This study presents a review of the instrumental seismicity of the Norcia-Amatrice area (central Italy) where a still on-going seismic sequence started on August 24th 2016 with a Mw6.0 earthquake.The ...review is based on the analysis of the seismic catalogs 1981-2016, the CMT (Centroid Moment Tensor) solutions and the TDMT (Time Domain Moment Tensor) solutions, dividing the area into three regions based on the main seismic sequences preceding the Amatrice 2016 mainshock.The seismicity of this region is characterized by different types of activity: single events, minor sequences and swarms with hypocenters within the upper 15 km of the crust. Small-magnitude seismic sequences on March 2007 with maximum Mw3.9, and one earthquake on March 2012, Mw37, not followed by significant seismicity, affected the area east of the Norcia, close to the Mw 5.4 aftershock of the Amatrice 2016 sequence. In the central area, near Accumoli, and in the southern sector close to Amatrice, minor seismic sequences occurred on February 2014 Ml3.5 and on November 2013 Mw3.7 respectively.We integrated hypocentral locations and fault plane solutions to give a first look at the main features of the instrumental seismicity compared to the present seismic sequence in order to relate the seismicity patterns to seismogenic structures of this area of the central Italy.
Diabetic foot is a significant cause of morbidity in diabetic patients, with a rate that is approximately twice that of patients without foot ulcers. "Metabolic memory" represents the epigenetic ...changes induced by chronic hyperglycaemia, despite the correction of the glucose levels themselves. These epigenetic modifications appear to perpetuate the damage caused by persistently elevated glucose levels even in their absence, acting at various levels, mostly affecting the molecular processes of diabetic ulcer healing.
The aim of our cross-sectional study was to analyse a cohort of patients with diabetes with and without lower limb ulcers. We examined the effects of epigenetic changes on miRNA 126, 305, and 217 expression and the frequency of the SNPs of genes encoding inflammatory molecules (e.g., IL-6 and TNF-alpha) and their correlations with serum levels of proangiogenic molecules (e.g., ENOS, VEGF and HIF-1alpha) and several adipokines as well as with endothelial dysfunction, assessed noninvasively by reactive hyperaemia peripheral artery tonometry. Between March 2021 and June 2022, 110 patients were enrolled into the study: 50 diabetic patients with diabetic foot injuries, 40 diabetic patients without ulcerative complications and 20 nondiabetic patients as the control group.
Diabetic subjects with lower limb ulcerative lesions exhibited higher levels of inflammatory cytokines, such as VEGF (191.40 ± 200 pg/mL vs. 98.27 ± 56.92 pg/mL vs. 71.01 ± 52.96 pg/mL; p = 0.22), HIF-1alpha (40.18 ± 10.80 ng/mL vs. 33.50 ± 6.16 ng/mL vs. 33.85 ± 6.84 ng/mL; p = 0.10), and Gremlin-1 (1.72 ± 0.512 ng/mL vs. 1.31 ± 0.21 ng/mL vs. 1.11 ± 0.19 ng/mL; p < 0.0005), than those without lower limb ulcers and healthy controls. Furthermore, we observed that miR-217-5p and miR-503-5p were 2.19-fold (p < 0.05) and 6.21-fold (p = 0.001) more highly expressed in diabetic foot patients than in healthy controls, respectively. Additionally, diabetic patients without lower limb ulcerative complications showed 2.41-fold (p = 0) and 2.24-fold (p = 0.029) higher expression of miR-217-5p and miR-503-5p, respectively, than healthy controls. Finally, diabetic patients with and without ulcerative complications of the lower limbs showed higher expression of the VEGFC2578A CC polymorphism (p = 0.001) and lower expression of the VEGFC2578A AC polymorphism (p < 0.005) than the healthy control population. We observed a significant increase in Gremlin-1 levels in patients with diabetic foot, suggesting that this inflammatory adipokine may serve as a predictive marker for the diagnosis of diabetic foot.
Our results highlighted that patients with diabetic foot showed predominant expression of the VEGF C2578A CC polymorphism and reduced expression of the AC allele. Additionally, we found an overexpression of miR-217-5p and miR-503-5p in diabetic patients with and without diabetic foot syndrome compared with healthy controls. These results align with those reported in the literature, in which the overexpression of miR-217-5p and miR-503-5p in the context of diabetic foot is reported. The identification of these epigenetic modifications could therefore be helpful in the early diagnosis of diabetic foot and the treatment of risk factors. However, further studies are necessary to confirm this hypothesis.
