15 research outputs found
PSI-based methodology to land subsidence mechanism recognition
No full textA methodology based on Persistent Scatterer Interferometry (PSI) is proposed in order to disentangle the contribution of different processes that act at different spatio-temporal scales in land subsidence (i.e. vadose zone processes as swelling/shrinkage of clay soils, soil consolidation and fluid extraction). The methodology was applied in different Italian geological contexts characterized by natural and anthropic processes (i.e. a Prealpine valley and the Po Plain in northern Italy)
Molecular basis of a novel renal amyloidosis due to N184K gelsolin variant
No full textMutations in gelsolin are responsible for a systemic amyloidosis first described in 1969. Until recently, the disease was associated with two substitutions of the same residue, leading to the loss of the calcium binding site. Novel interest arose in 2014 when the N184K variant of the protein was identified as the etiological agent of a novel kidney-localized amyloidosis. Here we provide a first rationale for N184K pathogenicity. We show that the mutation induces a destabilization of gelsolin second domain, without compromising its calcium binding capacity. X-ray data combined with molecular dynamics simulations demonstrates that the primary source of the destabilization is a loss of connectivity in proximity of the metal. Such rearrangement of the H-bond network does not have a major impact on the overall fold of the domain, nevertheless, it increases the flexibility of a stretch of the protein, which is consequently processed by furin protease. Overall our data suggest that the N184K variant is subjected to the same aberrant proteolytic events responsible for the formation of amyloidogenic fragments in the previously characterized mutants. At the same time our data suggest that a broader number of mutations, unrelated to the metal binding site, can lead to a pathogenic phenotype
Multi-sensor SAR data for landslide inventory updating: the case study of Piemonte Region
No full textIn the last decade, satellite radar differential interferometry (DInSAR) has been used in updating the landslides
inventories. The technique allows to monitor the deformation patterns over large areas, in order to verify and/or modify
the landslide boundaries. Moreover, it contributes to define the state of activity of a phenomenon. The improvements of
the SAR data, guaranteed by the COSMO-SkyMed satellites and by the future ESA Sentinel missions, that act at higher
spatio-temporal resolution, require appropriate methodologies for analyzing large datasets of points of measures.
To address to these problems, we present a guiding procedure to analyze multi-sensors SAR dataset with the aim of
updating landslides inventories. We applied the methodology in Piemonte region, a wide area of north-western Italy
affected by a big amount of different types of landslides. We use satellites images acquired, in ascending and descending
acquisition geometry, by C-band (ERS 1⁄2, ENVISAT, RADARSAT) and X-band (COSMO-SkyMed) sensors and
processed using SqueeSARTM, PSInSARTM and PSP-IfSAR techniques. The project was carried out in collaboration with
ARPA Piemonte and a part of the interferometric data were provided by the Italian Ministry of Environment in the frame
of the “Extraordinary Plan of Environmental Remote Sensing” (PST-A).
The developed methodology consists of three main steps: 1) post-processing elaborations of the SAR data, for
removing possible errors which could affect the dataset; 2) identification of the ground motion areas characterized by
different deformation style (i.e. lowering, uplift and non-linear trend) by the use of automatic and semi-automatic
statistical analysis, based on Principal Component Analysis, on the displacement time series; 3) analysis between the
identified ground motion areas and the landslides distribution (The Piemonte Landslide inventory–SIFRAP) both at
regional scale and at local scale, thanks to detailed in situ analysis for the most interesting sites.
