1,721,005 research outputs found
A comparative study of some soluble proteins of the genus Diplodus (Sparidae: Teleostei)
No full text1. Soluble eye lens and muscle proteins of four species of the genus Diplodus (D. annularis, D. sargus, D. vulgaris, D. puntazzo) were analyzed.
2. Species-specific electrophoretic and isoelectric focusing patterns were found in both proteins system.
3. Comparison of the soluble proteins of the eye lens and of the soluble proteins of the white skeletal muscle of the four species gave evidence that D. annularis and D. sargus are closely related and that they are only distantly related to D. vulgaris.
4. Comparison also showed the relative taxonomic distance of D. puntazzo and, thus, the early detachment of this species from a presumptive common ancestral lineag
The effects of phenylhydrazine and cobalt chloride on the electrophoretic and isoeletric focusing behaviour of some enzymes in Clarias gariepinus (Clariidae, Teleostei)
No full text1. The electrophoretic and isoelectric focusing behaviour of the LDH, MDH and GPI isozymes of seven tissues was compared for several examples of Clarias gariepinus.
2. Some specimens were injected with phenylhydrazine, others with cobalt chloride while the remaining untreated specimens constituted the normal controls.
3. A significant decrease in, or even the total disappearance of, the activity of the different isozymes considered was found in some tissues from specimens subjected to phenylhydrazine.
4. These results were then correlated to the following: specific enzyme and tissue activity; aerobic or anaerobic metabolism; the nature of the toxic contaminant; hepatic lipogenesis as a defence mechanism in fish; and carbohydrate metabolism
Genetic, developmental and comparative analysis of LDH, MDH and GPI isozymes in the sheepshead bream (Diplodus puntazzo GM.)
No full text1. The patterns of expression of lactate dehydrogenase, malate dehydrogenase and glucose-phosphate isomerase isozymes were investigated in both embryonic stages and differentiated adult tissues of Diplodus puntazzo.
2. The patterns of this species were compared with those of two distantly related Sparidae species (Sparus aurata, D. sargus).
3. Species-specific patterns were found in all protein systems.
4. Differences in enzyme-locus expression were used to infer the extent of species divergence.
5. Some locus expressions diverged markedly among species, while others were preserved.
6. Comparative analysis of the enzymes examined showed the existence of a taxonomic distance between these three Sparidae species
Study of the soluble white muscle tissue proteins from fifteen Sparidae species
No full textSoluble proteins of white skeletal muscle tissue of 15 species of Sparidae were analysed. Species-specific electrophoretic and isoelectric focusing patterns were found. Some bands exhibited the same mobility at genus level or at subfamily level, others differed significantly. Considerable similarity was observed in the species of the genera Sparus, Pagellus and Diplodus. Significant differences in the protein bands were noted between the contained subfamilies Denticinae, Sparinae and Boopsinae, confirming the existence of three separate phyletic lines within the family Sparidae. This study has shown that in these species there is a similarity between classifications based on morphological data and those derived from biochemical studies. Variation within species can be corrected for by carrying out multiple inter-specific comparisons and determining the variance of the similarity coefficients. Closely related species have similar patterns and, thus, higher similarity coefficients. The discrepancy in similarity matrices based on morphology and white skeletal muscle tissue proteins of sea bream species shows that electrophoretic methods provide additional information relevant to the systematic of fishes. Further work on comparison on soluble red muscle proteins of these species is prpose
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
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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