1,720,959 research outputs found

    Viral indicators of Hygienic–Sanitary Quality: Detection of somatic Coliphages in the Souther Adriatic Sea.

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    One of the objectives of microbiological water quality studies is to identify and minimise public health risks from exposure to bathing waters. Water-related diseases, particularly those caused by viral pathogens, are still of major concern. Gastrointestinal symptoms experienced by bathers following immersion in surface waters are mainly due to viral, rather than bacterial, infection. However, there does not appear to be a correlation between the number of pathogenic viruses present in the water matrices and Escherichia coli, the parameter most frequently used to establish microbial water quality. This study describes the spatial and temporal distribution of somatic coliphages compared with conventional bacterial indicators (E. coli and Enterococci) in the waters off San Cataldo (South Adriatic Sea, Lecce—Italy), a beach resort near the city of Lecce subject to high anthropogenic impact. Our results indicate that somatic coliphages are less sensitive to environmental factors (temperature and dilution) than the classical indicators of faecal contamination. These findings suggest that somatic coliphages could be used as potential indicators for evaluating the quality of coastal seawaters and treated wastewaters discharged into the sea, in order to provide a more accurate analysis of the hygienic-sanitary quality of this water matrix

    Rotavirus detection in environmental water samples by tangential flow ultrafiltration and RT-nested PCR

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    Environmental monitoring was conducted in Otranto (Italy), from January 2006 to April 2007, to monitor the circulation of rotaviruses in various water matrices (raw and treated sewage, surface waters and seawater) and to identify any correlation with the traditional bacteriological indices (faecal coliforms). The viruses were detected using tangential flow ultrafiltration and reverse transcriptase-nested polymerase chain reaction, whilst detection of feaecal coliform was performed according to standard methods. The results showed widespread viral contamination, particularly in spring, of the matrices tested, with the exception of seawater, which at all times tested negative for the presence of rotaviruses. The typing of the rotavirus strains identified the circulation in the studied area of only two genotypes: G1 (22%) and G2 (78%). The bacterial recoveries confirmed the presence of faecal pollution indicators in all examined samples, sometimes with high values. A very weak correlation was found between the presence of faecal coliforms and the circulation of rotaviruses in the environment. The presence of rotaviruses in the environmental water samples may constitute a potential health risk for the local populatio

    Study of the correlation between microfauna and the macrostructure of activated sludge and the efficiency of biological wastewater treatment plants

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    Assessment of protozoan populations is an important tool in evaluating the efficiency of activated sludge in the treatment of wastewater. In this process, protozoa play a significant role by grazing on dispersed bacteria, supporting a healthy food web in activated sludge artificial ecosystems. The objective of this study was to verify how the success of the purification process in activated sludge plants, mainly in terms of TSS, BOD, and COD, is related to ciliate protozoa communities and the presence of filamentous bacteria. Samples were collected from five water treatment plants in the Puglia region, in the period May 2007 - April 2008. Microfauna and filamentous bacteria were identified and quantified, and the sludge biotic index calculated. The data show a correlation between the biological components of activated sludge and traditional chemical parameters. Our results indicate that biological analyses represent a valid alternative to traditional chemical testing in assessing the performance of activated sludge systems

    Microbial and nutritional aspects on the production of live feeds in fish farming industry

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    Aquaculture is an enterprise in constant development, in particular relating to its effect on the environment and also the quality of its products. It represents a valid alternative to traditional fishing, facing the increasing demand for fish products. To guarantee to the consumer a product of high nutritional, organoleptic and hygienic quality, it is fundamental to monitor every phase of the fish farming industry, isolating the potential risk points. For this reason there has been a rapid evolution of productive technique, particularly in the technology, artificial reproduction and feed sectors. The aim of this research has been the monitoring of the evolution of certain microbial and nutritional quality indexes (total microbial counts and lipid analysis on suspensions of Rotifers and Artemia, used as live feed) in the larval phase of the productive cycle of the farm raised fish, in an intensive system. The study has shown an increment in the total microbial counts in the fish farming industry within the production of Rotifers and Artemia, more evident in the suspensions of Rotifers. In addition the study has demonstrated that the maintenance phase, in the enrichment protocol, can reduce the EPA and DHA content. The results confirm the importance of microbial and nutritional control of the live feeds before they get supplied to fish larvae

    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
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