1,720,961 research outputs found
Valutazione della qualità igienica di latte crudo (RTE) in provincia di Milano
No full textNell’ultimo decennio i processi di standardizzazione avviati dalle grandi imprese del sistema agro-alimentare operanti sui mercati globali hanno contribuito ad una omologazione dei gusti e dei consumi ed alla forte riduzione della possibilità per il consumatore di esercitare un controllo diretto sull’origine e sulle modalità di produzione di ciò che acquista e consuma. Si assiste ultimamente al moltiplicarsi di iniziative volte a ricondurre il prodotto al suo luogo di origine ed a ridare visibilità ai produttori. È nell’ambito di questo processo che si inserisce la vendita diretta da parte di allevatori-produttori ai consumatori di latte crudo, cioè di latte che non subisce alcun trattamento termico (pastorizzazione) prima della sua commercializzazione.
Nella Regione Lombardia è stato istituito il “Piano Regione Lombardia per la vendita del latte crudo” che riporta le linee guida per l’esecuzione dei controlli volti a garantire la conformità alla normativa comunitaria nell’ambito della produzione e conferimento del latte crudo per il consumo umano.
L’indagine, svolta presso il laboratorio di riferimento delle Aziende Sanitarie della Provincia di Milano, attivo presso l’Istituto Zooprofilattico della Lombardia e dell’Emilia Romagna, sezione di Milano (IZS-MI) ha riguardato campioni di latte crudo non pastorizzato prodotto in Provincia di Milano e Monza Brianza nel periodo aprile-ottobre 2012 e prelevati in regime di autocontrollo dalle aziende di produzione. Secondo il piano di autocontrollo la qualità igienica è stata determinata sulla base dei seguenti parametri: Enterobacteriaceae, Escherichia coli (indicatore di contaminazione fecale), Staphylococcus aureus (indicatore di igiene di processo) e Streptococcus agalactiae (indicatore di mastite bovina).
In totale, su 383 campioni di latte crudo, di cui 282 provenienti dai tank di stoccaggio di aziende agricole e 101 da erogatori, 70 (18,2%) sono risultati non conformi; di questi, 58 provenivano dai tank e 12 da erogatori. In particolare, il parametro per il quale l’esito sfavorevole è stato osservato con maggiore frequenza (12%) è quello delle Enterobacteriaceae, seguito dalla colimetria (6,8%); più sporadica è risultata la non conformità, S.aureus e S.agalactiae, rispettivamente osservata in soli 11(2,9%) e 2 (0,7%) casi.
Questo tipo di prodotto, come del resto tutti i prodotti di origine animale e vegetale consumati crudi, mantiene per sua propria natura, una intrinseca componente di rischio. Anche con controlli molto frequenti non è infatti possibile escludere, in senso assoluto, l’eventualità di una occasionale o fortuita contaminazione microbica, la cui ricaduta sui consumatori costituisce un rischio di grado diverso in funzione della suscettibilità del soggetto.
Per prevenire le possibili contaminazioni è bene rispettare: le buone pratiche igieniche di lavorazione e di produzione (GHP e GMP) già dalle fasi di mungitura, stoccaggio e trasporto del latte, con particolare attenzione al rispetto della catena del freddo al fine di evitare la produzione di tossine termoresistenti
Indagini di campo sulle infezioni da Prototheca zopfii biotipo II in un allevamento di bovine da latte
No full textVerocytotoxin-producing Escherichia coli in foodstuff of animal origin
No full textWhile much research effort has been targeted at the verocytotoxin-producing Escherichia coli (VTEC) serotype O157:H7, it is becoming more evident that other VTEC serotypes can also be associated with human foodborne disease. An increasing number of these non-O157 serotypes have been isolated from food sources and from humans suffering from haemolytic-uriaemic syndrome and diarrhoea. The aim of our work was to investigate the prevalence of VTEC O1517 and non-O157 in foodstuffs of animal origin using, two rapid enzymatic procedures. Various types of food samples, 352 in total, were tested: 233 with the Premier EHEC, a screening test which directly detects the presence of verocytotoxin, regardless of serotype, while 119 of these with the Vidas ECO, which is a specific screening test for E. coli O157:H7, together with the Premier EHEC. Two samples were positive for VTEC, one of serogroup O126 and the other was non-serotypable. Another sample was positive in the test specific for E. coli O157:H7, but was not confirmed by culture. This study suggests that VTEC strains are not prevalent in Italy, and that the isolation of serogroup O157 is relatively infrequent. This leads us to conclude that there is little chance of exposure to pathogen for the average consumer in Italy
Studio sulle nefropatie infiammatorie del vitello
No full textIncidence, pathological and microbiological findings of nephritis in calves were studied. Out of 2468 slaughtered calves, 125 (5,06%) showed a chronic interstitial nephritis. These 125 cases were grouped in 3 main classes on the basis of lesion mophology. Some etiopathogenetical hypothesis are proposed. Almost all kidneys examined were bacterilogically negative while antimicrobial agents were detected in the 32,4% of the case
Methicillin-Resistant Staphylococcus aureus in Raw Milk : Prevalence, SCCmec Typing, Enterotoxin Characterization, and Antimicrobial Resistance Patterns
Full text linkStaphylococcus aureus is a known major cause of foodborne illnesses, and raw milk and dairy products are often contaminated by enterotoxigenic and antimicrobial-resistant S. aureus strains. In the present study, 35 S. aureus strains were isolated from 383 raw milk samples collected from various dairy herds in the province of Milan (northern Italy). The isolates were characterized based on their antimicrobial susceptibility patterns and the presence of genes encoding staphylococcal enterotoxins
(sea, seb, sec, sed, and see). About half (45.7%) of the strains were enterotoxigenic, and 37.1% were resistant to at least one of the antimicrobial drugs tested. Seven (20%) of 35 isolates were identified as methicillin-resistant S. aureus (MRSA), and
SCCmec typing performed with a multiplex PCR assay revealed the presence of gene cassettes IV and V, typical of community acquired MRSA, and I and II, characteristic of health care–associated MRSA. The MRSA strains were evaluated for the presence
of the Panton-Valentine leukocidin gene, but this gene was not found. The results of the present study revealed the presence of toxin-producing S. aureus and MRSA strains in raw milk. MRSA and enterotoxigenic S. aureus in dairy farms are an important risk factor for the spread of staphylococcal infections; therefore, further studies are needed to find strategies for monitoring and controlling the presence of S. aureus, especially MRSA, in dairy products
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
