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Osservazioni con la tecnica della colorimetria tristimolo sul colore delle soluzioni idroalcoliche di antociani
No full textIdentification and functional characterization of the yeast peroxisomal adenine nucleotide transporter
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Three mitochondrial transporters of Saccharomyces cerevisiae are essential for ammonium fixation and lysine biosynthesis in synthetic minimal medium
No full textThe nuclear genes of Saccharomyces cerevisiae YHM2, ODC1 and ODC2 encode three transporters that are localized in the inner mitochondrial membrane. In this study, the roles of YHM2, ODC1 and ODC2 in the assimilation of nitrogen and in the biosynthesis of lysine have been investigated. Both the odc1Î ́. odc2Î ́ double knockout and the yhm2Î ́ mutant grew similarly as the YPH499 wild-type strain on synthetic minimal medium (SM) containing 2% glucose and ammonia as the main nitrogen source. In contrast, the yhm2Î ́. odc1Î ́. odc2Î ́ triple knockout exhibited a marked growth defect under the same conditions. This defect was fully restored by the individual expression of YHM2, ODC1 or ODC2 in the triple deletion strain. Furthermore, the lack of growth of yhm2Î ́. odc1Î ́. odc2Î ́ on 2% glucose SM was rescued by the addition of glutamate, but not glutamine, to the medium. Using lysine-prototroph YPH499-derived strains, the yhm2Î ́. odc1Î ́. odc2Î ́ knockout (but not the odc1Î ́. odc2Î ́ and yhm2Î ́ mutants) also displayed a growth defect in lysine biosynthesis on 2% glucose SM, which was rescued by the addition of lysine and, to a lesser extent, by the addition of 2-aminoadipate. Additional analysis of the triple mutant showed that it is not respiratory-deficient and does not display mitochondrial DNA instability. These results provide evidence that only the simultaneous absence of YHM2, ODC1 and ODC2 impairs the export from the mitochondrial matrix of i) 2-oxoglutarate which is necessary for the synthesis of glutamate and ammonium fixation in the cytosol and ii) 2-oxoadipate which is required for lysine biosynthesis in the cytosol. Finally, the data presented allow one to suggest that the yhm2Î ́. odc1Î ́. odc2Î ́ triple knockout is suitable in complementation studies aimed at assessing the pathogenic potential of human SLC25A21 (ODC) mutations
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
Identification and functional reconstitution of the yeast peroxisomal adenine nucleotide transporter
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
The yeast peroxisomal adenine nucleotide transporter: characterization of two transport modes and involvement in deltapH formation across peroxisomal membranes
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
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