Integrating seismological data, DInSAR measurements and numerical modelling to analyse seismic events: the Mw 6.5 Norcia earthquake case-study

Questa tesi di dottorato è incentrata sull’analisi dettagliata di sequenze sismiche e sull’applicazione di un approccio multidisciplinare basato sull’integrazione di diverse tecniche geofisiche e geodetiche. Nel contesto di uno studio più generale delle sequenze sismiche, abbiamo concentrato il lavoro sull’analisi ed il confronto di dieci sequenze sismiche (cinque estensionali e cinque compressive), al fine di comprendere le differenze tra questi due ambienti tettonici in termini di durata degli aftershocks. Infatti, il numero di aftershocks decade nel tempo in funzione di vari parametri che risultano essere peculiari di ogni area sismogenetica; tra questi si possono annoverare la magnitudo del mainshock, la reologia crostale e le variazioni dello stress lungo la faglia. Tuttavia, il ruolo esatto svolto da questi parametri nel controllo della durata delle sequenze di aftershocks non è ancora noto. Utilizzando due diverse metodologie, abbiamo evidenziato che l’ambiente tettonico gioca un ruolo primario nell’influenzare la durata degli aftershocks. In media e per una data magnitudo del mainshock, (i) le sequenze di aftershocks sono più lunghe e (ii) il numero di terremoti è maggiore negli ambienti tettonici estensionali rispetto a quelli compressivi. Una possibile spiegazione consiste nel fatto che questa differenza possa essere correlata al diverso tipo di energia dissipata durante i terremoti; in dettaglio, (i) un effetto congiunto di forza gravitazionale e di energia elastica governerebbe i terremoti estensionali, mentre (ii) il rilascio di pura energia elastica controllerebbe i terremoti compressivi. Infatti, le faglie normali operano a favore della gravità, preservando così l'inerzia per un periodo più lungo, e la sismicità dura fino a quando l'equilibrio gravitazionale non viene nuovamente raggiunto dal sistema. Viceversa, i thrusts agiscono contro la gravità, esauriscono la loro inerzia più velocemente e la dissipazione di energia elastica viene controbilanciata dalla forza gravitazionale. Quindi, per sequenze sismiche con magnitudo e parametri reologici paragonabili, gli aftershocks durano più a lungo negli ambienti estensionali poiché la gravità favorisce il collasso dei volumi di hangingwall. Il verificarsi della sequenza sismica del Centro Italia nel 2016 ha fornito un banco di prova per un'analisi dettagliata di un altro terremoto estensionale. Per questo motivo, abbiamo analizzato il terremoto di Norcia (Mw 6.5; Italia Centrale) per aggiungere un’altra sequenza sismica estensionale ai casi di studio precedentemente esaminati. I risultati di questa analisi mostrano che anche la sequenza sismica di Norcia presenta lo stesso comportamento delle altre sequenze estensionali in termini di evoluzione temporale e spaziale degli aftershocks. Inoltre, abbiamo deciso di prendere in considerazione il terremoto di Norcia come caso di studio per l’applicazione di un approccio multidisciplinare, al fine di cercare di comprendere la possibile cinematica e il ruolo della gravità durante i processi di enucleazione degli eventi estensionali. In particolare, abbiamo investigato il terremoto di Norcia, ricorrendo all’utilizzo di dati sismologici, di misure DInSAR e della modellazione numerica. In particolare, abbiamo prima di tutto preso in considerazione gli ipocentri rilocalizzati con 0.1≤Mw≤ 6.5, verificatisi tra il 24 agosto e il 29 novembre 2016 e registrati dalla rete sismometrica INGV; la proiezione su sezioni e la successiva analisi degli ipocentri considerati hanno consentito di comprendere quali strutture geologiche siano state coinvolte durante il processo di enucleazione del terremoto. In seguito, abbiamo analizzato la componente verticale (sollevamento e subsidenza) dei displacements che hanno interessato i blocchi di hangingwall e di footwall della faglia sismogenetica, precedentemente identificata in profondità mediante l’analisi della distribuzione ipocentrale; per fare ciò, abbiamo utilizzato le misure DInSAR ottenute dalla combinazione delle coppie di dati SAR cosismici acquisite dal sensore ALOS-2 lungo orbite ascendenti e discendenti. La mappa di deformazione verticale ottenuta mostra tre aree di deformazione principali: (i) una maggiore subsidenza che raggiunge il valore massimo di circa 98 cm in prossimità delle zone epicentrali vicine alla città di Norcia; (ii) due piccoli lobi di sollevamento che interessano sia il blocco di hangingwall (dove raggiunge valori massimi di circa 14 cm) sia quello di footwall (dove raggiunge valori massimi di circa 10 cm). Partendo da queste evidenze, abbiamo calcolato i volumi di roccia interessati dai fenomeni di sollevamento e subsidenza, evidenziando che quelli coinvolti dal fenomeno di subsidenza sono caratterizzati da valori di deformazione significativamente più alti di quelli affetti da sollevamento (circa 14 volte). Al fine di fornire una possibile interpretazione di questa asimmetria volumetrica, abbiamo esteso l'analisi elaborando un modello numerico 2D basato sul metodo degli elementi finiti, implementandolo in un quadro strutturale-meccanico e sfruttando i dati geologici e sismologici disponibili. I risultati della modellazione sono stati poi confrontati con le misure della deformazione del suolo ottenute dall'analisi DInSAR. Nel corso della realizzazione del modello numerico, abbiamo collaudato gli effetti di geometrie diverse, considerando in particolare due scenari: il primo si basa su una singola faglia immergente a sud-ovest, il secondo su una faglia principale immergente a sud-ovest e una fascia antitetica. In questo contesto, il modello caratterizzato dalla presenza della fascia antitetica fornisce il miglior fit quando confrontato con il pattern