1,721,037 research outputs found

    New procedure for the determination of nisin in milk.

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    A new procedure is described for the assay of nisin in milk by using capillary zonal electrophoresis. Since nisin assay in milk and in other matrices is hampered by its adsorption to both the protein and lipid milk fractions, a simple extraction procedure was devised to remove caseins and lipids, which interfere with nisin detection. An excellent linear response to nisin concentration was observed in the range from 10 to 100 mg/ml with a mean coefficient of variation of 3.8%

    Jacobello del Fiore a Fermo. Sui "quadriccioli rappresentanti le gesta dei santi apostoli Pietro e Paolo"

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    Il saggio prende in considerazione le commissioni avute da Jacobello del Fiore a Fermo, con particolare attenzione al polittico eseguito per la chiesa di San Pietro in Penn

    Going Beyond Counting First Authors in Author Co-citation Analysis

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    The 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

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    “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

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    We 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

    Buckwheat achenes antioxidant profile modulates Aspergillus flavus growth and aflatoxin production

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    Buckwheat (Fagopyrum spp.) is a "pseudo-cereal" of great interest in the production of healthy foods since its flour, derived from achenes, is enriched with bioactive compounds and, due to the absence of gluten, may be used in composition of celiac diets. Amongst buckwheat species, F. tataricum achenes possess a larger amount of the antioxidant flavenol rutin than the common buckwheat F. esculentum. Ongoing climate change may favor plant susceptibility to the attack by pathogenic, often mycotoxigenic, fungi with consequent increase of mycotoxins in previously unexploited feeds and foodstuffs. In particular, Aspergillus flavus, under suitable environmental conditions such as those currently occurring in Italy, may produce aflatoxin B1 (AFB1), the most carcinogenic compound of fungal origin which is classified by IARC as Category 1. In this study, the viable achenes of two buckwheat species, F. tataricum (var. Golden) and F. esculentum (var. Aelita) were inoculated with an AFB1-producing A. flavus NRRL 3357 to analyze their relative performances against fungal invasion and toxin contamination. Notably, we sought the existence of a correlation between the amount of tocols/flavonols in the achenes of buckwheat, infected and non-infected with A. flavus, and to analyze the ability of the pathogen to grow and produce toxin during achene infection. Results suggest that achenes of F. tataricum, the best producer of antioxidant compounds in this study, are less susceptible to A. flavus infection and consequently, but not proportionally, to mycotoxin contamination compared with F. esculentum. Moreover, rutin-derived quercetin appears to be more efficient in inhibiting aflatoxin biosynthesis than the parent compound. © 2014 Elsevier B.V

    Ionic content in plant extracts determined by ion chromatography with conductivity detection

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    A simple method is described for the determination of the ionic content of vegetable samples by ion chromatography with suppressed conductivity detection. Extracts of leaves of cucumber (Cucumis sativus), leaves and cotyledons of watermelon (Citrullus lanantus), cotyledons of zucchini (Cucurbita pepo), and leaves and roots of olive (Olea europaea) obtained at room temperature yielded chromatographic profiles with substantial differences in the relative contents of Cl-, NO3-, HPO42- and SO42- as well as of Na+, NH4+,K+, Mg2- and Ca2-. Although NO3-, Cl- and K- were common to each extracted sample and accounted for most of the ions present, two additional anion peaks (i.e. malate and oxalate) were detected. Among the vegetable tissues investigated, olive roots contained a considerable amount of oxalate (37 mg/g dry weight), while Na+, which is present in very low amount in extracted samples of leaves and cotyledons, represented ca. 30% of the cationic content of olive roots. In all the examined tissue extracts, K+ was the main cation (16–55 mg/g dry weight) and NO3-, Cl- and HPO42- were the main inorganic anions
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