Starting from late May 2012, the Emilia region (Northern Italy) was severely shaken by an intense seismic sequence, originated from a ML 5.9 earthquake on May 20th, at a hypocentral depth of 6.3km, ...with thrust-type focal mechanism. In the following days, the seismic rate remained high, counting 50 ML≥2.0 earthquakes a day, on average. Seismicity spreads along a 30km east–west elongated area, in the Po river alluvial plain, in the nearby of the cities Ferrara and Modena. Nine days after the first shock, another destructive thrust-type earthquake (ML 5.8) hit the area to the west, causing further damage and fatalities. Aftershocks following this second destructive event extended along the same east-westerly trend for further 20km to the west, thus illuminating an area of about 50km in length, on the whole. After the first shock struck, on May 20th, a dense network of temporary seismic stations, in addition to the permanent ones, was deployed in the meizoseismal area, leading to a sensible improvement of the earthquake monitoring capability there. A combined dataset, including three-component seismic waveforms recorded by both permanent and temporary stations, has been analyzed in order to obtain an appropriate 1-D velocity model for earthquake location in the study area. Here we describe the main seismological characteristics of this seismic sequence and, relying on refined earthquakes location, we make inferences on the geometry of the thrust system responsible for the two strongest shocks.
•First complete analysis of the 2012 Emilia mainshocks–aftershocks seismic sequence.•New catalog of the seismic sequence including data from temporary stations•Sensible improvement in terms of the activated fault system geometry definition•The different dip of the activated fault segments is highlighted and discussed.•Basic information are provided for further specific studies and hazard scenarios.
Background
The autonomic nervous system is linked to hyperdynamic circulation in cirrhosis and several studies have highlighted the crucial role that systemic inflammation elicits in altering ...sympathovagal equilibrium with the consequent reduction in heart rate variability (HRV).
To investigate the correlation between time‐domain HRV parameters, serum cytokines concentrations and portal hypertension, we studied a cohort of patients with cirrhosis, accounting for etiology and treatments.
Methods
In this cross‐sectional, observational cohort study, 107 outpatients with non‐alcoholic cirrhosis were assessed consecutively by abdominal ultrasound and by upper gastrointestinal endoscopy to search for esophagogastric varices. 24‐h electrocardiogram Holter monitoring with time‐domain HRV measurement (square root of the mean of successive differences of Normal‐to‐Normal NN RMSSD, standard deviation or the square root of variance SDNN and standard deviation of the means of the NN intervals calculated over a 5‐min period SDANN) was performed and serum concentrations of osteopontin (OPN), interleukin (IL)‐22, IL‐6, IL‐1Ra and IL‐17 were obtained in all patients.
Results
IL‐6, OPN, IL‐22 and IL‐1Ra concentrations in cirrhotic patients were associated with disease severity expressed by Child‐Pugh and MELD score, to some portal hypertension's indirect signs and some of its complications. A significant increase in systemic concentrations of OPN in patients with hepatocellular carcinoma was encountered. SDANN and SDNN values were indirectly related to serum levels of IL‐6, OPN, IL‐1Ra and IL‐22.
Conclusions
This study underlines the interaction between the alteration of the ANS and the activation of inflammatory pathways that characterize cirrhosis taking into account clinical characteristics and treatments.
Autonomic nervous system plays a role in immunomodulation but poor is known about its activity in cirrhosis.
IL‐6, OPN, IL‐1Ra and IL‐22 concentrations are associated with indirect signs of portal hypertension and its main complications.
Alteration of sympathovagal balance assessed by heart rate variability (HRV) is related to IL‐6, IL‐22, osteopontin and IL‐1Ra concentrations and accompanies inflammation across the progression of cirrhosis and portal hypertension
Adjoint tomography of the Italian lithosphere Magnoni, Federica; Casarotti, Emanuele; Komatitsch, Dimitri ...
Communications earth & environment,
12/2022, Letnik:
3, Številka:
1
Journal Article
Recenzirano
Odprti dostop
Abstract
The evolution and state of geological structure at Earth’s surface is best understood with an accurate characterization of the subsurface. Here we present seismic tomographic images of the ...Italian lithosphere based on ground motion recordings and characterized by compressional and shear wavespeed structure at remarkable resolution, corresponding to a minimum period of ~10 s. Enhanced accuracy is enabled by state-of-the-art three-dimensional wavefield simulations in combination with an adjoint-state method. We focus on three primary findings of our model
Im25.
It highlights the distribution of fluids and gas (CO
2
) within the Italian subsurface and their correlation with seismicity. It illuminates Mt. Etna volcano and supports the hypothesis of a deep reservoir (~30 km) feeding a shallower magma-filled intrusive body. Offshore of the eastern Italian coast, it reveals that the Adriatic plate is made of two distinct microplates, separated by the Gargano deformation zone, indicating a complex lithosphere and tectonic evolution.
