1,721,026 research outputs found

    Going Beyond Counting First Authors in Author Co-citation Analysis

    Full text link
    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

    Chemical, bacteriological and virological monitoring of seawater at the Arno and Serchio outfalls

    No full text
    The results of chemical and microbiological analysis of seawater at the outfalls of the Arno and Serchio rivers during the spring and summer months in 1990 and 1991 are reported. The values of chemical and bacteriological parameters were always below the legal limits, coliphage detection was often negative and enteroviruses were never found

    Assessment of estrogenic activity of flavonoids from Mediterranean plants using an in vitro short term test

    No full text
    Six isoflavones, daidzein (40,7,-dihydroxyisoflavone), genistein (40,5,7-trihydroxyisoflavone), genistin (genistein 7-O- b-D-glucopyranoside), isoprunetin (40,7-dihydroxy, 5-metoxyisoflavone), isoprunetin 7-O-b-D-glucopyranoside, iso- prunetin 40,7-di-O-b-D-glucopyranoside and four flavones, luteolin (30,40,5,7-tetrahydroxyflavone), luteolin 7-O-b-D- glucopyranoside, luteolin 40-O-b-D-glucopyranoside, licoflavone C (40,5,7-trihydroxy,8-isoprenylflavone) were purified from Mediterranean plants (Genista morisii and Genista ephedroides) and their estrogenic activity was assessed by a yeast reporter gene assay (Saccharomyces cerevisiae RMY326 ER-ERE). Licoflavone C showed a powerful estrogenic activity at 107 M (0.0338 mg/ml) and it was 47.45% than 108 M 17b-estradiol (0.00272 mg/ml). The estrogenicity of this flavone was found to be comparable to the activity showed by genistein at 106 M (0.27 mg/ml). This study points out that a glucose substituent in flavones and isoflavones modulates the hormone-like activity in a different way. Isoflavone aglycones showed a more estrogenic activity than the corresponding glucosides. Conversely, the glucosidation made estrogenic the flavone luteolin and the position of substitution differently influenced the estrogenic activity of compounds
    corecore