1,720,976 research outputs found
Immobilisation and ethanol stress induce the same molecular response at the level of cell wall in growing yeast
No full textThe effect of immobilization on the cell wall of Saccharomyces cerevisiae cells was investigated in comparison with freely suspended batch grown cells. The pattern of mannoproteins released from the cell wall after Zymolyase digestion showed the presence of new mannoprotein species when cell growth takes place in a state of immobilization. The same result was obtained by exposure of freely suspended cells to a stressful concentration of ethanol, showing that two different adverse culture conditions induce a similar molecular response at the cell wall level
Gelatin immobilized growing yeast cells: changes in the glycosylation level of external invertase and cell wall composition
Full text linkFree and gelatin immobilized yeast cells from two different strains were analyzed by means of SDS-PAGE as regards: i) the glycosylation levels of external invertase before and after treatment with endo-beta-N-acetylglycosaminidase (Endo H), ii) the pattern of mannoproteins released from the cell wall after extraction with SDS, beta-mercaptoethanol and Zymoliase digestion. The results obtain suggest that the composition and structure of the cell wall is modified when cell growth takes place in the state of immobilization
Electrophoretic mobility of external invertase from free and gel-immobilized yeast cells
No full textElectrophoretic mobility of secreted invertase (E.C.3.2.1.26) from gelatin immobilized yeast cells was analyzed and prepared with that of secreted invertase from freely suspended batch grown cells. Invertase from immobilized cells showed a lower mobility after 24 h opf incubation, in medium containing either glucose or raffinose as carbon source. Changes in invertase mobility were also followed in a time course both for immobilized and for freely suspended batch grown cells. Mobility of invertase from free cells increased an approximately 15 h of incubation, independently of the carbon source, whilst that of invertase from immobilized cells remained constant. The differences observed were attributed to a different level of glycosylation of the protein moiety in free and immobilized cells. The amount of mannnoproteins in the cell walls of immobilized cells was also investigated by ConA ferritin labelling and quantification of ferritin particle density in ultrathin sections; the results of this experiments showed a higher content of mannoproteins in the walls of immobilized cells when compared with free cells. As a whole, these results are indicative of physiological changes can be ascribed to the peculiar microenvironment of gel-immobilized cell
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
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