cosismico di deformazione superficiale. Questo risultato consente di interpretare i fenomeni di subsidenza e sollevamento causati dal terremoto di Norcia come il risultato di un collasso gravitazionale del blocco di hangigwall lungo la faglia principale e della forza frizionale che agisce in direzione opposta, consistentemente con il meccanismo di doppia coppia lungo il piano di faglia.This Ph.D. thesis is focused on the detailed analysis of seismic sequences and on the application of a multidisciplinary approach based on the integration of several geophysical and geodetic techniques. In the context of a more general study of seismic sequences, we focus this work on the analysis and comparison of five extensional and five compressional seismic sequences to understand the differences between these two tectonic settings in terms of aftershocks duration. In fact, aftershocks number decay through time, depending on several parameters peculiar to each seismogenic regions, including mainshock magnitude, crustal rheology, and stress changes along the fault. However, the exact role of these parameters in controlling the duration of the aftershock sequence is still unknown. Here, by using two methodologies, we show that the tectonic setting primarily controls the duration of aftershocks. On average and for a given mainshock magnitude, (i) aftershock sequences are longer and (ii) the number of earthquakes is greater in extensional than in compressional tectonic settings. We suggest as possible explanation that this difference can be related to the different type of energy dissipated during earthquakes; in detail, (i) a joint effect of gravitational forces and pure elastic stress release governs extensional earthquakes, whereas (ii) pure elastic stress release controls compressional earthquakes. Accordingly, normal faults operate in favour of gravity, preserving inertia for a longer period and seismicity lasts until gravitational equilibrium is reached. Vice versa, thrusts act against gravity, exhaust their inertia faster and the elastic energy dissipation is buffered by the gravitational force. Hence, for seismic sequences of comparable magnitude and rheological parameters, aftershocks last longer in extensional settings because gravity favours the collapse of the hangingwall volumes. The occurrence of the 2016 Central Italy seismic sequence furnishes a test-bed for a detailed analysis of a normal fault earthquake. Therefore, we analyse also the Mw 6.5 Norcia (Central Italy) earthquake to add another extensional seismic sequence to the previously examined case-studies. The results of this analysis show that, with respect to the other considered extensional seismic sequences, also the Mw 6.5 Norcia seismic sequence present the same behaviour about the aftershocks temporal and spatial evolution. Moreover, we decide to take into account the Mw 6.5 Norcia mainshock as case-study for the application of a multidisciplinary approach, in order to understand the kinematics and the role of gravity during nucleation processes of extensional events. In particular, we investigate the Mw 6.5 Norcia earthquake by exploiting seismological data, DInSAR measurements and a numerical modelling approach. In particular, we first take into consideration the relocated hypocentres with 0.1≤Mw≤ 6.5 that occurred between August 24th and November 29th, 2016, recorded by the INGV seismometric network; the projection onto sections and the subsequent analysis of the considered hypocentres allow us to identify the geological structures that were involved during earthquake nucleation process. Then, we retrieve the vertical component (uplift and subsidence) of the displacements affecting the hangingwall and the footwall blocks of the seismogenic faults identified, at depth, through the hypocentres distribution analysis; to do this, we combine the DInSAR measurements obtained from coseismic SAR data pairs collected by the ALOS-2 sensor from ascending and descending orbits. The achieved vertical deformation map displays three main deformation patterns: (i) a major subsidence that reaches the maximum value of about 98 cm near the epicentral zones nearby the town of Norcia; (ii) two smaller uplift lobes that affect both the hangingwall (reaching maximum values of about 14 cm) and the footwall blocks (reaching maximum values of about 10 cm). Also GPS measurements were used to compare the displacements recorded next to the epicentral area. Starting from this evidence, we compute the rock volumes affected by uplift and subsidence phenomena, highlighting that those involved by the retrieved subsidence are characterized by significantly higher deformation values than those affected by uplift (about 14 times). In order to provide a possible interpretation of this volumetric asymmetry, we extend the analysis by running a 2D numerical model based on the finite element method, implemented in a structural-mechanic framework and exploiting the available geological and seismological data. Modelling results are compared with the ground deformation measurements retrieved from the multi-orbit ALOS-2 DInSAR analysis. In the modelling approach, we test the effects of different geometries, by considering two different scenarios: the first is based on including only a single SW-dipping fault, the second includes a main SW-dipping fault and an antithetic zone. In this context, the model characterized by the occurrence of an antithetic zone presents the retrieved best fit coseismic surface deformation pattern. This result allows us to interpret the subsidence and uplift phenomena caused by the Mw 6.5 Norcia earthquake as the result of the gravitational sliding of the hangingwall along the main fault plane and of the frictional force acting in the opposite direction, consistently with the double couple fault plane mechanism

