1,721,010 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
Sequence analysis of the complete mitochondrial genome in patients with mitochondrial encephaloneuromyopathies lacking the common pathogienic DNA mutations
No full textThe purpose of this study was to identify novel mitochondrial deoxyribonucleic acid (mtDNA) mutations in a series of patients with clinical and/or morphological features of mitochondrial dysfunction, but still no genetic diagnosis. A heterogeneous group of clinical disorders is caused by mutations in mtDNA that damage respiratory chain function of cell energy production. We developed a method to systematically screen the entire mitochondrial genome. The sequence-data were obtained with a rapid automated system. In the six mitochondrial genomes analysed we found 20 variants of the revised Cambridge reference sequence [Nat. Genet. 23 (1999) 147]. In skeletal muscle nineteen novel mtDNA variants were homoplasmic, suggesting secondary pathogenicity or co-responsibility in determination of the disease. In one patient we identified a novel heteroplasmic mtDNA mutation which presumably has a pathogenic role. This screening is therefore useful to extend the mtDNA polymorphism database and should facilitate definition of disease-related mutations in human mtDN
Viscosità di miscele di grasso di lana e olio combustibile [Viscosities of Mixtures of Wool Grease and Fuel Oil]
No full textThe kinematic viscosities of binary mixtures obtained from two heavy fuel oils and five wool greases were measured in the temperature range from 60 to 120°C. The kinematic viscosities of the mixtures cannot be predicted from the viscosities of the individual components. The effect of temperature on the viscosities of the mixtures is well described by Walther's equation
Nuove possibilità di caratterizzazione del grasso di lana. Indagine sul comportamento reologico e relazioni con altri parametri chimico-fisici. [Wool grease characterisation.Physical-rheological behaviour and relashionship with other physical and chemical parameters]
No full textII grasso di lana costituisce un sottoprodotto di valore intrinseco potenzialmente elevato ricavato dalle operazioni di lavaggio della lana sucida. II comportamento reologico di tale prodotto risulta essere al momento ancora poco conosciuto e costituisce pertanto oggetto della presente indagine. Determinazioni sperimentali di viscosità dinamica, indice di rifrazione, numero di saponificazione, numero di acidità, tenore in umidità e sostanze volatili sono state effettuate su 14 campioni di grasso di lana. I dati sperimentali ottenuti mettono in evidenza correlazioni ampiamente significative tra il parametro viscosità dinamica ed i parametri indice di rifrazione e numero di esteri. Dalle correlazioni così ottenute appare evidente come la viscosità dinamica possa costituire un adeguato parametro di caratterizzazione tecnologica e merceoiogica del grasso di lana.
Abstract. Wool grease is a valuable and useful by-product of raw wool scouring but at the present time its rheological properties are not completely known. Thus measurements of dynamic viscosity, refractive index,saponification value, acid value, moisture and volatile substances at 105°C were carried out on 14 wool grease samples. The experimental results show significant correlations between dynamic viscosity and refractive index, between dynamic viscosity and ester value. The above correlations show that viscosity could be a highly promising parameter in technological characterisation of wool grease
Dispelling 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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