3,115 research outputs found
DNA, variations on the theme
No full textMolecular biology's central dogma, laid down in 1950s, affirmed that genetic information flows from DNA to RNA to protein synthesis. For a long time, the first element of this logic scheme, DNA, was regarded as inactive molecule with the sole purpose to act as a repository of genetic code. Indeed, the molecular dialogue between DNA and proteins has been generally interpreted as an univocal relationship between an inert partner (nucleic acid) and a versatile one (proteins), that remodels DNA as a clay object. Rather, has been emerged that each kind of interactions between macromolecules requires a mutual structural adaptation and chemical complementarity.
As in Kurosawa’s classic movie “Rashomon” (1950) the same central event, a heinous crime, is recalled from the differing perspective of each character (a bandit, a samurai, samurai’s wife and a woodcutter) this present study aims to highlight some different, but complementary, aspects of the full dynamic repertoire of DNA macromolecules. In the first part of this thesis, I will demonstrate that DNA, according to a peculiar three dimensional arrangement, is not only a simple recipe for proteins production but something more. In particular, I will focus on guanosine quadruplex structure, a not canonical B-form of DNA could be described through multiple points of view.
On one side, synthetic guanosine quadruplex can act as “smart” biomolecules able to recognize multiple targets, with potential implications both as diagnostic as well as therapeutic agent. This short DNA/RNA sequences, called aptamers, according to a unique molecular flexibility, are able to recognize and bind a broad range of targets with specificities reminiscent those exhibited by antibodies. As working model, here I will present a detailed characterization in vitro of not physiological guanosine rich sequences able to bind human thrombin, a protein of physiological and pathological relevance. Our research was aimed to describe the relative role of the structural modules composing their molecular architecture. This allowed us to propose a structure activity relationship of synthetic G quadruplex aptamers, in order to fully rationalize and optimize their binding property.
On the other side, G-quadruplex forming sequences are also found in human genome. Some of them have been described as unique biochemical on/off switch able to regulate tumorigenic pathways.
In particular, the expression of the oncogene c-Myc is controlled through the formation of non–B-form DNA structures within its promoter. The conformational shift of this promoter between a transcription inactive form (G-quadruplex form) to an active one (a canonical double strand form) is strictly regulated by several nuclear proteins. In the second section I’ll present a study concerning the heterologous expression, the purification scheme of the resulting products and the biochemical characterization of the functional domains of human nucleolin, a nucleolar protein that is able to inhibit c-Myc oncogene transcription by a peculiar recognition of its promoter in a G quadruplex form. This approach was pursued to deeper clarify the mechanism of this binding event. Doubtless, this represents a promising goal in order to develop new selective and effective chemotherapy drugs.
Although revolutionary, the idea that genetic information was encoded only by DNA sequence, in a protein-free mechanism has been appeared definitely too simplistic. Indeed, in organisms with nuclei chromosomal DNA is organized along with protein templates (histones), forming a complex called chromatin. This is target of diverse array of posttranslational modifications that modulate the interaction among chromatin-associated proteins, which ultimately dictate dynamic transitions between transcriptionally active (euchromatin) or transcriptionally silent chromatin states (heterochromatin). In the last section, I will focus on the structural insights standing on the recognition event between a modified histone N-terminal tail and a specialized ‘effector’ protein (ORC1b), generally known for its role in pre-replication complex assembly.
The identification of the molecular details that clarify how distinct protein modules are able to recognize specific histone modifications is a critical step to understanding how chromatin dynamics influence fundamental DNA-templated processes such as transcription, DNA recombination and DNA repair. In particular, our results identify the tandem PHD-BAH domains of Arabidopsis thaliana ORC1b as a novel unmethylated-lysine-binding module, thereby establishing the first direct link between histone methylation grade and the epigenetic role of ORC1b, previously known as a transcriptional regulation factor only for a series of specific interactions with silencing regulators
Laicità possibili
No full textNel dibattito, sovente confuso, che ruota attorno al “simbolo linguistico” della laicità, questo contributo cerca di ridefinirne, sinteticamente, i contenuti e i contorni come parola, principio e prassi.
Il tentativo è quello di proporre un modello temperato e aperto, verso il quale possano convergere i fili diversi, e spesso contrapposti, di prospettive e orientamenti di cultura.
