1,720,978 research outputs found
Development of rapid molecular diagnostics methods for the agro-food sector
No full textL’elaborato è stato strutturato in base alle matrici analizzate. Il primo capitolo è dedicato alla caratterizzazione genetica e conseguente possibilità di utilizzo dei marcatori microsatellitari all’interno di 28 popolazioni locali di mais. L’analisi ha permesso di valutare lo stato di conservazione delle accessioni e realizzare un albero filogenetico per individuare le relazioni esistenti tra le diverse varietà. Su un numero più ridotto di materiali è stata valutata la possibilità di utilizzare i marcatori molecolari per la tracciabilità della filiera maidicola, in particolare farina destinata al consumo umano. La seconda parte mostra un esempio di tracciabilità vegetale nel caso di cacao. L’uso di marcatori molecolari hai ha permesso di identificare un profilo microsatellitare per la cultivar CCN51 (clone) permettendo di distinguerla dalla varietà “National” (popolazione) e, quindi, creare una metodologia per la certificazione delle partite costituite esclusivamente dal clone CCN51. Il terzo capitolo è dedicato alla filiera enologica e vede l’ottimizzazione di metodologie per l’estrazione del DNA da uve, mosto, mosto durante le varie fasi di fermentazione, fino al vino finito sia pre che post imbottigliamento, ottenendo DNA amplificabile lungo tutta la filiera produttiva e utilizzabile per una analisi microsatellitare permettendo di identificare le uve utilizzate con attendibilità diversa nelle varie fasi di lavorazione.The thesis is organized according to the different experiments. The first chapter focus on genetic characterisation of 28 local maize populations. The analysis assessed the conservation status of the accessions and allowed the construction of a phylogenetic tree to identify the relationships existing between the different varieties. The possibility to use a molecular marker based traceability approach was evaluated on a smaller number of maize accession. This analysis focused on maize flour for direct human consumption. The second part is an example of food traceability along the cocoa-chocolate chain. The use of molecular markers allowed the identification of the genetic of the CCN51 cultivar (clone) allowing the discrimination between CCN51 and the 'National' variety (population). The identification and traceability of “pure” CCN51 cocoa batches is possible following this approach. The third chapter focused on wine production chain with the aim of the optimisation of methodologies for DNA extraction from grapes and must during the various winemaking steps until pre and post bottling. The obtained DNA was successfully amplified and used for a microsatellite analysis allowing the identification of the grape varieties used for winemaking process
Comparison of six methods for the recovery of PCR-compatible microbial DNA from an agricultural biogas plant
No full textSix different commercial methods were compared to evaluate their efficiency in recovering high quantity/quality
PCR compatible microbial DNA from an agricultural biogas plant. Within the last two decades, biogas plants have been
developed to produce energy from organic wastes and from devoted biomass. The complex biotransformations are performed
by a diverse consortium of microorganisms that is an important reserve of genes and enzymatic activities with a
huge range of applications in various commercial fields. In this respect, the ability to isolate DNA from a complex matrix
is of high importance. Important parameters of the recovered DNA are good yield, purity, and quality. The methods examined
showed considerable differences about quantity and quality of the recovered DNA and, usually, it was observed that a
higher amount was accompanied by more degradation. DNA purity was determined by its PCR amplificability. Only two
methods were able to provide DNA pure enough to be directly amplified. For the rest of the methods, a few intermediate
steps such as dilution and/or the addition of polyvinylpyrrolidone were necessary to remove the inhibitors present and to
amplify the DNA. Real-time PCR analysis evidenced that, as expected, prokaryotic DNA was much more abundant than
eukaryotic DNA, but some methods were more suited to recovering prokaryotic or eukaryotic DNA. The digestion
analysis of ribosomal DNA amplicons confirmed the influence of the methods on the final output, allowing the recovery
of only a fraction of the present species as determined by sequencing a small prokaryotic and eukaryotic ribosomal
library
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Genetic and Epigenetic Approaches for the Possible Detection of Adulteration and Auto-Adulteration in Saffron (Crocus sativus L.) Spice
No full textSaffron (Crocus sativus L.) is very expensive and, because of this, often subject to adulteration.
Modern genetic fingerprinting techniques are an alternative low cost technology to the existing
chemical techniques, which are used to control the purity of food products. Buddleja officinalis Maxim,
Gardenia jasminoides Ellis, Curcuma longa L., Carthamus tinctorius L. and Calendula officinalis L. are
among the most frequently-used adulterants in saffron spice. Three commercial kits were compared
concerning the ability to recover PCR-gradeDNAfrom saffron, truly adulterated samples and possible
adulterants, with a clear difference among them, mainly with the processed samples. Only one of
the three kits was able to obtain amplifiable DNA from almost all of the samples, with the exception
of extracts. On the recovered DNA, new markers were developed based on the sequence of the
plastid genes matK and rbcL. These primers, mainly those developed on matK, were able to recognize
saffron and the adulterant species and also in mixtures with very low percentages of adulterant.
Finally, considering that the addition of different parts of saffron flowers is one of the most widespread
adulterations, by analyzing the DNA of the different parts of the flower (styles, stamens and tepals)
at the genetic and epigenetic level, we succeeded in finding differences between the three tissues that
can be further evaluated for a possible detection of the kind of fraud
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