Integrating multi-sensor SAR data collected for a continuous period of 24 years (from 1992 to 2015) provided
important information on the landslides detection at regional and local scales, in the different geological,
geomorphological and environmental contexts of the Piemonte region. Three study areas, where SAR images of all the
considered sensors were available, were selected for representing the main contexts of Piemonte region: the Susa (528
km2 wide) and the Orco-Lanzo (996 km2 wide) valleys, representative of the Alps domain; the western Turin hill (404
km2 wide), representative of the Turin hill context. The availability of the large archive of SAR data allowed the backmonitoring
of the time evolution of different phenomena. In particular, different phases of activation, re-activation,
acceleration or stabilization of the phenomena were recognized. In addition we have assessed the performance of the
multi-sensors SAR data for monitoring different landslides types
A Simulation Analysis for Assessing the Reliability of AC/DC Hybrid Microgrids - Part II: Port Area and Residential Area
No full textThis paper reports the second part of a simulation study with the aim of evaluating the ability of two portions of a hybrid AC/DC MV/LV network in maintaining their operation in off-grid mode during the loss of the main AC grid due to a failure. In particular, this paper follows a dual purpose: first, it analysis two microgrids in a residential area and a port zone capability of operating in islanded mode, applying a probabilistic approach, while there is different energy use cases, and second is to evaluate some reliability indicators
A Simulation Analysis for Assessing the Reliability of AC/DC Hybrid Microgrids - Part I: Underground Station and Car Parking
No full textThis paper reports the results of a simulation study with the aim of evaluating the capability of two portions of a hybrid AC/DC MV/LV network of maintaining their operation in off-grid mode during the loss of the main AC grid due to a failure. In particular, the study aims to verify, in the case of islanded operation of the two microgrids, the continuity of the electricity service by exploiting the local generation plants, Energy Storage Systems (ESSs), and other flexible resources managed by suitable algorithms in different energy scenarios. The analysis was carried out considering two microgrids: an underground station and a car parking with Electric Vehicles (EVs). For assessing the performance of the network, specific indicators have been defined and calculated
LANDSLIDE FIELD MAPPING: IFFI-RESTART FORMS FOR DATA ACQUISITION AND MANAGEMENT
No full textOver the last few decades, the approach to geological and geomorphological surveys has changed remarkably. The advent of digital
tools has allowed significant advances in the acquisition and management of survey data. In this paper, we demonstrate the development
and testing of a new and effective digital survey method that allows for the fast acquisition and collaborative storage and management
of data and information. This method was tested in collaboration with five universities for the mapping and classification of landslides in
249 survey areas in Central Italy and, more precisely, in the municipalities affected by the 2016 Central Italy Earthquake. Geological and
geomorphological surveys were carried out in the field with tablet PCs, GPS, and cameras. The survey project for collecting field data was
based on the structure of the Italian Landslide Inventory (IFFI) and the Territorial Resilience Central Apennines Earthquake Reconstruction
(ReSTART) projects. The structure of the database and input forms were implemented for these aims. Moreover, the data and information
were retrieved and organised in detailed records useful to the administrative entities
Residual mechanisms and kinematics of the relict Lemeglio coastal landslide (Liguria, northwestern Italy)
No full textThe Lemeglio landslide is a deep-seated coastal landslide of the Liguria region (northeastern Italy) involving heterogeneous rock-masses formed by Miocene turbidide series, whose prevalent lithology varies from sandstones to mudrocks. It has been recognized since the end of the nineteenth century and characterized by a relict state of activity. Besides the general state of slope stability given by the current morpho-climatic conditions, different from those that determined its original paroxysmal evolution, a residual slow kinematics of the accumulation zone still exists, posing a threat to buildings and infrastructures located across the landslide foot. Consequently, the Lemeglio landslide represents a relevant case of study for advancing knowledge on residual kinematics, mechanisms and hazard inherited by a relict slope mass-movement phenomenon.