Ne scaturisce un’idea di laicità configurata, soprattutto, come uno stile e un metodo, fondati sull’esercizio sistematico del dubbio e cercando, costantemente, di “capire prima di discutere, discutere prima di condannare”, secondo la felice indicazione di Norberto Bobbio.
La riflessione mette in evidenza come sia plausibile e significativo parlare di laicità al plurale, sul piano culturale come su quello politico, evitando esclusioni rigide; allo stesso tempo, non si rinuncia al giudizio critico, puntando a riconoscere alcune “laicità possibili”, in particolare nell’orizzonte contemporaneo, italiano ed europeo.
Infine, un’attenzione del tutto peculiare è stata riservata al ruolo problematico della dimensione religiosa entro la dimensione pubblica, coniugandosi la consapevolezza e maturazione dell’esperienza religiosa con la complessità del nostro temp
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Trust in authorities monitoring the distribution of genetically modified foods: dimensionality, measurement issues, and determinants
No full textBased on a combined internet and mail survey in Germany the independence of indica-tors of trust in public authorities from indicators of attitudes toward genetically modified food is tested. Despite evidence of a link between trust indicators on the one hand and evaluation of benefits and perceived likelihoods of risks, correlation with other factors is found to be moderate on average. But the trust indicators exhibit only a moderate relation with the re-spondents’ preference for either sole public control or a cooperation of public and private bodies in the monitoring of GM food distribution. Instead, age and location in either the New or the Old Lander are found to be significantly related with such preferences
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A critical account of the relationship between institutional trust, risk perception, and technology acceptance with an application to genetically modified foods
No full textThis article critically reflects on the widely held view of a causal chain with trust in public authorities impacting technology acceptance via perceived risk. It first puts forward conceptual reason against this view, as the presence of risk is a precondition for trust playing a role in decision making. Second, results from consumer surveys in Italy and Germany are presented that support the associationist model as counter hypothesis. In that view, trust and risk judgments are driven by and thus simply indicators of higher order attitudes toward a certain technology which determine acceptance instead. The implications of these findings are discussed
PER UNA EDIZIONE CRITICA DELLE RIME DI BARTOLOMEO CAVASSICO
No full textThis PhD thesis consists of:
- An introductory part presenting the figure of the author, a description of the ms. bearing the Rime, an analysis of the form and content of the texts and the social, political and cultural context where they were produced;
- The critical edition of fifty-four poems in italian and fifteen in Bellunese dialect. An introductory cap presents the formal characteristics of the work and provides the context, if necessary; this is followed by the text, reproduced according to generally conservative criteria; at the bottom there is a first band of apparatus, aimed at containing corrections of servile errors; a second band, containing the actual genetic apparatus, bearing any variants or previous redactions of the text; and finally the commentary, aimed at clarifying critical places and pointing out parallels with other authors. For the Bellunese texts, a full translation was also provided.
- A caption index;
- Two lexical indexes, for italian and Bellunese texts, bearing the notable forms;
- Four appendices. Appendix I is a table containing all the poems, classified according to the following criteria: location in the ms., title, genre of the poem, language, possible addressee and brief summary, focusing, in particular, on the (recurring) themes present in the text. Appendix II houses vernacular texts not included in the edition, and Appendix III italian texts that the author has taken from other printings. Appendix IV contains the digital reproduction of six papers from ms. 396 of the Biblioteca Civica of Belluno.Questa tesi di dottorato si compone di:
- Una parte introduttiva che presenta la figura dell'autore, la descrizione del ms. recante le Rime, l'analisi della forma e dei contenuti dei testi e il contesto sociale, politico e culturale in cui sono stati prodotti;
- L'edizione critica commentata di cinquantaquattro poesie in volgare e quindici in dialetto bellunese. Un cappello introduttivo presenta le caratteristiche formali dell'opera e ne fornisce il contesto, qualora necessario; segue il testo, riprodotto secondo criteri generalmente conservativi; in calce si trovano una prima fascia di apparato, volta a contenere le correzioni degli errori servili, una seconda fascia, contenente l'apparato genetico vero e proprio, recante le eventuali varianti o redazioni precedenti del testo, e infine il commento, finalizzato a chiarire i luoghi critici e a segnalare paralleli con altri autori. Per i testi bellunesi si è fornita anche la traduzione integrale in calce.