Experimental investigation of the productivity of a wet separation process of traditional and bio-plastics

The separation process within a mechanical recycling plant plays a major role in the context of the production of high-quality secondary raw materials and the reduction of extensive waste disposal in landfills. Traditional plants for plastic separation employ dry or wet processes that rely on the different physical properties among the polymers. The hydraulic separator is a device employing a wet technology for particle separation. It allows the separation of two-polymer mixtures into two products, one collected within the instrument and the other one expelled through its outlet ducts. Apparatus performance were analyzed as a function of fluid and solid flow rates, flow patterns developing within the apparatus, in addition to the density, shape, and size of the polymers. For the hydraulic configurations tested, a two-way coupling takes place where the fluid exerts an influence on the plastic particles and the opposite occurs too. The interaction between the solid and liquid phases determines whether a certain polymer settles within the device or is expelled from the apparatus. Tests carried out with samples of increasing volumes of solid particles demonstrate that there are no significant differences in the apparatus effectiveness as far as a two-way interaction takes place. Almost pure concentrates of Polyethylene Terephthalate (PET), Polyvinyl Chloride (PVC), and Polycarbonate (PC) can be obtained from a mixture of traditional polymers. Tests conducted on Polylactic Acid (PLA) and Mater-Bi® samples showed that the hydraulic separator can be effectively employed to separate bio-plastics from conventional plastics with remarkable grade and recovery

Reconstruction of the adult hemifacial microsomia patient with temporomandibular joint total joint prosthesis and orthognathic surgery

