382 research outputs found

    Identificazione dinamica sperimentale di edifici strategici sotto sisma

    Get PDF
    Edifici pubblici quali ospedali, scuole, chiese e municipi costituiscono un patrimonio di importanza strategica per la vita di una comunità. La loro gestione richiede un periodico monitoraggio delle condizioni di sicurezza sia a breve che a lungo termine che può oggi essere condotto in modo efficace ed oggettivo mediante sistemi automatici e permanenti di misura delle vibrazioni strutturali. All'occorrenza di un evento sismico, tali sistemi hanno il merito di cogliere l'effettivo comportamento dinamico della struttura, permettendo la calibrazione sperimentale di modelli numerici, utili per una accurata valutazione del livello di sicurezza sismico e per la progettazione di interventi migliorativi. In quest'ottica assume particolare rilievo la rete di monitoraggio dinamico permanente di edifici strategici realizzata dal Dipartimento di Protezione Civile. Quattro di questi edifici sono stati scelti come casi studio allo scopo di analizzarne la risposta acquisita durante il recente evento sismico del Gennaio 2012 in Lunigiana/Garfagnana. Il presente articolo riporta i risultati della caratterizzazione dinamica condotta su uno di essi: il municipio di San Romano in Garfagnana (LU

    Leggere il teatro

    Get PDF
    The theatrical work of Maddalena Mazzocut-Mis, published in the volume Teatro da leggere. Mito e conflitto – with the accompaniment of detailed premises by the author herself – develops in two directions. The first one, looking at the past, leads to the rewriting of works of the literary tradition according to a new point of view. The reworking of famous classical characters relates the distant with the near, allowing us to reflect, among other things, on the function and value of illusions. The second, looking at the present, leads to the presentation of seemingly insignificant characters to highlight the tragic fate of rise and fall or desperate search for a recognized identity

    HuD is a neural translation enhancer acting on mTORC1-responsive genes and counteracted by the Y3 small non-coding RNA

    Get PDF
    The RNA-binding protein HuD promotes neurogenesis and favors recovery from peripheral axon injury. HuD interacts with many mRNAs, altering both stability and translation efficiency. We generated a nucleotide resolution map of the HuD RNA interactome in motor neuron-like cells, identifying HuD target sites in 1,304 mRNAs, almost exclusively in the 3' UTR. HuD binds many mRNAs encoding mTORC1-responsive ribosomal proteins and translation factors. Altered HuD expression correlates with the translation efficiency of these mRNAs and overall protein synthesis, in a mTORC1-independent fashion. The predominant HuD target is the abundant, small non-coding RNA Y3, amounting to 70% of the HuD interaction signal. Y3 functions as a molecular sponge for HuD, dynamically limiting its recruitment to polysomes and its activity as a translation and neuron differentiation enhancer. These findings uncover an alternative route to the mTORC1 pathway for translational control in motor neurons that is tunable by a small non-coding RNA

    Regulation of HuR structure and function by dihydrotanshinone-I

    Get PDF
    The Human antigen R protein (HuR) is an RNA-binding protein that recognizes U/AU-rich elements in diverse RNAs through two RNA-recognition motifs, RRM1 and RRM2, and post-transcriptionally regulates the fate of target RNAs. The natural product dihydrotanshinone-I (DHTS) prevents the association of HuR and target RNAs in vitro and in cultured cells by interfering with the binding of HuR to RNA. Here, we report the structural determinants of the interaction between DHTS and HuR and the impact of DHTS on HuR binding to target mRNAs transcriptome-wide. NMR titration and Molecular Dynamics simulation identified the residues within RRM1 and RRM2 responsible for the interaction between DHTS and HuR. RNA Electromobility Shifts and Alpha Screen Assays showed that DHTS interacts with HuR through the same binding regions as target RNAs, stabilizing HuR in a locked conformation that hampers RNA binding competitively. HuR ribonucleoprotein immunoprecipitation followed by microarray (RIP-chip) analysis showed that DHTS treatment of HeLa cells paradoxically enriched HuR binding to mRNAs with longer 3'UTR and with higher density of U/AU-rich elements, suggesting that DHTS inhibits the association of HuR to weaker target mRNAs. In vivo, DHTS potently inhibited xenograft tumor growth in a HuR-dependent model without systemic toxicity

    Innovative technique for the base isolation of existing buildings

    Get PDF
    An innovative base isolation system has been recently proposed for the retrofitting of existing buildings, in which the isolation layer is inserted under the building foundations so that the building, along with its foundations, is isolated from the surrounding soil. The isolation layer resides in closely-spaced micro-tunnels, constructed under the entire width of the building. These micro-tunnels, along with the trenches around the building, isolate the structure from the surrounding soil. The execution of these micro-tunnels is the most critical construction stage, because it may result in settlements which can damage the structure. In this paper, the behaviour of an existing structure, consisting of a masonry wall subjected to tunnelling-induced ground subsidence, is analysed. A parametric study is conducted using 2-D nonlinear finite element analyses to understand the role of key factors such as strength and stiffness of soil and masonry, roughness of soil-structure interface, excavation sequence of tunnels, wall dimensions and openings configuration. The study identifies the design variables which influence the most the risk of structural damage and suggests the most effective damage symptoms to be monitored during constructio
    corecore