102,438 research outputs found
Dante attraverso i documenti. II. Presupposti e contesti dell’impegno politico a Firenze (1295-1302)
No full textLa sezione monografica comprende dodici articoli volti a investigare il significato del breve impegno di Dante Alighieri nelle istituzioni politiche fiorentine avvenuto tra 1295 e 1302. Un primo blocco di testi (i contributi di E. Faini, A. Montefusco, P. Borsa, M. Grimaldi) dà conto dei presupposti di tale impegno, analizzando le valenze politiche della formazione culturale e poetica dei fiorentini alla fine del Duecento. Un secondo gruppo di contributi (di L. Tanzini, E. Brilli e A. Zorzi) indaga il contesto istituzionale e politico di quegli anni alla luce delle fonti normative e cronachistiche. Infine un terzo insieme di saggi (di D. Cappi, D. Carron, P. Gualtieri e D. Bortoluzzi) Dante e Firenze vengono comparati con comuni cittadini e personaggi ad essi legati. Conclude la sezione un saggio di G. Milani in cui, anche alla luce delle indagini raccolte, la documentazione relativa all’impegno politico del poeta è sottoposta a un complessivo riesame
Recensione a: Sara J. Newman, Aristotle and Style, Lewingston-Queenston-Lampeter: The Edwin Mellen Press, 2005
No full textWell fitting into the recent Aristotelian bibliography, as Alan G. Gross rightly points out in his preface to the book, Sara Newman’s work offers a very engaged commentary to the relationship between Aristotle’s theory and practice of metaphor and contemporary under-standings of it. As in a roundtrip, the author comes back at the end of her analysis to her open-ing question ‘Why Aristotle and Style?’ (p. 1) which she can now answer saying that “In spite of its limitations, Aristotle notion of style is more than ornamental and substitutive; it operates consistently in his texts to enhance, to facilitate, and to systematically guide certain concep-tual inquiries” (p. 263). Indeed the book has not only the merit to stress the role of Aristotle’s metaphor within the clarifying function of style and consequently its link with the logical process of persuasion, but it is also an important contribution to vindicate Aristotle’s rights in the development of the modern conceptual theory of metaphor
Effetto dello stress termico sull'incorporazione di N-acetil-D-glucosamina nelle glicoproteine di parete in coleottili di orzo (Hordeum vulgare L.)
No full textCold-stress effect on D-[U-14C]glucosamine metabolism in barley coleoptile segments (Hordeum vulgare L.)
No full textEffect of Brefeldin A on the biosynthesis of cell wall polysaccharides in avena coleoptiles
No full text8° incontro su Aspetti Molecolari e Fisiologici delle Interazioni pianta-patogen
From local to global modeling for characterizing calcium dynamics and their effects on electrical activity and exocytosis in excitable cells
No full textElectrical activity in neurons and other excitable cells is a result of complex interactions between the system of ion channels, involving both global coupling (e.g., via voltage or bulk cytosolic Ca2+concentration) of the channels, and local coupling in ion channel complexes (e.g., via local Ca2+ concentration surrounding Ca2+ channels (CaVs), the so-called Ca2+ nanodomains). We recently devised a model of large-conductance BKCapotassium currents, and hence BKCa–CaV complexes controlled locally by CaVs via Ca2+ nanodomains. We showed how different CaV types and BKCa–CaV stoichiometries affect whole-cell electrical behavior. Ca2+ nanodomains are also important for triggering exocytosis of hormone-containing granules, and in this regard, we implemented a strategy to characterize the local interactions between granules and CaVs. In this study, we coupled electrical and exocytosis models respecting the local effects via Ca2+ nanodomains. By simulating scenarios with BKCa–CaV complexes with different stoichiometries in pituitary cells, we achieved two main electrophysiological responses (continuous spiking or bursting) and investigated their effects on the downstream exocytosis process. By varying the number and distance of CaVs coupled with the granules, we found that bursting promotes exocytosis with faster rates than spiking. However, by normalizing to Ca2+ influx, we found that bursting is only slightly more efficient than spiking when CaVs are far away from granules, whereas no difference in efficiency between bursting and spiking is observed with close granule-CaV coupling
Control Engineering Approaches to Reverse Engineering Biomolecular NetworksHandbook of Statistical Systems Biology
No full textExplicit theoretical analysis of how the rate of exocytosis depends on local control by Ca2+ channels
No full textHormones and neurotransmitters are released from cells by calcium-regulated exocytosis, and local coupling between Ca2+ channels (CaVs) and secretory granules is a key factor determining the exocytosis rate. Here, we devise a methodology based on Markov chain models that allows us to obtain analytic results for the expected rate. First, we analyze the property of the secretory complex obtained by coupling a single granule with one CaV. Then, we extend our results to a more general case where the granule is coupled with n CaVs. We investigate how the exocytosis rate is affected by varying the location of granules and CaVs. Moreover, we assume that the single granule can form complexes with inactivating or non-inactivating CaVs. We find that increasing the number of CaVs coupled with the granule determines a much higher rise of the exocytosis rate that, in case of inactivating CaVs, is more pronounced when the granule is close to CaVs, while, surprisingly, in case of non-inactivating CaV..
Effect of the inhibitors on the biosynthesis and processing of N-linked oligosaccharide chains in coleoptile segments of barley (Hordeum vulgare L.)
No full textMetabolism of N-acetyl-D-[1-14C]glucosamine in avena coleoptile segnents during elongation growth
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