285 research outputs found

    High-frequency spectral decay in P-wave acceleration spectra and source parameters of microearthquakes in southeastern Sicily, Italy

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    In widely used -2 source models the characteristics of high frequency radiation are described as being flat for frequencies between the source corner frequency and an upper limiting frequency fmax. Deviations from this behavior are described in a parameter which is understood as a general measure of the changes the signal undergoes on its way from the source to the receiver. In this study, we calculated  in Southeastern Sicily by using microearthquakes belonging to three different seismic sequences occurring in the area in 1990, 1999-2001, and 2002. The selected events form four different clusters whose seismic sources are located within a 2 km radius. Although the source-to-station paths are approximately the same inside a given cluster, the values of  change considerably at the same recording site from one event to another, also in the case of events having the same magnitude. We parameterized  in terms of event (E), and path (P and Diff) contributions. The term P represents the contribution on total  of both the whole source-to- station path and the near-surface geology, while Diff models the possible spatial variation in the parameter measured with respect to a reference source-station direction. Results show that the source contribution is not negligible and that there is a positive correlation with source size exists. Moreover, the hypothesis of a laterally homogeneous crustal structure within the area in question is not appropriate and significant variation in attenuating properties of the medium may occur in a very small distance range (also in the order of a few tens of meters). Our analysis suggests that the origin of the above mentioned variability is located near the recording site. Synthetic spectra are also computed in order to verify the actual significance of the parameterization employed and its capacity to separate the source and the path contribution to . We describe our spectra as a product of a Brune-type source spectrum and an exponential shaping term accounting for propagation effects. The seismic moments range between 3.8 ×1011 and 5.2 ×1013 N·m, the source radii range between 176 and 669 m, while the stress drop varies from 0.01 to 0.67 MPa

    Rethinking the social impacts of the arts

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    The paper presents a critical discussion of the current debate over the social impacts of the arts in the UK. It argues that the accepted understanding of the terms of the debate is rooted in a number of assumptions and beliefs that are rarely questioned. The paper goes on to present the interim findings of a three‐year research project, which aims to rethink the social impact of the arts, with a view to determining how these impacts might be better understood. The desirability of a historical approach is articulated, and a classification of the claims made within the Western intellectual tradition for what the arts “do” to people is presented and discussed

    Calibration of input parameters in volcanic areas and an enlarged dataset by stochastic finite-fault simulations

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    The calibration of input parameters is an important task for stochastic finite-fault simulation in volcanic areas, and we manage this in the framework of the European project UPStrat-MaFa. The stochastic simulation method requires the knowledge of fault geometry, source, crust properties of the region, and local site effects. At first, we focused the present study in the pilot test areas: Mt Vesuvius, Campi Flegrei and Mt Etna. Later, we performed two applications for a large magnitude event in the Azores Islands and the South Iceland regions. A general preliminary database of ground-motion records was collected in the test areas, to set up the empirical laws of the ground-motion parameters. The results of the simulations have been compared with observed waveforms and response spectra, to determine the suitability of the parameters used. The results show good agreement between the observed and simulated time histories and response spectra, thus encouraging further efforts towards quantitative high resolution studies on input parameters.Co-financed by the EU - Civil Protection Financial Instrument, in the framework the European project ”Urban disaster Prevention Strategies using MAcroseismic Fields and FAult Sources (Acronym: UPStrat-MAFA, Grant Agreement N. 23031/2011/613486/SUB/A5). http://ec.europa.eu/echo/funding/cp_projects2011_en.htmPublishedLisbon - Portugal4.1. Metodologie sismologiche per l'ingegneria sismicaope

    Hypoxia up-regulates SERPINB3 through HIF-2\u3b1 in human liver cancer cells.

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    SERPINB3 is a cysteine-proteases inhibitor up-regulated in a significant number of cirrhotic patients carrying hepatocellular carcinoma (HCC) and recently proposed as a prognostic marker for HCC early recurrence. SERPINB3 has been reported to stimulate proliferation, inhibit apoptosis and, similar to what reported for hypoxia, to trigger epithelial-to-mesenchymal transition (EMT) and increased invasiveness in liver cancer cells. This study has investigated whether SERPINB3 expression is regulated by hypoxia-related mechanisms in liver cancer cells. Exposure of HepG2 and Huh7 cells to hypoxia up-regulated SERPINB3 transcription, protein synthesis and release in the extracellular medium. Hypoxia-dependent SERPINB3 up-regulation was selective (no change detected for SERPINB4) and operated through hypoxia inducible factor (HIF)-2\u3b1 (not HIF-1\u3b1) binding to SERPINB3 promoter, as confirmed by chromatin immuno-precipitation assay and silencing experiments employing specific siRNAs. HIF-2\u3b1-mediated SERPINB3 up-regulation under hypoxic conditions required intracellular generation of ROS. Immuno-histochemistry (IHC) and transcript analysis, performed in human HCC specimens, revealed co-localization of the two proteins in liver cancer cells and the existence of a positive correlation between HIF-2\u3b1 and SERPINB3 transcript levels, respectively. Hypoxia, through HIF-2\u3b1-dependent and redox-sensitive mechanisms, up-regulates the transcription, synthesis and release of SERPINB3, a molecule with a high oncogenic potential

