Seismic monitoring of gas emissions at mud volcanoes: The case of Nirano (northern Italy)

Seismic signals generated at the Nirano mud volcanoes in Northern Italy have been monitored by deploying a set of small dimensions seismic arrays of vertical geophones and thee-directional sensors. During two seismic surveys campaigns, seismic signals characterized by sequences of short impulsive signals (lasting 0.1 s–0.2 s) were identified above the background seismic noise. The respective seismic sources have been identified at shallow depths (<30 m) and results sparsely distributed over a wide area. Estimated propagation velocities and polarization analysis indicate that detected pulses also include a significant S waves contribution. These findings have been interpreted as the effect of a stick-slip mechanism due to the interaction between exsolved gas bubbles, mud plugs and the vent walls. On the basis of this model, an estimate of the gas outflow was attempted and results in line with independent measurements of CH4 and CO2 emissions carried out in the area

Mapping 1D seismic amplification effects in the range of periods of engineering interest based on geological data

Regional scale seismic hazard assessment including the effect of local seismo-stratigraphical conditions is a basic tool for seismic risk estimates. A novel physically based procedure is proposed for using geological maps to extensively estimate expected seismic amplification effects relative to spectral ordinates of main engineering interest (<0.8 s). Automatic GIS based analysis of geological maps, statistical data relative to the seismic/geotechnical properties of geological units and numerical modelling are combined to determine the probability distribution of expected amplification effects by accounting for uncertainty affecting the relevant parameters. To evaluate the feasibility of the proposed procedure, it has been applied to the Tuscany Region in Central Italy. Unbiasedness of outcomes has been tested by considering detailed microzonation studies available for the considered area. Results of the proposed approach could be easily implemented in extensive seismic risk analyses where detailed seismic microzonation studies are lacking

Seismic hazard assessment for Iran in terms of macroseismic intensity

We present the results of probabilistic seismic hazard assessment for Iran based on a statistical procedure specifically developed to manage macroseismic intensity data. This method takes into careful consideration the specific features of such data, which are characterized as ordinal, discrete, and confined within a finite interval, ensuring a logically coherent approach throughout the analysis. The results of our assessment are then compared with hazard maps generated using a standard approach, putting in evidence significant differences both on a national scale and relative to individual cities. This comparative analysis will be useful in identifying areas of utmost concern, where further studies are strongly recommended to yield hazard estimates of greater robustness and reliability. By pinpointing these critical scenarios, we aim to guide future research endeavors towards providing more accurate and reliable seismic hazard estimates. Identifying these critical situations facilitates the prioritization of resources and interventions, ultimately enhancing seismic risk mitigation efforts across Iran

Ki67 proliferative index of the neuroendocrine component drives MANEC prognosis.

Mixed adenoneuroendocrine carcinomas (MANECs) are composed of a poorly differentiated neuroendocrine carcinoma (NEC) and a non-neuroendocrine (non-NEC) neoplastic epithelial component, each representing at least 30% of the tumor. At present, prognostic factors for MANECs remain largely unexplored. We investigated the clinical-pathologic features of a large multicenter series of digestive system MANECs. Surgical specimens of 200 MANEC candidates were centrally reviewed; diagnosis was confirmed in 160 cases. While morphology, proliferation (mitotic count (MC), Ki67 index) and immunophenotype (p53, SSTR2a, beta-Catenin, Bcl-2, p16, Rb1, ALDH, mismatch repair proteins and CD117) were investigated separately in both components, genomic (TP53, KRAS, BRAF) alterations were searched for on the entire tumor. Data were correlated with overall survival (OS). MANEC sites were: 92 colorectal, 44 gastroesophageal and 24 pancreatobiliary. Median OS was 13.2 months. After adjustment for primary site, Ki67 index of the NEC component (but not of the non-NEC component) was the most powerful prognostic marker. At multivariable analysis, patients with Ki67 ≥ 55% had an 8-fold risk of death (hazard ratio (HR) 7.83; 95% confidence interval (CI) 4.17-14.7; P < 0.0001) and a median OS of 12.2 months compared to those with Ki67 < 55% (median OS 40.5 months). MC (HR 1.51; 95% CI 1.03-2.20, P = 0.04) was a weaker prognostic index. Colorectal primary site (HR 1.60; 95% CI 1.11-2.32; P = 0.01) was significantly associated with poorer survival. No single immunomarker, in either component, was statistically significant. This retrospective analysis of a large series of digestive system MANECs, showed that the NEC component, particularly its Ki67 index, was the main prognostic driver