The study is based on results of several drilling campaigns and geotechnical investigations carried out mainly by the Regione Liguria in the unstable landslide accumulation zone. Moreover, in this area ground deformations were assessed by inclinometer measurements and ADInSAR data covering two partially overlapping time spans, from June 2009 to July 2011 and from January 2004 to June 2014, respectively. By these data, joined with field geological and geomorphological surveys, an integrated and consistent landslide model was reconstructed, which was used for Limit Equilibrium (LEM) and Finite Elements Modelling (FEM) analyses. Among principal outcomes is the recognition, by field observations, stratigraphic and inclinometer data as well as slope stability modelling, of a basal sheared and softened band, made chiefly of remoulded mudrocks, which constrains the current landslide failure surface. Such basal band can be considered an inherited landslide structure, formed during the original paroxysmal stage of the Lemeglio landslide, which controls the current residual kinematics of the landslide deposits throughout the foot, depending also on the coastal marine erosion acting along the landslide toe
The structure of N184K amyloidogenic variant of gelsolin highlights the role of the H-bond network for protein stability and aggregation properties
No full textMutations in the gelsolin protein are responsible for a rare conformational disease known as AGel amyloidosis. Four of these mutations are hosted by the second domain of the protein (G2): D187N/Y, G167R and N184K. The impact of the latter has been so far evaluated only by studies on the isolated G2. Here we report the characterization of full-length gelsolin carrying the N184K mutation and compare the findings with those obtained on the wild type and the other variants. The crystallographic structure of the N184K variant in the Ca2+-free conformation shows remarkable similarities with the wild type protein. Only minimal local rearrangements can be observed and the mutant is as efficient as the wild type in severing filamentous actin. However, the thermal stability of the pathological variant is compromised in the Ca2+-free conditions. These data suggest that the N to K substitution causes a local disruption of the H-bond network in the core of the G2 domain. Such a subtle rearrangement of the connections does not lead to significant conformational changes but severely affects the stability of the protein
Advanced interpretation of ground motion using Persistent Scatterer Interferometry technique: the Alto Guadalentín Basin (Spain) case of study
No full textSubsidence related to fluid withdrawal has occurred in numerous regions of the world. The phenomena is an
important hazard closely related to the development of urban areas. The analysis of the deformations requires an
extensive and continuous spatial and temporal monitoring to prevent the negative effects of such risks on structures
and infrastructures. Deformation measurements are fundamental in order to identify the affected area extension,
to evaluate the temporal evolution of deformation velocities and to identify the main control mechanisms.
Differential SAR interferometry represents an advanced remote sensing tool, which can map displacements at very
high spatial resolution. The Persistent Scatterer Interferometry (PSI) technique is a class of SAR interferometry
that uses point-wise radar targets (PS) on the ground whose phase is not interested by temporal and geometrical
decorrelation. This technique generates starting from a set of images two main products: the displacement rate
along line of sight (LOS) of single PS; and the LOS displacement time series of individual PS.
In this work SAR data with different spatio-temporal resolution were used to study the displacements that occur
from 1992 to 2012 in the Alto Guadalentin Basin (southern Spain), where is located the city of Lorca The area is
affected by the highest rate of subsidence measured in Europe (>10 cm/yr-1) related to long-term exploitation of
the aquifer (González et al. 2011).
The objectives of the work were 1) to analyse land subsidence evolution over a 20-year period with PSI technique;
2) to compare the spatial and temporal resolution of SAR data acquired by different sensors, 3) to investigate the
causes that could explain this land motion.
The SAR data have been obtained with ERS-1/2 & ENVISAT (1992-2007), ALOS PALSAR (2007-2010) and
COSMO-SkyMed (2011-2012) images, processed with the Stable Point Network (SPN) technique. The PSI data
obtained from different satellite from 1992 to 2012 were compared with some predisposing and trigger factors as
geological units, isobaths of Plio-Quaternary filling, soft soil thickness and piezometric level. The PSI data were
compared with measurement obtained by two GPS station located near the Lorca city: the value of deformation
detected by satellites and ground-based tools are well correlated.
The results are the following: a) the subsidence processes are related to soft soil thickness distribution; b) land
subsidence rates shows that the area interested by the higher value is the same over the monitored period, a
deceleration rate of subsidence has been recorded during the period 2011- 2012; c) the deformation rates are
not correlated with the piezometric level trend, a delay time between piezometric level variations and ground
deformations is evident
Application of multi-sensor advanced DInSAR analysis to severe land subsidence recognition: Alto Guadalentín Basin (Spain)
No full textMulti-sensor advanced DInSAR analyses have been performed and compared with two GPS station measurements, in order to evaluate the land subsidence evolution in a 20-year period, in the Alto Guadalentín Basin where the highest rate of man-induced subsidence (> 10 cm yr
−1) of Europe had been detected. The control mechanisms have been examined comparing the advanced DInSAR data with conditioning and triggering factors (i.e. isobaths of Plio-Quaternary deposits, soft soil thickness and piezometric level)