    Calibration of input parameters in volcanic areas and an enlarged dataset by stochastic finite-fault simulations

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    The calibration of input parameters is an important task for stochastic finite-fault simulation in volcanic areas, and we manage this in the framework of the European project UPStrat-MaFa. The stochastic simulation method requires the knowledge of fault geometry, source, crust properties of the region, and local site effects. At first, we focused the present study in the pilot test areas: Mt Vesuvius, Campi Flegrei and Mt Etna. Later, we performed two applications for a large magnitude event in the Azores Islands and the South Iceland regions. A general preliminary database of ground-motion records was collected in the test areas, to set up the empirical laws of the ground-motion parameters. The results of the simulations have been compared with observed waveforms and response spectra, to determine the suitability of the parameters used. The results show good agreement between the observed and simulated time histories and response spectra, thus encouraging further efforts towards quantitative high resolution studies on input parameters

    VIRTUAL DIVING IN THE UNDERWATER ARCHAEOLOGICAL SITE OF CALA MINNOLA

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    The paper presents the application of the technologies and methods defined in the VISAS project for the case study of the underwater archaeological site of Cala Minnola located in the island of Levanzo, in the archipelago of the Aegadian Islands (Sicily, Italy). The VISAS project (http://visas-project.eu) aims to improve the responsible and sustainable exploitation of the Underwater Cultural Heritage by means the development of new methods and technologies including an innovative virtual tour of the submerged archaeological sites. In particular, the paper describes the 3D reconstruction of the underwater archaeological site of Cala Minnola and focus on the development of the virtual scene for its visualization and exploitation. The virtual dive of the underwater archaeological site allows users to live a recreational and educational experience by receiving historical, archaeological and biological information about the submerged exhibits, the flora and fauna of the place

    When probabilistic seismic hazard climbs volcanoes: the Mt. Etna case, Italy – Part 2: Computational implementation and first results

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    Abstract. This paper describes the model implementation and presents results of a probabilistic seismic hazard assessment (PSHA) for the Mt. Etna volcanic region in Sicily, Italy, considering local volcano-tectonic earthquakes. Working in a volcanic region presents new challenges not typically faced in standard PSHA, which are broadly due to the nature of the local volcano-tectonic earthquakes, the cone shape of the volcano and the attenuation properties of seismic waves in the volcanic region. These have been accounted for through the development of a seismic source model that integrates data from different disciplines (historical and instrumental earthquake datasets, tectonic data, etc.; presented in Part 1, by Azzaro et al., 2017) and through the development and software implementation of original tools for the computation, such as a new ground-motion prediction equation and magnitude–scaling relationship specifically derived for this volcanic area, and the capability to account for the surficial topography in the hazard calculation, which influences source-to-site distances. Hazard calculations have been carried out after updating the most recent releases of two widely used PSHA software packages (CRISIS, as in Ordaz et al., 2013; the OpenQuake engine, as in Pagani et al., 2014). Results are computed for short- to mid-term exposure times (10 % probability of exceedance in 5 and 30 years, Poisson and time dependent) and spectral amplitudes of engineering interest. A preliminary exploration of the impact of site-specific response is also presented for the densely inhabited Etna's eastern flank, and the change in expected ground motion is finally commented on. These results do not account for M  >  6 regional seismogenic sources which control the hazard at long return periods. However, by focusing on the impact of M  <  6 local volcano-tectonic earthquakes, which dominate the hazard at the short- to mid-term exposure times considered in this study, we present a different viewpoint that, in our opinion, is relevant for retrofitting the existing buildings and for driving impending interventions of risk reduction

    Giacomo Serpotta e il "pareggiamento delle arti": la decorazione degli oratori fra manipolazione vitalistica e vocazione classicista

