1,721,207 research outputs found
La scuola de'miracoli : ovvero omilie sopra le principali opere della potenza e della grazia di Gesù Cristo figliciolo di Dio e salvatore del mondo
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MUTAGENESI IN RICINO (Ricinus communis L.)PER LA SELEZIONE DI LINEE PIU' ADATTE ALLA VALORIZZAZIONE AGRONOMICA
No full textIl ricino (Ricinus communis L.) è una tra le dieci principali colture oleaginose a livello mondiale. La ricina, eliminata nei processi industriali per la produzione di olio di ricino, costituisce un rischio sia per lo sfruttamento della pianta come biomassa per la generazione di biocarburanti vegetali di seconda generazione, sia per la possibilità di ottenere scorie tossiche dalla lavorazione del materiale. L’utilizzo di tecniche di mutagenesi chimica, associata ad AFLP e metodiche di sequenziamento bersaglio specifiche (TILLING) hanno dimostrato la possibilità di ottenere e riconoscere, in tempi relativamente brevi e in modo specifico, mutazioni nel genoma d’interesse. A partire da una popolazione monovarietale di ricino, sono stati messi a punto diversi trattamenti (basati su EMS ed MNU), al fine di ottenere una popolazione mutagenizzata chimicamente al cui interno ricercare piante prive, o con un contenuto ridotto, di ricina nel seme e di conseguenza caratterizzate da un maggior valore agronomico ed economico. In seguito all’autoimpollinazione delle piante sopravvissute, analisi AFLP e di sequenziamento sulle generazioni successive hanno mostrato come le piante tendano ad accumulare variazioni nel loro genoma rispetto alla generazione precedente. Dall’analisi di sequenza di circa 1 Mb del gene per la ricina nella popolazione mutagenizzata non è emerso nessun cambiamento nella sequenza nucleotidica, in accordo con i risultati di altri studi in cui si è visto come la frequenza di mutagenesi possa variare con la specie considerata.Castor (Ricinus communis L.) is one of the ten major oil crops worldwide. Ricin, eliminated in industrial processes for the production of castor oil, constitutes a risk to both the exploitation of the plant as a biomass to generate second-generation biofuels, both for getting toxic waste from the processing of the material. The use of chemical mutagenesis techniques, AFLP and methods associated with specific target sequences (TILLING) have demonstrated the ability to obtain and recognize, in a relatively short time, and specifically, mutations in the genome of interest. Starting from a population of castor-variety, have been developed different treatments (based on EMS and MNU), in order to obtain a chemically mutagenized population of plants with a reduced content of ricin in the seed and therefore characterized by a greater agronomic and economic value. After self-pollination of the survived plants, AFLP analysis and sequencing showed how plants tend to accumulate changes in their genome than the previous generation. A sequence analysis of about 1 Mb of the gene for ricin in mutagenized populations has revealed no change in the nucleotide sequence, in agreement with results of other studies in which we have seen that the frequency of mutation may vary with the species under consideration
ModelGraft: Accurate, Scalable, and Flexible Performance Evaluation of General Cache Networks
Full text linkLarge scale deployments of general cache networks, such as Content Delivery Networks or Information Centric Networking architectures, arise new challenges regarding their performance evaluation for network planning. On the one hand, analytical models can hardly represent all the detailed interaction of complex replacement, replication, and routing policies on arbitrary topologies. On the other hand, the sheer size of network and content catalogs makes event-driven simulation techniques inherently non-scalable. We propose a new technique for the performance evaluation of large scale caching systems that intelligently integrates elements of stochastic analysis within a MonteCarlo simulative approach, that we colloquially refer to as ModelGraft. Our approach (i) leverages the intuition that complex scenarios can be mapped to a simpler equivalent scenario that builds upon Time-To-Live (TTL) caches; it (ii) significantly downscales the scenario to lower computation and memory complexity, while, at the same time, preserving its properties to limit accuracy loss; finally, it (iii) is simple to use and robust, as it autonomously converges to a consistent state through a feedback-loop control system, regardless of the initial state. Performance evaluation shows that, with respect to classic event-driven simulation, ModelGraft gains over two orders of magnitude in both CPU time and memory complexity, while limiting accuracy loss below 2%. In addition, we show that ModelGraft extends performance evaluation well beyond the boundaries of classic approaches, by enabling study of Internet scale scenarios with content catalogs comprising hundreds of billions objects
Support vector regression for link load prediction
Full text linkPosprintFrom weather to networks, forecasting techniques constitute an interesting challenge: rather than giving a faithful description of the current reality, as a looking glass would do, researchers seek crystal-ball models to speculate on the future. This work explores the use of Support Vector Regression (SVR) for the purpose of link load forecast. SVR works well in many learning situations, because they generalize to unseen data, and are amenable to continuous and adaptive online learning – an extremely desirable property in network environments. Motivated by the encouraging results recently gathered by means of SVR on other networking applications, our aim is to enlighten whether SVR is also successful for the prediction of network links load at short time scales. We consider the problem of link load forecast based only on its past measurements, which is referred to as “embedded process” regression in the SVR lingo, and adopt a hands-on approach to evaluate SVR performance. In more detail, we perform a sensitivity analysis of the parameters involved, assess the computational complexity for training and validation, dig into the correlation structure of the prediction errors and evaluate techniques to extend the forecasting horizon. Our finding is that accuracy results are close enough to be tempting, but not enough to be convincing. Yet, as SVR exhibit a number of advantages, such as good robustness and flexibility properties, furthermore at a price of a limited complexity, we then speculate on what directions can be undertaken to ameliorate its performance in this context.Celtic project TIGE
Augmented Reality Makes Me Feel So Excited: Evidence from Physiological and Self-Reported Measures
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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
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