1,721,047 research outputs found
ZEIN CODING SEQUENCE ANALYSES FOR MAIZE GENOTYPING AND ZEIN PROTEIN MANIPULATION TOWARDS THE IMPROVEMENT OF THE MAIZE SEED PROTEIN QUALITY
No full textMaize (Zea mays) is an important source of proteins for human and animal nutrition. However, because of the lack of lysine and the low content in methionine and tryptophan, maize’s proteins are of low quality. These deficiencies mainly result from the low levels of these essential amino acids in the zein storage proteins, which account for 50% of the total protein in mature seed. In this context, the first aim of this PhD thesis has been to develop artificial zein genes encoding for polypeptides with a higher content in lysine and methionine, and capable to be sorted and correctly accumulated into the endosperm, as occur for natural zein polypeptides.
Two strategies have been employed for maize bio-fortification. First, we exploited the natural heterogeneity among α-zein genes to create a synthetic gene, ZRK, in which six arginine residues have been substituted with lysine. Then, by combining the N-terminal methionine-rich G3 sequence and the C-terminal lysine-rich region of Histone3 and Histone4 of maize, the G3H3 and G3H4 artificial genes were created, respectively. In vitro and in vivo expression analyses of these genes showed that all synthetic proteins are synthesized and accumulated into the ER membranes of either the rabbit reticulocyte/canine membrane system or of transformed tobacco protoplasts. The second aim of this thesis has been to use the wide heterogeneity of zein gene family to obtain an intra-species recognition tool, or individual barcode, for inbreds and Lombard varieties discrimination. Lombard varieties and maize inbreds were analysed by 2D gel protein fractionations and DNA gel blot analyses. For each genotype the 2D and Southern blot pattern were converted into a binary code, and then into a barcode. In both the approaches, each genotype was univocally identified making zeins a valuable tool for identification of maize germplasm
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
Mutina sepolta: inquadramento geologico dell’area urbana di Modena
Full text linkLe pianure alluvionali sono tra le aree più popolate al mondo per le favorevoli caratteristiche morfologiche e la ricchezza di risorse. Sono piane formate dai sedimenti abbandonati dai corsi d'acqua durante le piene. Il divagare dei corsi d’acqua e le alluvioni rendono l’evoluzione di questi ambienti estremamente dinamica, caratteristica oggi notevolmente ridotta dalla costruzione degli argini artificiali. Uno dei risultati della complessa evoluzione delle pianure è che le vestigia di antiche civiltà non sono più visibili perché sepolte sotto spessi strati di sedimenti fluviali. Tra gli esempi più noti ricordiamo le civiltà mesopotamiche, dell’Antico Egitto e dell’età del bronzo della Cina. Proprio come a Modena, dove i resti della nostra antica città fondata 2200 anni fa giacciono ben al di sotto dell’area urbana moderna, a circa 5 metri di profondità. Ma com’è possibile che questo sia accaduto? Perché Mutina è sepolta a così grande profondità? La risposta a questa domanda è nascosta all’interno dei sedimenti stessi. I sedimenti rappresentano un vero e proprio archivio di inestimabile valore per ricostruire l’evoluzione degli ambienti e delle caratteristiche climatiche nelle quali hanno vissuto i nostri antenati. E per indagare le modalità con le quali è avvenuta la sedimentazione nella pianura modenese dobbiamo fare riferimento a due recenti fenomeni geologici che hanno sconvolto il nostro territorio: il terremoto del 2012 e l’alluvione del 2014. È proprio grazie allo studio di questi eventi che possiamo scoprire come la città romana sia stata lentamente “inghiottita” nel sottosuolo. Si tratta di una storia per molti versi drammatica, che ci racconta la lotta millenaria dei nostri antenati contro le alluvioni e i terremoti
Analisi dei costi di approvvigionamento della materia prima per la produzione di biogas in imprese agro-zootecniche
No full textLa redditività di un impianto a biogas è collegata ai costi di approvvigionamento delle materie prime, se queste rientrino nella definizione di sottoprodotto ovvero di rifiuto, quale quota ciascuna di esse rivesta nella composizione della “dieta” e se l’origine della stessa sia interna o extra-aziendale. Queste variabili, infatti, possono complicare la fase autorizzativa dell’impianto ed aumentare i costi in ingresso ed in uscita della materia prima.
Pertanto, la scelta della “dieta” è tra i momenti decisivi nell’impostazione dell’impianto, da cui cogliere quali possano essere le opportunità per un imprenditore agricolo di inserirsi in una filiera energetica, ovvero in sostituzione (parziale o completa) di acquistare e/o di coltivare specie dedicat
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