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    ABSTRACT GIACOMO SERPOTTA AND THE “EQUALIZATION OF THE ARTS”: DECORATION OF THE ORATORIES BETWEEN VITALISTIC MANIPULATION AND CLASSICIST VOCATION Ettore Sessa The value of the whole of Giacomo Serpotta's artistic vision in the orchestration of the figuÂŹrative apparatuses of his oratories was certainly one of the principal primers of his historical-critical raising in the modernist period. In 1901 Mauceri and in 1911 Ricci and Basile heighten a profile of it, however synthetic, of angling and above all of different breath from the rediscovery realized in positivist age. Classifiable, in fact, among the eighteenth century precedents of Gesamtkunstwerk aesthetical plant (according to a rather diffused custom within the artistic historiography of modernist culturaI area or of decadentist origin, as in different formalistic demonstrations of the wealthiest society Belle Époque) the progress of Serpottas artistic way towards tangible expressions of the idea of «the whole work of art» has a unmistakable imÂŹprint of his and, at the same time, a feasibility thanks to the plasticism of gestures and to the uniÂŹtary multiplicity of his modeled. In his oratories arrangements the "realist" component, not exempted from hedonistic sensual witty remarks, acts on a foundation of Hellenic taste (also in the use of profiles and architectural elements). With wise modulation and with dosing diversified for intensity, according the nature of the subjects, combines history (see the «teatrini» with perspective sceneries, among which the Lepanto battle), micro history (from feminine allegorical subjects, to attractive dames modernly adorned with ends and brocades, to "picciotti" proudly ragged and to the anecdotal of the daily life), mysticism (from the devotional subjects to the allegories of the virtues), obscurity (from numerological components to philosophical attributes) and, finally, mythology (from the allegorical correspondences between Christianity and paganism to classical simbology). Despite the actual halving of this group of oratories (was destroyed by traumatic events as earthquakes and war actions, or by villainous demolitions big part of Serpottas works, among which the SS. Sacrament oratories to Kalsa and those of Saint Maria del Ponticello), the comparison among the palermitan examples reached us entire allows the individualization of the characters of originality typical of the generaI composition, over that of those figurative unanimously accredited among the most valid of the late- Baroque European sculpture. The typical scheme of these oratories, places with a strong secular imprint (predisposed as for cultural reunions how as for the preclusive congregational assemblies, to which the only ones not admitted affiliate were the artists), has as constants: the hall with a rectangular plant; the skiff or pavilion vault with plaster decorations dissimulating the constructive geometry; the sculptural wall register above of a high plinth; windows on the greatest sides (in number of three); two doors in the counterfacade, originally with desk for the assemblies in central position, below the principal devotional allegorical composition. The first oratory to which Giacomo Serpotta imposes an unitary imprint, except the cappellone only defined between 1717 and the following year) is that of SS. Rosary in S. Cita; he has worked since 1685 to 1688 on behalf of SS. Rosary Company. Serpotta is twenty nine, but already since almost ten years, after the apprenticeship with subordinate roles, he showed himself almost beginning in mute with the decorations of Madonna of the Pity church in Monreale, where he operated like Procopio De' Ferrari's collaborator, and perhaps with his interventions in 1678 in the lateral walls of S. Mercurio oratory, to which follow the 1679 decoration works in the Charity oratory in St. Bartholomeo of the Incurable people (no more existing), perhaps S. Pietro and S. Paolo statues dating back to 1680 for the greatest altar in Gancia church, the marble model for Charles H's equestrian monument for Messina (then realized in 1684) and during the two years 1683-1684 the scenic decorations for the transept altars of Carmine Maggiore church (where he collaborates with his brother Giuseppe and realizes the couples of twisted columns gilded and commented by a theory of plaster miniature scenes disposed according to a spiral development). Immediately after S. Cita oratory he realized, between 1688 and 1691, the decorative apparatuses of the Sacrament oratory in S. NicolĂČ to Kalsa (destroyed because of 1823 earthquake). Only eight years after the completion of this work (about which it was hypothesized that it were an advancement in comparison to the intervention in S. Cita) Giacomo Serpotta is entrusted by S. Francesco from Assisi and S. Lorenzo Companies to realize the complex allegorical and explanatory cycle of the plasters of S. Lorenzo oratoÂŹry. He worked partly on Giacomo Amato's sketches (to which are probably owed the reform interventions that confer to this oratory a great architectural "squaring" in comparison to others), completing the presbytery within 1706, while already from 1701 he is busy in the definition of the walls. In 1703 he began the counter facade with the monumental wall framework and high-relief representation of St. Lorenzo Martyrdom

    Practice Parameter: Therapies for Benign Paroxysmal Positional Vertigo (An Evidence-Based Review): Report of the Quality Standards Subcommittee of the American Academy of Neurologysymbol Symbol

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    American Academy of Neurology; BPPV = benign paroxysmal positional vertigo; CONSORT = Consolidated Standards of Reporting Trials; CRP = canalith repositioning procedure; NNT = number needed to treat
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