1,720,962 research outputs found
Studio statistico applicato alla metodica di campionamento di sementi transgeniche
No full textLo sviluppo biotecnologico ha fortemente caratterizzato gli ultimi venti anni: in campo agrario la gran parte delle ricerche e delle produzioni sono volte alla costruzione e all’uso di piante geneticamente modificate di interesse alimentare soprattutto per aumentarne la produzione e, recentemente, anche per migliorarne la qualità. Accanto agli aspetti positivi che i prodotti biotecnologici assicurano, si aprono anche preoccupazioni sui rischi ambientali derivanti dal rilascio di organismi geneticamente modificati e sui rischi per la salute, derivanti dal consumo di cibi transgenici. Ciò ha reso necessario introdurre analisi accurate al fine di individuare e quantificare componenti transgeniche all’interno di prodotti agro-alimentari.
In quest’ottica, ben nota è l’importanza delle modalità di campionamento e della quantità di campione da analizzare. A livello comunitario, il campionamento delle sementi per le analisi di certificazione è fatto in accordo con le direttive 66/400/EEC, 66/401/EEC, 66/402/EEC, 66/403/EEC, 69/208/EEC e 70/458/EEC e i metodi di campionamento sono descritti nel ”Handbook on seed sampling” dell’ISTA (International Seed Testing Association) e nel “International Rules for Seed Teesting 1999”. Manca però attualmente un protocollo di campionamento specifico finalizzato all’analisi PCR o ELISA per il rilevamento di semi transgenici. Tutto questo, insieme all’accentuata disomogeneità della distribuzione delle partite, rende il campionamento delle sementi particolarmente delicato dato che la presenza di OGM in minime tracce necessita di un campionamento uniforme e statisticamente significativo
Safety evaluation of food derived by modern biotechnology. Exploitation of molecular profiling techniques
No full textSeveral strategies have been developed to identify unintended alterations in the composition of genetically modified (GM) food crops that may occur as a result of the genetic modification process. These include comparative chemical analysis of single compounds in GM food crops and their conventional non-GM counterparts, and profiling methods such as DNA/RNA microarray technologies, proteomics and metabolite profiling. The potential of profiling methods will be reported, although further exploration of specificity, sensitivity and validation is needed. Moreover, the successful application of profiling techniques to the safety evaluation of GM foods will require linked databases to be built containing information on variations in profiles associated with differences in developmental stages and environmental conditions
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
Possibile impiego di microRNA come biomarcatori nel monitoraggio dei lavoratori professionalmente esposti ad amianto
No full textExposure to asbestos is the predominant cause of pleural mesothelioma (PM). The PM is a tumor difficult to diagnose, chemoresistant, and with rising Incidence. The long latency periods and the lack of preventive and therapeutic strategies for the MP, suggest that asbestos will be a social and health issue in the near future. Therefore, this overview focuses on current knowledge of epigenetic alterations and on the key role of microRNAs, small RNAs that negatively regulate gene expression, as biomarkers in PM development. Dysregulated microRNA expression pattern is specific for different cancers, including MP. MicroRNA expression analysis is a promising tool for diagnosis, typing of MP than normal tissue and other lung tumors and monitoring of new therapies. However, a better knowledge of miRNA signatures in PM is still necessary to verify the contribution of specific miRNAs as diagnostic biomarkers, also compared to different asbestos forms, exposure and subject work history
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
Leptospirosis survey in wild rodents living in urban areas of Rome.
No full textThe aim of the study was to survey the current extension of the infected brown rats (Rattus norvegicus) living on the site Ripa Grande-San Michele port located in the center of the sity along the accessible right bank of the Tiber river by using a specific molecular technology. The detection of Leptospira, in 11 trapped brown rats, by tube-based Polymerase Chain Reaction (PCR) was performed. The amplified samples were analysed by capillary zone electrophoresis (CZE). Sequence analysis of the amplified DNAs confirmed the specificity of the detection of leptospires. Five out of 11 brown rats exhibited positivity for Leptospira. The survey points out the high rate of leptospiral infection in the brown rats living in the most ancient urban area of Rome
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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
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