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Pseudomonas reduction in drinking-water and wastewater distridution systems by chlorine disinfection
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Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Determination of Low-Level Acrylamide in Drinking Water by Liquid Chromatography/Tandem Mass Spectrometry
No full textA simple and sensitive liquid chromatographic-tandem mass spectrometric (LC/MS/MS) method has been developed and validated to confirm and quantify acrylamide monomer (AA) in drinking water using [13C3] acrylamide as internal standard (IS). After a preconcentration by solid-phase extraction with spherical activated carbon, analytes were chromatographed on IonPac ICE-AS1 column (9 x 250 mm) under isocratic conditions using acetonitrile-water-0.1 M formic acid (43 + 52 + 5, v/v/v) as the mobile phase. Analysis was achieved using a triple-quadrupole mass analyzer equipped with a turbo ion spray interface. For confirmation and quantification of the analytes, MS data acquisition was performed in the multireaction monitoring mode, selecting 2 precursor ion to product ion transitions for both AA and IS. The method was validated for linearity, sensitivity, accuracy, precision, extraction efficiency, and matrix effect. Linearity in tap water was observed over the concentration range 0.1-2.0 microg/L. Limits of detection and quantification were 0.02 and 0.1 microg/L, respectively. Interday and intraday assays were performed across 3 validation levels (0.1, 0.5, and 1.5 microg/L). Accuracy (as mean recovery) ranged from 89.3 to 96.2% with relative standard deviation <7.98%. Performance characteristics of this LC/MS/MS method make it suitable for regulatory confirmatory analysis of AA in drinking water in compliance with European Union and U.S. Environmental Protection Agency standards
Aspetti igienico-sanitari delle acque del fiume Tevere: presenza di protozoi patogeni e rapporti di correlazione con parametri microbiologici e chimico-fisici.
No full textAn investigation on the hygienic quality of the Tiber river was conducted with the aim both to enumerate Giardia cysts and Cryptosporidium oocysts in the water and to determine possible correlations between them and bacterial indicators, pathogens and physico-chemical parameters. A low hygienic water quality was evidenced, with high counts of microorganisms. Furthermore, variable concentrations of Giardia and Cryptosporidium were observed. No correlation was found between the protozoa concentrations and that of the other microorganisms, whilst a significant correlation with redox potential and Giardia cysts was calculated
Variations on the Author
Get PDF“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
Get PDFWe 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
New Approach Based on LC-ESI-MS/MS for Identification of MicrocystinVariants During Cyanobacterial Bloom Events
No full textThe aim of this work was the development of a rapid and efficient approach based on LC-ESI-MS/MS for identification of MC variants in emergencies related to cyanobacterial bloom
Genotoxicity of the disinfection by-products resulting from peracetic acid- or hypochlorite-disinfected sewage wastewater
No full textWastewater disinfection is routinely carried out to prevent the spread of human pathogens present in wastewater
effluents. To this aim, chemical and physical treatments are applied to the effluents before their emission in water
bodies. In this study, the influence of two widely used disinfectants, peracetic acid (PAA) and sodium hypochlorite
(NaClO), on the formation of mutagenic by-products was investigated. Wastewater samples were collected before and
after disinfection, in winter and in summer, at a pilot plant installed in a municipal wastewater-treatment plant. Samples
were adsorbed usingsilica C18 cartridges and the concentrates were tested for mutagenicity in the Salmonella
typhimurium reversion test with strains TA98 and TA100. Non-concentrated water samples were tested with two plant
genotoxicity assays (the Allium cepa root anaphase aberration test and the Tradescantia/micronucleus test).
Mutagenicity assays in bacteria and in Tradescantia showed borderline mutagenicity in some of the wastewater
samples, independent of the disinfection procedure applied. Negative results were obtained in the A. cepa anaphase
aberration test. These results indicate that, in the conditions applied, wastewater disinfection with PAA and NaClO
does not lead to the formation of significant amounts of genotoxic by-products
Inquinanti emergenti
No full textNel XXI secolo in Italia e non solo, importanti sfide, che non azzardato definire epocali, stanno sempre più caratterizzando il servizio idrico; fra queste gli effetti sul ciclo idrogeologico dei cambiamenti climatici (abbondanza/scarsità di precipitazioni) ed una crescente attenzione mista a preoccupazione collegata agli inquinanti definiti "emergenti". Questo testo, frutto del contributo di una molteplicità di competenze ed esperienze, affronta il tema degli inquinanti emergenti nelle acque ad uso umano. La pubblicazione raccoglie, analizza e valuta in maniera puntuale e operativa gli strumenti esistenti di gestione del rischio
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