1,720,972 research outputs found
Modellazione matematica degli effetti del pH, temperatura, NaCl ed aw sulle attività proteolitiche e lipolitiche di batteri lattici responsabili della maturazione dei formaggi
No full textShelf life definition and predictive approaches—modeling strategies for an effective control of food spoilage
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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
Study of the effects of temperature, pH, NaCl and aw on the proteolytic and lipolytic activities of cheese-related lactic acid bacteria
No full textPartial purification and characterization of an X-prolyl dipeptidyl aminopeptidase from Lactobacillus sanfranciscensis CB1
No full textAn X-prolyldipeptidylaminopeptidase (PepX) from LactobacillussanfranciscensisCB1, a key sourdough lactic acid bacterium, was partially purified by five chromatographic steps. As estimated by sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE) and gel filtration, the enzyme appeared to be a 49.2–56 kDa monomer. Optimal activity occurred at pH 6.0 and 30 °C, with Km of 0.6 mM and Vmax of 99.6 nmol mg−1 min−1. The D value, calculated at 45 °C, was ∼5.46 s. The enzyme hydrolyzed (almost exclusively) substrates with a X-Pro N-terminal sequence. It did not possess prolidase, aminopeptidase or endopeptidase activities. No hydrolysis of the Pro-rich 33-mer epitope (a potent inducer of gut-derived human T-cell lines in celiac patients) was found when it was treated with PepX alone. When the general aminopeptidase type N was combined with PepX, the hydrolysis of 33-mer peptide (0.2 mM) was complete after 24 h of incubation at 30 °C. Leucine and glutamine residues were liberated from the Pro-rich 33-mer peptide by aminopeptidase type N, thus favouring the subsequent PepX activity. PepX was inactivated by p-chloromercuribenzoate, 3,4-dichloroisocoumarin and phenanthroline which exerted a competitive mode of inhibition. Among divalent cations, only Zn2+, Hg2+ and Mn2+ markedly decreased the enzyme activity. Quadratic response surface methodology was used to study the individual and interactive effects of temperature, pH and NaCl on the PepX activity. The enzyme maintained considerable activity under the environmental conditions which characterize the sourdough fermentation
A study on the antimicrobial activity of thymol intended as natural preservative in food applications
No full textA quantitative investigation on the inhibitory activity of thymol against some microorganisms that could represent a potential spoilage risk both in acid and mild thermally treated foods is presented in this work. In order to assess potential biostatic or biocidal activity of thymol, both the growth kinetics and dose-response profiles were obtained and analyzed. A suitable macrodilution methodology based on a turbidimetric technique was adopted to produce inhibitory data used for characterizing microbial susceptibility against thymol at sub-MIC levels. Microbial growth was monitored through absorbance measurements at 420 nm as a function of contact time with the active compound. Moreover, for each tested microorganism, the noninhibitory concentration (NIC) and the MIC were quantified. Results prove that thymol can exert a significant antimicrobial effect on each phase of the growth cycle. The microbial susceptibility and resistance were found to be nonlinearly dose related. It is worth noting that significant biostatic effects were observed at sub-MIC level
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