1,721,124 research outputs found
Chromosome Y microsatellites: population genetic and evolutionary aspects.
No full textINT.J. LEGAL MED
Shining a light on the past
No full textInvisible to the naked eye, pinpricks of light from minerals reveal how long they have been hidden inside a brick. Researchers at Delft University of Technology have ways of detecting the light, but their dating method yields results that don¿t tally with those of archeologists
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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 PDFWe 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
Alu-repeat polymorphism in the tissue-type plasminogen activator (t-PA) gene, t-PA levels and risk of familial myocardial infarction (MI)
No full textSeveral authors have suggested that increased t-PA antigen levels were associated to thrombotic events in coronary, cerebral and peripheral arteries. Baseline and stimulated levels of t-PA in plasma appear highly heritable, therefore, it could be of interest to evaluate the role of genetic variations in the t-PA locus in determining its plasma levels and its association with a parental history of thrombosis. We studied an insertion deletion polymorphism located in the first Alu sequence in intron h of the t-PA gene, in a sample of the population, including 327 subjects (202 M,125 F, aged 20-78 years) from all over Italy. Genotype analysis was also performed on 114 patients with MI and at least one first degree relative affected by MI or stroke before 65 years compared with 145 controls, aged over 45 years. The genotype distribution in all groups were in Hardy-Weinberg equilibrium. The I and D allele frequencies in the Italian sample were 0.55 and 0.45 respectively. There were no differences in genotype distribution between MI patients with familial history of thrombosis and controls (29 and 31%, 51 and 50%, 20 and 20% for I/I, I/D and D/D, respectively in cases and controls). There was no significant interaction of sex or age on the association between t-PA polymorphism and familial MI. The levels of t-PA and PAI-1 (both antigen and activity) were not differently distributed among the t-PA genotypes in the healthy Italian population sample. However, an association between t-PA polymorphisms and PAI-1 antigen was found in patients with MI. Patients carrying the genotype I/I showed the higher levels of PAI-1 antigen (31 ± 17 in I/I vs. 20 ± 15 and 21 ± 14, respectively in I/D and D/D, P < 0.01). These data do not support a role for the Alu repeat polymorphism of t-PA gene in determining the blood levels of t-PA and the risk of familial MI in the Italian population. The relation found between t-PA polymorphism and PAI-1 antigen levels in Italian patients should be further clarified
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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