HFM patients' reconstruction has always been a challenge for maxillofacial surgeons, and numerous reconstructive techniques have been described. Surgical treatment depends on the patient's age and contemplates Temporomandibular Joint (TMJ) reconstruction in conjunction with orthognathic surgery, usually necessary following completion of growth to maximize the functional and esthetic results. Distraction osteogenesis had gained popularity as valid alternative in growing patients, but the two primary methods to reconstruct the TMJs involve the use of autogenous, using free or microvascular bone grafts, or alloplastic graft, but there is no widely accepted method

Popular Culture and Totalitarianism: Accounting for Propaganda in Italy under the Fascist Regime (1934-1945)

Throughout history both democratic and totalitarian States have sought to take advantage of the possible political contributions of art and culture. This study presents the first in-depth historical study of the relationship between accounting and culture in a totalitarian State; the Fascist State in Italy between 1934 and 1945. Accounting documents in the form of budgets and reports provided by the Fascist government, along with other accounts prepared by the Fascists, were used to build a narrative that identified the ways in which the Fascist regime sought to win the committed allegiance of the Italian people in unseen ways. Accounting documents and the cultural activities to which they relate show the ways in which the Fascists developed their own conception of popular culture and sought control of cultural organisations and intellectuals in spreading their values and beliefs through cultural artefacts. The study documents the importance of accounting records as a less obvious, often underscored source for social history. It also adds to the growing literature that has explored the place of accounting in totalitarian regimes by focusing on the unexplored context of Fascist popular culture and identifying the contributions of accounting to the management of propaganda activities

Tracking fish abundance by underwater image recognition

Marine cabled video-observatories allow the non-destructive sampling of species at frequencies and durations that have never been attained before. Nevertheless, the lack of appropriate methods to automatically process video imagery limits this technology for the purposes of ecosystem monitoring. Automation is a prerequisite to deal with the huge quantities of video footage captured by cameras, which can then transform these devices into true autonomous sensors. In this study, we have developed a novel methodology that is based on genetic programming for content-based image analysis. Our aim was to capture the temporal dynamics of fish abundance. We processed more than 20,000 images that were acquired in a challenging real-world coastal scenario at the OBSEA-EMSO testing-site. The images were collected at 30-min. frequency, continuously for two years, over day and night. The highly variable environmental conditions allowed us to test the effectiveness of our approach under changing light radiation, water turbidity, background confusion, and bio-fouling growth on the camera housing. The automated recognition results were highly correlated with the manual counts and they were highly reliable when used to track fish variations at different hourly, daily, and monthly time scales. In addition, our methodology could be easily transferred to other cabled video-observatories.Peer ReviewedPostprint (published version

Comprehensive RNA dataset of AGO2 associated RNAs in Jurkat cells following miR-21 over-expression

AbstractWe set out to identify miR-21 targets in Jurkat cells using a high-throughput biochemical approach (10.1016/j.biochi.2014.09.021 [1]). Using a specific monoclonal antibody raised against AGO2, RISC complexes were immunopurified in Jurkat cells over-expressing miR-21 following lentiviral trasduction as well as in Jurkat control cells lines. A parallel immunoprecipitation using isotype-matched rat IgG was performed as a control. AGO2 associated mRNAs were profiled by microarray (GEO: GSE37212). AGO2 bound miRNAs were profiled by RNA-seq

Neuroserpin polymers cause oxidative stress in a neuronal model of the dementia FENIB