This study presents a detailed analysis of minor seismic sequences recorded in the Amatrice-Norcia area (central Italy) before 2016 when the most important seismic sequence of the last 40 years ...struck the region with the Mw 6.0 Amatrice and the Mw 6.5 Norcia earthquakes. We observe that, in the four decades before the 2016–2018 Amatrice-Visso-Norcia sequence, the instrumental seismicity rate is low, with maximum magnitudes lower than Mw 4.0, and is characterized by different types of behaviours as single shock events, swarms and minor sequences. For the first time, we relocate the minor seismicity recorded before 2016 by the Italian National Seismic Network of the Istituto Nazionale di Geofisica e Vulcanologia by applying the nonlinear inversion code NonLinLoc in a local velocity model. Revised earthquake locations of the past seismic sequences are compared to the recent 2016–2018 seismicity in order to investigate some possible correlations with the seismogenic structures reactivated in 2016. With this goal, we also integrated our new hypocentral locations with fault plane solutions and geological data to interpret our results with respect to the 2016–2018 seismicity. Our results show how some of the structures identified by the minor seismicity before 2016 were reactivated during the recent sequence, while others seismic structures remained silent. We therefore highlight how the study of minor seismic sequences provides important information about the seismogenic attitude of less active or less known seismogenic structures with consequent impact on the evaluation of the seismic hazard.
•Before 2016 seismicity in the Amatrice-Norcia area was characterized by Ml<4.0 single shock events, swarms and minor sequences•New detailed image of seismogenic structures is obtained by nonlinear inversion of the seismicity recorded before 2016•Relocated minor seismic sequences are limited at depth by a basal subhorizontal zone
In this paper we present a new study on the High Tiber Valley earthquake occurred on April 26, 1917. Using the digitized data from mechanical seismograph records, we computed the source parameters ...like focal mechanism and moment magnitude from moment tensor (MT). The study of historical earthquakes from an instrumental perspective is crucial because of the complexity of problems associated with the study of seismograms of moderate to large earthquakes occurred from the late 19th century until the early 1960s. Since historical earthquake records show significant uncertainties in phase arrival times and have been recorded by seismograph generally with short natural period, we developed a code to compute the MT based on a forward modeling technique, which uses the amplitude spectra of the full waveform length and the first P-arrival polarities to constrain the P- and T-axes. The best solution is determined by the best fit between the observed and synthetic amplitude spectra and from the coherency between the observed and the theoretical first P-arrival polarities. The 1917 High Tiber Valley earthquake is one of the most important 20th century earthquake occurred in the Italian Peninsula for which the focal mechanism and moment magnitude from seismic records are not available. Additionally, we apply a multidisciplinary approach to characterize the source of this earthquake, combining instrumental, macroseismic, geological and tectonic data and investigations. The computed MT results in a north-south normal fault mechanism (strike: 147°, dip: 29°, slip: −94°), which is consistent with the strike estimated from the macroseismic data (157°). The moment magnitude calculated from the MT and that derived from the macroseismic data are Mw=5.5±0.2 and Mw=5.9±0.1, respectively.
We present an overview of the potential of active monitoring techniques to investigate the many factors affecting the concentration of radon in houses. We conducted two experiments measuring radon ...concentration in 25 apartments in Rome and suburban areas for two weeks and in three apartments in the historic center for several months. The reference levels of 300 and 100 Bq/m
are overcome in 17% and 60% of the cases, respectively, and these percentages rise to 20% and 76% for average overnight radon (more relevant for residents' exposure). Active detectors allowed us to identify seasonal radon fluctuations, dependent on indoor-to-outdoor temperature, and how radon travels from the ground to upper floors. High levels of radon are not limited to the lowest floors when the use of heating and ventilation produces massive convection of air. Lifestyle habits also reflect in the different values of gas concentration measured on different floors of the same building or in distinct rooms of the same apartment, which cannot be ascribed to the characteristics of the premises. However, the finding that high residential radon levels tend to concentrate in the historic center proves the influence of factors such as building age, construction materials, and geogenic radon.
In complex tectonics regions, seismological, geophysical, and geodynamic modeling require accurate definition of the Moho geometry. Various active and passive seismic experiments performed in the ...central Mediterranean region revealed local information on the Moho depth, in some cases used to produce interpolated maps. In this paper, we present a new and original map of the 3‐D Moho geometry obtained by integrating selected high‐quality controlled source seismic and teleseismic receiver function data. The very small cell size makes the retrieved model suitable for detailed regional studies, crustal corrections in teleseismic tomography, advanced 3‐D ray tracing in regional earthquake location, and local earthquake tomography. Our results show the geometry of three different Moho interfaces: the European, Adriatic‐Ionian, and Tyrrhenian. The three distinct Moho are fashioned following the Alpine and Apennines subduction, collision, and back‐arc spreading and show medium‐ to high‐frequency topographic undulations reflecting the complexity of the geodynamic evolution.
Key Points
Extension and update of the Moho map of Italy and surrounding region
Data consistency (only seismological data) and quality check
Reference data set and constraint for future geodynamic and geophysical modeling
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