- Un indice dei capoversi;
- Due indici lessicali, per i testi in volgare e per i testi in bellunese, recanti le forme notevoli;
- Quattro appendici. L'appendice I è una tabella contenente tutti i componimenti, classificati secondo i seguenti criteri: collocazione nel ms., titolo, genere del componimento, lingua, eventuale destinatario e breve riassunto, imperniato, in particolare, sui temi (ricorrenti) presenti nel testo. L'appendice II ospita i testi in volgare non inclusi nell'edizione, mentre l'appendice III i testi in volgare che l'autore ha tratto da altre stampe. L'appendice IV contiene la riproduzione digitale di sei carte del ms. 396 della Biblioteca Civica di Belluno, attraverso la quale si possono osservare la scrittura del notaio e gli interventi sui testi
Un possibile modello di gestione collettiva del Parco integrato “Terme Lucane” di Latronico (PZ)
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Do consumers want public or private bodies to monitor animal friendly production and marketing schemes? And does trust matter?
No full textProducing according to enhanced farm animal welfare (FAW) standards increases costs along the livestock value chain, especially for monitoring certified animal friendly products. In the choice between public or private bodies for carrying out and monitoring certification, consumer preferences and trust play a role. We explore this issue by applying logit analysis involving socio-economic and psychometric variables to survey data from Italy. Results
identify marked consumer preferences for public bodies and trust in stakeholders a key determinant
Etnografia digitale, netnografia e autoetnografia: ricerche tra vecchi punk, giovani neopagani e membri di una vasta comunità BDSM della Repubblica ceca
No full textIl capitolo presenta l'esperienza personale dell'autore, con l'utilizzo dei dati e delle esperienze raccolte attraverso internet, la netnografia come forma di ricerca qualitativa e l'accettazione personale dell'autoetnografia per la comprensione di sé, dell'altro e della cultura. Saranno analizzati 12 studi e ricerche realizzate dallo stesso autore, da solo o in qualità di coautore, tra gli anni 2005 e 2019, su temi di ricerca differenti, ma concentrati su selezionate sottoculture attive nella Repubblica Ceca. Il capitolo è concepito come un'introspezione diacronica in cui l'autore descrive i suoi primi tentativi di utilizzare pagine web e discussioni in internet come fonte di citazioni in articoli scientifici, fino al raggiungimento di una metodologia netnografica più matura.The chapter presents the personal experience of the author, with the use of data and experiences collected through the internet, the netnography as a form of qualitative research, and the personal acceptance of the autoethnography for the understanding of self, other, and culture. It will be analyzed 12 studies and researches realized by the same author, alone or as co-author, between the years 2005 and 2019, on different, but connected research topics concentred on selected sub-cultures active in the Czech Republic. The chapter is conceived as a diachronic introspection where the author describes his first attempts to use web pages and internet discussions as a source of quotations in scientific papers, up to the achievement of a more mature netnographic methodology
Il patrimonio collettivo dei centri storici siciliani tra norme inadeguate e nuove opportunità di rigenerazione
No full textNel 2015 la Regione Siciliana esitava la L.r. 13/2015 “Norme per favorire il recupero del patrimonio edilizio di base dei centri storici”, un provvedimento legislativo molto contestato in ambito accademico che, di fatto, costituisce un grave arretramento culturale e tecnico non tenendo in alcun conto gli avanzamenti metodologici sul tema dei centri storici a partire dalla Carta di Gubbio del 1960. La L.r. 13 ha avuto un’applicazione sinora abbastanza limitata rispetto a quello che la sua attrattività avrebbe fatto immaginare, infatti, solo poche decine di comuni hanno proceduto alla definizione dello “Studio con effetti costitutivi” del centro storico, e pochi ne hanno concluso l’iter di approvazione. Nei Comuni che hanno approvato lo Studio, peraltro, non si è registrata una significativa accelerazione nei procedimenti di rilascio dei permessi di costruire né tantomeno un incremento dell’attività edilizia. Oggi però il fermento che si registra in alcuni comuni è un chiaro segnale che tale situazione di stasi potrebbe presto cambiare, tenuto conto delle ingenti risorse finanziarie presto disponibili, collegate alle misure introdotte dal Piano Nazionale di Ripresa e Resilienza (PNRR). Appare quindi non rinviabile pervenire quanto prima alla definizione di alcuni correttivi legislativi per rimediare ai tanti errori e ai gravi difetti di impostazione della Legge, e allo stesso tempo individuare azioni più consapevoli ed equilibrate di rigenerazione dei centri storici da mettere in campo, strutturate sulla conoscenza dei luoghi e sul rispetto delle identità locali
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