children and pregnant women but not in the samples from bone marrow recipients.
CONCLUSION: This study has confirmed the high prevalence of BKV infection in immunocompromised patients and suggests that stable BKV subtypes with conserved sequences are circulating in the human population. The techniques of PCR-S and PCR-RE described in this study are sufficiently sensitive for subtyping BKV direct from clinical specimens
Enteroviral genome in the myocardium of patients with dilated cardiomyopathy: is it relevant?
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