155 research outputs found

    A tool for mapping the evolution of a lava field through the Etna video-surveillance camera network

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    In active volcanic areas it is often difficult carry out direct surveys during an eruption, remote sensing techniques based on airborne/satellite platforms and ground-based sensors have remarkable monitoring potentialities in terms of safety and observation capability. In addition, the recent development of high resolution digital cameras, laser scanners and SAR instruments have improved the ability to obtain reliable measurements for modelling the evolution of effusive and explosive eruptions by following the rate of advancement of a lava flow or the dispersal of a volcanic plume. In order to collect data at an adequate level of accuracy and frequency it is not possible to exclusively rely on airborne or satellite methods and it is necessary to carry out measurements using also remote sensing instruments operating on the ground. Among the other techniques, the use of a simplified photogrammetric approach based a video-surveillance camera network represents a straightforward alternative for rapid mapping in active volcanic areas. Therefore a procedure for optimizing and extending the observational capability of the Etna NEtwork of Thermal and VIsible cameras (NETVIS) for systematically monitoring and quantifying surface sin-eruptive processes was implemented. The activity included also the extension of the permanent video-surveillance network by installing additional mobile stations. A dedicated tool for automatic processing of image datasets was developed and tested in both simulated and real scenarios to obtain a time series of digital orthophotos for tracking the evolution of a lava flow emplacement. The developed tool was tested by processing images acquired by the Etna_NETVIS sensors, in particular from Monte Cagliato thermal camera, during the 2011 paroxysmal episodes of the New South East Crater that poured lava flows in the Valle del Bove.PublishedRoma, Italia5V. Sorveglianza vulcanica ed emergenzeope

    A multidimensional account of democratic legitimacy: how to make robust decisions in a non-idealized deliberative context

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    This paper analyses the possibility of granting legitimacy to democratic decisionmaking procedures in a context of deep pluralism. We defend a multidimensional account according to which a legitimate system needs to grant, on the one hand, that citizens should be included on an equal footing and acknowledged as reflexive political agents rather than mere beneficiaries of policies, and, on the other hand, that their decisions have an epistemic quality. While Estlund\u2019s account of imperfect epistemic proceduralism might seem to embody a dualistic conception of democratic legitimacy, we point out that it is not able to recognize citizens as reflexive political agents and is grounded in an idealized model of the circumstances of deliberation. To overcome these ambiguities, we develop an account of democratic legitimacy according to which disagreement is the proper expression of citizens\u2019 reflexive agency and the attribution of epistemic authority does not stem from a major expertise or specific ability, but it comes through the public confrontation among disagreeing agents. Consequently, the epistemic value of deliberation should be derived from the reasons-giving process rather than from the reference to the alleged quality of its outcomes. In this way, we demonstrate the validity of the multidimensional perspective of legitimacy, yet abstain from introducing any outcome-oriented criterion. Finally, we argue that this account of legitimacy is well suited for modeling deliberative democracy as a decision-making procedure that respects the agency of every citizen and grants her opportunity to influence public choices

    Assessing and improving the measuring capability of the Etna_NETVIS camera network for lava flow rapid mapping

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    This work is aimed at improving the performance of the ground NEtwork of Thermal and VIsible and cameras located on Mt. Etna volcano (Etna_NETVIS) by optimizing its observational capability on lava flows evolution and by developing dedicated tools for systematically measuring quantitative parameters of known accuracy. The first goal will be achieved through the analysis of the geometrical configuration and its improvement by means of the establishment of additional observation sites to be equipped with mobile stations, depending on the area of interest. This will increment the spatial coverage and improve the observation of the most active areas for surface sin-eruptive processes. For the second objective we will implement new processing tools to permit a reliable quantitative use of the data collected by the surveillance sensors of NETVIS, extending their capability in monitor the lava flow thermal and spatial evolution and by providing georeferenced data for rapid mapping scope. The tool will be used to automatically pre-process multitemporal datasets and will be tested on both simulated and real scenarios. Thanks to data collected and archive by the NETVIS INGV team, we will have the opportunity to develop and test the procedure in different operational conditions selected among the large number of lava flows coupled to lava fountan events occurred between 2011 and 2013. Additionally, Etna_NETVIS data can be used to downscale the information derived from satellite data and/or to integrate the satellite datasets in case of incomplete coverage or missing acquisitions (both due to low revisiting time or bad geometrical conditions). Therefore an additional goal is that of comparing/integrating quantitative data derived from visible and radar satellite sensors with the maps obtained using Etna_NETVIS. The procedure will take into account the discrepancy among the different datasets in terms of accuracy and resolution and will attempt to provide a combined approach (based on error analysis and data weighting) to evaluate the final results reliability. Preliminary results on the procedure and algorithm adopted for geometric and radiometric sensor calibration, definition of optimized configurations through simulation and for extracting updated mapping data from multi-temporal dataset will be presented. This work is developed in the framework of the EU-FP7 project “MED-SUV” (MEDiterranean SUpersite Volcanoes)

    Expression of auxin-binding protein1 during plum fruit ontogeny supports the potential role of auxin in initiating and enhancing climacteric ripening

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    Auxin-binding protein1 (ABP1) is an active element involved in auxin signaling and plays critical roles in auxin-mediated plant development. Here, we report the isolation and characterization of a putative sequence from Prunus salicina L., designated PslABP1. The expected protein exhibits a similar molecular structure to that of well-characterized maize-ABP1; however, PslABP1 displays more sequence polarity in the active-binding site due to substitution of some crucial amino-acid residues predicted to be involved in auxin-binding. Further, PslABP1 expression was assessed throughout fruit ontogeny to determine its role in fruit development. Comparing the expression data with the physiological aspects that characterize fruit-development stages indicates that PslABP1 up-regulation is usually associated with the signature events that are triggered in an auxin-dependent manner such as floral induction, fruit initiation, embryogenesis, and cell division and elongation. However, the diversity in PslABP1 expression profile during the ripening process of early and late plum cultivars seems to be due to the variability of endogenous auxin levels among the two cultivars, which consequently can change the levels of autocatalytic ethylene available for the fruit to co-ordinate ripening. The effect of auxin on stimulating ethylene production and in regulating PslABP1 was investigated. Our data suggest that auxin is involved in the transition of the mature green fruit into the ripening phase and in enhancing the ripening process in both auxin- and ethylene-dependent manners thereafter
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