The serpinopathies are human pathologies caused by mutations that promote polymerisation and intracellular deposition of proteins of the serpin superfamily, leading to a poorly understood cell toxicity. The dementia FENIB is caused by polymerisation of the neuronal serpin neuroserpin (NS) within the endoplasmic reticulum (ER) of neurons. With the aim of understanding the toxicity due to intracellular accumulation of neuroserpin polymers, we have generated transgenic neural progenitor cell (NPC) cultures from mouse foetal cerebral cortex, stably expressing the control protein GFP (green fluorescent protein), or human wild type, G392E or delta NS. We have characterised these cell lines in the proliferative state and after differentiation to neurons. Our results show that G392E NS formed polymers that were mostly retained within the ER, while wild type NS was correctly secreted as a monomeric protein into the culture medium. Delta NS was absent at steady state due to its rapid degradation, but it was easily detected upon proteasomal block. Looking at their intracellular distribution, wild type NS was found in partial co-localisation with ER and Golgi markers, while G392E NS was localised within the ER only. Furthermore, polymers of NS were detected by ELISA and immunofluorescence in neurons expressing the mutant but not the wild type protein. We used control GFP and G392E NPCs differentiated to neurons to investigate which cellular pathways were modulated by intracellular polymers by performing RNA sequencing. We identified 747 genes with a significant upregulation (623) or downregulation (124) in G392E NS-expressing cells, and we focused our attention on several genes involved in the defence against oxidative stress that were up-regulated in cells expressing G392E NS (Aldh1b1, Apoe, Gpx1, Gstm1, Prdx6, Scara3, Sod2). Inhibition of intracellular anti-oxidants by specific pharmacological reagents uncovered the damaging effects of NS polymers. Our results support a role for oxidative stress in the cellular toxicity underlying the neurodegenerative dementia FENIB

Ground deformation and source geometry of the 30 October 2016 Mw 6.5 Norcia earthquake (Central Italy) investigated through seismological data, DInSAR measurements, and numerical modelling

We investigate the Mw 6.5 Norcia (Central Italy) earthquake by exploiting seismological data, DInSAR measurements, and a numerical modelling approach. In particular, we first retrieve the vertical component (uplift and subsidence) of the displacements affecting the hangingwall and the footwall blocks of the seismogenic faults identified, at depth, through the hypocenters distribution analysis. To do this, we combine the DInSAR measurements obtained from coseismic SAR data pairs collected by the ALOS-2 sensor from ascending and descending orbits. The achieved vertical deformation map displays three main deformation patterns: (i) a major subsidence that reaches the maximum value of about 98 cm near the epicentral zones nearby the town of Norcia; (ii) two smaller uplift lobes that affect both the hangingwall (reaching maximum values of about 14 cm) and the footwall blocks (reaching maximum values of about 10 cm). Starting from this evidence, we compute the rock volumes affected by uplift and subsidence phenomena, highlighting that those involved by the retrieved subsidence are characterized by significantly higher deformation values than those affected by uplift (about 14 times). In order to provide a possible interpretation of this volumetric asymmetry, we extend our analysis by applying a 2D numerical modelling approach based on the finite element method, implemented in a structural-mechanic framework, and exploiting the available geological and seismological data, and the ground deformation measurements retrieved from the multi-orbit ALOS-2 DInSAR analysis. In this case, we consider two different scenarios: the first one based on a single SW-dipping fault, the latter on a main SW-dipping fault and an antithetic zone. In this context, the model characterized by the occurrence of an antithetic zone presents the retrieved best fit coseismic surface deformation pattern. This result allows us to interpret the subsidence and uplift phenomena caused by the Mw 6.5 Norcia earthquake as the result of the gravitational sliding of the hangingwall along the main fault plane and the frictional force acting in the opposite direction, consistently with the double couple fault plane mechanism

ARGONAUTE2 cooperates with SWI/SNF complex to determine nucleosome occupancy at human Transcription Start Sites.

Argonaute (AGO) proteins have a well-established role in post-transcriptional regulation of gene expression as key component of the RNA silencing pathways. Recent evidence involves AGO proteins in mammalian nuclear processes such as transcription and splicing, though the mechanistic aspects of AGO nuclear functions remain largely elusive. Here, by SILAC-based interaction proteomics, we identify the chromatin-remodelling complex SWI/SNF as a novel AGO2 interactor in human cells. Moreover, we show that nuclear AGO2 is loaded with a novel class of Dicer-dependent short RNAs (sRNAs), that we called swiRNAs, which map nearby the Transcription Start Sites (TSSs) bound by SWI/SNF. The knock-down of AGO2 decreases nucleosome occupancy at the first nucleosome located downstream of TSSs in a swiRNA-dependent manner. Our findings indicate that in human cells AGO2 binds SWI/SNF and a novel class of sRNAs to establish nucleosome occupancy on target TSSs